KVM: MMU: cache mmio info on page fault path
If the page fault is caused by mmio, we can cache the mmio info, later, we do
not need to walk guest page table and quickly know it is a mmio fault while we
emulate the mmio instruction
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index a1dbd04..028a0f2 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4016,6 +4016,14 @@
{
u32 access = (kvm_x86_ops->get_cpl(vcpu) == 3) ? PFERR_USER_MASK : 0;
+ if (vcpu_match_mmio_gva(vcpu, gva) &&
+ check_write_user_access(vcpu, write, access,
+ vcpu->arch.access)) {
+ *gpa = vcpu->arch.mmio_gfn << PAGE_SHIFT |
+ (gva & (PAGE_SIZE - 1));
+ return 1;
+ }
+
if (write)
access |= PFERR_WRITE_MASK;
@@ -4028,6 +4036,9 @@
if ((*gpa & PAGE_MASK) == APIC_DEFAULT_PHYS_BASE)
return 1;
+ if (vcpu_match_mmio_gpa(vcpu, *gpa))
+ return 1;
+
return 0;
}