Commit 8d76c49e authored May 08, 2013 by Gleb Natapov

KVM: VMX: fix halt emulation while emulating invalid guest sate



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 <tomas.papan@gmail.com>
Tested-by: Tomas Papan <tomas.papan@gmail.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
CC: stable@vger.kernel.org
Signed-off-by: Gleb Natapov <gleb@redhat.com>

parent 7dac16c3

arch/x86/kvm/vmx.c

+6 −0

Original line number	Original line	Diff line number	Diff line
	@@ -5434,6 +5434,12 @@ static int handle_invalid_guest_state(struct kvm_vcpu *vcpu)
	return 0;		return 0;
	}		}

			if (vcpu->arch.halt_request) {
			vcpu->arch.halt_request = 0;
			ret = kvm_emulate_halt(vcpu);
			goto out;
			}

	if (signal_pending(current))		if (signal_pending(current))
	goto out;		goto out;
	if (need_resched())		if (need_resched())