Re: [PATCH] vdpa/mlx5: Setup driver only if VIRTIO_CONFIG_S_DRIVER_OK
- Original Message -
> If the memory map changes before the driver status is
> VIRTIO_CONFIG_S_DRIVER_OK, don't attempt to create resources because it
> may fail. For example, if the VQ is not ready there is no point in
> creating resources.
>
> Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for supported mlx5 devices")
> Signed-off-by: Eli Cohen
> ---
> drivers/vdpa/mlx5/net/mlx5_vnet.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> index 9df69d5efe8c..c89cd48a0aab 100644
> --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> @@ -1645,6 +1645,9 @@ static int mlx5_vdpa_change_map(struct mlx5_vdpa_net
> *ndev, struct vhost_iotlb *
> if (err)
> goto err_mr;
>
> + if (!(ndev->mvdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
> + return 0;
> +
I'm not sure I get this.
It looks to me if set_map() is called before DRIVER_OK, we won't build
any mapping?
Thanks
> restore_channels_info(ndev);
> err = setup_driver(ndev);
> if (err)
> --
> 2.26.0
>
>
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Re: [PATCH] vdpa/mlx5: Setup driver only if VIRTIO_CONFIG_S_DRIVER_OK
On Mon, Sep 07, 2020 at 10:51:36AM +0300, Eli Cohen wrote:
> If the memory map changes before the driver status is
> VIRTIO_CONFIG_S_DRIVER_OK, don't attempt to create resources because it
> may fail. For example, if the VQ is not ready there is no point in
> creating resources.
>
> Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for supported mlx5 devices")
> Signed-off-by: Eli Cohen
Could you add a bit more data about the problem to the log?
To be more exact, what exactly happens right now?
> ---
> drivers/vdpa/mlx5/net/mlx5_vnet.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> index 9df69d5efe8c..c89cd48a0aab 100644
> --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> @@ -1645,6 +1645,9 @@ static int mlx5_vdpa_change_map(struct mlx5_vdpa_net
> *ndev, struct vhost_iotlb *
> if (err)
> goto err_mr;
>
> + if (!(ndev->mvdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
> + return 0;
> +
> restore_channels_info(ndev);
> err = setup_driver(ndev);
> if (err)
> --
> 2.26.0
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Re: [PATCH] vdpa/mlx5: Setup driver only if VIRTIO_CONFIG_S_DRIVER_OK
On Mon, Sep 07, 2020 at 02:43:51PM +0300, Eli Cohen wrote:
> On Mon, Sep 07, 2020 at 07:34:00AM -0400, Michael S. Tsirkin wrote:
> > On Mon, Sep 07, 2020 at 10:51:36AM +0300, Eli Cohen wrote:
> > > If the memory map changes before the driver status is
> > > VIRTIO_CONFIG_S_DRIVER_OK, don't attempt to create resources because it
> > > may fail. For example, if the VQ is not ready there is no point in
> > > creating resources.
> > >
> > > Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for supported mlx5
> > > devices")
> > > Signed-off-by: Eli Cohen
> >
> >
> > Could you add a bit more data about the problem to the log?
> > To be more exact, what exactly happens right now?
> >
>
> Sure I can.
>
> set_map() is used by mlx5 vdpa to create a memory region based on the
> address map passed by the iotlb argument. If I get successive calls, I
> will destroy the current memory region and build another one based on
> the new address mapping. I also need to setup the hardware resources
> since they depend on the memory region.
>
> If these calls happen before DRIVER_OK, It means it that driver VQs may
> also not been setup and I may not create them yet. In this case I want
> to avoid setting up the other resources and defer this till I get DRIVER
> OK.
>
> Let me know if that answers your question so I can post another patch.
it does, pls do.
> > > ---
> > > drivers/vdpa/mlx5/net/mlx5_vnet.c | 3 +++
> > > 1 file changed, 3 insertions(+)
> > >
> > > diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > index 9df69d5efe8c..c89cd48a0aab 100644
> > > --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > @@ -1645,6 +1645,9 @@ static int mlx5_vdpa_change_map(struct
> > > mlx5_vdpa_net *ndev, struct vhost_iotlb *
> > > if (err)
> > > goto err_mr;
> > >
> > > + if (!(ndev->mvdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
> > > + return 0;
> > > +
> > > restore_channels_info(ndev);
> > > err = setup_driver(ndev);
> > > if (err)
> > > --
> > > 2.26.0
> >
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Re: [PATCH] vdpa/mlx5: Setup driver only if VIRTIO_CONFIG_S_DRIVER_OK
- Original Message -
> On Mon, Sep 07, 2020 at 06:53:23AM -0400, Jason Wang wrote:
> >
> >
> > - Original Message -
> > > If the memory map changes before the driver status is
> > > VIRTIO_CONFIG_S_DRIVER_OK, don't attempt to create resources because it
> > > may fail. For example, if the VQ is not ready there is no point in
> > > creating resources.
> > >
> > > Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for supported mlx5
> > > devices")
> > > Signed-off-by: Eli Cohen
> > > ---
> > > drivers/vdpa/mlx5/net/mlx5_vnet.c | 3 +++
> > > 1 file changed, 3 insertions(+)
> > >
> > > diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > index 9df69d5efe8c..c89cd48a0aab 100644
> > > --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > @@ -1645,6 +1645,9 @@ static int mlx5_vdpa_change_map(struct
> > > mlx5_vdpa_net
> > > *ndev, struct vhost_iotlb *
> > > if (err)
> > > goto err_mr;
> > >
> > > + if (!(ndev->mvdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
> > > + return 0;
> > > +
> >
> > I'm not sure I get this.
> >
> > It looks to me if set_map() is called before DRIVER_OK, we won't build
> > any mapping?
> >
> What would prevent that? Is it some qemu logic you're relying upon?
Ok, I think the map is still there, we just avoid to create some
resources.
> With current qemu 5.1 with lack of batching support, I get plenty calls
> to set_map which result in calls to mlx5_vdpa_change_map().
> If that happens before VIRTIO_CONFIG_S_DRIVER_OK then Imay fail (in case
> I was not called to set VQs ready).
Right, this could be solved by adding the batched IOTLB updating.
Thanks
>
> >
> > > restore_channels_info(ndev);
> > > err = setup_driver(ndev);
> > > if (err)
> > > --
> > > 2.26.0
> > >
> > >
> >
>
>
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