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From: Jinrong Liang <ljr.kernel@gmail.com>
To: Sean Christopherson <seanjc@google.com>,
	Like Xu <like.xu.linux@gmail.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	"H . Peter Anvin" <hpa@zytor.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] KVM: x86/pmu: Remove redundant check for MSR_IA32_DS_AREA set handler
Date: Tue, 11 Apr 2023 21:03:38 +0800	[thread overview]
Message-ID: <20230411130338.8592-1-cloudliang@tencent.com> (raw)

From: Jinrong Liang <cloudliang@tencent.com>

After commit 2de154f541fc ("KVM: x86/pmu: Provide "error" semantics
for unsupported-but-known PMU MSRs"), the guest_cpuid_has(DS) check
is not necessary any more since if the guest supports X86_FEATURE_DS,
it never returns 1. And if the guest does not support this feature,
the set_msr handler will get false from kvm_pmu_is_valid_msr() before
reaching this point. Therefore, the check will not be true in all cases
and can be safely removed, which also simplifies the code and improves
its readability.

Signed-off-by: Jinrong Liang <cloudliang@tencent.com>
---
 arch/x86/kvm/vmx/pmu_intel.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index e8a3be0b9df9..b0d70a8b7613 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -443,8 +443,6 @@ static int intel_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		}
 		break;
 	case MSR_IA32_DS_AREA:
-		if (msr_info->host_initiated && data && !guest_cpuid_has(vcpu, X86_FEATURE_DS))
-			return 1;
 		if (is_noncanonical_address(data, vcpu))
 			return 1;
 		pmu->ds_area = data;
-- 
2.31.1


             reply	other threads:[~2023-04-11 13:04 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-04-11 13:03 Jinrong Liang [this message]
2023-06-02  1:25 ` [PATCH] KVM: x86/pmu: Remove redundant check for MSR_IA32_DS_AREA set handler Sean Christopherson

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