[PULL 36/53] memory: Optimize replay of guest mapping

[Michael S. Tsirkin]

From: Zhenzhong Duan <zhenzhong.duan@intel.com>

On x86, there are two notifiers registered due to vtd-ir memory region
splitting the whole address space. During replay of the address space
for each notifier, the whole address space is scanned which is
unnecessory.

We only need to scan the space belong to notifier montiored space.

Assert when notifier is used to monitor beyond iommu memory region's
address space.

Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Message-Id: <20230215065238.713041-1-zhenzhong.duan@intel.com>
Acked-by: Peter Xu <peterx@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/i386/intel_iommu.c | 2 +-
 softmmu/memory.c      | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index 98a5c304a7..6b1de80e85 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -3831,7 +3831,7 @@ static void vtd_iommu_replay(IOMMUMemoryRegion *iommu_mr, 
IOMMUNotifier *n)
                 .domain_id = vtd_get_domain_id(s, &ce, vtd_as->pasid),
             };
 
-            vtd_page_walk(s, &ce, 0, ~0ULL, &info, vtd_as->pasid);
+            vtd_page_walk(s, &ce, n->start, n->end, &info, vtd_as->pasid);
         }
     } else {
         trace_vtd_replay_ce_invalid(bus_n, PCI_SLOT(vtd_as->devfn),
diff --git a/softmmu/memory.c b/softmmu/memory.c
index 9d64efca26..da7d846619 100644
--- a/softmmu/memory.c
+++ b/softmmu/memory.c
@@ -1900,6 +1900,7 @@ int memory_region_register_iommu_notifier(MemoryRegion 
*mr,
     iommu_mr = IOMMU_MEMORY_REGION(mr);
     assert(n->notifier_flags != IOMMU_NOTIFIER_NONE);
     assert(n->start <= n->end);
+    assert(n->end <= memory_region_size(mr));
     assert(n->iommu_idx >= 0 &&
            n->iommu_idx < memory_region_iommu_num_indexes(iommu_mr));
 
@@ -1923,7 +1924,6 @@ uint64_t 
memory_region_iommu_get_min_page_size(IOMMUMemoryRegion *iommu_mr)
 
 void memory_region_iommu_replay(IOMMUMemoryRegion *iommu_mr, IOMMUNotifier *n)
 {
-    MemoryRegion *mr = MEMORY_REGION(iommu_mr);
     IOMMUMemoryRegionClass *imrc = IOMMU_MEMORY_REGION_GET_CLASS(iommu_mr);
     hwaddr addr, granularity;
     IOMMUTLBEntry iotlb;
@@ -1936,7 +1936,7 @@ void memory_region_iommu_replay(IOMMUMemoryRegion 
*iommu_mr, IOMMUNotifier *n)
 
     granularity = memory_region_iommu_get_min_page_size(iommu_mr);
 
-    for (addr = 0; addr < memory_region_size(mr); addr += granularity) {
+    for (addr = n->start; addr < n->end; addr += granularity) {
         iotlb = imrc->translate(iommu_mr, addr, IOMMU_NONE, n->iommu_idx);
         if (iotlb.perm != IOMMU_NONE) {
             n->notify(n, &iotlb);
-- 
MST