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>

1 files changed, 36 insertions, 0 deletions

diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index 256da82856b..d36fe237c66 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -75,6 +75,42 @@ static inline u32 bit(int bitno)
         return 1 << (bitno & 31);
 }
 
+static inline void vcpu_cache_mmio_info(struct kvm_vcpu *vcpu,
+                                        gva_t gva, gfn_t gfn, unsigned access)
+{
+        vcpu->arch.mmio_gva = gva & PAGE_MASK;
+        vcpu->arch.access = access;
+        vcpu->arch.mmio_gfn = gfn;
+}
+
+/*
+ * Clear the mmio cache info for the given gva,
+ * specially, if gva is ~0ul, we clear all mmio cache info.
+ */
+static inline void vcpu_clear_mmio_info(struct kvm_vcpu *vcpu, gva_t gva)
+{
+        if (gva != (~0ul) && vcpu->arch.mmio_gva != (gva & PAGE_MASK))
+                return;
+
+        vcpu->arch.mmio_gva = 0;
+}
+
+static inline bool vcpu_match_mmio_gva(struct kvm_vcpu *vcpu, unsigned long gva)
+{
+        if (vcpu->arch.mmio_gva && vcpu->arch.mmio_gva == (gva & PAGE_MASK))
+                return true;
+
+        return false;
+}
+
+static inline bool vcpu_match_mmio_gpa(struct kvm_vcpu *vcpu, gpa_t gpa)
+{
+        if (vcpu->arch.mmio_gfn && vcpu->arch.mmio_gfn == gpa >> PAGE_SHIFT)
+                return true;
+
+        return false;
+}
+
 void kvm_before_handle_nmi(struct kvm_vcpu *vcpu);
 void kvm_after_handle_nmi(struct kvm_vcpu *vcpu);
 int kvm_inject_realmode_interrupt(struct kvm_vcpu *vcpu, int irq, int inc_eip);