x86/virt: Drop unnecessary check on extended CPUID level in cpu_has_svm()

[ Upstream commit 5df8ecfe3632d5879d1f154f7aa8de441b5d1c89 ]

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()")
Link: https://lore.kernel.org/r/20230721201859.2307736-13-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/arch/x86/include/asm/virtext.h b/arch/x86/include/asm/virtext.h
index 3b12e6b99412370b6d71a3845500a5cdba46eb1f..6c2e3ff3cb28f9e19440301fd8de8bc38b466852 100644 (file)
--- a/arch/x86/include/asm/virtext.h
+++ b/arch/x86/include/asm/virtext.h
@@ -101,12 +101,6 @@ 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";