subject:"Re\: \[PATCH\] vdpa\/mlx5\: Use random MAC for the vdpa net instance"

On Wed, Dec 02, 2020 at 09:48:25PM +0800, Jason Wang wrote:
> 
> On 2020/12/2 下午5:23, Michael S. Tsirkin wrote:
> > On Wed, Dec 02, 2020 at 07:57:14AM +0200, Eli Cohen wrote:
> > > On Wed, Dec 02, 2020 at 12:18:36PM +0800, Jason Wang wrote:
> > > > On 2020/12/1 下午5:23, Cindy Lu wrote:
> > > > > On Mon, Nov 30, 2020 at 11:33 PM Michael S. Tsirkin  
> > > > > wrote:
> > > > > > On Mon, Nov 30, 2020 at 06:41:45PM +0800, Cindy Lu wrote:
> > > > > > > On Mon, Nov 30, 2020 at 5:33 PM Michael S. 
> > > > > > > Tsirkin  wrote:
> > > > > > > > On Mon, Nov 30, 2020 at 11:27:59AM +0200, Eli Cohen wrote:
> > > > > > > > > On Mon, Nov 30, 2020 at 04:00:51AM -0500, Michael S. Tsirkin 
> > > > > > > > > wrote:
> > > > > > > > > > On Mon, Nov 30, 2020 at 08:27:46AM +0200, Eli Cohen wrote:
> > > > > > > > > > > On Sun, Nov 29, 2020 at 03:08:22PM -0500, Michael S. 
> > > > > > > > > > > Tsirkin wrote:
> > > > > > > > > > > > On Sun, Nov 29, 2020 at 08:43:51AM +0200, Eli Cohen 
> > > > > > > > > > > > wrote:
> > > > > > > > > > > > > We should not try to use the VF MAC address as that 
> > > > > > > > > > > > > is used by the
> > > > > > > > > > > > > regular (e.g. mlx5_core) NIC implementation. Instead, 
> > > > > > > > > > > > > use a random
> > > > > > > > > > > > > generated MAC address.
> > > > > > > > > > > > > 
> > > > > > > > > > > > > Suggested by: Cindy Lu
> > > > > > > > > > > > > Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for 
> > > > > > > > > > > > > supported mlx5 devices")
> > > > > > > > > > > > > Signed-off-by: Eli Cohen
> > > > > > > > > > > > I didn't realise it's possible to use VF in two ways
> > > > > > > > > > > > with and without vdpa.
> > > > > > > > > > > Using a VF you can create quite a few resources, e.g. 
> > > > > > > > > > > send queues
> > > > > > > > > > > recieve queues, virtio_net queues etc. So you can 
> > > > > > > > > > > possibly create
> > > > > > > > > > > several instances of vdpa net devices and nic net devices.
> > > > > > > > > > > 
> > > > > > > > > > > > Could you include a bit more description on the failure
> > > > > > > > > > > > mode?
> > > > > > > > > > > Well, using the MAC address of the nic vport is wrong 
> > > > > > > > > > > since that is the
> > > > > > > > > > > MAC of the regular NIC implementation of mlx5_core.
> > > > > > > > > > Right but ATM it doesn't coexist with vdpa so what's the 
> > > > > > > > > > problem?
> > > > > > > > > > 
> > > > > > > > > This call is wrong:  mlx5_query_nic_vport_mac_address()
> > > > > > > > > 
> > > > > > > > > > > > Is switching to a random mac for such an unusual
> > > > > > > > > > > > configuration really justified?
> > > > > > > > > > > Since I can't use the NIC's MAC address, I have two 
> > > > > > > > > > > options:
> > > > > > > > > > > 1. To get the MAC address as was chosen by the user 
> > > > > > > > > > > administering the
> > > > > > > > > > >  NIC. This should invoke the set_config callback. 
> > > > > > > > > > > Unfortunately this
> > > > > > > > > > >  is not implemented yet.
> > > > > > > > > > > 
> > > > > > > > > > > 2. Use a random MAC address. This is OK since if (1) is 
> > > > > > > > > > > implemented it
> > > > > > > > > > >  can always override this random configuration.
> > > > > > > > > > > 
> > > > > > > > > > > > It looks like changing a MAC could break some guests,
> > > > > > > > > > > > can it not?
> > > > > > > > > > > > 
> > > > > > > > > > > No, it will not. The current version of mlx5 VDPA does 
> > > > > > > > > > > not allow regular
> > > > > > > > > > > NIC driver and VDPA to co-exist. I have patches ready 
> > > > > > > > > > > that enable that
> > > > > > > > > > > from steering point of view. I will post them here once 
> > > > > > > > > > > other patches on
> > > > > > > > > > > which they depend will be merged.
> > > > > > > > > > > 
> > > > > > > > > > > https://patchwork.ozlabs.org/project/netdev/patch/20201120230339.651609-12-sae...@nvidia.com/
> > > > > > > > > > Could you be more explicit on the following points:
> > > > > > > > > > - which configuration is broken ATM (as in, two device have 
> > > > > > > > > > identical
> > > > > > > > > > macs? any other issues)?
> > > > > > > > > The only wrong thing is the call to  
> > > > > > > > > mlx5_query_nic_vport_mac_address().
> > > > > > > > > It's not breaking anything yet is wrong. The random MAC 
> > > > > > > > > address setting
> > > > > > > > > is required for the steering patches.
> > > > > > > > Okay so I'm not sure the Fixes tag at least is appropriate if 
> > > > > > > > it's a
> > > > > > > > dependency of a new feature.
> > > > > > > > 
> > > > > > > > > > - why won't device MAC change from guest point of view?
> > > > > > > > > > 
> > > > > > > > > It's lack of implementation in qemu as far as I know.
> > > > > > > > Sorry not sure I understand. What's not implemented in QEMU?
> > > > > > > > 
> > > > > > > HI Michael, there are some bug in qemu to set_config, this will 
> > > > > > > fix in

Re: [PATCH] vdpa/mlx5: Use random MAC for the vdpa net instance

On 2020/12/2 下午5:23, Michael S. Tsirkin wrote:

On Wed, Dec 02, 2020 at 07:57:14AM +0200, Eli Cohen wrote:

On Wed, Dec 02, 2020 at 12:18:36PM +0800, Jason Wang wrote:

On 2020/12/1 下午5:23, Cindy Lu wrote:

On Mon, Nov 30, 2020 at 11:33 PM Michael S. Tsirkin wrote:

On Mon, Nov 30, 2020 at 06:41:45PM +0800, Cindy Lu wrote:

On Mon, Nov 30, 2020 at 5:33 PM Michael S. Tsirkin wrote:

On Mon, Nov 30, 2020 at 11:27:59AM +0200, Eli Cohen wrote:

On Mon, Nov 30, 2020 at 04:00:51AM -0500, Michael S. Tsirkin wrote:

On Mon, Nov 30, 2020 at 08:27:46AM +0200, Eli Cohen wrote:

On Sun, Nov 29, 2020 at 03:08:22PM -0500, Michael S. Tsirkin wrote:

On Sun, Nov 29, 2020 at 08:43:51AM +0200, Eli Cohen wrote:

We should not try to use the VF MAC address as that is used by the
regular (e.g. mlx5_core) NIC implementation. Instead, use a random
generated MAC address.

Suggested by: Cindy Lu
Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for supported mlx5 devices")
Signed-off-by: Eli Cohen

I didn't realise it's possible to use VF in two ways
with and without vdpa.

Using a VF you can create quite a few resources, e.g. send queues
recieve queues, virtio_net queues etc. So you can possibly create
several instances of vdpa net devices and nic net devices.

Could you include a bit more description on the failure
mode?

Well, using the MAC address of the nic vport is wrong since that is the
MAC of the regular NIC implementation of mlx5_core.

Right but ATM it doesn't coexist with vdpa so what's the problem?

This call is wrong: mlx5_query_nic_vport_mac_address()

Is switching to a random mac for such an unusual
configuration really justified?

Since I can't use the NIC's MAC address, I have two options:
1. To get the MAC address as was chosen by the user administering the
NIC. This should invoke the set_config callback. Unfortunately this
is not implemented yet.

2. Use a random MAC address. This is OK since if (1) is implemented it
can always override this random configuration.

It looks like changing a MAC could break some guests,
can it not?

No, it will not. The current version of mlx5 VDPA does not allow regular
NIC driver and VDPA to co-exist. I have patches ready that enable that
from steering point of view. I will post them here once other patches on
which they depend will be merged.

https://patchwork.ozlabs.org/project/netdev/patch/20201120230339.651609-12-sae...@nvidia.com/

Could you be more explicit on the following points:
- which configuration is broken ATM (as in, two device have identical
macs? any other issues)?

The only wrong thing is the call to mlx5_query_nic_vport_mac_address().
It's not breaking anything yet is wrong. The random MAC address setting
is required for the steering patches.

Okay so I'm not sure the Fixes tag at least is appropriate if it's a
dependency of a new feature.

- why won't device MAC change from guest point of view?

It's lack of implementation in qemu as far as I know.

Sorry not sure I understand. What's not implemented in QEMU?

HI Michael, there are some bug in qemu to set_config, this will fix in future,
But this patch is still needed, because without this patch the mlx
driver will give an 0 mac address to qemu
and qemu will overwrite the default mac address. This will cause traffic down.

Hmm the patch description says VF mac address, not 0 address. Confused.
If there's no mac we can clear VIRTIO_NET_F_MAC and have guest
use a random value ...

I'm not sure this can work for all types of vDPA (e.g it could not be a
learning bridge in the swtich).

hi Michael，
I have tried as your suggestion, seems even remove the
VIRTIO_NET_F_MAC the qemu will still call get_cinfig and overwrite the
default address in VM,

This looks a bug in qemu, in guest driver we had:

/* Configuration may specify what MAC to use. Otherwise random. */
if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
virtio_cread_bytes(vdev,
offsetof(struct virtio_net_config, mac),
dev->dev_addr, dev->addr_len);
else
eth_hw_addr_random(dev);

this process is like
vdpa _init -->qemu call get_config ->mlx driver will give an mac
address with all 0-->
qemu will not check this mac address and use it --> overwrite the mac
address in qemu

So for my understanding there are several method to fix this problem

1, qemu check the mac address, if the mac address is all 0, qemu will
ignore it and set the random mac address to mlx driver.

So my understanding is that, if mac address is all 0, vDPA parent should not
advertise VIRTIO_NET_F_MAC. And qemu should emulate this feature as you did:

Thinking it over, at least in mlx5, I should always advertise
VIRTIO_NET_F_MAC and set a non zero MAC value. The source of the MAC can
be either randomly generated value by mlx5_vdpa or by a management tool.
This is important becauase we should not let the VM modify the MAC. If
we do it can set a MAC value identical to the mlx5 NIC

Re: [PATCH] vdpa/mlx5: Use random MAC for the vdpa net instance

On 2020/12/2 下午9:04, Michael S. Tsirkin wrote:

On Wed, Dec 02, 2020 at 08:56:37PM +0800, Jason Wang wrote:

On 2020/12/2 下午5:30, Michael S. Tsirkin wrote:

On Wed, Dec 02, 2020 at 12:18:36PM +0800, Jason Wang wrote:

On 2020/12/1 下午5:23, Cindy Lu wrote:

On Mon, Nov 30, 2020 at 11:33 PM Michael S. Tsirkin wrote:

On Mon, Nov 30, 2020 at 06:41:45PM +0800, Cindy Lu wrote:

On Mon, Nov 30, 2020 at 5:33 PM Michael S. Tsirkin wrote:

On Mon, Nov 30, 2020 at 11:27:59AM +0200, Eli Cohen wrote:

On Mon, Nov 30, 2020 at 04:00:51AM -0500, Michael S. Tsirkin wrote:

On Mon, Nov 30, 2020 at 08:27:46AM +0200, Eli Cohen wrote:

On Sun, Nov 29, 2020 at 03:08:22PM -0500, Michael S. Tsirkin wrote:

On Sun, Nov 29, 2020 at 08:43:51AM +0200, Eli Cohen wrote:

We should not try to use the VF MAC address as that is used by the
regular (e.g. mlx5_core) NIC implementation. Instead, use a random
generated MAC address.

Suggested by: Cindy Lu
Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for supported mlx5 devices")
Signed-off-by: Eli Cohen

I didn't realise it's possible to use VF in two ways
with and without vdpa.

Using a VF you can create quite a few resources, e.g. send queues
recieve queues, virtio_net queues etc. So you can possibly create
several instances of vdpa net devices and nic net devices.

Could you include a bit more description on the failure
mode?

Well, using the MAC address of the nic vport is wrong since that is the
MAC of the regular NIC implementation of mlx5_core.

Right but ATM it doesn't coexist with vdpa so what's the problem?

This call is wrong: mlx5_query_nic_vport_mac_address()

Is switching to a random mac for such an unusual
configuration really justified?

2. Use a random MAC address. This is OK since if (1) is implemented it
can always override this random configuration.

It looks like changing a MAC could break some guests,
can it not?

https://patchwork.ozlabs.org/project/netdev/patch/20201120230339.651609-12-sae...@nvidia.com/

Could you be more explicit on the following points:
- which configuration is broken ATM (as in, two device have identical
macs? any other issues)?

The only wrong thing is the call to mlx5_query_nic_vport_mac_address().
It's not breaking anything yet is wrong. The random MAC address setting
is required for the steering patches.

Okay so I'm not sure the Fixes tag at least is appropriate if it's a
dependency of a new feature.

- why won't device MAC change from guest point of view?

It's lack of implementation in qemu as far as I know.

Sorry not sure I understand. What's not implemented in QEMU?

Hmm the patch description says VF mac address, not 0 address. Confused.
If there's no mac we can clear VIRTIO_NET_F_MAC and have guest
use a random value ...

