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intel_iommu: Use correct shift for 256 bits qi descriptor

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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>
This commit is contained in:
Liu Yi L 2020-07-04 01:07:15 -07:00 committed by Michael S. Tsirkin
parent 9b3a35ec82
commit a4544c45e1
2 changed files with 8 additions and 2 deletions
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7
hw/i386/intel_iommu.c
View File

@ -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);
}
}

3
hw/i386/intel_iommu_internal.h
View File

@ -230,7 +230,8 @@
#define VTD_IQA_DW_MASK 0x800
/* IQH_REG */
#define VTD_IQH_QH_SHIFT 4
#define VTD_IQH_QH_SHIFT_4 4
#define VTD_IQH_QH_SHIFT_5 5
#define VTD_IQH_QH_MASK 0x7fff0ULL
/* ICS_REG */