Re: [PATCH 16/24] iommu/amd: Introduce IOMMUFD vDevice support for AMD

[Suthikulpanit, Suravee]

On 8/19/2026 8:34 PM, guanghuifeng@xxxxxxxxxxxxxxxxx wrote:
> 在 2026/7/27 21:29, Suravee Suthikulpanit 写道:
> > Initialize vDevice for AMD vIOMMU by setting up the Device ID Mapping
> > table using the guest device ID.
> >
> > Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
> > ---
> >   drivers/iommu/amd/amd_iommu_types.h | 10 ++++++++++
> >   drivers/iommu/amd/iommufd.c         | 31 +++++++++++++++++++++++++++++
> >   drivers/iommu/amd/nested.c          | 27 ++++++++++++++++++++++---
> >   3 files changed, 65 insertions(+), 3 deletions(-)
> >
> > ....
> >
> > diff --git a/drivers/iommu/amd/iommufd.c b/drivers/iommu/amd/iommufd.c
> > index bfc4b0ec22a9..1975b2932107 100644
> > --- a/drivers/iommu/amd/iommufd.c
> > +++ b/drivers/iommu/amd/iommufd.c
> > @@ -9,6 +9,7 @@
> >   #include "amd_iommu.h"
> >   #include "amd_viommu.h"
> >   #include "amd_iommu_types.h"
> > +#include "../iommufd/iommufd_private.h"
> >   static const struct iommufd_viommu_ops amd_viommu_ops;
> > @@ -126,6 +127,34 @@ static void amd_iommufd_viommu_destroy(struct 
> > iommufd_viommu *viommu)
> >       amd_iommu_gid_free(iommu, aviommu->gid);
> >   }
> > +/*
> > + * Called from drivers/iommu/iommufd/viommu.c: 
> > iommufd_vdevice_alloc_ioctl()
> > + */
> > +static int _amd_viommu_vdevice_init(struct iommufd_vdevice *vdev)
> > +{
> > +    struct iommu_dev_data *dev_data;
> > +    struct pci_dev *pdev = to_pci_dev(vdev->idev->dev);
> > +    struct iommufd_viommu *viommu = vdev->viommu;
> > +    struct amd_iommu_viommu *aviommu = container_of(viommu, struct 
> > amd_iommu_viommu, core);
> > +
> > +    if (!pdev) {
> > +        pr_err("%s: not a PCI device\n", __func__);
> > +        return -EINVAL;
> > +    }
> > +
>
> to_pci_dev() is a container_of(), so it can never return NULL and the
> !pdev check is dead code. Worse, for a non-PCI device it yields a bogus
> pointer which is then dereferenced through dev_iommu_priv_get() below.

I will fix the code to check dev_is_pci() properly.

Thanks,
Suravee