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/mmu.c b/arch/x86/kvm/mmu.c
index 02c839f..d1986b7 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -217,11 +217,6 @@
}
EXPORT_SYMBOL_GPL(kvm_mmu_set_mask_ptes);
-static bool is_write_protection(struct kvm_vcpu *vcpu)
-{
- return kvm_read_cr0_bits(vcpu, X86_CR0_WP);
-}
-
static int is_cpuid_PSE36(void)
{
return 1;
@@ -243,11 +238,6 @@
return pte & PT_PAGE_SIZE_MASK;
}
-static int is_writable_pte(unsigned long pte)
-{
- return pte & PT_WRITABLE_MASK;
-}
-
static int is_dirty_gpte(unsigned long pte)
{
return pte & PT_DIRTY_MASK;
@@ -2247,15 +2237,17 @@
send_sig_info(SIGBUS, &info, tsk);
}
-static int kvm_handle_bad_page(struct kvm *kvm, gfn_t gfn, pfn_t pfn)
+static int kvm_handle_bad_page(struct kvm_vcpu *vcpu, gva_t gva,
+ unsigned access, gfn_t gfn, pfn_t pfn)
{
kvm_release_pfn_clean(pfn);
if (is_hwpoison_pfn(pfn)) {
- kvm_send_hwpoison_signal(gfn_to_hva(kvm, gfn), current);
+ kvm_send_hwpoison_signal(gfn_to_hva(vcpu->kvm, gfn), current);
return 0;
} else if (is_fault_pfn(pfn))
return -EFAULT;
+ vcpu_cache_mmio_info(vcpu, gva, gfn, access);
return 1;
}
@@ -2337,7 +2329,7 @@
/* mmio */
if (is_error_pfn(pfn))
- return kvm_handle_bad_page(vcpu->kvm, gfn, pfn);
+ return kvm_handle_bad_page(vcpu, v, ACC_ALL, gfn, pfn);
spin_lock(&vcpu->kvm->mmu_lock);
if (mmu_notifier_retry(vcpu, mmu_seq))
@@ -2564,6 +2556,7 @@
if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
return;
+ vcpu_clear_mmio_info(vcpu, ~0ul);
trace_kvm_mmu_audit(vcpu, AUDIT_PRE_SYNC);
if (vcpu->arch.mmu.root_level == PT64_ROOT_LEVEL) {
hpa_t root = vcpu->arch.mmu.root_hpa;
@@ -2710,7 +2703,7 @@
/* mmio */
if (is_error_pfn(pfn))
- return kvm_handle_bad_page(vcpu->kvm, gfn, pfn);
+ return kvm_handle_bad_page(vcpu, 0, 0, gfn, pfn);
spin_lock(&vcpu->kvm->mmu_lock);
if (mmu_notifier_retry(vcpu, mmu_seq))
goto out_unlock;