I'm not sure this can work for all types of vDPA (e.g it could not be a
learning bridge in the swtich).

hi Michael，
I have tried as your suggestion, seems even remove the
VIRTIO_NET_F_MAC the qemu will still call get_cinfig and overwrite the
default address in VM,

This looks a bug in qemu, in guest driver we had:

this process is like
vdpa _init -->qemu call get_config ->mlx driver will give an mac
address with all 0-->
qemu will not check this mac address and use it --> overwrite the mac
address in qemu

So for my understanding there are several method to fix this problem

1, qemu check the mac address, if the mac address is all 0, qemu will
ignore it and set the random mac address to mlx driver.

So my understanding is that, if mac address is all 0, vDPA parent should not
advertise VIRTIO_NET_F_MAC. And qemu should emulate this feature as you did:

1) get a random mac

To me this looks like a spec violation.

If the driver negotiates the VIRTIO_NET_F_MAC feature, the driver MUST set
the physical address of the NIC to \field{mac}. Otherwise, it SHOULD
use a locally-administered MAC address (see \hyperref[intro:IEEE

Re: [PATCH] vdpa/mlx5: Use random MAC for the vdpa net instance




On 2020/12/2 下午9:07, Michael S. Tsirkin wrote:

Two questions here:
1. Now we don't have support for control virtqueue. Yet, we must filter
packets based on MAC, what do you suggest to do here?

How about an ioctl to pass the mac to the device?
Maybe mirroring the control vq struct format ...

I think we'd better avoid such ad-hoc ioctls to make vhost-vDPA type
independent.

Fundamentally this is about handling some VQs in QEMU, right?
Maybe a generic ioctl along the lines of "CTRL_VQ" passing
vq number and a command buffer from guest?
Seems generic enough for you?



It looks to me you want to invent a synchronized API (or vDPA config 
ops) for submitting virtio descriptors.


Several issues I can think for this:

1) control vq allows the request to be handled asynchronously
2) we still need a way to isolate the DMA if there's a hardware 
virtqueue for the device that use DMA
3) new vDPA config operations need to be invented, new uAPI for 
vhost-vDPA, new virtio config ops for virtio-vDPA


It looks to me we can overcome 1) and 2) if we just stick to a virtqueue 
interface in vhost-vDPA as I proposed in [1]. For issue 3) it also 
requires much less work.


Thanks

[1] https://lkml.org/lkml/2020/9/23/1243

Re: [PATCH] vdpa/mlx5: Use random MAC for the vdpa net instance

On Wed, Dec 02, 2020 at 09:00:07PM +0800, Jason Wang wrote:
> 
> On 2020/12/2 下午8:17, Michael S. Tsirkin wrote:
> > On Wed, Dec 02, 2020 at 02:12:41PM +0200, Eli Cohen wrote:
> > > On Wed, Dec 02, 2020 at 04:23:11AM -0500, Michael S. Tsirkin wrote:
> > > > On Wed, Dec 02, 2020 at 07:57:14AM +0200, Eli Cohen wrote:
> > > > > On Wed, Dec 02, 2020 at 12:18:36PM +0800, Jason Wang wrote:
> > > > > > On 2020/12/1 下午5:23, Cindy Lu wrote:
> > > > > > > On Mon, Nov 30, 2020 at 11:33 PM Michael S. 
> > > > > > > Tsirkin  wrote:
> > > > > > > > On Mon, Nov 30, 2020 at 06:41:45PM +0800, Cindy Lu wrote:
> > > > > > > > > On Mon, Nov 30, 2020 at 5:33 PM Michael S. 
> > > > > > > > > Tsirkin  wrote:
> > > > > > > > > > On Mon, Nov 30, 2020 at 11:27:59AM +0200, Eli Cohen wrote:
> > > > > > > > > > > On Mon, Nov 30, 2020 at 04:00:51AM -0500, Michael S. 
> > > > > > > > > > > Tsirkin wrote:
> > > > > > > > > > > > On Mon, Nov 30, 2020 at 08:27:46AM +0200, Eli Cohen 
> > > > > > > > > > > > wrote:
> > > > > > > > > > > > > On Sun, Nov 29, 2020 at 03:08:22PM -0500, Michael S. 
> > > > > > > > > > > > > Tsirkin wrote:
> > > > > > > > > > > > > > On Sun, Nov 29, 2020 at 08:43:51AM +0200, Eli Cohen 
> > > > > > > > > > > > > > wrote:
> > > > > > > > > > > > > > > We should not try to use the VF MAC address as 
> > > > > > > > > > > > > > > that is used by the
> > > > > > > > > > > > > > > regular (e.g. mlx5_core) NIC implementation. 
> > > > > > > > > > > > > > > Instead, use a random
> > > > > > > > > > > > > > > generated MAC address.
> > > > > > > > > > > > > > > 
> > > > > > > > > > > > > > > Suggested by: Cindy Lu
> > > > > > > > > > > > > > > Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver 
> > > > > > > > > > > > > > > for supported mlx5 devices")
> > > > > > > > > > > > > > > Signed-off-by: Eli Cohen
> > > > > > > > > > > > > > I didn't realise it's possible to use VF in two ways
> > > > > > > > > > > > > > with and without vdpa.
> > > > > > > > > > > > > Using a VF you can create quite a few resources, e.g. 
> > > > > > > > > > > > > send queues
> > > > > > > > > > > > > recieve queues, virtio_net queues etc. So you can 
> > > > > > > > > > > > > possibly create
> > > > > > > > > > > > > several instances of vdpa net devices and nic net 
> > > > > > > > > > > > > devices.
> > > > > > > > > > > > > 
> > > > > > > > > > > > > > Could you include a bit more description on the 
> > > > > > > > > > > > > > failure
> > > > > > > > > > > > > > mode?
> > > > > > > > > > > > > Well, using the MAC address of the nic vport is wrong 
> > > > > > > > > > > > > since that is the
> > > > > > > > > > > > > MAC of the regular NIC implementation of mlx5_core.
> > > > > > > > > > > > Right but ATM it doesn't coexist with vdpa so what's 
> > > > > > > > > > > > the problem?
> > > > > > > > > > > > 
> > > > > > > > > > > This call is wrong:  mlx5_query_nic_vport_mac_address()
> > > > > > > > > > > 
> > > > > > > > > > > > > > Is switching to a random mac for such an unusual
> > > > > > > > > > > > > > configuration really justified?
> > > > > > > > > > > > > Since I can't use the NIC's MAC address, I have two 
> > > > > > > > > > > > > options:
> > > > > > > > > > > > > 1. To get the MAC address as was chosen by the user 
> > > > > > > > > > > > > administering the
> > > > > > > > > > > > >  NIC. This should invoke the set_config callback. 
> > > > > > > > > > > > > Unfortunately this
> > > > > > > > > > > > >  is not implemented yet.
> > > > > > > > > > > > > 
> > > > > > > > > > > > > 2. Use a random MAC address. This is OK since if (1) 
> > > > > > > > > > > > > is implemented it
> > > > > > > > > > > > >  can always override this random configuration.
> > > > > > > > > > > > > 
> > > > > > > > > > > > > > It looks like changing a MAC could break some 
> > > > > > > > > > > > > > guests,
> > > > > > > > > > > > > > can it not?
> > > > > > > > > > > > > > 
> > > > > > > > > > > > > No, it will not. The current version of mlx5 VDPA 
> > > > > > > > > > > > > does not allow regular
> > > > > > > > > > > > > NIC driver and VDPA to co-exist. I have patches ready 
> > > > > > > > > > > > > that enable that
> > > > > > > > > > > > > from steering point of view. I will post them here 
> > > > > > > > > > > > > once other patches on
> > > > > > > > > > > > > which they depend will be merged.
> > > > > > > > > > > > > 
> > > > > > > > > > > > > https://patchwork.ozlabs.org/project/netdev/patch/20201120230339.651609-12-sae...@nvidia.com/
> > > > > > > > > > > > Could you be more explicit on the following points:
> > > > > > > > > > > > - which configuration is broken ATM (as in, two device 
> > > > > > > > > > > > have identical
> > > > > > > > > > > > macs? any other issues)?
> > > > > > > > > > > The only wrong thing is the call to  
> > > > > > > > > > > mlx5_query_nic_vport_mac_address().
> > > > > > > > > > > It's not breaking anything yet is wrong. The random MAC 
> > > > > > > > > > > address setting
> > > > > > > > > > >

Re: [PATCH] vdpa/mlx5: Use random MAC for the vdpa net instance

On Wed, Dec 02, 2020 at 08:56:37PM +0800, Jason Wang wrote:
> 
> On 2020/12/2 下午5:30, Michael S. Tsirkin wrote:
> > On Wed, Dec 02, 2020 at 12:18:36PM +0800, Jason Wang wrote:
> > > On 2020/12/1 下午5:23, Cindy Lu wrote:
> > > > On Mon, Nov 30, 2020 at 11:33 PM Michael S. Tsirkin  
> > > > wrote:
> > > > > On Mon, Nov 30, 2020 at 06:41:45PM +0800, Cindy Lu wrote:
> > > > > > On Mon, Nov 30, 2020 at 5:33 PM Michael S. Tsirkin 
> > > > > >  wrote:
> > > > > > > On Mon, Nov 30, 2020 at 11:27:59AM +0200, Eli Cohen wrote:
> > > > > > > > On Mon, Nov 30, 2020 at 04:00:51AM -0500, Michael S. Tsirkin 
> > > > > > > > wrote:
> > > > > > > > > On Mon, Nov 30, 2020 at 08:27:46AM +0200, Eli Cohen wrote:
> > > > > > > > > > On Sun, Nov 29, 2020 at 03:08:22PM -0500, Michael S. 
> > > > > > > > > > Tsirkin wrote:
> > > > > > > > > > > On Sun, Nov 29, 2020 at 08:43:51AM +0200, Eli Cohen wrote:
> > > > > > > > > > > > We should not try to use the VF MAC address as that is 
> > > > > > > > > > > > used by the
> > > > > > > > > > > > regular (e.g. mlx5_core) NIC implementation. Instead, 
> > > > > > > > > > > > use a random
> > > > > > > > > > > > generated MAC address.
> > > > > > > > > > > > 
> > > > > > > > > > > > Suggested by: Cindy Lu 
> > > > > > > > > > > > Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for 
> > > > > > > > > > > > supported mlx5 devices")
> > > > > > > > > > > > Signed-off-by: Eli Cohen 
> > > > > > > > > > > I didn't realise it's possible to use VF in two ways
> > > > > > > > > > > with and without vdpa.
> > > > > > > > > > Using a VF you can create quite a few resources, e.g. send 
> > > > > > > > > > queues
> > > > > > > > > > recieve queues, virtio_net queues etc. So you can possibly 
> > > > > > > > > > create
> > > > > > > > > > several instances of vdpa net devices and nic net devices.
> > > > > > > > > > 
> > > > > > > > > > > Could you include a bit more description on the failure
> > > > > > > > > > > mode?
> > > > > > > > > > Well, using the MAC address of the nic vport is wrong since 
> > > > > > > > > > that is the
> > > > > > > > > > MAC of the regular NIC implementation of mlx5_core.
> > > > > > > > > Right but ATM it doesn't coexist with vdpa so what's the 
> > > > > > > > > problem?
> > > > > > > > > 
> > > > > > > > This call is wrong:  mlx5_query_nic_vport_mac_address()
> > > > > > > > 
> > > > > > > > > > > Is switching to a random mac for such an unusual
> > > > > > > > > > > configuration really justified?
> > > > > > > > > > Since I can't use the NIC's MAC address, I have two options:
> > > > > > > > > > 1. To get the MAC address as was chosen by the user 
> > > > > > > > > > administering the
> > > > > > > > > >  NIC. This should invoke the set_config callback. 
> > > > > > > > > > Unfortunately this
> > > > > > > > > >  is not implemented yet.
> > > > > > > > > > 
> > > > > > > > > > 2. Use a random MAC address. This is OK since if (1) is 
> > > > > > > > > > implemented it
> > > > > > > > > >  can always override this random configuration.
> > > > > > > > > > 
> > > > > > > > > > > It looks like changing a MAC could break some guests,
> > > > > > > > > > > can it not?
> > > > > > > > > > > 
> > > > > > > > > > No, it will not. The current version of mlx5 VDPA does not 
> > > > > > > > > > allow regular
> > > > > > > > > > NIC driver and VDPA to co-exist. I have patches ready that 
> > > > > > > > > > enable that
> > > > > > > > > > from steering point of view. I will post them here once 
> > > > > > > > > > other patches on
> > > > > > > > > > which they depend will be merged.
> > > > > > > > > > 
> > > > > > > > > > https://patchwork.ozlabs.org/project/netdev/patch/20201120230339.651609-12-sae...@nvidia.com/
> > > > > > > > > Could you be more explicit on the following points:
> > > > > > > > > - which configuration is broken ATM (as in, two device have 
> > > > > > > > > identical
> > > > > > > > > macs? any other issues)?
> > > > > > > > The only wrong thing is the call to  
> > > > > > > > mlx5_query_nic_vport_mac_address().
> > > > > > > > It's not breaking anything yet is wrong. The random MAC address 
> > > > > > > > setting
> > > > > > > > is required for the steering patches.
> > > > > > > Okay so I'm not sure the Fixes tag at least is appropriate if 
> > > > > > > it's a
> > > > > > > dependency of a new feature.
> > > > > > > 
> > > > > > > > > - why won't device MAC change from guest point of view?
> > > > > > > > > 
> > > > > > > > It's lack of implementation in qemu as far as I know.
> > > > > > > Sorry not sure I understand. What's not implemented in QEMU?
> > > > > > > 
> > > > > > HI Michael, there are some bug in qemu to set_config, this will fix 
> > > > > > in future,
> > > > > > But this patch is still needed, because without this patch the mlx
> > > > > > driver will give an 0 mac address to qemu
> > > > > > and qemu will overwrite the default mac address.  This will cause 
> > > > > > traffic down.
> > > > > Hmm the patch description

Re: [PATCH] vdpa/mlx5: Use random MAC for the vdpa net instance

On 2020/12/2 下午8:17, Michael S. Tsirkin wrote:

On Wed, Dec 02, 2020 at 02:12:41PM +0200, Eli Cohen wrote:

On Wed, Dec 02, 2020 at 04:23:11AM -0500, Michael S. Tsirkin wrote:

On Wed, Dec 02, 2020 at 07:57:14AM +0200, Eli Cohen wrote:

On Wed, Dec 02, 2020 at 12:18:36PM +0800, Jason Wang wrote:

On 2020/12/1 下午5:23, Cindy Lu wrote:

On Mon, Nov 30, 2020 at 11:33 PM Michael S. Tsirkin wrote:

On Mon, Nov 30, 2020 at 06:41:45PM +0800, Cindy Lu wrote:

On Mon, Nov 30, 2020 at 5:33 PM Michael S. Tsirkin wrote:

On Mon, Nov 30, 2020 at 11:27:59AM +0200, Eli Cohen wrote:

On Mon, Nov 30, 2020 at 04:00:51AM -0500, Michael S. Tsirkin wrote:

On Mon, Nov 30, 2020 at 08:27:46AM +0200, Eli Cohen wrote:

On Sun, Nov 29, 2020 at 03:08:22PM -0500, Michael S. Tsirkin wrote:

On Sun, Nov 29, 2020 at 08:43:51AM +0200, Eli Cohen wrote:

We should not try to use the VF MAC address as that is used by the
regular (e.g. mlx5_core) NIC implementation. Instead, use a random
generated MAC address.

