KVM: nVMX: consult PFEC_MASK and PFEC_MATCH when generating #PF VM-exit

When generating #PF VM-exit, check equality:
(PFEC & PFEC_MASK) == PFEC_MATCH
If there is equality, the 14 bit of exception bitmap is used to take decision
about generating #PF VM-exit. If there is inequality, inverted 14 bit is used.

Signed-off-by: Eugene Korenevsky <ekorenevsky@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 13 insertions, 2 deletions

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 70bdcf946f95..e14c96e574ff 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -8206,6 +8206,18 @@ static void nested_ept_uninit_mmu_context(struct kvm_vcpu *vcpu)
         vcpu->arch.walk_mmu = &vcpu->arch.mmu;
 }
 
+static bool nested_vmx_is_page_fault_vmexit(struct vmcs12 *vmcs12,
+                                            u16 error_code)
+{
+        bool inequality, bit;
+
+        bit = (vmcs12->exception_bitmap & (1u << PF_VECTOR)) != 0;
+        inequality =
+                (error_code & vmcs12->page_fault_error_code_mask) !=
+                 vmcs12->page_fault_error_code_match;
+        return inequality ^ bit;
+}
+
 static void vmx_inject_page_fault_nested(struct kvm_vcpu *vcpu,
                 struct x86_exception *fault)
 {
@@ -8213,8 +8225,7 @@ static void vmx_inject_page_fault_nested(struct kvm_vcpu *vcpu,
 
         WARN_ON(!is_guest_mode(vcpu));
 
-        /* TODO: also check PFEC_MATCH/MASK, not just EB.PF. */
-        if (vmcs12->exception_bitmap & (1u << PF_VECTOR))
+        if (nested_vmx_is_page_fault_vmexit(vmcs12, fault->error_code))
                 nested_vmx_vmexit(vcpu, to_vmx(vcpu)->exit_reason,
                                   vmcs_read32(VM_EXIT_INTR_INFO),
                                   vmcs_readl(EXIT_QUALIFICATION));