From 4bef13da0022e3a748f9e6afc8ff197c2fb6764c Mon Sep 17 00:00:00 2001
From: Brijesh Singh <brijesh.singh@amd.com>
Date: Fri, 25 Aug 2017 06:37:47 -0400
Subject: [PATCH] OvmfPkg/VirtioRngDxe: negotiate VIRTIO_F_IOMMU_PLATFORM

VirtioRngDxe 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>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
---
 OvmfPkg/VirtioRngDxe/VirtioRng.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/OvmfPkg/VirtioRngDxe/VirtioRng.c b/OvmfPkg/VirtioRngDxe/VirtioRng.c
index 4e67997881..80380bcdf8 100644
--- a/OvmfPkg/VirtioRngDxe/VirtioRng.c
+++ b/OvmfPkg/VirtioRngDxe/VirtioRng.c
@@ -279,7 +279,7 @@ VirtioRngInit (
     goto Failed;
   }
 
-  Features &= VIRTIO_F_VERSION_1;
+  Features &= VIRTIO_F_VERSION_1 | VIRTIO_F_IOMMU_PLATFORM;
 
   //
   // In virtio-1.0, feature negotiation is expected to complete before queue
@@ -360,7 +360,7 @@ VirtioRngInit (
   // step 5 -- Report understood features and guest-tuneables.
   //
   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;