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authorJoerg Roedel <joerg.roedel@amd.com>2010-05-06 11:38:43 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2010-07-05 11:23:05 -0700
commitce9fea841204616bc21fe42bdfbd60db8ae12d9e (patch)
tree6b5a61c6c859d09d14e427064cc5dcb9747d3426
parent8d3c865a11cc027bee53985237e12b086a6d7f41 (diff)
KVM: x86: Inject #GP with the right rip on efer writes
This patch fixes a bug in the KVM efer-msr write path. If a guest writes to a reserved efer bit the set_efer function injects the #GP directly. The architecture dependent wrmsr function does not see this, assumes success and advances the rip. This results in a #GP in the guest with the wrong rip. This patch fixes this by reporting efer write errors back to the architectural wrmsr function. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> (Cherry-picked from commit b69e8caef5b190af48c525f6d715e7b7728a77f6)
-rw-r--r--arch/x86/kvm/x86.c31
1 files changed, 12 insertions, 19 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 5b66418a7cdb..a6517a28fc34 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -624,37 +624,29 @@ static u32 emulated_msrs[] = {
MSR_IA32_MISC_ENABLE,
};
-static void set_efer(struct kvm_vcpu *vcpu, u64 efer)
+static int set_efer(struct kvm_vcpu *vcpu, u64 efer)
{
- if (efer & efer_reserved_bits) {
- kvm_inject_gp(vcpu, 0);
- return;
- }
+ if (efer & efer_reserved_bits)
+ return 1;
if (is_paging(vcpu)
- && (vcpu->arch.efer & EFER_LME) != (efer & EFER_LME)) {
- kvm_inject_gp(vcpu, 0);
- return;
- }
+ && (vcpu->arch.efer & EFER_LME) != (efer & EFER_LME))
+ return 1;
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))) {
- kvm_inject_gp(vcpu, 0);
- return;
- }
+ if (!feat || !(feat->edx & bit(X86_FEATURE_FXSR_OPT)))
+ return 1;
}
if (efer & EFER_SVME) {
struct kvm_cpuid_entry2 *feat;
feat = kvm_find_cpuid_entry(vcpu, 0x80000001, 0);
- if (!feat || !(feat->ecx & bit(X86_FEATURE_SVM))) {
- kvm_inject_gp(vcpu, 0);
- return;
- }
+ if (!feat || !(feat->ecx & bit(X86_FEATURE_SVM)))
+ return 1;
}
efer &= ~EFER_LMA;
@@ -666,6 +658,8 @@ static void set_efer(struct kvm_vcpu *vcpu, u64 efer)
vcpu->arch.mmu.base_role.nxe = (efer & EFER_NX) && !tdp_enabled;
kvm_mmu_reset_context(vcpu);
+
+ return 0;
}
void kvm_enable_efer_bits(u64 mask)
@@ -1094,8 +1088,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data)
{
switch (msr) {
case MSR_EFER:
- set_efer(vcpu, data);
- break;
+ return set_efer(vcpu, data);
case MSR_K7_HWCR:
data &= ~(u64)0x40; /* ignore flush filter disable */
if (data != 0) {