linux-kernel - [PATCH v10 01/50] KVM: SVM: INTERCEPT_RDTSCP is never intercepted anyway

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Message-ID: <20231016132819.1002933-2-michael.roth@amd.com>
Date:   Mon, 16 Oct 2023 08:27:30 -0500
From:   Michael Roth <michael.roth@....com>
To:     <kvm@...r.kernel.org>
CC:     <linux-coco@...ts.linux.dev>, <linux-mm@...ck.org>,
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Subject: [PATCH v10 01/50] KVM: SVM: INTERCEPT_RDTSCP is never intercepted anyway

From: Paolo Bonzini <pbonzini@...hat.com>

svm_recalc_instruction_intercepts() is always called at least once
before the vCPU is started, so the setting or clearing of the RDTSCP
intercept can be dropped from the TSC_AUX virtualization support.

Extracted from a patch by Tom Lendacky.

Cc: stable@...r.kernel.org
Fixes: 296d5a17e793 ("KVM: SEV-ES: Use V_TSC_AUX if available instead of RDTSC/MSR_TSC_AUX intercepts")
Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
(cherry picked from commit e8d93d5d93f85949e7299be289c6e7e1154b2f78)
Signed-off-by: Michael Roth <michael.roth@....com>
---
 arch/x86/kvm/svm/sev.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index b9a0a939d59f..fa1fb81323b5 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -3027,11 +3027,8 @@ static void sev_es_init_vmcb(struct vcpu_svm *svm)
 
 	if (boot_cpu_has(X86_FEATURE_V_TSC_AUX) &&
 	    (guest_cpuid_has(&svm->vcpu, X86_FEATURE_RDTSCP) ||
-	     guest_cpuid_has(&svm->vcpu, X86_FEATURE_RDPID))) {
+	     guest_cpuid_has(&svm->vcpu, X86_FEATURE_RDPID)))
 		set_msr_interception(vcpu, svm->msrpm, MSR_TSC_AUX, 1, 1);
-		if (guest_cpuid_has(&svm->vcpu, X86_FEATURE_RDTSCP))
-			svm_clr_intercept(svm, INTERCEPT_RDTSCP);
-	}
 }
 
 void sev_init_vmcb(struct vcpu_svm *svm)
-- 
2.25.1