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由 Peter Xu 提交于
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: NFam Zheng <famz@redhat.com> Signed-off-by: NPeter Xu <peterx@redhat.com> Reviewed-by: NMichael S. Tsirkin <mst@redhat.com> Signed-off-by: NMichael S. Tsirkin <mst@redhat.com> (cherry picked from commit 1d9efa73) Signed-off-by: NMichael Roth <mdroth@linux.vnet.ibm.com>
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