[Xen-devel] xen-pci-passthrough PCI Express support? (Re: [Qemu-devel] [PATCH v2 4/5] pci: Add INTERFACE_CONVENTIONAL_PCI_DEVICE to Conventional PCI devices)
On Thu, Sep 28, 2017 at 10:12:34AM -0300, Eduardo Habkost wrote:
> On Thu, Sep 28, 2017 at 02:33:57AM -0600, Jan Beulich wrote:
> > >>> On 27.09.17 at 21:56, wrote:
> > > --- a/hw/xen/xen_pt.c
> > > +++ b/hw/xen/xen_pt.c
> > > @@ -964,6 +964,10 @@ static const TypeInfo xen_pci_passthrough_info = {
> > > .instance_size = sizeof(XenPCIPassthroughState),
> > > .instance_finalize = xen_pci_passthrough_finalize,
> > > .class_init = xen_pci_passthrough_class_init,
> > > +.interfaces = (InterfaceInfo[]) {
> > > +{ INTERFACE_CONVENTIONAL_PCI_DEVICE },
> > > +{ },
> > > +},
> > > };
> >
> > Passed through devices can be both PCI and PCIe, so following
> > the description of the patch I don't think these can be statically
> > given either property. Granted quite a bit of PCIe specific
> > functionality may be missing in the Xen code ...
>
> This is just static data about what the device type supports, not
> about what a given device instance really is. Deciding if the
> device is PCIe or Conventional at runtime is out of the scope of
> this series.
>
> That said, if passed through PCI Express devices are really
> supported, it looks like this should be marked as hybrid.
Can anybody confirm if PCI Express devices are really supported
by xen-pci-passthrough?
I suggest we add only INTERFACE_CONVENTIONAL_PCI_DEVICE to the
class info until we confirm that.
(In other words, apply this patch as-is, and add
INTERFACE_PCIE_DEVICE later as a follow-up patch if appropriate.)
--
Eduardo
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[Xen-devel] xen-pci-passthrough PCI Express support? (Re: [Qemu-devel] [PATCH v2 4/5] pci: Add INTERFACE_CONVENTIONAL_PCI_DEVICE to Conventional PCI devices)
>>> On 03.10.17 at 02:12, wrote:
> On Thu, Sep 28, 2017 at 10:12:34AM -0300, Eduardo Habkost wrote:
>> On Thu, Sep 28, 2017 at 02:33:57AM -0600, Jan Beulich wrote:
>> > >>> On 27.09.17 at 21:56, wrote:
>> > > --- a/hw/xen/xen_pt.c
>> > > +++ b/hw/xen/xen_pt.c
>> > > @@ -964,6 +964,10 @@ static const TypeInfo xen_pci_passthrough_info = {
>> > > .instance_size = sizeof(XenPCIPassthroughState),
>> > > .instance_finalize = xen_pci_passthrough_finalize,
>> > > .class_init = xen_pci_passthrough_class_init,
>> > > +.interfaces = (InterfaceInfo[]) {
>> > > +{ INTERFACE_CONVENTIONAL_PCI_DEVICE },
>> > > +{ },
>> > > +},
>> > > };
>> >
>> > Passed through devices can be both PCI and PCIe, so following
>> > the description of the patch I don't think these can be statically
>> > given either property. Granted quite a bit of PCIe specific
>> > functionality may be missing in the Xen code ...
>>
>> This is just static data about what the device type supports, not
>> about what a given device instance really is. Deciding if the
>> device is PCIe or Conventional at runtime is out of the scope of
>> this series.
>>
>> That said, if passed through PCI Express devices are really
>> supported, it looks like this should be marked as hybrid.
>
> Can anybody confirm if PCI Express devices are really supported
> by xen-pci-passthrough?
I think I've clearly said they're supported, with some limitations.
