From: Chenyi Qiang <chenyi.qiang@intel.com>
Date: Thu, 21 Oct 2021 07:10:22 +0000 (+0800)
Subject: KVM: MMU: Reset mmu->pkru_mask to avoid stale data
X-Git-Tag: howlett/maple/20220722_2~2064^2~8
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=a3ca5281bb771d8103ea16f0a6a8a5df9a7fb4f3;p=users%2Fjedix%2Flinux-maple.git

KVM: MMU: Reset mmu->pkru_mask to avoid stale data

When updating mmu->pkru_mask, the value can only be added but it isn't
reset in advance. This will make mmu->pkru_mask keep the stale data.
Fix this issue.

Fixes: 2d344105f57c ("KVM, pkeys: introduce pkru_mask to cache conditions")
Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com>
Message-Id: <20211021071022.1140-1-chenyi.qiang@intel.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 1a64ba5b9437..0cc58901bf7a 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4596,10 +4596,10 @@ static void update_pkru_bitmask(struct kvm_mmu *mmu)
 	unsigned bit;
 	bool wp;
 
-	if (!is_cr4_pke(mmu)) {
-		mmu->pkru_mask = 0;
+	mmu->pkru_mask = 0;
+
+	if (!is_cr4_pke(mmu))
 		return;
-	}
 
 	wp = is_cr0_wp(mmu);