Suggested by: Cindy Lu
Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for supported mlx5 devices")
Signed-off-by: Eli Cohen

I didn't realise it's possible to use VF in two ways
with and without vdpa.

Using a VF you can create quite a few resources, e.g. send queues
recieve queues, virtio_net queues etc. So you can possibly create
several instances of vdpa net devices and nic net devices.

Could you include a bit more description on the failure
mode?

Well, using the MAC address of the nic vport is wrong since that is the
MAC of the regular NIC implementation of mlx5_core.

Right but ATM it doesn't coexist with vdpa so what's the problem?

This call is wrong: mlx5_query_nic_vport_mac_address()

Is switching to a random mac for such an unusual
configuration really justified?

2. Use a random MAC address. This is OK since if (1) is implemented it
can always override this random configuration.

It looks like changing a MAC could break some guests,
can it not?

https://patchwork.ozlabs.org/project/netdev/patch/20201120230339.651609-12-sae...@nvidia.com/

Could you be more explicit on the following points:
- which configuration is broken ATM (as in, two device have identical
macs? any other issues)?

The only wrong thing is the call to mlx5_query_nic_vport_mac_address().
It's not breaking anything yet is wrong. The random MAC address setting
is required for the steering patches.

Okay so I'm not sure the Fixes tag at least is appropriate if it's a
dependency of a new feature.

- why won't device MAC change from guest point of view?

It's lack of implementation in qemu as far as I know.

Sorry not sure I understand. What's not implemented in QEMU?

Hmm the patch description says VF mac address, not 0 address. Confused.
If there's no mac we can clear VIRTIO_NET_F_MAC and have guest
use a random value ...

I'm not sure this can work for all types of vDPA (e.g it could not be a
learning bridge in the swtich).

hi Michael，
I have tried as your suggestion, seems even remove the
VIRTIO_NET_F_MAC the qemu will still call get_cinfig and overwrite the
default address in VM,

This looks a bug in qemu, in guest driver we had:

this process is like
vdpa _init -->qemu call get_config ->mlx driver will give an mac
address with all 0-->
qemu will not check this mac address and use it --> overwrite the mac
address in qemu

So for my understanding there are several method to fix this problem

1, qemu check the mac address, if the mac address is all 0, qemu will
ignore it and set the random mac address to mlx driver.

So my understanding is that, if mac address is all 0, vDPA parent should not
advertise VIRTIO_NET_F_MAC. And qemu should emulate this feature as you did:

Re: [PATCH] vdpa/mlx5: Use random MAC for the vdpa net instance

On 2020/12/2 下午5:30, Michael S. Tsirkin wrote:

On Wed, Dec 02, 2020 at 12:18:36PM +0800, Jason Wang wrote:

On 2020/12/1 下午5:23, Cindy Lu wrote:

On Mon, Nov 30, 2020 at 11:33 PM Michael S. Tsirkin wrote:

On Mon, Nov 30, 2020 at 06:41:45PM +0800, Cindy Lu wrote:

On Mon, Nov 30, 2020 at 5:33 PM Michael S. Tsirkin wrote:

On Mon, Nov 30, 2020 at 11:27:59AM +0200, Eli Cohen wrote:

On Mon, Nov 30, 2020 at 04:00:51AM -0500, Michael S. Tsirkin wrote:

On Mon, Nov 30, 2020 at 08:27:46AM +0200, Eli Cohen wrote:

On Sun, Nov 29, 2020 at 03:08:22PM -0500, Michael S. Tsirkin wrote:

On Sun, Nov 29, 2020 at 08:43:51AM +0200, Eli Cohen wrote:

We should not try to use the VF MAC address as that is used by the
regular (e.g. mlx5_core) NIC implementation. Instead, use a random
generated MAC address.

Suggested by: Cindy Lu
Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for supported mlx5 devices")
Signed-off-by: Eli Cohen

I didn't realise it's possible to use VF in two ways
with and without vdpa.

Using a VF you can create quite a few resources, e.g. send queues
recieve queues, virtio_net queues etc. So you can possibly create
several instances of vdpa net devices and nic net devices.

Could you include a bit more description on the failure
mode?

Well, using the MAC address of the nic vport is wrong since that is the
MAC of the regular NIC implementation of mlx5_core.

Right but ATM it doesn't coexist with vdpa so what's the problem?

This call is wrong: mlx5_query_nic_vport_mac_address()

Is switching to a random mac for such an unusual
configuration really justified?

2. Use a random MAC address. This is OK since if (1) is implemented it
can always override this random configuration.

It looks like changing a MAC could break some guests,
can it not?

https://patchwork.ozlabs.org/project/netdev/patch/20201120230339.651609-12-sae...@nvidia.com/

Could you be more explicit on the following points:
- which configuration is broken ATM (as in, two device have identical
macs? any other issues)?

The only wrong thing is the call to mlx5_query_nic_vport_mac_address().
It's not breaking anything yet is wrong. The random MAC address setting
is required for the steering patches.

Okay so I'm not sure the Fixes tag at least is appropriate if it's a
dependency of a new feature.

- why won't device MAC change from guest point of view?

It's lack of implementation in qemu as far as I know.

Sorry not sure I understand. What's not implemented in QEMU?

Hmm the patch description says VF mac address, not 0 address. Confused.
If there's no mac we can clear VIRTIO_NET_F_MAC and have guest
use a random value ...

I'm not sure this can work for all types of vDPA (e.g it could not be a
learning bridge in the swtich).

hi Michael，
I have tried as your suggestion, seems even remove the
VIRTIO_NET_F_MAC the qemu will still call get_cinfig and overwrite the
default address in VM,

This looks a bug in qemu, in guest driver we had:

this process is like
vdpa _init -->qemu call get_config ->mlx driver will give an mac
address with all 0-->
qemu will not check this mac address and use it --> overwrite the mac
address in qemu

So for my understanding there are several method to fix this problem

1, qemu check the mac address, if the mac address is all 0, qemu will
ignore it and set the random mac address to mlx driver.

So my understanding is that, if mac address is all 0, vDPA parent should not
advertise VIRTIO_NET_F_MAC. And qemu should emulate this feature as you did:

1) get a random mac

To me this looks like a spec violation.

One question here, what did "set" mean here consider the

Re: [PATCH] vdpa/mlx5: Use random MAC for the vdpa net instance

On Wed, Dec 02, 2020 at 02:12:41PM +0200, Eli Cohen wrote:
> On Wed, Dec 02, 2020 at 04:23:11AM -0500, Michael S. Tsirkin wrote:
> > On Wed, Dec 02, 2020 at 07:57:14AM +0200, Eli Cohen wrote:
> > > On Wed, Dec 02, 2020 at 12:18:36PM +0800, Jason Wang wrote:
> > > > 
> > > > On 2020/12/1 下午5:23, Cindy Lu wrote:
> > > > > On Mon, Nov 30, 2020 at 11:33 PM Michael S. Tsirkin  
> > > > > wrote:
> > > > > > On Mon, Nov 30, 2020 at 06:41:45PM +0800, Cindy Lu wrote:
> > > > > > > On Mon, Nov 30, 2020 at 5:33 PM Michael S. Tsirkin 
> > > > > > >  wrote:
> > > > > > > > On Mon, Nov 30, 2020 at 11:27:59AM +0200, Eli Cohen wrote:
> > > > > > > > > On Mon, Nov 30, 2020 at 04:00:51AM -0500, Michael S. Tsirkin 
> > > > > > > > > wrote:
> > > > > > > > > > On Mon, Nov 30, 2020 at 08:27:46AM +0200, Eli Cohen wrote:
> > > > > > > > > > > On Sun, Nov 29, 2020 at 03:08:22PM -0500, Michael S. 
> > > > > > > > > > > Tsirkin wrote:
> > > > > > > > > > > > On Sun, Nov 29, 2020 at 08:43:51AM +0200, Eli Cohen 
> > > > > > > > > > > > wrote:
> > > > > > > > > > > > > We should not try to use the VF MAC address as that 
> > > > > > > > > > > > > is used by the
> > > > > > > > > > > > > regular (e.g. mlx5_core) NIC implementation. Instead, 
> > > > > > > > > > > > > use a random
> > > > > > > > > > > > > generated MAC address.
> > > > > > > > > > > > > 
> > > > > > > > > > > > > Suggested by: Cindy Lu 
> > > > > > > > > > > > > Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for 
> > > > > > > > > > > > > supported mlx5 devices")
> > > > > > > > > > > > > Signed-off-by: Eli Cohen 
> > > > > > > > > > > > I didn't realise it's possible to use VF in two ways
> > > > > > > > > > > > with and without vdpa.
> > > > > > > > > > > Using a VF you can create quite a few resources, e.g. 
> > > > > > > > > > > send queues
> > > > > > > > > > > recieve queues, virtio_net queues etc. So you can 
> > > > > > > > > > > possibly create
> > > > > > > > > > > several instances of vdpa net devices and nic net devices.
> > > > > > > > > > > 
> > > > > > > > > > > > Could you include a bit more description on the failure
> > > > > > > > > > > > mode?
> > > > > > > > > > > Well, using the MAC address of the nic vport is wrong 
> > > > > > > > > > > since that is the
> > > > > > > > > > > MAC of the regular NIC implementation of mlx5_core.
> > > > > > > > > > Right but ATM it doesn't coexist with vdpa so what's the 
> > > > > > > > > > problem?
> > > > > > > > > > 
> > > > > > > > > This call is wrong:  mlx5_query_nic_vport_mac_address()
> > > > > > > > > 
> > > > > > > > > > > > Is switching to a random mac for such an unusual
> > > > > > > > > > > > configuration really justified?
> > > > > > > > > > > Since I can't use the NIC's MAC address, I have two 
> > > > > > > > > > > options:
> > > > > > > > > > > 1. To get the MAC address as was chosen by the user 
> > > > > > > > > > > administering the
> > > > > > > > > > > NIC. This should invoke the set_config callback. 
> > > > > > > > > > > Unfortunately this
> > > > > > > > > > > is not implemented yet.
> > > > > > > > > > > 
> > > > > > > > > > > 2. Use a random MAC address. This is OK since if (1) is 
> > > > > > > > > > > implemented it
> > > > > > > > > > > can always override this random configuration.
> > > > > > > > > > > 
> > > > > > > > > > > > It looks like changing a MAC could break some guests,
> > > > > > > > > > > > can it not?
> > > > > > > > > > > > 
> > > > > > > > > > > No, it will not. The current version of mlx5 VDPA does 
> > > > > > > > > > > not allow regular
> > > > > > > > > > > NIC driver and VDPA to co-exist. I have patches ready 
> > > > > > > > > > > that enable that
> > > > > > > > > > > from steering point of view. I will post them here once 
> > > > > > > > > > > other patches on
> > > > > > > > > > > which they depend will be merged.
> > > > > > > > > > > 
> > > > > > > > > > > https://patchwork.ozlabs.org/project/netdev/patch/20201120230339.651609-12-sae...@nvidia.com/
> > > > > > > > > > Could you be more explicit on the following points:
> > > > > > > > > > - which configuration is broken ATM (as in, two device have 
> > > > > > > > > > identical
> > > > > > > > > >macs? any other issues)?
> > > > > > > > > The only wrong thing is the call to  
> > > > > > > > > mlx5_query_nic_vport_mac_address().
> > > > > > > > > It's not breaking anything yet is wrong. The random MAC 
> > > > > > > > > address setting
> > > > > > > > > is required for the steering patches.
> > > > > > > > Okay so I'm not sure the Fixes tag at least is appropriate if 
> > > > > > > > it's a
> > > > > > > > dependency of a new feature.
> > > > > > > > 
> > > > > > > > > > - why won't device MAC change from guest point of view?
> > > > > > > > > > 
> > > > > > > > > It's lack of implementation in qemu as far as I know.
> > > > > > > > Sorry not sure I understand. What's not implemented in QEMU?
> > > > > > > > 
> > > > > > > HI Michael, there are some bug in qemu to set_config, this

