Re: iommu/vt-d: Cure VF irqdomain hickup

[Lu Baolu]

On 2020/11/16 17:47, Geert Uytterhoeven wrote:
> Hi Thomas,
>
> On Thu, Nov 12, 2020 at 8:16 PM Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
> > The recent changes to store the MSI irqdomain pointer in struct device
> > missed that Intel DMAR does not register virtual function devices.  Due to
> > that a VF device gets the plain PCI-MSI domain assigned and then issues
> > compat MSI messages which get caught by the interrupt remapping unit.
> >
> > Cure that by inheriting the irq domain from the physical function
> > device.
> >
> > That's a temporary workaround. The correct fix is to inherit the irq domain
> > from the bus, but that's a larger effort which needs quite some other
> > changes to the way how x86 manages PCI and MSI domains.
> >
> > Fixes: 85a8dfc57a0b ("iommm/vt-d: Store irq domain in struct device")
> > Reported-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
> > Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> > ---
> >   drivers/iommu/intel/dmar.c |   19 ++++++++++++++++++-
> >   1 file changed, 18 insertions(+), 1 deletion(-)
> >
> > --- a/drivers/iommu/intel/dmar.c
> > +++ b/drivers/iommu/intel/dmar.c
> > @@ -333,6 +333,11 @@ static void  dmar_pci_bus_del_dev(struct
> >          dmar_iommu_notify_scope_dev(info);
> >   }
> >
> > +static inline void vf_inherit_msi_domain(struct pci_dev *pdev)
> > +{
> > +       dev_set_msi_domain(&pdev->dev, dev_get_msi_domain(&pdev->physfn->dev));
>
> If CONFIG_PCI_ATS is not set:
>
>      error: 'struct pci_dev' has no member named 'physfn'
>
> http://kisskb.ellerman.id.au/kisskb/buildresult/14400927/

Maybe pci_physfn() helper should be used here.

Best regards,
baolu