[patch 4/4] KVM: MMU audit: audit_mappings tweaks

Marcelo Tosatti
2009-06-02T21:44:37Z

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- 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>

Index: kvm/arch/x86/kvm/mmu.c
===================================================================
--- kvm.orig/arch/x86/kvm/mmu.c
+++ kvm/arch/x86/kvm/mmu.c
@@ -3089,6 +3089,11 @@ static void audit_mappings_page(struct k
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"
@@ -3256,7 +3261,8 @@ static void kvm_mmu_audit(struct kvm_vcp
audit_msg = msg;
audit_rmap(vcpu);
audit_write_protection(vcpu);
- audit_mappings(vcpu);
+ if (strcmp("pre pte write", audit_msg))
+ audit_mappings(vcpu);
audit_writable_sptes_have_rmaps(vcpu);
dbg = olddbg;
}

--