Re: [PATCH] vdpa/mlx5: Use random MAC for the vdpa net instance

2020-12-02 Thread Eli Cohen

On Wed, Dec 02, 2020 at 04:23:11AM -0500, Michael S. Tsirkin wrote:
> On Wed, Dec 02, 2020 at 07:57:14AM +0200, Eli Cohen wrote:
> > On Wed, Dec 02, 2020 at 12:18:36PM +0800, Jason Wang wrote:
> > > 
> > > On 2020/12/1 下午5:23, Cindy Lu wrote:
> > > > On Mon, Nov 30, 2020 at 11:33 PM Michael S. Tsirkin  
> > > > wrote:
> > > > > On Mon, Nov 30, 2020 at 06:41:45PM +0800, Cindy Lu wrote:
> > > > > > On Mon, Nov 30, 2020 at 5:33 PM Michael S. Tsirkin 
> > > > > >  wrote:
> > > > > > > On Mon, Nov 30, 2020 at 11:27:59AM +0200, Eli Cohen wrote:
> > > > > > > > On Mon, Nov 30, 2020 at 04:00:51AM -0500, Michael S. Tsirkin 
> > > > > > > > wrote:
> > > > > > > > > On Mon, Nov 30, 2020 at 08:27:46AM +0200, Eli Cohen wrote:
> > > > > > > > > > On Sun, Nov 29, 2020 at 03:08:22PM -0500, Michael S. 
> > > > > > > > > > Tsirkin wrote:
> > > > > > > > > > > On Sun, Nov 29, 2020 at 08:43:51AM +0200, Eli Cohen wrote:
> > > > > > > > > > > > We should not try to use the VF MAC address as that is 
> > > > > > > > > > > > used by the
> > > > > > > > > > > > regular (e.g. mlx5_core) NIC implementation. Instead, 
> > > > > > > > > > > > use a random
> > > > > > > > > > > > generated MAC address.
> > > > > > > > > > > > 
> > > > > > > > > > > > Suggested by: Cindy Lu 
> > > > > > > > > > > > Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for 
> > > > > > > > > > > > supported mlx5 devices")
> > > > > > > > > > > > Signed-off-by: Eli Cohen 
> > > > > > > > > > > I didn't realise it's possible to use VF in two ways
> > > > > > > > > > > with and without vdpa.
> > > > > > > > > > Using a VF you can create quite a few resources, e.g. send 
> > > > > > > > > > queues
> > > > > > > > > > recieve queues, virtio_net queues etc. So you can possibly 
> > > > > > > > > > create
> > > > > > > > > > several instances of vdpa net devices and nic net devices.
> > > > > > > > > > 
> > > > > > > > > > > Could you include a bit more description on the failure
> > > > > > > > > > > mode?
> > > > > > > > > > Well, using the MAC address of the nic vport is wrong since 
> > > > > > > > > > that is the
> > > > > > > > > > MAC of the regular NIC implementation of mlx5_core.
> > > > > > > > > Right but ATM it doesn't coexist with vdpa so what's the 
> > > > > > > > > problem?
> > > > > > > > > 
> > > > > > > > This call is wrong:  mlx5_query_nic_vport_mac_address()
> > > > > > > > 
> > > > > > > > > > > Is switching to a random mac for such an unusual
> > > > > > > > > > > configuration really justified?
> > > > > > > > > > Since I can't use the NIC's MAC address, I have two options:
> > > > > > > > > > 1. To get the MAC address as was chosen by the user 
> > > > > > > > > > administering the
> > > > > > > > > > NIC. This should invoke the set_config callback. 
> > > > > > > > > > Unfortunately this
> > > > > > > > > > is not implemented yet.
> > > > > > > > > > 
> > > > > > > > > > 2. Use a random MAC address. This is OK since if (1) is 
> > > > > > > > > > implemented it
> > > > > > > > > > can always override this random configuration.
> > > > > > > > > > 
> > > > > > > > > > > It looks like changing a MAC could break some guests,
> > > > > > > > > > > can it not?
> > > > > > > > > > > 
> > > > > > > > > > No, it will not. The current version of mlx5 VDPA does not 
> > > > > > > > > > allow regular
> > > > > > > > > > NIC driver and VDPA to co-exist. I have patches ready that 
> > > > > > > > > > enable that
> > > > > > > > > > from steering point of view. I will post them here once 
> > > > > > > > > > other patches on
> > > > > > > > > > which they depend will be merged.
> > > > > > > > > > 
> > > > > > > > > > https://patchwork.ozlabs.org/project/netdev/patch/20201120230339.651609-12-sae...@nvidia.com/
> > > > > > > > > Could you be more explicit on the following points:
> > > > > > > > > - which configuration is broken ATM (as in, two device have 
> > > > > > > > > identical
> > > > > > > > >macs? any other issues)?
> > > > > > > > The only wrong thing is the call to  
> > > > > > > > mlx5_query_nic_vport_mac_address().
> > > > > > > > It's not breaking anything yet is wrong. The random MAC address 
> > > > > > > > setting
> > > > > > > > is required for the steering patches.
> > > > > > > Okay so I'm not sure the Fixes tag at least is appropriate if 
> > > > > > > it's a
> > > > > > > dependency of a new feature.
> > > > > > > 
> > > > > > > > > - why won't device MAC change from guest point of view?
> > > > > > > > > 
> > > > > > > > It's lack of implementation in qemu as far as I know.
> > > > > > > Sorry not sure I understand. What's not implemented in QEMU?
> > > > > > > 
> > > > > > HI Michael, there are some bug in qemu to set_config, this will fix 
> > > > > > in future,
> > > > > > But this patch is still needed, because without this patch the mlx
> > > > > > driver will give an 0 mac address to qemu
> > > > > > and qemu will overwrite the default mac address.  This will cause 
> > > > > > traffic down.
> > > > > Hmm

Re: [PATCH] vdpa/mlx5: Use random MAC for the vdpa net instance

On Wed, Dec 02, 2020 at 12:18:36PM +0800, Jason Wang wrote:
> 
> On 2020/12/1 下午5:23, Cindy Lu wrote:
> > On Mon, Nov 30, 2020 at 11:33 PM Michael S. Tsirkin  wrote:
> > > On Mon, Nov 30, 2020 at 06:41:45PM +0800, Cindy Lu wrote:
> > > > On Mon, Nov 30, 2020 at 5:33 PM Michael S. Tsirkin  
> > > > wrote:
> > > > > On Mon, Nov 30, 2020 at 11:27:59AM +0200, Eli Cohen wrote:
> > > > > > On Mon, Nov 30, 2020 at 04:00:51AM -0500, Michael S. Tsirkin wrote:
> > > > > > > On Mon, Nov 30, 2020 at 08:27:46AM +0200, Eli Cohen wrote:
> > > > > > > > On Sun, Nov 29, 2020 at 03:08:22PM -0500, Michael S. Tsirkin 
> > > > > > > > wrote:
> > > > > > > > > On Sun, Nov 29, 2020 at 08:43:51AM +0200, Eli Cohen wrote:
> > > > > > > > > > We should not try to use the VF MAC address as that is used 
> > > > > > > > > > by the
> > > > > > > > > > regular (e.g. mlx5_core) NIC implementation. Instead, use a 
> > > > > > > > > > random
> > > > > > > > > > generated MAC address.
> > > > > > > > > > 
> > > > > > > > > > Suggested by: Cindy Lu 
> > > > > > > > > > Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for 
> > > > > > > > > > supported mlx5 devices")
> > > > > > > > > > Signed-off-by: Eli Cohen 
> > > > > > > > > I didn't realise it's possible to use VF in two ways
> > > > > > > > > with and without vdpa.
> > > > > > > > Using a VF you can create quite a few resources, e.g. send 
> > > > > > > > queues
> > > > > > > > recieve queues, virtio_net queues etc. So you can possibly 
> > > > > > > > create
> > > > > > > > several instances of vdpa net devices and nic net devices.
> > > > > > > > 
> > > > > > > > > Could you include a bit more description on the failure
> > > > > > > > > mode?
> > > > > > > > Well, using the MAC address of the nic vport is wrong since 
> > > > > > > > that is the
> > > > > > > > MAC of the regular NIC implementation of mlx5_core.
> > > > > > > Right but ATM it doesn't coexist with vdpa so what's the problem?
> > > > > > > 
> > > > > > This call is wrong:  mlx5_query_nic_vport_mac_address()
> > > > > > 
> > > > > > > > > Is switching to a random mac for such an unusual
> > > > > > > > > configuration really justified?
> > > > > > > > Since I can't use the NIC's MAC address, I have two options:
> > > > > > > > 1. To get the MAC address as was chosen by the user 
> > > > > > > > administering the
> > > > > > > > NIC. This should invoke the set_config callback. 
> > > > > > > > Unfortunately this
> > > > > > > > is not implemented yet.
> > > > > > > > 
> > > > > > > > 2. Use a random MAC address. This is OK since if (1) is 
> > > > > > > > implemented it
> > > > > > > > can always override this random configuration.
> > > > > > > > 
> > > > > > > > > It looks like changing a MAC could break some guests,
> > > > > > > > > can it not?
> > > > > > > > > 
> > > > > > > > No, it will not. The current version of mlx5 VDPA does not 
> > > > > > > > allow regular
> > > > > > > > NIC driver and VDPA to co-exist. I have patches ready that 
> > > > > > > > enable that
> > > > > > > > from steering point of view. I will post them here once other 
> > > > > > > > patches on
> > > > > > > > which they depend will be merged.
> > > > > > > > 
> > > > > > > > https://patchwork.ozlabs.org/project/netdev/patch/20201120230339.651609-12-sae...@nvidia.com/
> > > > > > > Could you be more explicit on the following points:
> > > > > > > - which configuration is broken ATM (as in, two device have 
> > > > > > > identical
> > > > > > >macs? any other issues)?
> > > > > > The only wrong thing is the call to  
> > > > > > mlx5_query_nic_vport_mac_address().
> > > > > > It's not breaking anything yet is wrong. The random MAC address 
> > > > > > setting
> > > > > > is required for the steering patches.
> > > > > Okay so I'm not sure the Fixes tag at least is appropriate if it's a
> > > > > dependency of a new feature.
> > > > > 
> > > > > > > - why won't device MAC change from guest point of view?
> > > > > > > 
> > > > > > It's lack of implementation in qemu as far as I know.
> > > > > Sorry not sure I understand. What's not implemented in QEMU?
> > > > > 
> > > > HI Michael, there are some bug in qemu to set_config, this will fix in 
> > > > future,
> > > > But this patch is still needed, because without this patch the mlx
> > > > driver will give an 0 mac address to qemu
> > > > and qemu will overwrite the default mac address.  This will cause 
> > > > traffic down.
> > > Hmm the patch description says VF mac address, not 0 address. Confused.
> > > If there's no mac we can clear VIRTIO_NET_F_MAC and have guest
> > > use a random value ...
> 
> 
> I'm not sure this can work for all types of vDPA (e.g it could not be a
> learning bridge in the swtich).
> 
> 
> > > 
> > hi Michael，
> > I have tried as your suggestion, seems even remove the
> > VIRTIO_NET_F_MAC the qemu will still call get_cinfig and overwrite the
> > default address in  VM,
> 
> 
> This looks a bug in qemu, in guest driver we had:
> 
>     /*

Re: [PATCH] vdpa/mlx5: Use random MAC for the vdpa net instance

On Wed, Dec 02, 2020 at 07:57:14AM +0200, Eli Cohen wrote:
> On Wed, Dec 02, 2020 at 12:18:36PM +0800, Jason Wang wrote:
> > 
> > On 2020/12/1 下午5:23, Cindy Lu wrote:
> > > On Mon, Nov 30, 2020 at 11:33 PM Michael S. Tsirkin  
> > > wrote:
> > > > On Mon, Nov 30, 2020 at 06:41:45PM +0800, Cindy Lu wrote:
> > > > > On Mon, Nov 30, 2020 at 5:33 PM Michael S. Tsirkin  
> > > > > wrote:
> > > > > > On Mon, Nov 30, 2020 at 11:27:59AM +0200, Eli Cohen wrote:
> > > > > > > On Mon, Nov 30, 2020 at 04:00:51AM -0500, Michael S. Tsirkin 
> > > > > > > wrote:
> > > > > > > > On Mon, Nov 30, 2020 at 08:27:46AM +0200, Eli Cohen wrote:
> > > > > > > > > On Sun, Nov 29, 2020 at 03:08:22PM -0500, Michael S. Tsirkin 
> > > > > > > > > wrote:
> > > > > > > > > > On Sun, Nov 29, 2020 at 08:43:51AM +0200, Eli Cohen wrote:
> > > > > > > > > > > We should not try to use the VF MAC address as that is 
> > > > > > > > > > > used by the
> > > > > > > > > > > regular (e.g. mlx5_core) NIC implementation. Instead, use 
> > > > > > > > > > > a random
> > > > > > > > > > > generated MAC address.
> > > > > > > > > > > 
> > > > > > > > > > > Suggested by: Cindy Lu 
> > > > > > > > > > > Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for 
> > > > > > > > > > > supported mlx5 devices")
> > > > > > > > > > > Signed-off-by: Eli Cohen 
> > > > > > > > > > I didn't realise it's possible to use VF in two ways
> > > > > > > > > > with and without vdpa.
> > > > > > > > > Using a VF you can create quite a few resources, e.g. send 
> > > > > > > > > queues
> > > > > > > > > recieve queues, virtio_net queues etc. So you can possibly 
> > > > > > > > > create
> > > > > > > > > several instances of vdpa net devices and nic net devices.
> > > > > > > > > 
> > > > > > > > > > Could you include a bit more description on the failure
> > > > > > > > > > mode?
> > > > > > > > > Well, using the MAC address of the nic vport is wrong since 
> > > > > > > > > that is the
> > > > > > > > > MAC of the regular NIC implementation of mlx5_core.
> > > > > > > > Right but ATM it doesn't coexist with vdpa so what's the 
> > > > > > > > problem?
> > > > > > > > 
> > > > > > > This call is wrong:  mlx5_query_nic_vport_mac_address()
> > > > > > > 
> > > > > > > > > > Is switching to a random mac for such an unusual
> > > > > > > > > > configuration really justified?
> > > > > > > > > Since I can't use the NIC's MAC address, I have two options:
> > > > > > > > > 1. To get the MAC address as was chosen by the user 
> > > > > > > > > administering the
> > > > > > > > > NIC. This should invoke the set_config callback. 
> > > > > > > > > Unfortunately this
> > > > > > > > > is not implemented yet.
> > > > > > > > > 
> > > > > > > > > 2. Use a random MAC address. This is OK since if (1) is 
> > > > > > > > > implemented it
> > > > > > > > > can always override this random configuration.
> > > > > > > > > 
> > > > > > > > > > It looks like changing a MAC could break some guests,
> > > > > > > > > > can it not?
> > > > > > > > > > 
> > > > > > > > > No, it will not. The current version of mlx5 VDPA does not 
> > > > > > > > > allow regular
> > > > > > > > > NIC driver and VDPA to co-exist. I have patches ready that 
> > > > > > > > > enable that
> > > > > > > > > from steering point of view. I will post them here once other 
> > > > > > > > > patches on
> > > > > > > > > which they depend will be merged.
> > > > > > > > > 
> > > > > > > > > https://patchwork.ozlabs.org/project/netdev/patch/20201120230339.651609-12-sae...@nvidia.com/
> > > > > > > > Could you be more explicit on the following points:
> > > > > > > > - which configuration is broken ATM (as in, two device have 
> > > > > > > > identical
> > > > > > > >macs? any other issues)?
> > > > > > > The only wrong thing is the call to  
> > > > > > > mlx5_query_nic_vport_mac_address().
> > > > > > > It's not breaking anything yet is wrong. The random MAC address 
> > > > > > > setting
> > > > > > > is required for the steering patches.
> > > > > > Okay so I'm not sure the Fixes tag at least is appropriate if it's a
> > > > > > dependency of a new feature.
> > > > > > 
> > > > > > > > - why won't device MAC change from guest point of view?
> > > > > > > > 
> > > > > > > It's lack of implementation in qemu as far as I know.
> > > > > > Sorry not sure I understand. What's not implemented in QEMU?
> > > > > > 
> > > > > HI Michael, there are some bug in qemu to set_config, this will fix 
> > > > > in future,
> > > > > But this patch is still needed, because without this patch the mlx
> > > > > driver will give an 0 mac address to qemu
> > > > > and qemu will overwrite the default mac address.  This will cause 
> > > > > traffic down.
> > > > Hmm the patch description says VF mac address, not 0 address. Confused.
> > > > If there's no mac we can clear VIRTIO_NET_F_MAC and have guest
> > > > use a random value ...
> > 
> > 
> > I'm not sure this can work for all types of vDPA (e.g it could not be a
> > learning

