Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
KVM: SVM: Skip OSVW MSR reads if current CPU doesn't support the feature
Skip the OSVW RDMSRs if the current CPU doesn't enumerate support for the
MSRs. In practice, checking only the boot CPU's capabilities is
sufficient, as the RDMSRs should fault when unsupported, but there's no
downside to being more precise, and checking only the boot CPU _looks_
wrong given the rather odd semantics of the MSRs. E.g. if a CPU doesn't
support OVSW, then KVM must assume all errata are present.
Link: https://patch.msgid.link/20251113231420.1695919-6-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
+2
-6
+2
-6
arch/x86/kvm/svm/svm.c
+2
-6
arch/x86/kvm/svm/svm.c
···
447
447
if (!osvw_len)
448
448
return;
449
449
450
-
if (!boot_cpu_has(X86_FEATURE_OSVW)) {
451
-
osvw_status = osvw_len = 0;
452
-
return;
453
-
}
454
-
455
-
if (native_read_msr_safe(MSR_AMD64_OSVW_ID_LENGTH, &len) ||
450
+
if (!this_cpu_has(X86_FEATURE_OSVW) ||
451
+
native_read_msr_safe(MSR_AMD64_OSVW_ID_LENGTH, &len) ||
456
452
native_read_msr_safe(MSR_AMD64_OSVW_STATUS, &status))
457
453
len = status = 0;
458
454