KVM: svm: writes to MSR_K7_HWCR generates GPE in guest

Since commit 575203 the MCE subsystem in the Linux kernel for AMD sets bit 18
in MSR_K7_HWCR. Running such a kernel as a guest in KVM on an AMD host results
in a GPE injected into the guest because kvm_set_msr_common returns 1. This
patch fixes this by masking bit 18 from the MSR value desired by the guest.

Signed-off-by: Matthias Lange <matthias.lange@kernkonzept.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index b13f3a3..7553530 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2035,6 +2035,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
                data &= ~(u64)0x40;     /* ignore flush filter disable */
                data &= ~(u64)0x100;    /* ignore ignne emulation enable */
                data &= ~(u64)0x8;      /* ignore TLB cache disable */
+               data &= ~(u64)0x40000;  /* ignore Mc status write enable */
                if (data != 0) {
                        vcpu_unimpl(vcpu, "unimplemented HWCR wrmsr: 0x%llx\n",
                                    data);