[Qemu-devel] [PATCH v1 3/3] intel-iommu: search iotlb for levels supported by the address width.

[Yu Zhang <yu.c.zhang@linux.intel.com>]

This patch updates vtd_lookup_iotlb() to search cached mappings only
for all page levels supported by address width of current vIOMMU. Also,
to cover 57-bit width, the shift of source id(VTD_IOTLB_SID_SHIFT) and
of page level(VTD_IOTLB_LVL_SHIFT) are enlarged by 9 - the stride of
one paging structure level.

Signed-off-by: Yu Zhang <yu.c.zhang@linux.intel.com>
---
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
Cc: Paolo Bonzini <pbonzini@redhat.com> 
Cc: Richard Henderson <rth@twiddle.net> 
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
---
 hw/i386/intel_iommu.c          | 5 +++--
 hw/i386/intel_iommu_internal.h | 7 ++-----
 2 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index 9cdf755..ce7e17e 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -254,11 +254,12 @@ static uint64_t vtd_get_iotlb_gfn(hwaddr addr, uint32_t level)
 static VTDIOTLBEntry *vtd_lookup_iotlb(IntelIOMMUState *s, uint16_t source_id,
                                        hwaddr addr)
 {
-    VTDIOTLBEntry *entry;
+    VTDIOTLBEntry *entry = NULL;
     uint64_t key;
     int level;
+    int max_level = (s->aw_bits - VTD_PAGE_SHIFT_4K) / VTD_SL_LEVEL_BITS;
 
-    for (level = VTD_SL_PT_LEVEL; level < VTD_SL_PML4_LEVEL; level++) {
+    for (level = VTD_SL_PT_LEVEL; level < max_level; level++) {
         key = vtd_get_iotlb_key(vtd_get_iotlb_gfn(addr, level),
                                 source_id, level);
         entry = g_hash_table_lookup(s->iotlb, &key);
diff --git a/hw/i386/intel_iommu_internal.h b/hw/i386/intel_iommu_internal.h
index a7ef24b..bdf2b7c 100644
--- a/hw/i386/intel_iommu_internal.h
+++ b/hw/i386/intel_iommu_internal.h
@@ -114,8 +114,8 @@
                                      VTD_INTERRUPT_ADDR_FIRST + 1)
 
 /* The shift of source_id in the key of IOTLB hash table */
-#define VTD_IOTLB_SID_SHIFT         36
-#define VTD_IOTLB_LVL_SHIFT         52
+#define VTD_IOTLB_SID_SHIFT         45
+#define VTD_IOTLB_LVL_SHIFT         61
 #define VTD_IOTLB_MAX_SIZE          1024    /* Max size of the hash table */
 
 /* IOTLB_REG */
@@ -450,9 +450,6 @@ typedef struct VTDRootEntry VTDRootEntry;
 #define VTD_SL_LEVEL_BITS           9
 
 /* Second Level Paging Structure */
-#define VTD_SL_PML4_LEVEL           4
-#define VTD_SL_PDP_LEVEL            3
-#define VTD_SL_PD_LEVEL             2
 #define VTD_SL_PT_LEVEL             1
 #define VTD_SL_PT_ENTRY_NR          512
 
-- 
1.9.1