intel_iommu_accel: Bypass PASID entry addition for just deleted entry

For VTD_INV_DESC_PASIDC_G_PASID_SI typed pc_inv_dsc invalidation, if an
pasid entry is just removed, it can never be a new entry to add. So
calling vtd_replay_pasid_bind_for_dev() is unnecessary.

Introduce a new field accel_pce_deleted in VTDPASIDCacheInfo to mark
this case and to do the bypassing.

Suggested-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Xudong Hao <xudong.hao@intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20260527054658.1021096-14-zhenzhong.duan@intel.com>

diff --git a/hw/i386/intel_iommu_accel.c b/hw/i386/intel_iommu_accel.c
index ed0d6bda7ecbba652401b437fdb66e43796f2802..b823c405a113dec93e7623e33977bc16c0ed5596 100644 (file)
--- a/hw/i386/intel_iommu_accel.c
+++ b/hw/i386/intel_iommu_accel.c
@@ -280,10 +280,15 @@ static void vtd_accel_fill_pc(VTDHostIOMMUDevice *vtd_hiod, uint32_t pasid,
     QLIST_INSERT_HEAD(&vtd_hiod->pasid_cache_list, vtd_pce, next);
 }
 
-static void vtd_accel_delete_pc(VTDAccelPASIDCacheEntry *vtd_pce)
+static void vtd_accel_delete_pc(VTDAccelPASIDCacheEntry *vtd_pce,
+                                VTDPASIDCacheInfo *pc_info)
 {
     QLIST_REMOVE(vtd_pce, next);
     g_free(vtd_pce);
+
+    if (pc_info->type == VTD_INV_DESC_PASIDC_G_PASID_SI) {
+        pc_info->accel_pce_deleted = true;
+    }
 }
 
 static void
@@ -319,7 +324,7 @@ vtd_accel_pasid_cache_invalidate_one(VTDAccelPASIDCacheEntry *vtd_pce,
          * to be either all-zero or non-present. Either case means existing
          * pasid cache should be invalidated.
          */
-        vtd_accel_delete_pc(vtd_pce);
+        vtd_accel_delete_pc(vtd_pce, pc_info);
     }
 }
 
@@ -472,7 +477,12 @@ void vtd_accel_pasid_cache_sync(IntelIOMMUState *s, VTDPASIDCacheInfo *pc_info)
          * removals before additions to optimize the replay process.
          */
         vtd_accel_pasid_cache_invalidate(vtd_hiod, pc_info);
-        vtd_accel_replay_pasid_bind_for_dev(vtd_hiod, start, end, pc_info);
+
+        if (pc_info->accel_pce_deleted) {
+            pc_info->accel_pce_deleted = false;
+        } else {
+            vtd_accel_replay_pasid_bind_for_dev(vtd_hiod, start, end, pc_info);
+        }
     }
 }
 

diff --git a/hw/i386/intel_iommu_internal.h b/hw/i386/intel_iommu_internal.h
index 9307825017ff00d6a220f427f880bdc1f2267838..64a38afa85cb42e21719cbef913fab6a6a1d4998 100644 (file)
--- a/hw/i386/intel_iommu_internal.h
+++ b/hw/i386/intel_iommu_internal.h
@@ -630,6 +630,7 @@ typedef struct VTDPASIDCacheInfo {
     uint8_t type;
     uint16_t did;
     uint32_t pasid;
+    bool accel_pce_deleted;
 } VTDPASIDCacheInfo;
 
 typedef struct VTDPIOTLBInvInfo {