[PATCH 5/7] intel_iommu: Handle insufficient permissions during translation requests

CLEMENT MATHIEU--DRIF posted 7 patches 2 weeks, 2 days ago
Maintainers: "Michael S. Tsirkin" <mst@redhat.com>, Jason Wang <jasowang@redhat.com>, Yi Liu <yi.l.liu@intel.com>, "Clément Mathieu--Drif" <clement.mathieu--drif@eviden.com>, Paolo Bonzini <pbonzini@redhat.com>, Richard Henderson <richard.henderson@linaro.org>, Eduardo Habkost <eduardo@habkost.net>, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
[PATCH 5/7] intel_iommu: Handle insufficient permissions during translation requests
Posted by CLEMENT MATHIEU--DRIF 2 weeks, 2 days ago
ATS translations should not fail when the write permission is not set.

Signed-off-by: Clement Mathieu--Drif <clement.mathieu--drif@eviden.com>
---
 hw/i386/intel_iommu.c          | 14 ++++++++------
 hw/i386/intel_iommu_internal.h |  3 ++-
 2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index 9753f4bb75..e89f31da02 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -1980,7 +1980,7 @@ static int vtd_iova_to_flpte(IntelIOMMUState *s, VTDContextEntry *ce,
                              uint64_t iova, bool is_write,
                              uint64_t *flptep, uint32_t *flpte_level,
                              bool *reads, bool *writes, uint8_t aw_bits,
-                             uint32_t pasid)
+                             uint32_t pasid, int iommu_idx)
 {
     dma_addr_t addr = vtd_get_iova_pgtbl_base(s, ce, pasid);
     uint32_t offset;
@@ -2021,7 +2021,8 @@ static int vtd_iova_to_flpte(IntelIOMMUState *s, VTDContextEntry *ce,
 
         *reads = true;
         *writes = (*writes) && (flpte & VTD_FL_RW);
-        if (is_write && !(flpte & VTD_FL_RW)) {
+        /* ATS should not fail when the write permission is not set */
+        if (is_write && !(flpte & VTD_FL_RW) && iommu_idx != VTD_IDX_ATS) {
             return -VTD_FR_SM_WRITE;
         }
         if (vtd_flpte_nonzero_rsvd(flpte, *flpte_level)) {
@@ -2080,7 +2081,7 @@ static void vtd_report_fault(IntelIOMMUState *s,
  */
 static bool vtd_do_iommu_translate(VTDAddressSpace *vtd_as, PCIBus *bus,
                                    uint8_t devfn, hwaddr addr, bool is_write,
-                                   IOMMUTLBEntry *entry)
+                                   IOMMUTLBEntry *entry, int iommu_idx)
 {
     IntelIOMMUState *s = vtd_as->iommu_state;
     VTDContextEntry ce;
@@ -2202,7 +2203,8 @@ static bool vtd_do_iommu_translate(VTDAddressSpace *vtd_as, PCIBus *bus,
 
     if (s->flts && s->root_scalable) {
         ret_fr = vtd_iova_to_flpte(s, &ce, addr, is_write, &pte, &level,
-                                   &reads, &writes, s->aw_bits, pasid);
+                                   &reads, &writes, s->aw_bits, pasid,
+                                   iommu_idx);
         pgtt = VTD_SM_PASID_ENTRY_FLT;
     } else {
         ret_fr = vtd_iova_to_slpte(s, &ce, addr, is_write, &pte, &level,
@@ -3827,7 +3829,7 @@ static IOMMUTLBEntry vtd_iommu_translate(IOMMUMemoryRegion *iommu, hwaddr addr,
             }
         } else {
             success = vtd_do_iommu_translate(vtd_as, vtd_as->bus, vtd_as->devfn,
-                                            addr, is_write, &iotlb);
+                                            addr, is_write, &iotlb, iommu_idx);
         }
     } else {
         /* DMAR disabled, passthrough, use 4k-page*/
@@ -4923,7 +4925,7 @@ static IOMMUTLBEntry vtd_iommu_ats_do_translate(IOMMUMemoryRegion *iommu,
         vtd_prepare_error_entry(&entry);
         entry.target_as = &address_space_memory;
     } else {
-        entry = vtd_iommu_translate(iommu, addr, flags, VTD_IDX_UNTRANSLATED);
+        entry = vtd_iommu_translate(iommu, addr, flags, VTD_IDX_ATS);
     }
 
     return entry;
diff --git a/hw/i386/intel_iommu_internal.h b/hw/i386/intel_iommu_internal.h
index 3a1f7a1d99..10a452c0dd 100644
--- a/hw/i386/intel_iommu_internal.h
+++ b/hw/i386/intel_iommu_internal.h
@@ -664,7 +664,8 @@ typedef struct VTDRootEntry VTDRootEntry;
 typedef enum VTDIOMMUIndex {
     VTD_IDX_UNTRANSLATED = 0, /* Default */
     VTD_IDX_TRANSLATED = 1,
-    VTD_IDX_COUNT = 2, /* Number of supported indexes */
+    VTD_IDX_ATS = 2,
+    VTD_IDX_COUNT = 3, /* Number of supported indexes */
 } VTDIOMMUIndex;
 
 #endif
-- 
2.51.0