linux-kernel - [PATCH v1] KVM: x86: 0-initialize kvm_caps.supported

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Date: Fri,  3 May 2024 22:25:48 +0800
From: Wei Wang <wei.w.wang@...el.com>
To: seanjc@...gle.com,
	pbonzini@...hat.com
Cc: kvm@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Wei Wang <wei.w.wang@...el.com>
Subject: [PATCH v1] KVM: x86: 0-initialize kvm_caps.supported_xss on definition

0-initialize kvm_caps.supported_xss on definition, so that it doesn't
need to be explicitly zero-ed either in the common x86 or VMX/SVM
initialization paths. This simplifies the code and reduces LOCs.

No functional changes intended.

Signed-off-by: Wei Wang <wei.w.wang@...el.com>
---
 arch/x86/kvm/svm/svm.c | 1 -
 arch/x86/kvm/vmx/vmx.c | 2 --
 arch/x86/kvm/x86.c     | 4 +---
 3 files changed, 1 insertion(+), 6 deletions(-)

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 9aaf83c8d57d..8105e5383b62 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -5092,7 +5092,6 @@ static __init void svm_set_cpu_caps(void)
 	kvm_set_cpu_caps();
 
 	kvm_caps.supported_perf_cap = 0;
-	kvm_caps.supported_xss = 0;
 
 	/* CPUID 0x80000001 and 0x8000000A (SVM features) */
 	if (nested) {
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 22411f4aff53..495125723c15 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7952,8 +7952,6 @@ static __init void vmx_set_cpu_caps(void)
 	if (vmx_umip_emulated())
 		kvm_cpu_cap_set(X86_FEATURE_UMIP);
 
-	/* CPUID 0xD.1 */
-	kvm_caps.supported_xss = 0;
 	if (!cpu_has_vmx_xsaves())
 		kvm_cpu_cap_clear(X86_FEATURE_XSAVES);
 
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 91478b769af0..6a97592950ff 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -94,6 +94,7 @@
 
 struct kvm_caps kvm_caps __read_mostly = {
 	.supported_mce_cap = MCG_CTL_P | MCG_SER_P,
+	.supported_xss = 0,
 };
 EXPORT_SYMBOL_GPL(kvm_caps);
 
@@ -9795,9 +9796,6 @@ int kvm_x86_vendor_init(struct kvm_x86_init_ops *ops)
 
 	kvm_register_perf_callbacks(ops->handle_intel_pt_intr);
 
-	if (!kvm_cpu_cap_has(X86_FEATURE_XSAVES))
-		kvm_caps.supported_xss = 0;
-
 #define __kvm_cpu_cap_has(UNUSED_, f) kvm_cpu_cap_has(f)
 	cr4_reserved_bits = __cr4_reserved_bits(__kvm_cpu_cap_has, UNUSED_);
 #undef __kvm_cpu_cap_has

base-commit: 16c20208b9c2fff73015ad4e609072feafbf81ad
-- 
2.27.0