Received-SPF: pass (google.com: domain of linux-kernel+bounces-182474-linux.lists.archive=gmail.com@vger.kernel.org designates 139.178.88.99 as permitted sender) client-ip=139.178.88.99;
Reply-To: Sean Christopherson <seanjc@google.com>
Date: Fri, 17 May 2024 10:39:18 -0700
In-Reply-To: <20240517173926.965351-1-seanjc@google.com>
Precedence: bulk
Mime-Version: 1.0
References: <20240517173926.965351-1-seanjc@google.com>
Message-ID: <20240517173926.965351-42-seanjc@google.com>
Subject: [PATCH v2 41/49] KVM: x86: Avoid double CPUID lookup when updating
 MWAIT at runtime
From: Sean Christopherson <seanjc@google.com>
To: Paolo Bonzini <pbonzini@redhat.com>, Sean Christopherson <seanjc@google.com>, 
	Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, 
	Hou Wenlong <houwenlong.hwl@antgroup.com>, Kechen Lu <kechenl@nvidia.com>, 
	Oliver Upton <oliver.upton@linux.dev>, Maxim Levitsky <mlevitsk@redhat.com>, 
	Binbin Wu <binbin.wu@linux.intel.com>, Yang Weijiang <weijiang.yang@intel.com>, 
	Robert Hoo <robert.hoo.linux@gmail.com>
Content-Type: text/plain; charset="UTF-8"

Move the handling of X86_FEATURE_MWAIT during CPUID runtime updates to
utilize the lookup done for other CPUID.0x1 features.

No functional change intended.

Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/x86/kvm/cpuid.c | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 8ada1cac8fcb..258c5fce87fc 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -343,6 +343,11 @@ void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu)
 
 		cpuid_entry_change(best, X86_FEATURE_APIC,
 			   vcpu->arch.apic_base & MSR_IA32_APICBASE_ENABLE);
+
+		if (!kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT))
+			cpuid_entry_change(best, X86_FEATURE_MWAIT,
+					   vcpu->arch.ia32_misc_enable_msr &
+					   MSR_IA32_MISC_ENABLE_MWAIT);
 	}
 
 	best = kvm_find_cpuid_entry_index(vcpu, 7, 0);
@@ -358,14 +363,6 @@ void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu)
 	if (best && (cpuid_entry_has(best, X86_FEATURE_XSAVES) ||
 		     cpuid_entry_has(best, X86_FEATURE_XSAVEC)))
 		best->ebx = xstate_required_size(vcpu->arch.xcr0, true);
-
-	if (!kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT)) {
-		best = kvm_find_cpuid_entry(vcpu, 0x1);
-		if (best)
-			cpuid_entry_change(best, X86_FEATURE_MWAIT,
-					   vcpu->arch.ia32_misc_enable_msr &
-					   MSR_IA32_MISC_ENABLE_MWAIT);
-	}
 }
 EXPORT_SYMBOL_GPL(kvm_update_cpuid_runtime);
 
-- 
2.45.0.215.g3402c0e53f-goog