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From: Sean Christopherson <seanjc@google.com>
To: Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	x86@kernel.org, Sean Christopherson <seanjc@google.com>,
	Paolo Bonzini <pbonzini@redhat.com>
Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
	Andrew Cooper <Andrew.Cooper3@citrix.com>,
	Kai Huang <kai.huang@intel.com>, Chao Gao <chao.gao@intel.com>
Subject: [PATCH v4 09/19] x86/virt: KVM: Open code cpu_has_vmx() in KVM VMX
Date: Fri, 21 Jul 2023 13:18:49 -0700	[thread overview]
Message-ID: <20230721201859.2307736-10-seanjc@google.com> (raw)
In-Reply-To: <20230721201859.2307736-1-seanjc@google.com>

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>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/x86/include/asm/virtext.h | 10 ----------
 arch/x86/kvm/vmx/vmx.c         |  2 +-
 2 files changed, 1 insertion(+), 11 deletions(-)

diff --git a/arch/x86/include/asm/virtext.h b/arch/x86/include/asm/virtext.h
index aaed66249ccf..b1171a5ad452 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 682c20b33a96..71571cd9adbb 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2718,7 +2718,7 @@ 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;
 	}
-- 
2.41.0.487.g6d72f3e995-goog


  parent reply	other threads:[~2023-07-21 20:19 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-07-21 20:18 [PATCH v4 00/19] x86/reboot: KVM: Clean up "emergency" virt code Sean Christopherson
2023-07-21 20:18 ` [PATCH v4 01/19] x86/reboot: VMCLEAR active VMCSes before emergency reboot Sean Christopherson
2023-07-21 20:18 ` [PATCH v4 02/19] x86/reboot: Harden virtualization hooks for " Sean Christopherson
2023-07-21 20:18 ` [PATCH v4 03/19] x86/reboot: KVM: Handle VMXOFF in KVM's reboot callback Sean Christopherson
2023-07-24 23:57   ` Huang, Kai
2023-07-21 20:18 ` [PATCH v4 04/19] x86/reboot: KVM: Disable SVM during reboot via virt/KVM " Sean Christopherson
2023-07-21 20:18 ` [PATCH v4 05/19] x86/reboot: Assert that IRQs are disabled when turning off virtualization Sean Christopherson
2023-07-24 21:19   ` Peter Zijlstra
2023-07-24 21:41     ` Sean Christopherson
2023-07-21 20:18 ` [PATCH v4 06/19] x86/reboot: Hoist "disable virt" helpers above "emergency reboot" path Sean Christopherson
2023-07-21 20:18 ` [PATCH v4 07/19] x86/reboot: Disable virtualization during reboot iff callback is registered Sean Christopherson
2023-07-24 23:57   ` Huang, Kai
2023-07-21 20:18 ` [PATCH v4 08/19] x86/reboot: Expose VMCS crash hooks if and only if KVM_{INTEL,AMD} is enabled Sean Christopherson
2023-07-21 20:18 ` Sean Christopherson [this message]
2023-07-21 20:18 ` [PATCH v4 10/19] x86/virt: KVM: Move VMXOFF helpers into KVM VMX Sean Christopherson
2023-07-28  9:08   ` Xu Yilun
2023-07-28  9:43     ` Huang, Kai
2023-07-21 20:18 ` [PATCH v4 11/19] KVM: SVM: Make KVM_AMD depend on CPU_SUP_AMD or CPU_SUP_HYGON Sean Christopherson
2023-07-21 20:18 ` [PATCH v4 12/19] x86/virt: Drop unnecessary check on extended CPUID level in cpu_has_svm() Sean Christopherson
2023-07-21 20:18 ` [PATCH v4 13/19] x86/virt: KVM: Open code cpu_has_svm() into kvm_is_svm_supported() Sean Christopherson
2023-07-21 20:18 ` [PATCH v4 14/19] KVM: SVM: Check that the current CPU supports SVM in kvm_is_svm_supported() Sean Christopherson
2023-07-24 21:21   ` Peter Zijlstra
2023-07-24 21:40     ` Sean Christopherson
2023-07-25  9:16       ` Peter Zijlstra
2023-07-27 16:39         ` Sean Christopherson
2023-07-24 22:29   ` Dmitry Torokhov
2023-07-24 23:53     ` Sean Christopherson
2023-07-21 20:18 ` [PATCH v4 15/19] KVM: VMX: Ensure CPU is stable when probing basic VMX support Sean Christopherson
2023-07-21 20:18 ` [PATCH v4 16/19] x86/virt: KVM: Move "disable SVM" helper into KVM SVM Sean Christopherson
2023-07-21 20:18 ` [PATCH v4 17/19] KVM: x86: Force kvm_rebooting=true during emergency reboot/crash Sean Christopherson
2023-07-21 20:18 ` [PATCH v4 18/19] KVM: SVM: Use "standard" stgi() helper when disabling SVM Sean Christopherson
2023-07-21 20:18 ` [PATCH v4 19/19] KVM: VMX: Skip VMCLEAR logic during emergency reboots if CR4.VMXE=0 Sean Christopherson
2023-07-25  3:51   ` Huang, Kai
2023-07-25 18:15     ` Sean Christopherson
2023-07-25 22:20       ` Huang, Kai
2023-08-04  0:40 ` [PATCH v4 00/19] x86/reboot: KVM: Clean up "emergency" virt code Sean Christopherson

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