intel_iommu: Fix invalidation descriptor type field

According to spec, invalidation descriptor type is 7bits which is
concatenation of bits[11:9] and bits[3:0] of invalidation descriptor.

Currently we only pick bits[3:0] as the invalidation type and treat
bits[11:9] as reserved zero. This is not a problem for now as bits[11:9]
is zero for all current invalidation types. But it will break if newer
type occupies bits[11:9].

Fix it by taking bits[11:9] into type and make reserved bits check accurate.

Suggested-by: Clément Mathieu--Drif<clement.mathieu--drif@eviden.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Clément Mathieu--Drif<clement.mathieu--drif@eviden.com>
Message-Id: <20240814071321.2621384-2-zhenzhong.duan@intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index 16d2885fcc..68cb72a481 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -2744,7 +2744,7 @@ static bool vtd_process_inv_desc(IntelIOMMUState *s)
         return false;
     }
 
-    desc_type = inv_desc.lo & VTD_INV_DESC_TYPE;
+    desc_type = VTD_INV_DESC_TYPE(inv_desc.lo);
     /* FIXME: should update at first or at last? */
     s->iq_last_desc_type = desc_type;