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authorLiu Yi L <yi.l.liu@intel.com>2020-07-04 01:07:15 -0700
committerMichael S. Tsirkin <mst@redhat.com>2020-07-22 07:57:07 -0400
commita4544c45e109ceee87ee8c19baff28be3890d788 (patch)
treef5b5eb70e2da31fefede2ccf6e738dfc77bf0af7 /hw/i386/intel_iommu.c
parent9b3a35ec8236933ab958a4c3ad883163f1ca66e7 (diff)
intel_iommu: Use correct shift for 256 bits qi descriptor
In chapter 10.4.23 of VT-d spec 3.0, Descriptor Width bit was introduced in VTD_IQA_REG. Software could set this bit to tell VT-d the QI descriptor from software would be 256 bits. Accordingly, the VTD_IQH_QH_SHIFT should be 5 when descriptor size is 256 bits. This patch adds the DW bit check when deciding the shift used to update VTD_IQH_REG. Signed-off-by: Liu Yi L <yi.l.liu@intel.com> Message-Id: <1593850035-35483-1-git-send-email-yi.l.liu@intel.com> Reviewed-by: Peter Xu <peterx@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Cc: qemu-stable@nongnu.org Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'hw/i386/intel_iommu.c')
-rw-r--r--hw/i386/intel_iommu.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index c56398e991..0c286635cf 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -2549,6 +2549,11 @@ static bool vtd_process_inv_desc(IntelIOMMUState *s)
/* Try to fetch and process more Invalidation Descriptors */
static void vtd_fetch_inv_desc(IntelIOMMUState *s)
{
+ int qi_shift;
+
+ /* Refer to 10.4.23 of VT-d spec 3.0 */
+ qi_shift = s->iq_dw ? VTD_IQH_QH_SHIFT_5 : VTD_IQH_QH_SHIFT_4;
+
trace_vtd_inv_qi_fetch();
if (s->iq_tail >= s->iq_size) {
@@ -2567,7 +2572,7 @@ static void vtd_fetch_inv_desc(IntelIOMMUState *s)
}
/* Must update the IQH_REG in time */
vtd_set_quad_raw(s, DMAR_IQH_REG,
- (((uint64_t)(s->iq_head)) << VTD_IQH_QH_SHIFT) &
+ (((uint64_t)(s->iq_head)) << qi_shift) &
VTD_IQH_QH_MASK);
}
}