[PATCH rfcv1 22/23] intel_iommu: refresh pasid bind after pasid cache force reset

[Zhenzhong Duan]

From: Yi Liu <yi.l.liu@intel.com>

The force reset clears the vtd_pasid_as and also unbinds the pasid on
host side. This is bad when the reset is triggered after some pasid
binding is setup. e.g. gcmd.TE enabling will reset cache, but wishes
to keep the pasid #0 (gIOVA) binding. So needs to refresh the pasid
bind per guest pasid table accordingly. Without this, issue has been
observed when legacy device passthrough (e.g. NIC without PASID support).

Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
---
 hw/i386/intel_iommu.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index 2f3d3a28b0..e418305f6e 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -72,6 +72,7 @@ struct vtd_iotlb_key {
 
 static void vtd_address_space_refresh_all(IntelIOMMUState *s);
 static void vtd_address_space_unmap(VTDAddressSpace *as, IOMMUNotifier *n);
+static void vtd_refresh_pasid_bind(IntelIOMMUState *s);
 
 static void vtd_pasid_cache_reset(IntelIOMMUState *s);
 static void vtd_pasid_cache_sync(IntelIOMMUState *s,
@@ -3292,6 +3293,7 @@ static void vtd_handle_gcmd_srtp(IntelIOMMUState *s)
     vtd_set_clear_mask_long(s, DMAR_GSTS_REG, 0, VTD_GSTS_RTPS);
     vtd_reset_caches(s);
     vtd_address_space_refresh_all(s);
+    vtd_refresh_pasid_bind(s);
 }
 
 /* Set Interrupt Remap Table Pointer */
@@ -3326,6 +3328,7 @@ static void vtd_handle_gcmd_te(IntelIOMMUState *s, bool 
en)
 
     vtd_reset_caches(s);
     vtd_address_space_refresh_all(s);
+    vtd_refresh_pasid_bind(s);
 }
 
 /* Handle Interrupt Remap Enable/Disable */
@@ -3960,6 +3963,28 @@ static void 
vtd_replay_guest_pasid_bindings(IntelIOMMUState *s,
     }
 }
 
+static void vtd_refresh_pasid_bind(IntelIOMMUState *s)
+{
+    VTDPASIDCacheInfo pc_info = { .error_happened = false,
+                                  .type = VTD_PASID_CACHE_GLOBAL_INV };
+
+    /*
+     * Only when dmar is enabled, should pasid bindings replayed,
+     * otherwise no need to replay.
+     */
+    if (!s->dmar_enabled) {
+        return;
+    }
+
+    if (!s->scalable_modern || !s->root_scalable) {
+        return;
+    }
+
+    vtd_iommu_lock(s);
+    vtd_replay_guest_pasid_bindings(s, &pc_info);
+    vtd_iommu_unlock(s);
+}
+
 /*
  * This function syncs the pasid bindings between guest and host.
  * It includes updating the pasid cache in vIOMMU and updating the
@@ -6051,6 +6076,7 @@ static void vtd_reset(DeviceState *dev)
 
     vtd_init(s);
     vtd_address_space_refresh_all(s);
+    vtd_refresh_pasid_bind(s);
 }
 
 static AddressSpace *vtd_host_dma_iommu(PCIBus *bus, void *opaque, int devfn)
-- 
2.34.1