diff options
| author | Peter Xu <peterx@redhat.com> | 2018-05-18 15:25:11 +0800 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2018-05-23 17:33:57 +0300 |
| commit | 1d9efa73e12ddf361ea997c2d532cc4afa6674d1 (patch) | |
| tree | 885f2de689980de529f1f9cb364591433b387cc2 /include/hw/i386 | |
| parent | b4a4ba0d68f50f218ee3957b6638dbee32a5eeef (diff) | |
intel-iommu: add iommu lock
SECURITY IMPLICATION: this patch fixes a potential race when multiple
threads access the IOMMU IOTLB cache.
Add a per-iommu big lock to protect IOMMU status. Currently the only
thing to be protected is the IOTLB/context cache, since that can be
accessed even without BQL, e.g., in IO dataplane.
Note that we don't need to protect device page tables since that's fully
controlled by the guest kernel. However there is still possibility that
malicious drivers will program the device to not obey the rule. In that
case QEMU can't really do anything useful, instead the guest itself will
be responsible for all uncertainties.
CC: QEMU Stable <qemu-stable@nongnu.org>
Reported-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'include/hw/i386')
| -rw-r--r-- | include/hw/i386/intel_iommu.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h index 032e33bcb2..016e74bedb 100644 --- a/include/hw/i386/intel_iommu.h +++ b/include/hw/i386/intel_iommu.h @@ -300,6 +300,12 @@ struct IntelIOMMUState { OnOffAuto intr_eim; /* Toggle for EIM cabability */ bool buggy_eim; /* Force buggy EIM unless eim=off */ uint8_t aw_bits; /* Host/IOVA address width (in bits) */ + + /* + * Protects IOMMU states in general. Currently it protects the + * per-IOMMU IOTLB cache, and context entry cache in VTDAddressSpace. + */ + QemuMutex iommu_lock; }; /* Find the VTD Address space associated with the given bus pointer, |