> -----Original Message-----
> From: Zhangfei Gao <zhangfei.gao@xxxxxxxxxx>
> Sent: Thursday, October 17, 2024 1:35 PM
> To: Jason Gunthorpe <jgg@xxxxxxxx>
> Cc: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>; Kevin Tian
> <kevin.tian@xxxxxxxxx>; Joerg Roedel <joro@xxxxxxxxxx>; Will Deacon
> <will@xxxxxxxxxx>; Robin Murphy <robin.murphy@xxxxxxx>; Jean-
> Philippe Brucker <jean-philippe@xxxxxxxxxx>; Nicolin Chen
> <nicolinc@xxxxxxxxxx>; Yi Liu <yi.l.liu@xxxxxxxxx>; Jacob Pan
> <jacob.jun.pan@xxxxxxxxxxxxxxx>; Joel Granados
> <j.granados@xxxxxxxxxxx>; iommu@xxxxxxxxxxxxxxx;
> virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> Shameerali Kolothum Thodi <shameerali.kolothum.thodi@xxxxxxxxxx>
> Subject: Re: [PATCH v8 07/10] iommufd: Fault-capable hwpt
> attach/detach/replace
>
> On Thu, 17 Oct 2024 at 20:05, Jason Gunthorpe <jgg@xxxxxxxx> wrote:
> >
> > On Thu, Oct 17, 2024 at 09:44:18AM +0800, Zhangfei Gao wrote:
> > > On Wed, 16 Oct 2024 at 23:25, Jason Gunthorpe <jgg@xxxxxxxx> wrote:
> > > >
> > > > On Wed, Oct 16, 2024 at 09:58:36AM +0800, Zhangfei Gao wrote:
> > > > > On Tue, 15 Oct 2024 at 20:54, Jason Gunthorpe <jgg@xxxxxxxx>
> wrote:
> > > > > >
> > > > > > On Tue, Oct 15, 2024 at 11:19:33AM +0800, Zhangfei Gao wrote:
> > > > > > > > +static int iommufd_fault_iopf_enable(struct
> > > > > > > > +iommufd_device *idev) {
> > > > > > > > + struct device *dev = idev->dev;
> > > > > > > > + int ret;
> > > > > > > > +
> > > > > > > > + /*
> > > > > > > > + * Once we turn on PCI/PRI support for VF, the response
> failure code
> > > > > > > > + * should not be forwarded to the hardware due to PRI
> being a shared
> > > > > > > > + * resource between PF and VFs. There is no coordination
> for this
> > > > > > > > + * shared capability. This waits for a vPRI reset to recover.
> > > > > > > > + */
> > > > > > > > + if (dev_is_pci(dev) && to_pci_dev(dev)->is_virtfn)
> > > > > > > > + return -EINVAL;
> > > > > > >
> > > > > > > I am using the SMMUv3 stall feature, and need to forward
> > > > > > > this to hardware, And now I am hacking to comment this check.
> > > > > > > Any suggestions?
> > > > > >
> > > > > > Are you using PCI SRIOV and stall together?
> > > > >
> > > > > Only use smmuv3 stall feature.
> Sorry, this is not correct
>
> > > >
> > > > Then isn't to_pci_dev(dev)->is_virtfn == false?
> > > >
> > > > That should only be true with SRIOV
> > >
> > > Do you mean
> > > if (dev_is_pci(dev) && to_pci_dev(dev)->is_virtfn == false)
> > > return -EINVAL;
> > >
> > > This is fine
> >
> > No, I mean on your test system you are not using SRIOV so all your PCI
> > devices will have is_virtfn == false and the above if shouldn't be a
> > problem. is_virtfn indicates the PCI device is a SRIOV VF.
> >
> > Your explanation for your problem doesn't really make sense, or there
> > is something wrong someplace else to get a bogus is_virtfn..
> >
> > If you are doing SRIOV with stall, then that is understandable.
>
> 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
May be this will help to get the background:
https://lore.kernel.org/all/1626144876-11352-1-git-send-email-zhangfei.gao@xxxxxxxxxx/
Shameer
