From 8b3c3104c3f4f706e99365c3e0d2aa61b95f969f Mon Sep 17 00:00:00 2001 From: Andy Honig Date: Wed, 27 Aug 2014 11:16:44 -0700 Subject: KVM: x86: Prevent host from panicking on shared MSR writes. The previous patch blocked invalid writes directly when the MSR is written. As a precaution, prevent future similar mistakes by gracefulling handle GPs caused by writes to shared MSRs. Cc: stable@vger.kernel.org Signed-off-by: Andrew Honig [Remove parts obsoleted by Nadav's patch. - Paolo] Signed-off-by: Paolo Bonzini --- arch/x86/kvm/vmx.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'arch/x86/kvm/vmx.c') diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 148020a7dd98..7e2c098b59c9 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2659,12 +2659,15 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) default: msr = find_msr_entry(vmx, msr_index); if (msr) { + u64 old_msr_data = msr->data; msr->data = data; if (msr - vmx->guest_msrs < vmx->save_nmsrs) { preempt_disable(); - kvm_set_shared_msr(msr->index, msr->data, - msr->mask); + ret = kvm_set_shared_msr(msr->index, msr->data, + msr->mask); preempt_enable(); + if (ret) + msr->data = old_msr_data; } break; } -- cgit v1.2.3