KVM: MMU: mmio page fault support
The idea is from Avi: | We could cache the result of a miss in an spte by using a reserved bit, and | checking the page fault error code (or seeing if we get an ept violation or | ept misconfiguration), so if we get repeated mmio on a page, we don't need to | search the slot list/tree. | (https://lkml.org/lkml/2011/2/22/221) When the page fault is caused by mmio, we cache the info in the shadow page table, and also set the reserved bits in the shadow page table, so if the mmio is caused again, we can quickly identify it and emulate it directly Searching mmio gfn in memslots is heavy since we need to walk all memeslots, it can be reduced by this feature, and also avoid walking guest page table for soft mmu. [jan: fix operator precedence issue] Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com> Signed-off-by: NAvi Kivity <avi@redhat.com>
Showing
想要评论请 注册 或 登录