Re: [PATCH] vdpa/mlx5: Use random MAC for the vdpa net instance

2020-12-01 Thread Eli Cohen

On Wed, Dec 02, 2020 at 12:18:36PM +0800, Jason Wang wrote:
> 
> On 2020/12/1 下午5:23, Cindy Lu wrote:
> > On Mon, Nov 30, 2020 at 11:33 PM Michael S. Tsirkin  wrote:
> > > On Mon, Nov 30, 2020 at 06:41:45PM +0800, Cindy Lu wrote:
> > > > On Mon, Nov 30, 2020 at 5:33 PM Michael S. Tsirkin  
> > > > wrote:
> > > > > On Mon, Nov 30, 2020 at 11:27:59AM +0200, Eli Cohen wrote:
> > > > > > On Mon, Nov 30, 2020 at 04:00:51AM -0500, Michael S. Tsirkin wrote:
> > > > > > > On Mon, Nov 30, 2020 at 08:27:46AM +0200, Eli Cohen wrote:
> > > > > > > > On Sun, Nov 29, 2020 at 03:08:22PM -0500, Michael S. Tsirkin 
> > > > > > > > wrote:
> > > > > > > > > On Sun, Nov 29, 2020 at 08:43:51AM +0200, Eli Cohen wrote:
> > > > > > > > > > We should not try to use the VF MAC address as that is used 
> > > > > > > > > > by the
> > > > > > > > > > regular (e.g. mlx5_core) NIC implementation. Instead, use a 
> > > > > > > > > > random
> > > > > > > > > > generated MAC address.
> > > > > > > > > > 
> > > > > > > > > > Suggested by: Cindy Lu 
> > > > > > > > > > Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for 
> > > > > > > > > > supported mlx5 devices")
> > > > > > > > > > Signed-off-by: Eli Cohen 
> > > > > > > > > I didn't realise it's possible to use VF in two ways
> > > > > > > > > with and without vdpa.
> > > > > > > > Using a VF you can create quite a few resources, e.g. send 
> > > > > > > > queues
> > > > > > > > recieve queues, virtio_net queues etc. So you can possibly 
> > > > > > > > create
> > > > > > > > several instances of vdpa net devices and nic net devices.
> > > > > > > > 
> > > > > > > > > Could you include a bit more description on the failure
> > > > > > > > > mode?
> > > > > > > > Well, using the MAC address of the nic vport is wrong since 
> > > > > > > > that is the
> > > > > > > > MAC of the regular NIC implementation of mlx5_core.
> > > > > > > Right but ATM it doesn't coexist with vdpa so what's the problem?
> > > > > > > 
> > > > > > This call is wrong:  mlx5_query_nic_vport_mac_address()
> > > > > > 
> > > > > > > > > Is switching to a random mac for such an unusual
> > > > > > > > > configuration really justified?
> > > > > > > > Since I can't use the NIC's MAC address, I have two options:
> > > > > > > > 1. To get the MAC address as was chosen by the user 
> > > > > > > > administering the
> > > > > > > > NIC. This should invoke the set_config callback. 
> > > > > > > > Unfortunately this
> > > > > > > > is not implemented yet.
> > > > > > > > 
> > > > > > > > 2. Use a random MAC address. This is OK since if (1) is 
> > > > > > > > implemented it
> > > > > > > > can always override this random configuration.
> > > > > > > > 
> > > > > > > > > It looks like changing a MAC could break some guests,
> > > > > > > > > can it not?
> > > > > > > > > 
> > > > > > > > No, it will not. The current version of mlx5 VDPA does not 
> > > > > > > > allow regular
> > > > > > > > NIC driver and VDPA to co-exist. I have patches ready that 
> > > > > > > > enable that
> > > > > > > > from steering point of view. I will post them here once other 
> > > > > > > > patches on
> > > > > > > > which they depend will be merged.
> > > > > > > > 
> > > > > > > > https://patchwork.ozlabs.org/project/netdev/patch/20201120230339.651609-12-sae...@nvidia.com/
> > > > > > > Could you be more explicit on the following points:
> > > > > > > - which configuration is broken ATM (as in, two device have 
> > > > > > > identical
> > > > > > >macs? any other issues)?
> > > > > > The only wrong thing is the call to  
> > > > > > mlx5_query_nic_vport_mac_address().
> > > > > > It's not breaking anything yet is wrong. The random MAC address 
> > > > > > setting
> > > > > > is required for the steering patches.
> > > > > Okay so I'm not sure the Fixes tag at least is appropriate if it's a
> > > > > dependency of a new feature.
> > > > > 
> > > > > > > - why won't device MAC change from guest point of view?
> > > > > > > 
> > > > > > It's lack of implementation in qemu as far as I know.
> > > > > Sorry not sure I understand. What's not implemented in QEMU?
> > > > > 
> > > > HI Michael, there are some bug in qemu to set_config, this will fix in 
> > > > future,
> > > > But this patch is still needed, because without this patch the mlx
> > > > driver will give an 0 mac address to qemu
> > > > and qemu will overwrite the default mac address.  This will cause 
> > > > traffic down.
> > > Hmm the patch description says VF mac address, not 0 address. Confused.
> > > If there's no mac we can clear VIRTIO_NET_F_MAC and have guest
> > > use a random value ...
> 
> 
> I'm not sure this can work for all types of vDPA (e.g it could not be a
> learning bridge in the swtich).
> 
> 
> > > 
> > hi Michael，
> > I have tried as your suggestion, seems even remove the
> > VIRTIO_NET_F_MAC the qemu will still call get_cinfig and overwrite the
> > default address in  VM,
> 
> 
> This looks a bug in qemu, in guest driver we had:
> 
>     /*

Re: [PATCH] vdpa/mlx5: Use random MAC for the vdpa net instance

2020-12-01 Thread Jason Wang

On 2020/12/1 下午5:23, Cindy Lu wrote:

On Mon, Nov 30, 2020 at 11:33 PM Michael S. Tsirkin wrote:

On Mon, Nov 30, 2020 at 06:41:45PM +0800, Cindy Lu wrote:

On Mon, Nov 30, 2020 at 5:33 PM Michael S. Tsirkin wrote:

On Mon, Nov 30, 2020 at 11:27:59AM +0200, Eli Cohen wrote:

On Mon, Nov 30, 2020 at 04:00:51AM -0500, Michael S. Tsirkin wrote:

On Mon, Nov 30, 2020 at 08:27:46AM +0200, Eli Cohen wrote:

On Sun, Nov 29, 2020 at 03:08:22PM -0500, Michael S. Tsirkin wrote:

On Sun, Nov 29, 2020 at 08:43:51AM +0200, Eli Cohen wrote:

We should not try to use the VF MAC address as that is used by the
regular (e.g. mlx5_core) NIC implementation. Instead, use a random
generated MAC address.

Suggested by: Cindy Lu
Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for supported mlx5 devices")
Signed-off-by: Eli Cohen

I didn't realise it's possible to use VF in two ways
with and without vdpa.

Using a VF you can create quite a few resources, e.g. send queues
recieve queues, virtio_net queues etc. So you can possibly create
several instances of vdpa net devices and nic net devices.

Could you include a bit more description on the failure
mode?

Well, using the MAC address of the nic vport is wrong since that is the
MAC of the regular NIC implementation of mlx5_core.

Right but ATM it doesn't coexist with vdpa so what's the problem?

This call is wrong: mlx5_query_nic_vport_mac_address()

Is switching to a random mac for such an unusual
configuration really justified?

2. Use a random MAC address. This is OK since if (1) is implemented it
can always override this random configuration.

It looks like changing a MAC could break some guests,
can it not?

https://patchwork.ozlabs.org/project/netdev/patch/20201120230339.651609-12-sae...@nvidia.com/

Could you be more explicit on the following points:
- which configuration is broken ATM (as in, two device have identical
macs? any other issues)?

The only wrong thing is the call to mlx5_query_nic_vport_mac_address().
It's not breaking anything yet is wrong. The random MAC address setting
is required for the steering patches.

Okay so I'm not sure the Fixes tag at least is appropriate if it's a
dependency of a new feature.

- why won't device MAC change from guest point of view?

It's lack of implementation in qemu as far as I know.

Sorry not sure I understand. What's not implemented in QEMU?

Hmm the patch description says VF mac address, not 0 address. Confused.
If there's no mac we can clear VIRTIO_NET_F_MAC and have guest
use a random value ...

I'm not sure this can work for all types of vDPA (e.g it could not be a
learning bridge in the swtich).

hi Michael，
I have tried as your suggestion, seems even remove the
VIRTIO_NET_F_MAC the qemu will still call get_cinfig and overwrite the
default address in VM,

This looks a bug in qemu, in guest driver we had:

this process is like
vdpa _init -->qemu call get_config ->mlx driver will give an mac
address with all 0-->
qemu will not check this mac address and use it --> overwrite the mac
address in qemu

So for my understanding there are several method to fix this problem

1, qemu check the mac address, if the mac address is all 0, qemu will
ignore it and set the random mac address to mlx driver.

So my understanding is that, if mac address is all 0, vDPA parent should
not advertise VIRTIO_NET_F_MAC. And qemu should emulate this feature as
you did:

1) get a random mac
2) advertise VIRTIO_NET_F_MAC
3) set the random mac to vDPA through set_config
4) advertise the random mac to emulated config to guest

2. mlx driver checks the mac address and if this mac is 0, return fail
to qemu, but this need to change the UAPI.

uAPI is probably fine since ioctl can fail. We can change the to allow
the set_config to fail but virito spec doesn't have a way to advertise
the error in this case. Anyway, the driver only risk itself for setting
a wrong

