From: "Singh, Brijesh" <brijesh.si...@amd.com>
Currently, the amdvi_validate_dte() assumes that a valid DTE will
always have V=1. This is not true. The V=1 means that bit[127:1] are
valid. A valid DTE can have IV=1 and V=0 (i.e address translation
disabled and interrupt remapping enabled)
Remove the V=1 check from amdvi_validate_dte(), make the caller
responsible to check for V or IV bits.
This also fixes a bug in existing code that when error is
detected during the translation we'll fail the translation
instead of assuming a passthrough mode.
Signed-off-by: Brijesh Singh <brijesh.si...@amd.com>
Reviewed-by: Peter Xu <pet...@redhat.com>
Cc: Peter Xu <pet...@redhat.com>
Cc: "Michael S. Tsirkin" <m...@redhat.com>
Cc: Paolo Bonzini <pbonz...@redhat.com>
Cc: Richard Henderson <r...@twiddle.net>
Cc: Eduardo Habkost <ehabk...@redhat.com>
Cc: Marcel Apfelbaum <marcel.apfelb...@gmail.com>
Cc: Tom Lendacky <thomas.lenda...@amd.com>
Cc: Suravee Suthikulpanit <suravee.suthikulpa...@amd.com>
Reviewed-by: Michael S. Tsirkin <m...@redhat.com>
Signed-off-by: Michael S. Tsirkin <m...@redhat.com>
---
hw/i386/amd_iommu.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/hw/i386/amd_iommu.c b/hw/i386/amd_iommu.c
index 1fd669fef8..7206bb09c2 100644
--- a/hw/i386/amd_iommu.c
+++ b/hw/i386/amd_iommu.c
@@ -807,7 +807,7 @@ static inline uint64_t amdvi_get_perms(uint64_t entry)
AMDVI_DEV_PERM_SHIFT;
}
-/* a valid entry should have V = 1 and reserved bits honoured */
+/* validate that reserved bits are honoured */
static bool amdvi_validate_dte(AMDVIState *s, uint16_t devid,
uint64_t *dte)
{
@@ -820,7 +820,7 @@ static bool amdvi_validate_dte(AMDVIState *s, uint16_t
devid,
return false;
}
- return dte[0] & AMDVI_DEV_VALID;
+ return true;
}
/* get a device table entry given the devid */
@@ -966,8 +966,12 @@ static void amdvi_do_translate(AMDVIAddressSpace *as,
hwaddr addr,
return;
}
- /* devices with V = 0 are not translated */
if (!amdvi_get_dte(s, devid, entry)) {
+ return;
+ }
+
+ /* devices with V = 0 are not translated */
+ if (!(entry[0] & AMDVI_DEV_VALID)) {
goto out;
}
--
MST
