Re: [PATCH v11 1/2] vhost-vdpa: Skip the range check while MR is IOMMU

[Jason Wang]

On Wed, Nov 30, 2022 at 1:33 PM Cindy Lu <lulu@redhat.com> wrote:
>
> Skip the check in vhost_vdpa_listener_skipped_section() while
> MR is IOMMU, Move this check to  vhost_vdpa_iommu_map_notify()
>
> Signed-off-by: Cindy Lu <lulu@redhat.com>
> ---
>  hw/virtio/vhost-vdpa.c | 21 ++++++++++++++-------
>  1 file changed, 14 insertions(+), 7 deletions(-)
>
> diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
> index 3ff9ce3501..f0e9963d19 100644
> --- a/hw/virtio/vhost-vdpa.c
> +++ b/hw/virtio/vhost-vdpa.c
> @@ -60,15 +60,22 @@ static bool 
> vhost_vdpa_listener_skipped_section(MemoryRegionSection *section,
>                       iova_min, section->offset_within_address_space);
>          return true;
>      }
> +    /*
> +     * While using vIOMMU, Sometimes the section will be larger than iova_max
> +     * but the memory that  actually mapping is smaller, So skip the check
> +     * here. Will add the check in vhost_vdpa_iommu_map_notify,
> +     *There is the real size that maps to the kernel
> +     */
>

I suggest squashing this into the next patch since we haven't
implemented vhost_vdpa_iommu_map_notify() yet.

Thanks

> -    llend = vhost_vdpa_section_end(section);
> -    if (int128_gt(llend, int128_make64(iova_max))) {
> -        error_report("RAM section out of device range (max=0x%" PRIx64
> -                     ", end addr=0x%" PRIx64 ")",
> -                     iova_max, int128_get64(llend));
> -        return true;
> +    if (!memory_region_is_iommu(section->mr)) {
> +        llend = vhost_vdpa_section_end(section);
> +        if (int128_gt(llend, int128_make64(iova_max))) {
> +            error_report("RAM section out of device range (max=0x%" PRIx64
> +                         ", end addr=0x%" PRIx64 ")",
> +                         iova_max, int128_get64(llend));
> +            return true;
> +        }
>      }
> -
>      return false;
>  }
>
> --
> 2.34.3
>