Re: [PATCH] vdpa/mlx5: Use random MAC for the vdpa net instance

2020-12-01 Thread Cindy Lu

On Tue, Dec 1, 2020 at 7:32 PM Michael S. Tsirkin  wrote:
>
> On Tue, Dec 01, 2020 at 05:23:18PM +0800, Cindy Lu wrote:
> > On Mon, Nov 30, 2020 at 11:33 PM Michael S. Tsirkin  wrote:
> > >
> > > On Mon, Nov 30, 2020 at 06:41:45PM +0800, Cindy Lu wrote:
> > > > On Mon, Nov 30, 2020 at 5:33 PM Michael S. Tsirkin  
> > > > wrote:
> > > > >
> > > > > On Mon, Nov 30, 2020 at 11:27:59AM +0200, Eli Cohen wrote:
> > > > > > On Mon, Nov 30, 2020 at 04:00:51AM -0500, Michael S. Tsirkin wrote:
> > > > > > > On Mon, Nov 30, 2020 at 08:27:46AM +0200, Eli Cohen wrote:
> > > > > > > > On Sun, Nov 29, 2020 at 03:08:22PM -0500, Michael S. Tsirkin 
> > > > > > > > wrote:
> > > > > > > > > On Sun, Nov 29, 2020 at 08:43:51AM +0200, Eli Cohen wrote:
> > > > > > > > > > We should not try to use the VF MAC address as that is used 
> > > > > > > > > > by the
> > > > > > > > > > regular (e.g. mlx5_core) NIC implementation. Instead, use a 
> > > > > > > > > > random
> > > > > > > > > > generated MAC address.
> > > > > > > > > >
> > > > > > > > > > Suggested by: Cindy Lu 
> > > > > > > > > > Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for 
> > > > > > > > > > supported mlx5 devices")
> > > > > > > > > > Signed-off-by: Eli Cohen 
> > > > > > > > >
> > > > > > > > > I didn't realise it's possible to use VF in two ways
> > > > > > > > > with and without vdpa.
> > > > > > > >
> > > > > > > > Using a VF you can create quite a few resources, e.g. send 
> > > > > > > > queues
> > > > > > > > recieve queues, virtio_net queues etc. So you can possibly 
> > > > > > > > create
> > > > > > > > several instances of vdpa net devices and nic net devices.
> > > > > > > >
> > > > > > > > > Could you include a bit more description on the failure
> > > > > > > > > mode?
> > > > > > > >
> > > > > > > > Well, using the MAC address of the nic vport is wrong since 
> > > > > > > > that is the
> > > > > > > > MAC of the regular NIC implementation of mlx5_core.
> > > > > > >
> > > > > > > Right but ATM it doesn't coexist with vdpa so what's the problem?
> > > > > > >
> > > > > >
> > > > > > This call is wrong:  mlx5_query_nic_vport_mac_address()
> > > > > >
> > > > > > > > > Is switching to a random mac for such an unusual
> > > > > > > > > configuration really justified?
> > > > > > > >
> > > > > > > > Since I can't use the NIC's MAC address, I have two options:
> > > > > > > > 1. To get the MAC address as was chosen by the user 
> > > > > > > > administering the
> > > > > > > >NIC. This should invoke the set_config callback. 
> > > > > > > > Unfortunately this
> > > > > > > >is not implemented yet.
> > > > > > > >
> > > > > > > > 2. Use a random MAC address. This is OK since if (1) is 
> > > > > > > > implemented it
> > > > > > > >can always override this random configuration.
> > > > > > > >
> > > > > > > > > It looks like changing a MAC could break some guests,
> > > > > > > > > can it not?
> > > > > > > > >
> > > > > > > >
> > > > > > > > No, it will not. The current version of mlx5 VDPA does not 
> > > > > > > > allow regular
> > > > > > > > NIC driver and VDPA to co-exist. I have patches ready that 
> > > > > > > > enable that
> > > > > > > > from steering point of view. I will post them here once other 
> > > > > > > > patches on
> > > > > > > > which they depend will be merged.
> > > > > > > >
> > > > > > > > https://patchwork.ozlabs.org/project/netdev/patch/20201120230339.651609-12-sae...@nvidia.com/
> > > > > > >
> > > > > > > Could you be more explicit on the following points:
> > > > > > > - which configuration is broken ATM (as in, two device have 
> > > > > > > identical
> > > > > > >   macs? any other issues)?
> > > > > >
> > > > > > The only wrong thing is the call to  
> > > > > > mlx5_query_nic_vport_mac_address().
> > > > > > It's not breaking anything yet is wrong. The random MAC address 
> > > > > > setting
> > > > > > is required for the steering patches.
> > > > >
> > > > > Okay so I'm not sure the Fixes tag at least is appropriate if it's a
> > > > > dependency of a new feature.
> > > > >
> > > > > > > - why won't device MAC change from guest point of view?
> > > > > > >
> > > > > >
> > > > > > It's lack of implementation in qemu as far as I know.
> > > > >
> > > > > Sorry not sure I understand. What's not implemented in QEMU?
> > > > >
> > > > HI Michael, there are some bug in qemu to set_config, this will fix in 
> > > > future,
> > > > But this patch is still needed, because without this patch the mlx
> > > > driver will give an 0 mac address to qemu
> > > > and qemu will overwrite the default mac address.  This will cause 
> > > > traffic down.
> > >
> > > Hmm the patch description says VF mac address, not 0 address. Confused.
> > > If there's no mac we can clear VIRTIO_NET_F_MAC and have guest
> > > use a random value ...
> > >
> > hi Michael，
> > I have tried as your suggestion, seems even remove the
> > VIRTIO_NET_F_MAC the qemu will still call get_cinfig and overwrite the
> > default address in  VM,
> >

Re: [PATCH] vdpa/mlx5: Use random MAC for the vdpa net instance

2020-12-01 Thread Michael S. Tsirkin

On Tue, Dec 01, 2020 at 05:23:18PM +0800, Cindy Lu wrote:
> On Mon, Nov 30, 2020 at 11:33 PM Michael S. Tsirkin  wrote:
> >
> > On Mon, Nov 30, 2020 at 06:41:45PM +0800, Cindy Lu wrote:
> > > On Mon, Nov 30, 2020 at 5:33 PM Michael S. Tsirkin  
> > > wrote:
> > > >
> > > > On Mon, Nov 30, 2020 at 11:27:59AM +0200, Eli Cohen wrote:
> > > > > On Mon, Nov 30, 2020 at 04:00:51AM -0500, Michael S. Tsirkin wrote:
> > > > > > On Mon, Nov 30, 2020 at 08:27:46AM +0200, Eli Cohen wrote:
> > > > > > > On Sun, Nov 29, 2020 at 03:08:22PM -0500, Michael S. Tsirkin 
> > > > > > > wrote:
> > > > > > > > On Sun, Nov 29, 2020 at 08:43:51AM +0200, Eli Cohen wrote:
> > > > > > > > > We should not try to use the VF MAC address as that is used 
> > > > > > > > > by the
> > > > > > > > > regular (e.g. mlx5_core) NIC implementation. Instead, use a 
> > > > > > > > > random
> > > > > > > > > generated MAC address.
> > > > > > > > >
> > > > > > > > > Suggested by: Cindy Lu 
> > > > > > > > > Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for 
> > > > > > > > > supported mlx5 devices")
> > > > > > > > > Signed-off-by: Eli Cohen 
> > > > > > > >
> > > > > > > > I didn't realise it's possible to use VF in two ways
> > > > > > > > with and without vdpa.
> > > > > > >
> > > > > > > Using a VF you can create quite a few resources, e.g. send queues
> > > > > > > recieve queues, virtio_net queues etc. So you can possibly create
> > > > > > > several instances of vdpa net devices and nic net devices.
> > > > > > >
> > > > > > > > Could you include a bit more description on the failure
> > > > > > > > mode?
> > > > > > >
> > > > > > > Well, using the MAC address of the nic vport is wrong since that 
> > > > > > > is the
> > > > > > > MAC of the regular NIC implementation of mlx5_core.
> > > > > >
> > > > > > Right but ATM it doesn't coexist with vdpa so what's the problem?
> > > > > >
> > > > >
> > > > > This call is wrong:  mlx5_query_nic_vport_mac_address()
> > > > >
> > > > > > > > Is switching to a random mac for such an unusual
> > > > > > > > configuration really justified?
> > > > > > >
> > > > > > > Since I can't use the NIC's MAC address, I have two options:
> > > > > > > 1. To get the MAC address as was chosen by the user administering 
> > > > > > > the
> > > > > > >NIC. This should invoke the set_config callback. Unfortunately 
> > > > > > > this
> > > > > > >is not implemented yet.
> > > > > > >
> > > > > > > 2. Use a random MAC address. This is OK since if (1) is 
> > > > > > > implemented it
> > > > > > >can always override this random configuration.
> > > > > > >
> > > > > > > > It looks like changing a MAC could break some guests,
> > > > > > > > can it not?
> > > > > > > >
> > > > > > >
> > > > > > > No, it will not. The current version of mlx5 VDPA does not allow 
> > > > > > > regular
> > > > > > > NIC driver and VDPA to co-exist. I have patches ready that enable 
> > > > > > > that
> > > > > > > from steering point of view. I will post them here once other 
> > > > > > > patches on
> > > > > > > which they depend will be merged.
> > > > > > >
> > > > > > > https://patchwork.ozlabs.org/project/netdev/patch/20201120230339.651609-12-sae...@nvidia.com/
> > > > > >
> > > > > > Could you be more explicit on the following points:
> > > > > > - which configuration is broken ATM (as in, two device have 
> > > > > > identical
> > > > > >   macs? any other issues)?
> > > > >
> > > > > The only wrong thing is the call to  
> > > > > mlx5_query_nic_vport_mac_address().
> > > > > It's not breaking anything yet is wrong. The random MAC address 
> > > > > setting
> > > > > is required for the steering patches.
> > > >
> > > > Okay so I'm not sure the Fixes tag at least is appropriate if it's a
> > > > dependency of a new feature.
> > > >
> > > > > > - why won't device MAC change from guest point of view?
> > > > > >
> > > > >
> > > > > It's lack of implementation in qemu as far as I know.
> > > >
> > > > Sorry not sure I understand. What's not implemented in QEMU?
> > > >
> > > HI Michael, there are some bug in qemu to set_config, this will fix in 
> > > future,
> > > But this patch is still needed, because without this patch the mlx
> > > driver will give an 0 mac address to qemu
> > > and qemu will overwrite the default mac address.  This will cause traffic 
> > > down.
> >
> > Hmm the patch description says VF mac address, not 0 address. Confused.
> > If there's no mac we can clear VIRTIO_NET_F_MAC and have guest
> > use a random value ...
> >
> hi Michael，
> I have tried as your suggestion, seems even remove the
> VIRTIO_NET_F_MAC the qemu will still call get_cinfig and overwrite the
> default address in  VM,
> this process is like
> vdpa _init -->qemu call get_config ->mlx driver will give  an mac
> address with all 0-->
> qemu will not check this mac address and use it --> overwrite the mac
> address in qemu

Right but guest will ignore it then, right?

> So for my understanding there are several method to fix this

Re: [PATCH] vdpa/mlx5: Use random MAC for the vdpa net instance

2020-12-01 Thread Cindy Lu

On Mon, Nov 30, 2020 at 11:33 PM Michael S. Tsirkin  wrote:
>
> On Mon, Nov 30, 2020 at 06:41:45PM +0800, Cindy Lu wrote:
> > On Mon, Nov 30, 2020 at 5:33 PM Michael S. Tsirkin  wrote:
> > >
> > > On Mon, Nov 30, 2020 at 11:27:59AM +0200, Eli Cohen wrote:
> > > > On Mon, Nov 30, 2020 at 04:00:51AM -0500, Michael S. Tsirkin wrote:
> > > > > On Mon, Nov 30, 2020 at 08:27:46AM +0200, Eli Cohen wrote:
> > > > > > On Sun, Nov 29, 2020 at 03:08:22PM -0500, Michael S. Tsirkin wrote:
> > > > > > > On Sun, Nov 29, 2020 at 08:43:51AM +0200, Eli Cohen wrote:
> > > > > > > > We should not try to use the VF MAC address as that is used by 
> > > > > > > > the
> > > > > > > > regular (e.g. mlx5_core) NIC implementation. Instead, use a 
> > > > > > > > random
> > > > > > > > generated MAC address.
> > > > > > > >
> > > > > > > > Suggested by: Cindy Lu 
> > > > > > > > Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for supported 
> > > > > > > > mlx5 devices")
> > > > > > > > Signed-off-by: Eli Cohen 
> > > > > > >
> > > > > > > I didn't realise it's possible to use VF in two ways
> > > > > > > with and without vdpa.
> > > > > >
> > > > > > Using a VF you can create quite a few resources, e.g. send queues
> > > > > > recieve queues, virtio_net queues etc. So you can possibly create
> > > > > > several instances of vdpa net devices and nic net devices.
> > > > > >
> > > > > > > Could you include a bit more description on the failure
> > > > > > > mode?
> > > > > >
> > > > > > Well, using the MAC address of the nic vport is wrong since that is 
> > > > > > the
> > > > > > MAC of the regular NIC implementation of mlx5_core.
> > > > >
> > > > > Right but ATM it doesn't coexist with vdpa so what's the problem?
> > > > >
> > > >
> > > > This call is wrong:  mlx5_query_nic_vport_mac_address()
> > > >
> > > > > > > Is switching to a random mac for such an unusual
> > > > > > > configuration really justified?
> > > > > >
> > > > > > Since I can't use the NIC's MAC address, I have two options:
> > > > > > 1. To get the MAC address as was chosen by the user administering 
> > > > > > the
> > > > > >NIC. This should invoke the set_config callback. Unfortunately 
> > > > > > this
> > > > > >is not implemented yet.
> > > > > >
> > > > > > 2. Use a random MAC address. This is OK since if (1) is implemented 
> > > > > > it
> > > > > >can always override this random configuration.
> > > > > >
> > > > > > > It looks like changing a MAC could break some guests,
> > > > > > > can it not?
> > > > > > >
> > > > > >
> > > > > > No, it will not. The current version of mlx5 VDPA does not allow 
> > > > > > regular
> > > > > > NIC driver and VDPA to co-exist. I have patches ready that enable 
> > > > > > that
> > > > > > from steering point of view. I will post them here once other 
> > > > > > patches on
> > > > > > which they depend will be merged.
> > > > > >
> > > > > > https://patchwork.ozlabs.org/project/netdev/patch/20201120230339.651609-12-sae...@nvidia.com/
> > > > >
> > > > > Could you be more explicit on the following points:
> > > > > - which configuration is broken ATM (as in, two device have identical
> > > > >   macs? any other issues)?
> > > >
> > > > The only wrong thing is the call to  mlx5_query_nic_vport_mac_address().
> > > > It's not breaking anything yet is wrong. The random MAC address setting
> > > > is required for the steering patches.
> > >
> > > Okay so I'm not sure the Fixes tag at least is appropriate if it's a
> > > dependency of a new feature.
> > >
> > > > > - why won't device MAC change from guest point of view?
> > > > >
> > > >
> > > > It's lack of implementation in qemu as far as I know.
> > >
> > > Sorry not sure I understand. What's not implemented in QEMU?
> > >
> > HI Michael, there are some bug in qemu to set_config, this will fix in 
> > future,
> > But this patch is still needed, because without this patch the mlx
> > driver will give an 0 mac address to qemu
> > and qemu will overwrite the default mac address.  This will cause traffic 
> > down.
>
> Hmm the patch description says VF mac address, not 0 address. Confused.
> If there's no mac we can clear VIRTIO_NET_F_MAC and have guest
> use a random value ...
>
hi Michael，
I have tried as your suggestion, seems even remove the
VIRTIO_NET_F_MAC the qemu will still call get_cinfig and overwrite the
default address in  VM,
this process is like
vdpa _init -->qemu call get_config ->mlx driver will give  an mac
address with all 0-->
qemu will not check this mac address and use it --> overwrite the mac
address in qemu

So for my understanding there are several method to fix this problem

1, qemu check the mac address, if the mac address is all 0, qemu will
ignore it and set the random mac address to mlx driver.
2. mlx driver checks the mac address and if this mac is 0, return fail
to qemu, but this need to change the UAPI.
3. mlx driver it shelf should get an correct mac address while it init.
4. add check in qemu get_config function  , if there

