github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-05-26 16:12:59 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

KVM: SVM: Skip OSVW MSR reads if current CPU doesn't support the feature

Browse Source 
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>
This commit is contained in:
Sean Christopherson 2025-11-13 15:14:20 -08:00
parent 3b7a320e49
commit a56444d5e7
1 changed files with 2 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
arch/x86/kvm/svm/svm.c
View File

@ -447,12 +447,8 @@ static void svm_init_os_visible_workarounds(void)
if (!osvw_len)
return;
if (!boot_cpu_has(X86_FEATURE_OSVW)) {
osvw_status = osvw_len = 0;
return;
}
if (native_read_msr_safe(MSR_AMD64_OSVW_ID_LENGTH, &len) ||
if (!this_cpu_has(X86_FEATURE_OSVW) ||
native_read_msr_safe(MSR_AMD64_OSVW_ID_LENGTH, &len) ||
native_read_msr_safe(MSR_AMD64_OSVW_STATUS, &status))
len = status = 0;