KVM: MMU audit: audit_mappings tweaks

- Fail early in case gfn_to_pfn returns is_error_pfn.
- For the pre pte write case, avoid spurious "gva is valid but spte is notrap"
  messages (the emulation code does the guest write first, so this particular
  case is OK).

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 86433513fb71c2a9413609a6d101f2494fe8d468..50fe8541ed3906f5f8f3991d26b2c084adbac9d6 100644 (file)
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -3117,6 +3117,11 @@ static void audit_mappings_page(struct kvm_vcpu *vcpu, u64 page_pte,
                        pfn_t pfn = gfn_to_pfn(vcpu->kvm, gfn);
                        hpa_t hpa = (hpa_t)pfn << PAGE_SHIFT;
 
+                       if (is_error_pfn(pfn)) {
+                               kvm_release_pfn_clean(pfn);
+                               continue;
+                       }
+
                        if (is_shadow_present_pte(ent)
                            && (ent & PT64_BASE_ADDR_MASK) != hpa)
                                printk(KERN_ERR "xx audit error: (%s) levels %d"
@@ -3288,7 +3293,8 @@ static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg)
        audit_msg = msg;
        audit_rmap(vcpu);
        audit_write_protection(vcpu);
-       audit_mappings(vcpu);
+       if (strcmp("pre pte write", audit_msg) != 0)
+               audit_mappings(vcpu);
        audit_writable_sptes_have_rmaps(vcpu);
        dbg = olddbg;
 }