Re: [PATCH] vdpa/mlx5: Use random MAC for the vdpa net instance

On Mon, Nov 30, 2020 at 06:41:45PM +0800, Cindy Lu wrote:
> On Mon, Nov 30, 2020 at 5:33 PM Michael S. Tsirkin  wrote:
> >
> > On Mon, Nov 30, 2020 at 11:27:59AM +0200, Eli Cohen wrote:
> > > On Mon, Nov 30, 2020 at 04:00:51AM -0500, Michael S. Tsirkin wrote:
> > > > On Mon, Nov 30, 2020 at 08:27:46AM +0200, Eli Cohen wrote:
> > > > > On Sun, Nov 29, 2020 at 03:08:22PM -0500, Michael S. Tsirkin wrote:
> > > > > > On Sun, Nov 29, 2020 at 08:43:51AM +0200, Eli Cohen wrote:
> > > > > > > We should not try to use the VF MAC address as that is used by the
> > > > > > > regular (e.g. mlx5_core) NIC implementation. Instead, use a random
> > > > > > > generated MAC address.
> > > > > > >
> > > > > > > Suggested by: Cindy Lu 
> > > > > > > Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for supported 
> > > > > > > mlx5 devices")
> > > > > > > Signed-off-by: Eli Cohen 
> > > > > >
> > > > > > I didn't realise it's possible to use VF in two ways
> > > > > > with and without vdpa.
> > > > >
> > > > > Using a VF you can create quite a few resources, e.g. send queues
> > > > > recieve queues, virtio_net queues etc. So you can possibly create
> > > > > several instances of vdpa net devices and nic net devices.
> > > > >
> > > > > > Could you include a bit more description on the failure
> > > > > > mode?
> > > > >
> > > > > Well, using the MAC address of the nic vport is wrong since that is 
> > > > > the
> > > > > MAC of the regular NIC implementation of mlx5_core.
> > > >
> > > > Right but ATM it doesn't coexist with vdpa so what's the problem?
> > > >
> > >
> > > This call is wrong:  mlx5_query_nic_vport_mac_address()
> > >
> > > > > > Is switching to a random mac for such an unusual
> > > > > > configuration really justified?
> > > > >
> > > > > Since I can't use the NIC's MAC address, I have two options:
> > > > > 1. To get the MAC address as was chosen by the user administering the
> > > > >NIC. This should invoke the set_config callback. Unfortunately this
> > > > >is not implemented yet.
> > > > >
> > > > > 2. Use a random MAC address. This is OK since if (1) is implemented it
> > > > >can always override this random configuration.
> > > > >
> > > > > > It looks like changing a MAC could break some guests,
> > > > > > can it not?
> > > > > >
> > > > >
> > > > > No, it will not. The current version of mlx5 VDPA does not allow 
> > > > > regular
> > > > > NIC driver and VDPA to co-exist. I have patches ready that enable that
> > > > > from steering point of view. I will post them here once other patches 
> > > > > on
> > > > > which they depend will be merged.
> > > > >
> > > > > https://patchwork.ozlabs.org/project/netdev/patch/20201120230339.651609-12-sae...@nvidia.com/
> > > >
> > > > Could you be more explicit on the following points:
> > > > - which configuration is broken ATM (as in, two device have identical
> > > >   macs? any other issues)?
> > >
> > > The only wrong thing is the call to  mlx5_query_nic_vport_mac_address().
> > > It's not breaking anything yet is wrong. The random MAC address setting
> > > is required for the steering patches.
> >
> > Okay so I'm not sure the Fixes tag at least is appropriate if it's a
> > dependency of a new feature.
> >
> > > > - why won't device MAC change from guest point of view?
> > > >
> > >
> > > It's lack of implementation in qemu as far as I know.
> >
> > Sorry not sure I understand. What's not implemented in QEMU?
> >
> HI Michael, there are some bug in qemu to set_config, this will fix in future,
> But this patch is still needed, because without this patch the mlx
> driver will give an 0 mac address to qemu
> and qemu will overwrite the default mac address.  This will cause traffic 
> down.

Hmm the patch description says VF mac address, not 0 address. Confused.
If there's no mac we can clear VIRTIO_NET_F_MAC and have guest
use a random value ...

> > > >
> > > > > > > ---
> > > > > > >  drivers/vdpa/mlx5/net/mlx5_vnet.c | 5 +
> > > > > > >  1 file changed, 1 insertion(+), 4 deletions(-)
> > > > > > >
> > > > > > > diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c 
> > > > > > > b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > > > > > index 1fa6fcac8299..80d06d958b8b 100644
> > > > > > > --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > > > > > +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > > > > > @@ -1955,10 +1955,7 @@ void *mlx5_vdpa_add_dev(struct 
> > > > > > > mlx5_core_dev *mdev)
> > > > > > >   if (err)
> > > > > > >   goto err_mtu;
> > > > > > >
> > > > > > > - err = mlx5_query_nic_vport_mac_address(mdev, 0, 0, 
> > > > > > > config->mac);
> > > > > > > - if (err)
> > > > > > > - goto err_mtu;
> > > > > > > -
> > > > > > > + eth_random_addr(config->mac);
> > > > > > >   mvdev->vdev.dma_dev = mdev->device;
> > > > > > >   err = mlx5_vdpa_alloc_resources(>mvdev);
> > > > > > >   if (err)
> > > > > > > --
> > > > > > > 2.26.2
> > > > > >
> > > >
> >

Re: [PATCH] vdpa/mlx5: Use random MAC for the vdpa net instance

On Mon, Nov 30, 2020 at 01:51:06PM +0200, Eli Cohen wrote:
> On Mon, Nov 30, 2020 at 04:33:09AM -0500, Michael S. Tsirkin wrote:
> > On Mon, Nov 30, 2020 at 11:27:59AM +0200, Eli Cohen wrote:
> > > On Mon, Nov 30, 2020 at 04:00:51AM -0500, Michael S. Tsirkin wrote:
> > > > On Mon, Nov 30, 2020 at 08:27:46AM +0200, Eli Cohen wrote:
> > > > > On Sun, Nov 29, 2020 at 03:08:22PM -0500, Michael S. Tsirkin wrote:
> > > > > > On Sun, Nov 29, 2020 at 08:43:51AM +0200, Eli Cohen wrote:
> > > > > > > We should not try to use the VF MAC address as that is used by the
> > > > > > > regular (e.g. mlx5_core) NIC implementation. Instead, use a random
> > > > > > > generated MAC address.
> > > > > > > 
> > > > > > > Suggested by: Cindy Lu 
> > > > > > > Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for supported 
> > > > > > > mlx5 devices")
> > > > > > > Signed-off-by: Eli Cohen 
> > > > > > 
> > > > > > I didn't realise it's possible to use VF in two ways
> > > > > > with and without vdpa.
> > > > > 
> > > > > Using a VF you can create quite a few resources, e.g. send queues
> > > > > recieve queues, virtio_net queues etc. So you can possibly create
> > > > > several instances of vdpa net devices and nic net devices.
> > > > > 
> > > > > > Could you include a bit more description on the failure
> > > > > > mode?
> > > > > 
> > > > > Well, using the MAC address of the nic vport is wrong since that is 
> > > > > the
> > > > > MAC of the regular NIC implementation of mlx5_core.
> > > > 
> > > > Right but ATM it doesn't coexist with vdpa so what's the problem?
> > > > 
> > > 
> > > This call is wrong:  mlx5_query_nic_vport_mac_address()
> > > 
> > > > > > Is switching to a random mac for such an unusual
> > > > > > configuration really justified?
> > > > > 
> > > > > Since I can't use the NIC's MAC address, I have two options:
> > > > > 1. To get the MAC address as was chosen by the user administering the
> > > > >NIC. This should invoke the set_config callback. Unfortunately this
> > > > >is not implemented yet.
> > > > > 
> > > > > 2. Use a random MAC address. This is OK since if (1) is implemented it
> > > > >can always override this random configuration.
> > > > > 
> > > > > > It looks like changing a MAC could break some guests,
> > > > > > can it not?
> > > > > >
> > > > > 
> > > > > No, it will not. The current version of mlx5 VDPA does not allow 
> > > > > regular
> > > > > NIC driver and VDPA to co-exist. I have patches ready that enable that
> > > > > from steering point of view. I will post them here once other patches 
> > > > > on
> > > > > which they depend will be merged.
> > > > > 
> > > > > https://patchwork.ozlabs.org/project/netdev/patch/20201120230339.651609-12-sae...@nvidia.com/
> > > > 
> > > > Could you be more explicit on the following points:
> > > > - which configuration is broken ATM (as in, two device have identical
> > > >   macs? any other issues)?
> > > 
> > > The only wrong thing is the call to  mlx5_query_nic_vport_mac_address().
> > > It's not breaking anything yet is wrong. The random MAC address setting
> > > is required for the steering patches.
> > 
> > Okay so I'm not sure the Fixes tag at least is appropriate if it's a
> > dependency of a new feature.
> > 
> 
> OK, let's leave it for now. I will push along with the steering patches.
> The meaning is the the VDPA net device instance is create with a MAC of
> all zeros which also mean the link is down. You can set a MAC which will
> let the link come up.
> The vdpa driver will not get a callback as I
> stated but since current mode of steering directs all traffic to the
> vdpa instance it will work. In the future this must be fixed.

So at the moment the MAC is in the config space and that is read during
probe.  So I guess userspace will do that before passing device to
guest.

> 
> > > > - why won't device MAC change from guest point of view?
> > > > 
> > > 
> > > It's lack of implementation in qemu as far as I know.
> > 
> > Sorry not sure I understand. What's not implemented in QEMU?
> > 
> 
> vdpa config operation set_config() should be called whenever the MAC is
> changed, e.g. when administrator of the vdpa net device changes the mac.
> This does not happen which is a bug.

I am not sure that's a good interface for that, I think set_config
is for guest writes into config space.
Will let Jason comment once patches are posted.

> > > > 
> > > > > > > ---
> > > > > > >  drivers/vdpa/mlx5/net/mlx5_vnet.c | 5 +
> > > > > > >  1 file changed, 1 insertion(+), 4 deletions(-)
> > > > > > > 
> > > > > > > diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c 
> > > > > > > b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > > > > > index 1fa6fcac8299..80d06d958b8b 100644
> > > > > > > --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > > > > > +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > > > > > @@ -1955,10 +1955,7 @@ void *mlx5_vdpa_add_dev(struct 
> > > > > > > mlx5_core_dev *mdev)
> > > > > > >   if (err)
> > > > > > >   goto

Re: [PATCH] vdpa/mlx5: Use random MAC for the vdpa net instance

2020-11-30 Thread Eli Cohen

On Mon, Nov 30, 2020 at 04:33:09AM -0500, Michael S. Tsirkin wrote:
> On Mon, Nov 30, 2020 at 11:27:59AM +0200, Eli Cohen wrote:
> > On Mon, Nov 30, 2020 at 04:00:51AM -0500, Michael S. Tsirkin wrote:
> > > On Mon, Nov 30, 2020 at 08:27:46AM +0200, Eli Cohen wrote:
> > > > On Sun, Nov 29, 2020 at 03:08:22PM -0500, Michael S. Tsirkin wrote:
> > > > > On Sun, Nov 29, 2020 at 08:43:51AM +0200, Eli Cohen wrote:
> > > > > > We should not try to use the VF MAC address as that is used by the
> > > > > > regular (e.g. mlx5_core) NIC implementation. Instead, use a random
> > > > > > generated MAC address.
> > > > > > 
> > > > > > Suggested by: Cindy Lu 
> > > > > > Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for supported mlx5 
> > > > > > devices")
> > > > > > Signed-off-by: Eli Cohen 
> > > > > 
> > > > > I didn't realise it's possible to use VF in two ways
> > > > > with and without vdpa.
> > > > 
> > > > Using a VF you can create quite a few resources, e.g. send queues
> > > > recieve queues, virtio_net queues etc. So you can possibly create
> > > > several instances of vdpa net devices and nic net devices.
> > > > 
> > > > > Could you include a bit more description on the failure
> > > > > mode?
> > > > 
> > > > Well, using the MAC address of the nic vport is wrong since that is the
> > > > MAC of the regular NIC implementation of mlx5_core.
> > > 
> > > Right but ATM it doesn't coexist with vdpa so what's the problem?
> > > 
> > 
> > This call is wrong:  mlx5_query_nic_vport_mac_address()
> > 
> > > > > Is switching to a random mac for such an unusual
> > > > > configuration really justified?
> > > > 
> > > > Since I can't use the NIC's MAC address, I have two options:
> > > > 1. To get the MAC address as was chosen by the user administering the
> > > >NIC. This should invoke the set_config callback. Unfortunately this
> > > >is not implemented yet.
> > > > 
> > > > 2. Use a random MAC address. This is OK since if (1) is implemented it
> > > >can always override this random configuration.
> > > > 
> > > > > It looks like changing a MAC could break some guests,
> > > > > can it not?
> > > > >
> > > > 
> > > > No, it will not. The current version of mlx5 VDPA does not allow regular
> > > > NIC driver and VDPA to co-exist. I have patches ready that enable that
> > > > from steering point of view. I will post them here once other patches on
> > > > which they depend will be merged.
> > > > 
> > > > https://patchwork.ozlabs.org/project/netdev/patch/20201120230339.651609-12-sae...@nvidia.com/
> > > 
> > > Could you be more explicit on the following points:
> > > - which configuration is broken ATM (as in, two device have identical
> > >   macs? any other issues)?
> > 
> > The only wrong thing is the call to  mlx5_query_nic_vport_mac_address().
> > It's not breaking anything yet is wrong. The random MAC address setting
> > is required for the steering patches.
> 
> Okay so I'm not sure the Fixes tag at least is appropriate if it's a
> dependency of a new feature.
> 

OK, let's leave it for now. I will push along with the steering patches.
The meaning is the the VDPA net device instance is create with a MAC of
all zeros which also mean the link is down. You can set a MAC which will
let the link come up. The vdpa driver will not get a callback as I
stated but since current mode of steering directs all traffic to the
vdpa instance it will work. In the future this must be fixed.

> > > - why won't device MAC change from guest point of view?
> > > 
> > 
> > It's lack of implementation in qemu as far as I know.
> 
> Sorry not sure I understand. What's not implemented in QEMU?
> 

vdpa config operation set_config() should be called whenever the MAC is
changed, e.g. when administrator of the vdpa net device changes the mac.
This does not happen which is a bug.

