OvmfPkg/Virtio: take RingBaseShift in SetQueueAddress()

For the case when an IOMMU is used for translating system physical
addresses to DMA bus master addresses, the transport-independent
virtio device drivers will be required to map their VRING areas to
bus addresses with VIRTIO_DEVICE_PROTOCOL.MapSharedBuffer() calls.

- MMIO and legacy virtio transport do not support IOMMU to translate the
  addresses hence RingBaseShift will always be set to zero.

- modern virtio transport supports IOMMU to translate the address, in
  next patch we will update the Virtio10Dxe to use RingBaseShift offset.

Suggested-by: Laszlo Ersek <lersek@redhat.com>
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>
[lersek@redhat.com: remove commit msg paragraph with VirtioLib reference]
[lersek@redhat.com: fix typo in VIRTIO_SET_QUEUE_ADDRESS comment block]
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/OvmfPkg/Virtio10Dxe/Virtio10.c b/OvmfPkg/Virtio10Dxe/Virtio10.c
index 89ccac8c1c..ef9a007106 100644
--- a/OvmfPkg/Virtio10Dxe/Virtio10.c
+++ b/OvmfPkg/Virtio10Dxe/Virtio10.c
@@ -489,7 +489,8 @@ EFI_STATUS
 EFIAPI

 Virtio10SetQueueAddress (

   IN VIRTIO_DEVICE_PROTOCOL  *This,

-  IN VRING                   *Ring

+  IN VRING                   *Ring,

+  IN UINT64                  RingBaseShift

   )

 {

   VIRTIO_1_0_DEV *Dev;

@@ -497,6 +498,8 @@ Virtio10SetQueueAddress (
   UINT64         Address;

   UINT16         Enable;

 

+  ASSERT (RingBaseShift == 0);

+

   Dev = VIRTIO_1_0_FROM_VIRTIO_DEVICE (This);

 

   Address = (UINTN)Ring->Desc;