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authorRoedel, Joerg <Joerg.Roedel@amd.com>2010-05-06 13:38:43 +0400
committerAvi Kivity <avi@redhat.com>2010-05-19 12:36:39 +0400
commitb69e8caef5b190af48c525f6d715e7b7728a77f6 (patch)
tree102d0728a1c8ae0b698e6f746cd40a67dfc2db94 /arch/x86
parent0d945bd9351199744c1e89d57a70615b6ee9f394 (diff)
downloadlinux-b69e8caef5b190af48c525f6d715e7b7728a77f6.tar.xz
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>
Diffstat (limited to 'arch/x86')
-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 161ede2b5f91..fe6d126633d8 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -683,37 +683,29 @@ 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;
}
kvm_x86_ops->set_efer(vcpu, efer);
@@ -725,6 +717,8 @@ 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)
@@ -1153,8 +1147,7 @@ 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 */
data &= ~(u64)0x100; /* ignore ignne emulation enable */