[PULL v3 42/55] intel-iommu: correctly check passthrough during translation

["Michael S. Tsirkin" <mst@redhat.com>]

From: Jason Wang <jasowang@redhat.com>

When scalable mode is enabled, the passthrough more is not determined
by the context entry but PASID entry, so switch to use the logic of
vtd_dev_pt_enabled() to determine the passthrough mode in
vtd_do_iommu_translate().

Signed-off-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20220105041945.13459-2-jasowang@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/i386/intel_iommu.c | 38 +++++++++++++++++++++++---------------
 1 file changed, 23 insertions(+), 15 deletions(-)

diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index 5b865ac08c..4c6c016388 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -1516,11 +1516,29 @@ static int vtd_sync_shadow_page_table(VTDAddressSpace *vtd_as)
  * 1st-level translation or 2nd-level translation, it depends
  * on PGTT setting.
  */
-static bool vtd_dev_pt_enabled(VTDAddressSpace *as)
+static bool vtd_dev_pt_enabled(IntelIOMMUState *s, VTDContextEntry *ce)
+{
+    VTDPASIDEntry pe;
+    int ret;
+
+    if (s->root_scalable) {
+        ret = vtd_ce_get_rid2pasid_entry(s, ce, &pe);
+        if (ret) {
+            error_report_once("%s: vtd_ce_get_rid2pasid_entry error: %"PRId32,
+                              __func__, ret);
+            return false;
+        }
+        return (VTD_PE_GET_TYPE(&pe) == VTD_SM_PASID_ENTRY_PT);
+    }
+
+    return (vtd_ce_get_type(ce) == VTD_CONTEXT_TT_PASS_THROUGH);
+
+}
+
+static bool vtd_as_pt_enabled(VTDAddressSpace *as)
 {
     IntelIOMMUState *s;
     VTDContextEntry ce;
-    VTDPASIDEntry pe;
     int ret;
 
     assert(as);
@@ -1538,17 +1556,7 @@ static bool vtd_dev_pt_enabled(VTDAddressSpace *as)
         return false;
     }
 
-    if (s->root_scalable) {
-        ret = vtd_ce_get_rid2pasid_entry(s, &ce, &pe);
-        if (ret) {
-            error_report_once("%s: vtd_ce_get_rid2pasid_entry error: %"PRId32,
-                              __func__, ret);
-            return false;
-        }
-        return (VTD_PE_GET_TYPE(&pe) == VTD_SM_PASID_ENTRY_PT);
-    }
-
-    return (vtd_ce_get_type(&ce) == VTD_CONTEXT_TT_PASS_THROUGH);
+    return vtd_dev_pt_enabled(s, &ce);
 }
 
 /* Return whether the device is using IOMMU translation. */
@@ -1560,7 +1568,7 @@ static bool vtd_switch_address_space(VTDAddressSpace *as)
 
     assert(as);
 
-    use_iommu = as->iommu_state->dmar_enabled && !vtd_dev_pt_enabled(as);
+    use_iommu = as->iommu_state->dmar_enabled && !vtd_as_pt_enabled(as);
 
     trace_vtd_switch_address_space(pci_bus_num(as->bus),
                                    VTD_PCI_SLOT(as->devfn),
@@ -1753,7 +1761,7 @@ static bool vtd_do_iommu_translate(VTDAddressSpace *vtd_as, PCIBus *bus,
      * We don't need to translate for pass-through context entries.
      * Also, let's ignore IOTLB caching as well for PT devices.
      */
-    if (vtd_ce_get_type(&ce) == VTD_CONTEXT_TT_PASS_THROUGH) {
+    if (vtd_dev_pt_enabled(s, &ce)) {
         entry->iova = addr & VTD_PAGE_MASK_4K;
         entry->translated_addr = entry->iova;
         entry->addr_mask = ~VTD_PAGE_MASK_4K;
-- 
MST