x86: allow disabling the emulated IOMMU

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>

diff --git a/xen/drivers/passthrough/amd/iommu_guest.c b/xen/drivers/passthrough/amd/iommu_guest.c
index e74f4692f494b62fa1e729ae6fe555d65533e2f4..b4e75ac565116a7338ed2788cd1f863da98cc7ba 100644 (file)
--- a/xen/drivers/passthrough/amd/iommu_guest.c
+++ b/xen/drivers/passthrough/amd/iommu_guest.c
@@ -887,7 +887,8 @@ int guest_iommu_init(struct domain* d)
     struct guest_iommu *iommu;
     struct hvm_iommu *hd  = domain_hvm_iommu(d);
 
-    if ( !is_hvm_domain(d) || !iommu_enabled || !iommuv2_enabled )
+    if ( !is_hvm_domain(d) || !iommu_enabled || !iommuv2_enabled ||
+         !has_viommu(d) )
         return 0;
 
     iommu = xzalloc(struct guest_iommu);