From: Sean Christopherson <seanjc@google.com>
Date: Fri, 21 Jul 2023 20:18:49 +0000 (-0700)
Subject: x86/virt: KVM: Open code cpu_has_vmx() in KVM VMX
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=b6a6af0d19cea17a3c1e34f81f0d521775f94ab5;p=linux.git

x86/virt: KVM: Open code cpu_has_vmx() in KVM VMX

Fold the raw CPUID check for VMX into kvm_is_vmx_supported(), its sole
user.  Keep the check even though KVM also checks X86_FEATURE_VMX, as the
intent is to provide a unique error message if VMX is unsupported by
hardware, whereas X86_FEATURE_VMX may be clear due to firmware and/or
kernel actions.

No functional change intended.

Reviewed-by: Kai Huang <kai.huang@intel.com>
Link: https://lore.kernel.org/r/20230721201859.2307736-10-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
---

diff --git a/arch/x86/include/asm/virtext.h b/arch/x86/include/asm/virtext.h
index aaed66249ccf3..b1171a5ad4525 100644
--- a/arch/x86/include/asm/virtext.h
+++ b/arch/x86/include/asm/virtext.h
@@ -22,14 +22,6 @@
 /*
  * VMX functions:
  */
-
-static inline int cpu_has_vmx(void)
-{
-	unsigned long ecx = cpuid_ecx(1);
-	return test_bit(5, &ecx); /* CPUID.1:ECX.VMX[bit 5] -> VT */
-}
-
-
 /**
  * cpu_vmxoff() - Disable VMX on the current CPU
  *
@@ -61,8 +53,6 @@ static inline int cpu_vmx_enabled(void)
 }
 
 /** Disable VMX if it is enabled on the current CPU
- *
- * You shouldn't call this if cpu_has_vmx() returns 0.
  */
 static inline void __cpu_emergency_vmxoff(void)
 {
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index df991f15baf49..4b9d688261726 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2699,7 +2699,7 @@ static bool kvm_is_vmx_supported(void)
 {
 	int cpu = raw_smp_processor_id();
 
-	if (!cpu_has_vmx()) {
+	if (!(cpuid_ecx(1) & feature_bit(VMX))) {
 		pr_err("VMX not supported by CPU %d\n", cpu);
 		return false;
 	}