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From: Emanuele Giuseppe Esposito <eesposit@redhat.com>
To: kvm@vger.kernel.org
Cc: Paolo Bonzini <pbonzini@redhat.com>,
	Maxim Levitsky <mlevitsk@redhat.com>,
	Sean Christopherson <seanjc@google.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
	linux-kernel@vger.kernel.org,
	Emanuele Giuseppe Esposito <eesposit@redhat.com>
Subject: [PATCH 1/2] KVM: nSVM: move nested_vmcb_check_cr3_cr4 logic in nested_vmcb_valid_sregs
Date: Mon,  9 Aug 2021 16:53:42 +0200	[thread overview]
Message-ID: <20210809145343.97685-2-eesposit@redhat.com> (raw)
In-Reply-To: <20210809145343.97685-1-eesposit@redhat.com>

nested_vmcb_check_cr3_cr4 is not called by anyone else, and removing the
call simplifies next patch

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
 arch/x86/kvm/svm/nested.c | 35 +++++++++++++----------------------
 1 file changed, 13 insertions(+), 22 deletions(-)

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 5e13357da21e..0ac2d14add15 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -257,27 +257,6 @@ static bool nested_vmcb_check_controls(struct kvm_vcpu *vcpu,
 	return true;
 }
 
-static bool nested_vmcb_check_cr3_cr4(struct kvm_vcpu *vcpu,
-				      struct vmcb_save_area *save)
-{
-	/*
-	 * These checks are also performed by KVM_SET_SREGS,
-	 * except that EFER.LMA is not checked by SVM against
-	 * CR0.PG && EFER.LME.
-	 */
-	if ((save->efer & EFER_LME) && (save->cr0 & X86_CR0_PG)) {
-		if (CC(!(save->cr4 & X86_CR4_PAE)) ||
-		    CC(!(save->cr0 & X86_CR0_PE)) ||
-		    CC(kvm_vcpu_is_illegal_gpa(vcpu, save->cr3)))
-			return false;
-	}
-
-	if (CC(!kvm_is_valid_cr4(vcpu, save->cr4)))
-		return false;
-
-	return true;
-}
-
 /* Common checks that apply to both L1 and L2 state.  */
 static bool nested_vmcb_valid_sregs(struct kvm_vcpu *vcpu,
 				    struct vmcb_save_area *save)
@@ -299,7 +278,19 @@ static bool nested_vmcb_valid_sregs(struct kvm_vcpu *vcpu,
 	if (CC(!kvm_dr6_valid(save->dr6)) || CC(!kvm_dr7_valid(save->dr7)))
 		return false;
 
-	if (!nested_vmcb_check_cr3_cr4(vcpu, save))
+	/*
+	 * These checks are also performed by KVM_SET_SREGS,
+	 * except that EFER.LMA is not checked by SVM against
+	 * CR0.PG && EFER.LME.
+	 */
+	if ((save->efer & EFER_LME) && (save->cr0 & X86_CR0_PG)) {
+		if (CC(!(save->cr4 & X86_CR4_PAE)) ||
+		    CC(!(save->cr0 & X86_CR0_PE)) ||
+		    CC(kvm_vcpu_is_illegal_gpa(vcpu, save->cr3)))
+			return false;
+	}
+
+	if (CC(!kvm_is_valid_cr4(vcpu, save->cr4)))
 		return false;
 
 	if (CC(!kvm_valid_efer(vcpu, save->efer)))
-- 
2.31.1


  reply	other threads:[~2021-08-09 14:55 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-09 14:53 [PATCH 0/2] KVM: nSVM: avoid TOC/TOU race when checking vmcb12 Emanuele Giuseppe Esposito
2021-08-09 14:53 ` Emanuele Giuseppe Esposito [this message]
2021-08-11 20:37   ` [PATCH 1/2] KVM: nSVM: move nested_vmcb_check_cr3_cr4 logic in nested_vmcb_valid_sregs Maxim Levitsky
2021-08-09 14:53 ` [PATCH 2/2] KVM: nSVM: temporarly save vmcb12's efer, cr0 and cr4 to avoid TOC/TOU races Emanuele Giuseppe Esposito
2021-08-10  9:15   ` Paolo Bonzini
2021-08-11 20:37   ` Maxim Levitsky
2021-08-11 23:25     ` Sean Christopherson
2021-08-25 12:40       ` Emanuele Giuseppe Esposito

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