[PATCH v5 07/20] intel_iommu: Check if the input address is canonical

[Zhenzhong Duan <zhenzhong.duan@intel.com>]

From: Clément Mathieu--Drif <clement.mathieu--drif@eviden.com>

First stage translation must fail if the address to translate is
not canonical.

Signed-off-by: Clément Mathieu--Drif <clement.mathieu--drif@eviden.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
---
 hw/i386/intel_iommu_internal.h |  1 +
 hw/i386/intel_iommu.c          | 23 +++++++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/hw/i386/intel_iommu_internal.h b/hw/i386/intel_iommu_internal.h
index 86d3354198..3e7365dfff 100644
--- a/hw/i386/intel_iommu_internal.h
+++ b/hw/i386/intel_iommu_internal.h
@@ -326,6 +326,7 @@ typedef enum VTDFaultReason {
     /* Non-zero reserved field in present first-stage paging entry */
     VTD_FR_FS_PAGING_ENTRY_RSVD = 0x72,
     VTD_FR_PASID_ENTRY_FSPTPTR_INV = 0x73, /* Invalid FSPTPTR in PASID entry */
+    VTD_FR_FS_NON_CANONICAL = 0x80, /* SNG.1 : Address for FS not canonical.*/
     VTD_FR_FS_PAGING_ENTRY_US = 0x81,      /* Privilege violation */
     VTD_FR_SM_WRITE = 0x85,                /* No write permission */
 
diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index dbd64d608f..4cc4d668fc 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -1824,6 +1824,7 @@ static const bool vtd_qualified_faults[] = {
     [VTD_FR_FS_PAGING_ENTRY_P] = true,
     [VTD_FR_FS_PAGING_ENTRY_RSVD] = true,
     [VTD_FR_PASID_ENTRY_FSPTPTR_INV] = true,
+    [VTD_FR_FS_NON_CANONICAL] = true,
     [VTD_FR_FS_PAGING_ENTRY_US] = true,
     [VTD_FR_SM_WRITE] = true,
     [VTD_FR_SM_INTERRUPT_ADDR] = true,
@@ -1930,6 +1931,22 @@ static inline bool vtd_flpte_present(uint64_t flpte)
     return !!(flpte & VTD_FL_P);
 }
 
+/* Return true if IOVA is canonical, otherwise false. */
+static bool vtd_iova_fl_check_canonical(IntelIOMMUState *s, uint64_t iova,
+                                        VTDContextEntry *ce, uint32_t pasid)
+{
+    uint64_t iova_limit = vtd_iova_limit(s, ce, s->aw_bits, pasid);
+    uint64_t upper_bits_mask = ~(iova_limit - 1);
+    uint64_t upper_bits = iova & upper_bits_mask;
+    bool msb = ((iova & (iova_limit >> 1)) != 0);
+
+    if (msb) {
+        return upper_bits == upper_bits_mask;
+    } else {
+        return !upper_bits;
+    }
+}
+
 /*
  * Given the @iova, get relevant @flptep. @flpte_level will be the last level
  * of the translation, can be used for deciding the size of large page.
@@ -1945,6 +1962,12 @@ static int vtd_iova_to_flpte(IntelIOMMUState *s, VTDContextEntry *ce,
     uint32_t offset;
     uint64_t flpte;
 
+    if (!vtd_iova_fl_check_canonical(s, iova, ce, pasid)) {
+        error_report_once("%s: detected non canonical IOVA (iova=0x%" PRIx64 ","
+                          "pasid=0x%" PRIx32 ")", __func__, iova, pasid);
+        return -VTD_FR_FS_NON_CANONICAL;
+    }
+
     while (true) {
         offset = vtd_iova_level_offset(iova, level);
         flpte = vtd_get_pte(addr, offset);
-- 
2.34.1