diff options
| author | Jan Beulich <jbeulich@suse.com> | 2020-11-20 08:28:58 +0100 |
|---|---|---|
| committer | Jan Beulich <jbeulich@suse.com> | 2020-11-20 08:28:58 +0100 |
| commit | 846d22d54f24f336fb80d052338e0cd030d54fee (patch) | |
| tree | 6e442499e68a004e0bd7cfd4a1483ea3d101399b /xen | |
| parent | dee7d981b99435b6c37126821af7826bd9a9d36c (diff) | |
AMD/IOMMU: avoid UB in guest CR3 retrieval
Found by looking for patterns similar to the one Julien did spot in
pci_vtd_quirks(). (Not that it matters much here, considering the code
is dead right now.)
Fixes: 3a7947b69011 ("amd-iommu: use a bitfield for DTE")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Diffstat (limited to 'xen')
| -rw-r--r-- | xen/drivers/passthrough/amd/iommu_guest.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/xen/drivers/passthrough/amd/iommu_guest.c b/xen/drivers/passthrough/amd/iommu_guest.c index 30b7353cd6..2a3def9a5d 100644 --- a/xen/drivers/passthrough/amd/iommu_guest.c +++ b/xen/drivers/passthrough/amd/iommu_guest.c @@ -70,7 +70,8 @@ static void guest_iommu_disable(struct guest_iommu *iommu) static uint64_t get_guest_cr3_from_dte(struct amd_iommu_dte *dte) { - return ((dte->gcr3_trp_51_31 << 31) | (dte->gcr3_trp_30_15 << 15) | + return (((uint64_t)dte->gcr3_trp_51_31 << 31) | + (dte->gcr3_trp_30_15 << 15) | (dte->gcr3_trp_14_12 << 12)) >> PAGE_SHIFT; } |