KVM: VMX: Fix exceptions of mov to dr
Injecting GP without an error code is a bad idea (causes unhandled guest
exits). Moreover, we must not skip the instruction if we injected an
exception.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 516084f..9727773 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -3045,6 +3045,7 @@
unsigned long val;
int dr, reg;
+ /* Do not handle if the CPL > 0, will trigger GP on re-entry */
if (!kvm_require_cpl(vcpu, 0))
return 1;
dr = vmcs_readl(GUEST_DR7);
@@ -3099,20 +3100,22 @@
vcpu->arch.eff_db[dr] = val;
break;
case 4 ... 5:
- if (kvm_read_cr4_bits(vcpu, X86_CR4_DE))
+ if (kvm_read_cr4_bits(vcpu, X86_CR4_DE)) {
kvm_queue_exception(vcpu, UD_VECTOR);
+ return 1;
+ }
break;
case 6:
if (val & 0xffffffff00000000ULL) {
- kvm_queue_exception(vcpu, GP_VECTOR);
- break;
+ kvm_inject_gp(vcpu, 0);
+ return 1;
}
vcpu->arch.dr6 = (val & DR6_VOLATILE) | DR6_FIXED_1;
break;
case 7:
if (val & 0xffffffff00000000ULL) {
- kvm_queue_exception(vcpu, GP_VECTOR);
- break;
+ kvm_inject_gp(vcpu, 0);
+ return 1;
}
vcpu->arch.dr7 = (val & DR7_VOLATILE) | DR7_FIXED_1;
if (!(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)) {