Hello Zhenzhong
On 4/3/26 05:55, Zhenzhong Duan wrote:
> When both device and vIOMMU have PASID enabled, then guest may setup
> pasid attached translation.
>
> VFIO needs to be aware of potential pasid usage and should attach the
> non-pasid part of pasid-capable device to hwpt flagged with
> IOMMU_HWPT_ALLOC_PASID.
>
> ARM SMMU doesn't support IOMMU_HWPT_ALLOC_PASID, only VTD need it. So
> we can't check the existing vIOMMU flag VIOMMU_FLAG_PASID_SUPPORTED to
> determine if set flag IOMMU_HWPT_ALLOC_PASID. Instead, introduce a new
> flag VIOMMU_FLAG_WANT_PASID_ATTACH which will only be exposed by VTD.
>
> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
> Reviewed-by: Yi Liu <yi.l.liu@intel.com>
> Tested-by: Xudong Hao <xudong.hao@intel.com>
> ---
> include/hw/core/iommu.h | 1 +
> include/hw/vfio/vfio-device.h | 1 +
> hw/vfio/device.c | 11 +++++++++++
> hw/vfio/iommufd.c | 8 +++++++-
> 4 files changed, 20 insertions(+), 1 deletion(-)
>
> diff --git a/include/hw/core/iommu.h b/include/hw/core/iommu.h
> index bfcd511013..67c575b08c 100644
> --- a/include/hw/core/iommu.h
> +++ b/include/hw/core/iommu.h
> @@ -21,6 +21,7 @@ enum viommu_flags {
> /* vIOMMU needs nesting parent HWPT to create nested HWPT */
> VIOMMU_FLAG_WANT_NESTING_PARENT = BIT_ULL(0),
> VIOMMU_FLAG_PASID_SUPPORTED = BIT_ULL(1),
> + VIOMMU_FLAG_WANT_PASID_ATTACH = BIT_ULL(2),
VIOMMU_FLAG_WANT_NESTING_DIRTY_TRACKING was introduced since. The change
is on vfio-next.
You will need to rebase. While at it, I think the documentation of each
of these VIOMMU_FLAGs can be improved.
Thanks,
C.
> };
>
> /* Host IOMMU quirks. Extracted from host IOMMU capabilities */
> diff --git a/include/hw/vfio/vfio-device.h b/include/hw/vfio/vfio-device.h
> index 828a31c006..d6e522f8b8 100644
> --- a/include/hw/vfio/vfio-device.h
> +++ b/include/hw/vfio/vfio-device.h
> @@ -268,6 +268,7 @@ void vfio_device_prepare(VFIODevice *vbasedev, VFIOContainer *bcontainer,
> void vfio_device_unprepare(VFIODevice *vbasedev);
>
> bool vfio_device_get_viommu_flags_want_nesting(VFIODevice *vbasedev);
> +bool vfio_device_get_viommu_flags_want_pasid_attach(VFIODevice *vbasedev);
> bool vfio_device_get_host_iommu_quirk_bypass_ro(VFIODevice *vbasedev,
> uint32_t type, void *caps,
> uint32_t size);
> diff --git a/hw/vfio/device.c b/hw/vfio/device.c
> index 973fc35b59..bc1d37e776 100644
> --- a/hw/vfio/device.c
> +++ b/hw/vfio/device.c
> @@ -533,6 +533,17 @@ bool vfio_device_get_viommu_flags_want_nesting(VFIODevice *vbasedev)
> return false;
> }
>
> +bool vfio_device_get_viommu_flags_want_pasid_attach(VFIODevice *vbasedev)
> +{
> + VFIOPCIDevice *vdev = vfio_pci_from_vfio_device(vbasedev);
> +
> + if (vdev) {
> + return !!(pci_device_get_viommu_flags(PCI_DEVICE(vdev)) &
> + VIOMMU_FLAG_WANT_PASID_ATTACH);
> + }
> + return false;
> +}
> +
> bool vfio_device_get_host_iommu_quirk_bypass_ro(VFIODevice *vbasedev,
> uint32_t type, void *caps,
> uint32_t size)
> diff --git a/hw/vfio/iommufd.c b/hw/vfio/iommufd.c
> index ecabc33064..ead40b6617 100644
> --- a/hw/vfio/iommufd.c
> +++ b/hw/vfio/iommufd.c
> @@ -363,6 +363,7 @@ static bool iommufd_cdev_autodomains_get(VFIODevice *vbasedev,
> VendorCaps caps;
> VFIOIOASHwpt *hwpt;
> uint32_t hwpt_id;
> + uint8_t max_pasid_log2 = 0;
> int ret;
>
> /* Try to find a domain */
> @@ -408,7 +409,7 @@ static bool iommufd_cdev_autodomains_get(VFIODevice *vbasedev,
> */
> if (!iommufd_backend_get_device_info(vbasedev->iommufd, vbasedev->devid,
> &type, &caps, sizeof(caps), &hw_caps,
> - NULL, errp)) {
> + &max_pasid_log2, errp)) {
> return false;
> }
>
> @@ -430,6 +431,11 @@ static bool iommufd_cdev_autodomains_get(VFIODevice *vbasedev,
> }
> }
>
> + if (max_pasid_log2 &&
> + vfio_device_get_viommu_flags_want_pasid_attach(vbasedev)) {
> + flags |= IOMMU_HWPT_ALLOC_PASID;
> + }
> +
> if (cpr_is_incoming()) {
> hwpt_id = vbasedev->cpr.hwpt_id;
> goto skip_alloc;