linux-kernel - [PATCH v2 07/18] KVM: x86/mmu: Do not use guest root level in audit

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Message-Id: <20220217210340.312449-8-pbonzini@redhat.com>
Date:   Thu, 17 Feb 2022 16:03:29 -0500
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:     seanjc@...gle.com, Lai Jiangshan <laijs@...ux.alibaba.com>
Subject: [PATCH v2 07/18] KVM: x86/mmu: Do not use guest root level in audit

From: Lai Jiangshan <laijs@...ux.alibaba.com>

Walking from the root page of the shadow page table should start with
the level of the shadow page table: shadow_root_level; do not
consult the level in order to check whether the root has a single
root or uses pae_root, either, and use to_shadow_page instead.

Also tweak audit_mappings(), where the current walking level is more
valuable to print.

Signed-off-by: Lai Jiangshan <laijs@...ux.alibaba.com>
Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
---
 arch/x86/kvm/mmu/mmu_audit.c | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu_audit.c b/arch/x86/kvm/mmu/mmu_audit.c
index 3e5d62a25350..d1c59aed0465 100644
--- a/arch/x86/kvm/mmu/mmu_audit.c
+++ b/arch/x86/kvm/mmu/mmu_audit.c
@@ -53,17 +53,16 @@ static void __mmu_spte_walk(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
 
 static void mmu_spte_walk(struct kvm_vcpu *vcpu, inspect_spte_fn fn)
 {
-	int i;
+	hpa_t root = vcpu->arch.mmu->root.hpa;
 	struct kvm_mmu_page *sp;
+	int i;
 
-	if (!VALID_PAGE(vcpu->arch.mmu->root.hpa))
+	if (!VALID_PAGE(root))
 		return;
 
-	if (vcpu->arch.mmu->root_level >= PT64_ROOT_4LEVEL) {
-		hpa_t root = vcpu->arch.mmu->root.hpa;
-
-		sp = to_shadow_page(root);
-		__mmu_spte_walk(vcpu, sp, fn, vcpu->arch.mmu->root_level);
+	sp = to_shadow_page(root);
+	if (sp) {
+		__mmu_spte_walk(vcpu, sp, fn, vcpu->arch.mmu->shadow_root_level);
 		return;
 	}
 
@@ -119,8 +118,7 @@ static void audit_mappings(struct kvm_vcpu *vcpu, u64 *sptep, int level)
 	hpa =  pfn << PAGE_SHIFT;
 	if ((*sptep & PT64_BASE_ADDR_MASK) != hpa)
 		audit_printk(vcpu->kvm, "levels %d pfn %llx hpa %llx "
-			     "ent %llxn", vcpu->arch.mmu->root_level, pfn,
-			     hpa, *sptep);
+			     "ent %llxn", level, pfn, hpa, *sptep);
 }
 
 static void inspect_spte_has_rmap(struct kvm *kvm, u64 *sptep)
-- 
2.31.1