> > > 
> > > > > > ---
> > > > > >  drivers/vdpa/mlx5/net/mlx5_vnet.c | 5 +
> > > > > >  1 file changed, 1 insertion(+), 4 deletions(-)
> > > > > > 
> > > > > > diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c 
> > > > > > b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > > > > index 1fa6fcac8299..80d06d958b8b 100644
> > > > > > --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > > > > +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > > > > @@ -1955,10 +1955,7 @@ void *mlx5_vdpa_add_dev(struct mlx5_core_dev 
> > > > > > *mdev)
> > > > > > if (err)
> > > > > > goto err_mtu;
> > > > > >  
> > > > > > -   err = mlx5_query_nic_vport_mac_address(mdev, 0, 0, config->mac);
> > > > > > -   if (err)
> > > > > > -   goto err_mtu;
> > > > > > -
> > > > > > +   eth_random_addr(config->mac);
> > > > > > mvdev->vdev.dma_dev = mdev->device;
> > > > > > err = mlx5_vdpa_alloc_resources(>mvdev);
> > > > > > if (err)
> > > > > > -- 
> > > > > > 2.26.2
> > > > > 
> > > 
>

Re: [PATCH] vdpa/mlx5: Use random MAC for the vdpa net instance

2020-11-30 Thread Cindy Lu

On Mon, Nov 30, 2020 at 5:33 PM Michael S. Tsirkin  wrote:
>
> On Mon, Nov 30, 2020 at 11:27:59AM +0200, Eli Cohen wrote:
> > On Mon, Nov 30, 2020 at 04:00:51AM -0500, Michael S. Tsirkin wrote:
> > > On Mon, Nov 30, 2020 at 08:27:46AM +0200, Eli Cohen wrote:
> > > > On Sun, Nov 29, 2020 at 03:08:22PM -0500, Michael S. Tsirkin wrote:
> > > > > On Sun, Nov 29, 2020 at 08:43:51AM +0200, Eli Cohen wrote:
> > > > > > We should not try to use the VF MAC address as that is used by the
> > > > > > regular (e.g. mlx5_core) NIC implementation. Instead, use a random
> > > > > > generated MAC address.
> > > > > >
> > > > > > Suggested by: Cindy Lu 
> > > > > > Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for supported mlx5 
> > > > > > devices")
> > > > > > Signed-off-by: Eli Cohen 
> > > > >
> > > > > I didn't realise it's possible to use VF in two ways
> > > > > with and without vdpa.
> > > >
> > > > Using a VF you can create quite a few resources, e.g. send queues
> > > > recieve queues, virtio_net queues etc. So you can possibly create
> > > > several instances of vdpa net devices and nic net devices.
> > > >
> > > > > Could you include a bit more description on the failure
> > > > > mode?
> > > >
> > > > Well, using the MAC address of the nic vport is wrong since that is the
> > > > MAC of the regular NIC implementation of mlx5_core.
> > >
> > > Right but ATM it doesn't coexist with vdpa so what's the problem?
> > >
> >
> > This call is wrong:  mlx5_query_nic_vport_mac_address()
> >
> > > > > Is switching to a random mac for such an unusual
> > > > > configuration really justified?
> > > >
> > > > Since I can't use the NIC's MAC address, I have two options:
> > > > 1. To get the MAC address as was chosen by the user administering the
> > > >NIC. This should invoke the set_config callback. Unfortunately this
> > > >is not implemented yet.
> > > >
> > > > 2. Use a random MAC address. This is OK since if (1) is implemented it
> > > >can always override this random configuration.
> > > >
> > > > > It looks like changing a MAC could break some guests,
> > > > > can it not?
> > > > >
> > > >
> > > > No, it will not. The current version of mlx5 VDPA does not allow regular
> > > > NIC driver and VDPA to co-exist. I have patches ready that enable that
> > > > from steering point of view. I will post them here once other patches on
> > > > which they depend will be merged.
> > > >
> > > > https://patchwork.ozlabs.org/project/netdev/patch/20201120230339.651609-12-sae...@nvidia.com/
> > >
> > > Could you be more explicit on the following points:
> > > - which configuration is broken ATM (as in, two device have identical
> > >   macs? any other issues)?
> >
> > The only wrong thing is the call to  mlx5_query_nic_vport_mac_address().
> > It's not breaking anything yet is wrong. The random MAC address setting
> > is required for the steering patches.
>
> Okay so I'm not sure the Fixes tag at least is appropriate if it's a
> dependency of a new feature.
>
> > > - why won't device MAC change from guest point of view?
> > >
> >
> > It's lack of implementation in qemu as far as I know.
>
> Sorry not sure I understand. What's not implemented in QEMU?
>
HI Michael, there are some bug in qemu to set_config, this will fix in future,
But this patch is still needed, because without this patch the mlx
driver will give an 0 mac address to qemu
and qemu will overwrite the default mac address.  This will cause traffic down.

> > >
> > > > > > ---
> > > > > >  drivers/vdpa/mlx5/net/mlx5_vnet.c | 5 +
> > > > > >  1 file changed, 1 insertion(+), 4 deletions(-)
> > > > > >
> > > > > > diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c 
> > > > > > b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > > > > index 1fa6fcac8299..80d06d958b8b 100644
> > > > > > --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > > > > +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > > > > @@ -1955,10 +1955,7 @@ void *mlx5_vdpa_add_dev(struct mlx5_core_dev 
> > > > > > *mdev)
> > > > > >   if (err)
> > > > > >   goto err_mtu;
> > > > > >
> > > > > > - err = mlx5_query_nic_vport_mac_address(mdev, 0, 0, 
> > > > > > config->mac);
> > > > > > - if (err)
> > > > > > - goto err_mtu;
> > > > > > -
> > > > > > + eth_random_addr(config->mac);
> > > > > >   mvdev->vdev.dma_dev = mdev->device;
> > > > > >   err = mlx5_vdpa_alloc_resources(>mvdev);
> > > > > >   if (err)
> > > > > > --
> > > > > > 2.26.2
> > > > >
> > >
>

Re: [PATCH] vdpa/mlx5: Use random MAC for the vdpa net instance

On Mon, Nov 30, 2020 at 11:27:59AM +0200, Eli Cohen wrote:
> On Mon, Nov 30, 2020 at 04:00:51AM -0500, Michael S. Tsirkin wrote:
> > On Mon, Nov 30, 2020 at 08:27:46AM +0200, Eli Cohen wrote:
> > > On Sun, Nov 29, 2020 at 03:08:22PM -0500, Michael S. Tsirkin wrote:
> > > > On Sun, Nov 29, 2020 at 08:43:51AM +0200, Eli Cohen wrote:
> > > > > We should not try to use the VF MAC address as that is used by the
> > > > > regular (e.g. mlx5_core) NIC implementation. Instead, use a random
> > > > > generated MAC address.
> > > > > 
> > > > > Suggested by: Cindy Lu 
> > > > > Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for supported mlx5 
> > > > > devices")
> > > > > Signed-off-by: Eli Cohen 
> > > > 
> > > > I didn't realise it's possible to use VF in two ways
> > > > with and without vdpa.
> > > 
> > > Using a VF you can create quite a few resources, e.g. send queues
> > > recieve queues, virtio_net queues etc. So you can possibly create
> > > several instances of vdpa net devices and nic net devices.
> > > 
> > > > Could you include a bit more description on the failure
> > > > mode?
> > > 
> > > Well, using the MAC address of the nic vport is wrong since that is the
> > > MAC of the regular NIC implementation of mlx5_core.
> > 
> > Right but ATM it doesn't coexist with vdpa so what's the problem?
> > 
> 
> This call is wrong:  mlx5_query_nic_vport_mac_address()
> 
> > > > Is switching to a random mac for such an unusual
> > > > configuration really justified?
> > > 
> > > Since I can't use the NIC's MAC address, I have two options:
> > > 1. To get the MAC address as was chosen by the user administering the
> > >NIC. This should invoke the set_config callback. Unfortunately this
> > >is not implemented yet.
> > > 
> > > 2. Use a random MAC address. This is OK since if (1) is implemented it
> > >can always override this random configuration.
> > > 
> > > > It looks like changing a MAC could break some guests,
> > > > can it not?
> > > >
> > > 
> > > No, it will not. The current version of mlx5 VDPA does not allow regular
> > > NIC driver and VDPA to co-exist. I have patches ready that enable that
> > > from steering point of view. I will post them here once other patches on
> > > which they depend will be merged.
> > > 
> > > https://patchwork.ozlabs.org/project/netdev/patch/20201120230339.651609-12-sae...@nvidia.com/
> > 
> > Could you be more explicit on the following points:
> > - which configuration is broken ATM (as in, two device have identical
> >   macs? any other issues)?
> 
> The only wrong thing is the call to  mlx5_query_nic_vport_mac_address().
> It's not breaking anything yet is wrong. The random MAC address setting
> is required for the steering patches.

Okay so I'm not sure the Fixes tag at least is appropriate if it's a
dependency of a new feature.

> > - why won't device MAC change from guest point of view?
> > 
> 
> It's lack of implementation in qemu as far as I know.

Sorry not sure I understand. What's not implemented in QEMU?

> > 
> > > > > ---
> > > > >  drivers/vdpa/mlx5/net/mlx5_vnet.c | 5 +
> > > > >  1 file changed, 1 insertion(+), 4 deletions(-)
> > > > > 
> > > > > diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c 
> > > > > b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > > > index 1fa6fcac8299..80d06d958b8b 100644
> > > > > --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > > > +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > > > @@ -1955,10 +1955,7 @@ void *mlx5_vdpa_add_dev(struct mlx5_core_dev 
> > > > > *mdev)
> > > > >   if (err)
> > > > >   goto err_mtu;
> > > > >  
> > > > > - err = mlx5_query_nic_vport_mac_address(mdev, 0, 0, config->mac);
> > > > > - if (err)
> > > > > - goto err_mtu;
> > > > > -
> > > > > + eth_random_addr(config->mac);
> > > > >   mvdev->vdev.dma_dev = mdev->device;
> > > > >   err = mlx5_vdpa_alloc_resources(>mvdev);
> > > > >   if (err)
> > > > > -- 
> > > > > 2.26.2
> > > > 
> >

Re: [PATCH] vdpa/mlx5: Use random MAC for the vdpa net instance

2020-11-30 Thread Eli Cohen

On Mon, Nov 30, 2020 at 04:00:51AM -0500, Michael S. Tsirkin wrote:
> On Mon, Nov 30, 2020 at 08:27:46AM +0200, Eli Cohen wrote:
> > On Sun, Nov 29, 2020 at 03:08:22PM -0500, Michael S. Tsirkin wrote:
> > > On Sun, Nov 29, 2020 at 08:43:51AM +0200, Eli Cohen wrote:
> > > > We should not try to use the VF MAC address as that is used by the
> > > > regular (e.g. mlx5_core) NIC implementation. Instead, use a random
> > > > generated MAC address.
> > > > 
> > > > Suggested by: Cindy Lu 
> > > > Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for supported mlx5 
> > > > devices")
> > > > Signed-off-by: Eli Cohen 
> > > 
> > > I didn't realise it's possible to use VF in two ways
> > > with and without vdpa.
> > 
> > Using a VF you can create quite a few resources, e.g. send queues
> > recieve queues, virtio_net queues etc. So you can possibly create
> > several instances of vdpa net devices and nic net devices.
> > 
> > > Could you include a bit more description on the failure
> > > mode?
> > 
> > Well, using the MAC address of the nic vport is wrong since that is the
> > MAC of the regular NIC implementation of mlx5_core.
> 
> Right but ATM it doesn't coexist with vdpa so what's the problem?
> 

This call is wrong:  mlx5_query_nic_vport_mac_address()

> > > Is switching to a random mac for such an unusual
> > > configuration really justified?
> > 
> > Since I can't use the NIC's MAC address, I have two options:
> > 1. To get the MAC address as was chosen by the user administering the
> >NIC. This should invoke the set_config callback. Unfortunately this
> >is not implemented yet.
> > 
> > 2. Use a random MAC address. This is OK since if (1) is implemented it
> >can always override this random configuration.
> > 
> > > It looks like changing a MAC could break some guests,
> > > can it not?
> > >
> > 
> > No, it will not. The current version of mlx5 VDPA does not allow regular
> > NIC driver and VDPA to co-exist. I have patches ready that enable that
> > from steering point of view. I will post them here once other patches on
> > which they depend will be merged.
> > 
> > https://patchwork.ozlabs.org/project/netdev/patch/20201120230339.651609-12-sae...@nvidia.com/
> 
> Could you be more explicit on the following points:
> - which configuration is broken ATM (as in, two device have identical
>   macs? any other issues)?

The only wrong thing is the call to  mlx5_query_nic_vport_mac_address().
It's not breaking anything yet is wrong. The random MAC address setting
is required for the steering patches.

> - why won't device MAC change from guest point of view?
> 

It's lack of implementation in qemu as far as I know.

> 
> > > > ---
> > > >  drivers/vdpa/mlx5/net/mlx5_vnet.c | 5 +
> > > >  1 file changed, 1 insertion(+), 4 deletions(-)
> > > > 
> > > > diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c 
> > > > b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > > index 1fa6fcac8299..80d06d958b8b 100644
> > > > --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > > +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > > @@ -1955,10 +1955,7 @@ void *mlx5_vdpa_add_dev(struct mlx5_core_dev 
> > > > *mdev)
> > > > if (err)
> > > > goto err_mtu;
> > > >  
> > > > -   err = mlx5_query_nic_vport_mac_address(mdev, 0, 0, config->mac);
> > > > -   if (err)
> > > > -   goto err_mtu;
> > > > -
> > > > +   eth_random_addr(config->mac);
> > > > mvdev->vdev.dma_dev = mdev->device;
> > > > err = mlx5_vdpa_alloc_resources(>mvdev);
> > > > if (err)
> > > > -- 
> > > > 2.26.2
> > > 
>

Re: [PATCH] vdpa/mlx5: Use random MAC for the vdpa net instance