[PATCH rfcv2 19/20] intel_iommu: Bypass replay in stage-1 page table mode

[Zhenzhong Duan]

VFIO utilizes replay to setup initial shadow iommu mappings.
But when stage-1 page table is configured, it is passed to
host to construct nested page table, there is no replay needed.

Signed-off-by: Zhenzhong Duan <zhenzhong.d...@intel.com>
---
 hw/i386/intel_iommu.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index 225e332132..e4b83cbe50 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -5743,6 +5743,14 @@ static void vtd_iommu_replay(IOMMUMemoryRegion 
*iommu_mr, IOMMUNotifier *n)
     VTDContextEntry ce;
     DMAMap map = { .iova = 0, .size = HWADDR_MAX };
 
+    /*
+     * Replay on stage-1 page table is meaningless as stage-1 page table
+     * is passthroughed to host to construct nested page table
+     */
+    if (s->flts && s->root_scalable) {
+        return;
+    }
+
     /* replay is protected by BQL, page walk will re-setup it safely */
     iova_tree_remove(vtd_as->iova_tree, map);
 
-- 
2.34.1