Re: [PATCH 3/3] OvmfPkg/VirtioBlkDxe: negotiate VIRTIO_F_IOMMU_PLATFORM

[Laszlo Ersek <lersek@redhat.com>]

On 08/25/17 23:43, Brijesh Singh wrote:
> VirtioBlkDxe driver has been updated to use IOMMU-like member functions
> from VIRTIO_DEVICE_PROTOCOL to translate the system physical address to
> device address. We do not need to do anything special when
> VIRTIO_F_IOMMU_PLATFORM bit is present hence treat it in parallel with
> VIRTIO_F_VERSION_1.
> 
> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> Cc: Jordan Justen <jordan.l.justen@intel.com>
> Cc: Tom Lendacky <thomas.lendacky@amd.com>
> Cc: Laszlo Ersek <lersek@redhat.com>
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
> ---
>  OvmfPkg/VirtioBlkDxe/VirtioBlk.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/OvmfPkg/VirtioBlkDxe/VirtioBlk.c b/OvmfPkg/VirtioBlkDxe/VirtioBlk.c
> index ab69cb08a625..3c4d9dfd4d54 100644
> --- a/OvmfPkg/VirtioBlkDxe/VirtioBlk.c
> +++ b/OvmfPkg/VirtioBlkDxe/VirtioBlk.c
> @@ -825,7 +825,8 @@ VirtioBlkInit (
>    }
>  
>    Features &= VIRTIO_BLK_F_BLK_SIZE | VIRTIO_BLK_F_TOPOLOGY | VIRTIO_BLK_F_RO |
> -              VIRTIO_BLK_F_FLUSH | VIRTIO_F_VERSION_1;
> +              VIRTIO_BLK_F_FLUSH | VIRTIO_F_VERSION_1 |
> +              VIRTIO_F_IOMMU_PLATFORM;
>  
>    //
>    // In virtio-1.0, feature negotiation is expected to complete before queue
> @@ -903,7 +904,7 @@ VirtioBlkInit (
>    // step 5 -- Report understood features.
>    //
>    if (Dev->VirtIo->Revision < VIRTIO_SPEC_REVISION (1, 0, 0)) {
> -    Features &= ~(UINT64)VIRTIO_F_VERSION_1;
> +    Features &= ~(UINT64)(VIRTIO_F_VERSION_1 | VIRTIO_F_IOMMU_PLATFORM);
>      Status = Dev->VirtIo->SetGuestFeatures (Dev->VirtIo, Features);
>      if (EFI_ERROR (Status)) {
>        goto UnmapQueue;
> 

Reviewed-by: Laszlo Ersek <lersek@redhat.com>