KVM: nVMX: Validate EFER values for VM_ENTRY/EXIT_LOAD_IA32_EFER
As we may emulate the loading of EFER on VM-entry and VM-exit, implement
the checks that VMX performs on the guest and host values on vmlaunch/
vmresume. Factor out kvm_valid_efer for this purpose which checks for
set reserved bits.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index e730a46..2a434bf 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -845,23 +845,17 @@
MSR_IA32_MCG_CTL,
};
-static int set_efer(struct kvm_vcpu *vcpu, u64 efer)
+bool kvm_valid_efer(struct kvm_vcpu *vcpu, u64 efer)
{
- u64 old_efer = vcpu->arch.efer;
-
if (efer & efer_reserved_bits)
- return 1;
-
- if (is_paging(vcpu)
- && (vcpu->arch.efer & EFER_LME) != (efer & EFER_LME))
- return 1;
+ return false;
if (efer & EFER_FFXSR) {
struct kvm_cpuid_entry2 *feat;
feat = kvm_find_cpuid_entry(vcpu, 0x80000001, 0);
if (!feat || !(feat->edx & bit(X86_FEATURE_FXSR_OPT)))
- return 1;
+ return false;
}
if (efer & EFER_SVME) {
@@ -869,9 +863,24 @@
feat = kvm_find_cpuid_entry(vcpu, 0x80000001, 0);
if (!feat || !(feat->ecx & bit(X86_FEATURE_SVM)))
- return 1;
+ return false;
}
+ return true;
+}
+EXPORT_SYMBOL_GPL(kvm_valid_efer);
+
+static int set_efer(struct kvm_vcpu *vcpu, u64 efer)
+{
+ u64 old_efer = vcpu->arch.efer;
+
+ if (!kvm_valid_efer(vcpu, efer))
+ return 1;
+
+ if (is_paging(vcpu)
+ && (vcpu->arch.efer & EFER_LME) != (efer & EFER_LME))
+ return 1;
+
efer &= ~EFER_LMA;
efer |= vcpu->arch.efer & EFER_LMA;