From: Sean Christopherson <seanjc@google.com>
To: Sean Christopherson <seanjc@google.com>,
Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Andrew Cooper <Andrew.Cooper3@citrix.com>,
Kai Huang <kai.huang@intel.com>, Chao Gao <chao.gao@intel.com>
Subject: [PATCH v3 12/18] x86/virt: Drop unnecessary check on extended CPUID level in cpu_has_svm()
Date: Fri, 12 May 2023 16:50:20 -0700 [thread overview]
Message-ID: <20230512235026.808058-13-seanjc@google.com> (raw)
In-Reply-To: <20230512235026.808058-1-seanjc@google.com>
Drop the explicit check on the extended CPUID level in cpu_has_svm(), the
kernel's cached CPUID info will leave the entire SVM leaf unset if said
leaf is not supported by hardware. Prior to using cached information,
the check was needed to avoid false positives due to Intel's rather crazy
CPUID behavior of returning the values of the maximum supported leaf if
the specified leaf is unsupported.
Fixes: 682a8108872f ("x86/kvm/svm: Simplify cpu_has_svm()")
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/include/asm/virtext.h | 6 ------
1 file changed, 6 deletions(-)
diff --git a/arch/x86/include/asm/virtext.h b/arch/x86/include/asm/virtext.h
index a27801f2bc71..be50c414efe4 100644
--- a/arch/x86/include/asm/virtext.h
+++ b/arch/x86/include/asm/virtext.h
@@ -39,12 +39,6 @@ static inline int cpu_has_svm(const char **msg)
return 0;
}
- if (boot_cpu_data.extended_cpuid_level < SVM_CPUID_FUNC) {
- if (msg)
- *msg = "can't execute cpuid_8000000a";
- return 0;
- }
-
if (!boot_cpu_has(X86_FEATURE_SVM)) {
if (msg)
*msg = "svm not available";
--
2.40.1.606.ga4b1b128d6-goog
next prev parent reply other threads:[~2023-05-12 23:52 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-12 23:50 [PATCH v3 00/18] x86/reboot: KVM: Clean up "emergency" virt code Sean Christopherson
2023-05-12 23:50 ` [PATCH v3 01/18] x86/reboot: VMCLEAR active VMCSes before emergency reboot Sean Christopherson
2023-05-12 23:50 ` [PATCH v3 02/18] x86/reboot: Harden virtualization hooks for " Sean Christopherson
2023-05-22 12:46 ` Huang, Kai
2023-05-12 23:50 ` [PATCH v3 03/18] x86/reboot: KVM: Handle VMXOFF in KVM's reboot callback Sean Christopherson
2023-05-22 12:55 ` Huang, Kai
2023-05-22 17:58 ` Sean Christopherson
2023-05-22 23:11 ` Huang, Kai
2023-05-12 23:50 ` [PATCH v3 04/18] x86/reboot: KVM: Disable SVM during reboot via virt/KVM " Sean Christopherson
2023-05-22 12:56 ` Huang, Kai
2023-05-12 23:50 ` [PATCH v3 05/18] x86/reboot: Disable virtualization during reboot iff callback is registered Sean Christopherson
2023-05-22 13:04 ` Huang, Kai
2023-05-22 17:51 ` Sean Christopherson
2023-05-22 23:13 ` Huang, Kai
2023-05-12 23:50 ` [PATCH v3 06/18] x86/reboot: Assert that IRQs are disabled when turning off virtualization Sean Christopherson
2023-05-22 13:05 ` Huang, Kai
2023-05-12 23:50 ` [PATCH v3 07/18] x86/reboot: Hoist "disable virt" helpers above "emergency reboot" path Sean Christopherson
2023-05-22 13:11 ` Huang, Kai
2023-05-12 23:50 ` [PATCH v3 08/18] x86/reboot: Expose VMCS crash hooks if and only if KVM_{INTEL,AMD} is enabled Sean Christopherson
2023-05-22 13:11 ` Huang, Kai
2023-05-12 23:50 ` [PATCH v3 09/18] x86/virt: KVM: Open code cpu_has_vmx() in KVM VMX Sean Christopherson
2023-05-22 23:41 ` Huang, Kai
2023-05-12 23:50 ` [PATCH v3 10/18] x86/virt: KVM: Move VMXOFF helpers into " Sean Christopherson
2023-05-22 13:15 ` Huang, Kai
2023-05-12 23:50 ` [PATCH v3 11/18] KVM: SVM: Make KVM_AMD depend on CPU_SUP_AMD or CPU_SUP_HYGON Sean Christopherson
2023-05-12 23:50 ` Sean Christopherson [this message]
2023-05-12 23:50 ` [PATCH v3 13/18] x86/virt: KVM: Open code cpu_has_svm() into kvm_is_svm_supported() Sean Christopherson
2023-05-22 23:44 ` Huang, Kai
2023-05-12 23:50 ` [PATCH v3 14/18] KVM: SVM: Check that the current CPU supports SVM in kvm_is_svm_supported() Sean Christopherson
2023-05-22 23:18 ` Huang, Kai
2023-05-12 23:50 ` [PATCH v3 15/18] KVM: VMX: Ensure CPU is stable when probing basic VMX support Sean Christopherson
2023-05-22 23:30 ` Huang, Kai
2023-05-12 23:50 ` [PATCH v3 16/18] x86/virt: KVM: Move "disable SVM" helper into KVM SVM Sean Christopherson
2023-05-22 23:26 ` Huang, Kai
2023-05-12 23:50 ` [PATCH v3 17/18] KVM: x86: Force kvm_rebooting=true during emergency reboot/crash Sean Christopherson
2023-05-22 23:25 ` Huang, Kai
2023-05-23 2:02 ` Huang, Kai
2023-05-12 23:50 ` [PATCH v3 18/18] KVM: SVM: Use "standard" stgi() helper when disabling SVM Sean Christopherson
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