Add domain flag DOMAIN_FLAG_VIRTUAL_MACHINE

Add this flag for VT-d used in virtual machine, like KVM.

Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index 104e99df2ade..ffbe4c573729 100644
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -206,6 +206,11 @@ static inline bool dma_pte_present(struct dma_pte *pte)
 /* devices under the same p2p bridge are owned in one domain */
 #define DOMAIN_FLAG_P2P_MULTIPLE_DEVICES (1 < 0)
 
+/* domain represents a virtual machine, more than one devices
+ * across iommus may be owned in one domain, e.g. kvm guest.
+ */
+#define DOMAIN_FLAG_VIRTUAL_MACHINE     (1 << 1)
+
 struct dmar_domain {
         int     id;                     /* domain id */
         unsigned long iommu_bmp;        /* bitmap of iommus this domain uses*/
@@ -391,6 +396,8 @@ static struct intel_iommu *domain_get_iommu(struct dmar_domain *domain)
 {
         int iommu_id;
 
+        BUG_ON(domain->flags & DOMAIN_FLAG_VIRTUAL_MACHINE);
+
         iommu_id = find_first_bit(&domain->iommu_bmp, g_num_of_iommus);
         if (iommu_id < 0 || iommu_id >= g_num_of_iommus)
                 return NULL;