[Qemu-devel] [PATCH] intel_iommu: fixing source id during IOTLB hash key calculation

[Qemu-devel] [PATCH] intel_iommu: fixing source id during IOTLB hash key calculation

[Jason Wang]

Using uint8_t for source id will lose bus num and get the
wrong/invalid IOTLB entry. Fixing by using uint16_t instead and
enlarge level shift.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 hw/i386/intel_iommu.c          | 2 +-
 hw/i386/intel_iommu_internal.h | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index 2efd69b..1c5d40e 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -215,7 +215,7 @@ static void vtd_reset_iotlb(IntelIOMMUState *s)
     g_hash_table_remove_all(s->iotlb);
 }
 
-static uint64_t vtd_get_iotlb_key(uint64_t gfn, uint8_t source_id,
+static uint64_t vtd_get_iotlb_key(uint64_t gfn, uint16_t source_id,
                                   uint32_t level)
 {
     return gfn | ((uint64_t)(source_id) << VTD_IOTLB_SID_SHIFT) |
diff --git a/hw/i386/intel_iommu_internal.h b/hw/i386/intel_iommu_internal.h
index 0829a50..11abfa2 100644
--- a/hw/i386/intel_iommu_internal.h
+++ b/hw/i386/intel_iommu_internal.h
@@ -115,7 +115,7 @@
 
 /* The shift of source_id in the key of IOTLB hash table */
 #define VTD_IOTLB_SID_SHIFT         36
-#define VTD_IOTLB_LVL_SHIFT         44
+#define VTD_IOTLB_LVL_SHIFT         52
 #define VTD_IOTLB_MAX_SIZE          1024    /* Max size of the hash table */
 
 /* IOTLB_REG */
-- 
2.7.4

Re: [Qemu-devel] [PATCH] intel_iommu: fixing source id during IOTLB hash key calculation

[Peter Xu]

On Thu, Nov 03, 2016 at 09:22:23AM +0800, Jason Wang wrote:
> Using uint8_t for source id will lose bus num and get the
> wrong/invalid IOTLB entry. Fixing by using uint16_t instead and
> enlarge level shift.
> 
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: Richard Henderson <rth@twiddle.net>
> Cc: Eduardo Habkost <ehabkost@redhat.com>
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Jason Wang <jasowang@redhat.com>

Reviewed-by: Peter Xu <peterx@redhat.com>