[RFC v1 0/3] Add VIRTIO_F_IOMMU_PLATFORM support

[Brijesh Singh <brijesh.singh@amd.com>]

I have found that OVMF fails to detect the disk when iommu_platform is set from
qemu cli. The failure occurs during the feature bit negotiation.

Recently, EDKII introduced IOMMU protocol d1fddc4533bf. SEV patch series introduced
a IoMmu protocol driver f9d129e68a45 to set a DMA access attribute and methods to
allocate, free, map and unmap the DMA memory for the master bus devices

In this patch series, I have tried to enable the IOMMU_PLATFORM feature for
VirtioBlkDevice. I am sending this as RFC to seek feedback before I extend the support
for other Virtio devices. The patch has been tested in SEV guest - mainly because
IoMmuDxe driver installs the IOMMU protocol for SEV guest only. If needed, I can
extend the IoMmuDxe driver to install IOMMU protocol for non SEV guests.

qemu cli used for testing:

# $QEMU \
  ...
  -drive file=${HDA_FILE},if=none,id=disk0,format=qcow2 \
  -device virtio-blk-pci,drive=disk0,disable-legacy=on,iommu_platform=true,disable-modern=off,scsi=off
  ...

Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>

Brijesh Singh (3):
  OvmfPkg/Include/Virtio10: Define VIRTIO_F_IOMMU_PLATFORM feature bit
  OvmfPkg/VirtioLib: Add IOMMU_PLATFORM support
  OvmfPkg/VirtioBlkDxe: Add VIRITO_F_IOMMU_PLATFORM support

 OvmfPkg/Library/VirtioLib/VirtioLib.inf      |   1 +
 OvmfPkg/VirtioBlkDxe/VirtioBlk.inf           |   5 +
 OvmfPkg/VirtioGpuDxe/VirtioGpu.inf           |   1 +
 OvmfPkg/VirtioNetDxe/VirtioNet.inf           |   1 +
 OvmfPkg/VirtioRngDxe/VirtioRng.inf           |   1 +
 OvmfPkg/VirtioScsiDxe/VirtioScsi.inf         |   1 +
 OvmfPkg/Include/IndustryStandard/Virtio095.h |   1 +
 OvmfPkg/Include/IndustryStandard/Virtio10.h  |   5 +
 OvmfPkg/Include/Library/VirtioLib.h          |  20 ++++
 OvmfPkg/Library/VirtioLib/VirtioLib.c        |  96 ++++++++++++++-
 OvmfPkg/VirtioBlkDxe/VirtioBlk.c             | 125 ++++++++++++++++++--
 11 files changed, 244 insertions(+), 13 deletions(-)

-- 
Brijesh Singh
2.7.4