Jan
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Re: [Xen-devel] xen-pci-passthrough PCI Express support? (Re: [Qemu-devel] [PATCH v2 4/5] pci: Add INTERFACE_CONVENTIONAL_PCI_DEVICE to Conventional PCI devices)
On Mon, 2 Oct 2017, Eduardo Habkost wrote:
> On Thu, Sep 28, 2017 at 10:12:34AM -0300, Eduardo Habkost wrote:
> > On Thu, Sep 28, 2017 at 02:33:57AM -0600, Jan Beulich wrote:
> > > >>> On 27.09.17 at 21:56, wrote:
> > > > --- a/hw/xen/xen_pt.c
> > > > +++ b/hw/xen/xen_pt.c
> > > > @@ -964,6 +964,10 @@ static const TypeInfo xen_pci_passthrough_info = {
> > > > .instance_size = sizeof(XenPCIPassthroughState),
> > > > .instance_finalize = xen_pci_passthrough_finalize,
> > > > .class_init = xen_pci_passthrough_class_init,
> > > > +.interfaces = (InterfaceInfo[]) {
> > > > +{ INTERFACE_CONVENTIONAL_PCI_DEVICE },
> > > > +{ },
> > > > +},
> > > > };
> > >
> > > Passed through devices can be both PCI and PCIe, so following
> > > the description of the patch I don't think these can be statically
> > > given either property. Granted quite a bit of PCIe specific
> > > functionality may be missing in the Xen code ...
> >
> > This is just static data about what the device type supports, not
> > about what a given device instance really is. Deciding if the
> > device is PCIe or Conventional at runtime is out of the scope of
> > this series.
> >
> > That said, if passed through PCI Express devices are really
> > supported, it looks like this should be marked as hybrid.
>
> Can anybody confirm if PCI Express devices are really supported
> by xen-pci-passthrough?
>
> I suggest we add only INTERFACE_CONVENTIONAL_PCI_DEVICE to the
> class info until we confirm that.
>
> (In other words, apply this patch as-is, and add
> INTERFACE_PCIE_DEVICE later as a follow-up patch if appropriate.)
Yes, xen-pci-passthrough can expose PCI Express devices to the guest. I
don't think the old xen-pci-passthrough code does anything special to
mark it as such internally in QEMU, but it can deal with the PCI Express
Capabilities and expose/emulate them for the guest's benefit.
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Re: [Xen-devel] xen-pci-passthrough PCI Express support? (Re: [Qemu-devel] [PATCH v2 4/5] pci: Add INTERFACE_CONVENTIONAL_PCI_DEVICE to Conventional PCI devices)
On Wed, Oct 04, 2017 at 03:08:15AM -0600, Jan Beulich wrote:
> >>> On 03.10.17 at 02:12, wrote:
> > On Thu, Sep 28, 2017 at 10:12:34AM -0300, Eduardo Habkost wrote:
> >> On Thu, Sep 28, 2017 at 02:33:57AM -0600, Jan Beulich wrote:
> >> > >>> On 27.09.17 at 21:56, wrote:
> >> > > --- a/hw/xen/xen_pt.c
> >> > > +++ b/hw/xen/xen_pt.c
> >> > > @@ -964,6 +964,10 @@ static const TypeInfo xen_pci_passthrough_info = {
> >> > > .instance_size = sizeof(XenPCIPassthroughState),
> >> > > .instance_finalize = xen_pci_passthrough_finalize,
> >> > > .class_init = xen_pci_passthrough_class_init,
> >> > > +.interfaces = (InterfaceInfo[]) {
> >> > > +{ INTERFACE_CONVENTIONAL_PCI_DEVICE },
> >> > > +{ },
> >> > > +},
> >> > > };
> >> >
> >> > Passed through devices can be both PCI and PCIe, so following
> >> > the description of the patch I don't think these can be statically
> >> > given either property. Granted quite a bit of PCIe specific
> >> > functionality may be missing in the Xen code ...
> >>
> >> This is just static data about what the device type supports, not
> >> about what a given device instance really is. Deciding if the
> >> device is PCIe or Conventional at runtime is out of the scope of
> >> this series.
> >>
> >> That said, if passed through PCI Express devices are really
> >> supported, it looks like this should be marked as hybrid.
> >
> > Can anybody confirm if PCI Express devices are really supported
> > by xen-pci-passthrough?
>
> I think I've clearly said they're supported, with some limitations.
Sorry, thanks. I thought the possible missing PCIe functionality
could mean the device couldn't appear as PCI Express to the
guest.
I will submit a follow-up patch adding INTERFACE_PCIE_DEVICE to
xen-pci-passthrough.
--
Eduardo
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