Re: [PATCH v8 07/10] iommufd: Fault-capable hwpt attach/detach/replace

[Zhangfei Gao]

Hi, Baolu

On Fri, 18 Oct 2024 at 10:45, Zhangfei Gao <zhangfei.gao@xxxxxxxxxx> wrote:
>
> Hi, Baolu
>
> On Fri, 18 Oct 2024 at 09:58, Baolu Lu <baolu.lu@xxxxxxxxxxxxxxx> wrote:
> >
> > On 2024/10/17 21:08, Jason Gunthorpe wrote:
> > > On Thu, Oct 17, 2024 at 08:35:24PM +0800, Zhangfei Gao wrote:
> > >
> > >> Yes, you are right
> > >>   I am using SRIOV vf and stall feature, so is_virtfn == true
> > >>
> > >> Our ACC devices are fake pci endpoint devices which supports stall,
> > >> And they also supports sriov
> > >>
> > >> So I have to ignore the limitation.
> > > I see, so that is more complicated.
> > >
> > > Lu, what do you think about also checking if the PCI function has PRI
> > > ? If not PRI assume the fault is special and doesn't follow PRI rules?
> > >
> > > Or maybe we can have the iommu driver tag the event as a PRI/not-PRI
> > > fault?
> >
> > This limitation applies to PRI on PCI/SRIOV VFs because the PRI might be
> > a shared resource and current iommu subsystem is not ready to support
> > enabling/disabling PRI on a VF without any impact on others.
> >
> > In my understanding, it's fine to remove this limitation from the use
> > case of non-PRI on SRIOV VFs. Perhaps something like below?
> >
> #include <linux/pci-ats.h>
> >         if (dev_is_pci(dev)) {
> >                 struct pci_dev *pdev = to_pci_dev(dev);
> >                 if (pdev->is_virtfn && pci_pri_supported(pdev))
> >                         return -EINVAL;
> >         }
>
> Yes, this works on our platform.

Will you send this patch?

Tested-by: Zhangfei Gao <zhangfei.gao@xxxxxxxxxx>

Thanks