From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tomas Papan , Paolo Bonzini , Gleb Natapov Subject: [ 001/102] KVM: VMX: fix halt emulation while emulating invalid guest sate Date: Fri, 17 May 2013 14:35:16 -0700 Message-Id: <20130517213244.472625200@linuxfoundation.org> In-Reply-To: <20130517213244.277411019@linuxfoundation.org> References: <20130517213244.277411019@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Gleb Natapov commit 8d76c49e9ffeee839bc0b7a3278a23f99101263e upstream. The invalid guest state emulation loop does not check halt_request which causes 100% cpu loop while guest is in halt and in invalid state, but more serious issue is that this leaves halt_request set, so random instruction emulated by vm86 #GP exit can be interpreted as halt which causes guest hang. Fix both problems by handling halt_request in emulation loop. Reported-by: Tomas Papan Tested-by: Tomas Papan Reviewed-by: Paolo Bonzini Signed-off-by: Gleb Natapov Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/vmx.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -5197,6 +5197,12 @@ static int handle_invalid_guest_state(st return 0; } + if (vcpu->arch.halt_request) { + vcpu->arch.halt_request = 0; + ret = kvm_emulate_halt(vcpu); + goto out; + } + if (signal_pending(current)) goto out; if (need_resched())