diff options
| author | Jim Mattson <jmattson@google.com> | 2026-02-11 02:45:42 +0300 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2026-03-03 03:01:44 +0300 |
| commit | 690dc03859e7907bc995f389618c748619559477 (patch) | |
| tree | b06dab846e6cb1dfb2cc2e0629c7db53ad2d87af | |
| parent | e907b4e72488f1df878e7e8acf88d23e49cb3ca7 (diff) | |
| download | linux-690dc03859e7907bc995f389618c748619559477.tar.xz | |
KVM: x86: Ignore cpuid faulting in SMM
The Intel Virtualization Technology FlexMigration Application Note says,
"When CPUID faulting is enabled, all executions of the CPUID instruction
outside system-management mode (SMM) cause a general-protection exception
(#GP(0)) if the current privilege level (CPL) is greater than 0."
Always allow the execution of CPUID in SMM.
Fixes: db2336a80489 ("KVM: x86: virtualize cpuid faulting")
Signed-off-by: Jim Mattson <jmattson@google.com>
Link: https://patch.msgid.link/20260210234613.1383279-1-jmattson@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
| -rw-r--r-- | arch/x86/kvm/cpuid.c | 3 | ||||
| -rw-r--r-- | arch/x86/kvm/emulate.c | 6 |
2 files changed, 5 insertions, 4 deletions
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index d2486506a808..baf9a2860d98 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -2157,7 +2157,8 @@ int kvm_emulate_cpuid(struct kvm_vcpu *vcpu) { u32 eax, ebx, ecx, edx; - if (cpuid_fault_enabled(vcpu) && !kvm_require_cpl(vcpu, 0)) + if (!is_smm(vcpu) && cpuid_fault_enabled(vcpu) && + !kvm_require_cpl(vcpu, 0)) return 1; eax = kvm_rax_read(vcpu); diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 20ed588015f1..500711c6f069 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -3583,10 +3583,10 @@ static int em_cpuid(struct x86_emulate_ctxt *ctxt) u64 msr = 0; ctxt->ops->get_msr(ctxt, MSR_MISC_FEATURES_ENABLES, &msr); - if (msr & MSR_MISC_FEATURES_ENABLES_CPUID_FAULT && - ctxt->ops->cpl(ctxt)) { + if (!ctxt->ops->is_smm(ctxt) && + (msr & MSR_MISC_FEATURES_ENABLES_CPUID_FAULT) && + ctxt->ops->cpl(ctxt)) return emulate_gp(ctxt, 0); - } eax = reg_read(ctxt, VCPU_REGS_RAX); ecx = reg_read(ctxt, VCPU_REGS_RCX); |