linux-kernel - [PATCH v2 2/5] KVM: x86/tdp_mmu: Merge prefetch and access checks for spurious faults

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250318013210.5701-1-yan.y.zhao@intel.com>
Date: Tue, 18 Mar 2025 09:32:10 +0800
From: Yan Zhao <yan.y.zhao@...el.com>
To: pbonzini@...hat.com,
	seanjc@...gle.com
Cc: linux-kernel@...r.kernel.org,
	kvm@...r.kernel.org,
	Yan Zhao <yan.y.zhao@...el.com>
Subject: [PATCH v2 2/5] KVM: x86/tdp_mmu: Merge prefetch and access checks for spurious faults

Combine prefetch and is_access_allowed() checks into a unified path to
detect spurious faults, since both cases now share identical logic.

No functional changes.

Signed-off-by: Yan Zhao <yan.y.zhao@...el.com>
---
 arch/x86/kvm/mmu/tdp_mmu.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index ab65fd915ef2..6365eb6c1390 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -1137,12 +1137,8 @@ static int tdp_mmu_map_handle_target_level(struct kvm_vcpu *vcpu,
 	if (WARN_ON_ONCE(sp->role.level != fault->goal_level))
 		return RET_PF_RETRY;
 
-	if (fault->prefetch && is_shadow_present_pte(iter->old_spte) &&
-	    is_last_spte(iter->old_spte, iter->level))
-		return RET_PF_SPURIOUS;
-
 	if (is_shadow_present_pte(iter->old_spte) &&
-	    is_access_allowed(fault, iter->old_spte) &&
+	    (fault->prefetch || is_access_allowed(fault, iter->old_spte)) &&
 	    is_last_spte(iter->old_spte, iter->level))
 		return RET_PF_SPURIOUS;
 
-- 
2.43.2