Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit d24d2c1c authored by Jes Sorensen's avatar Jes Sorensen Committed by Avi Kivity
Browse files

KVM: ia64: fix locking order entering guest 



Reorder locking as down_read() may return with local interrupts enabled,
which means we could go into vti_vcpu_run() with interrupts enabled.

This caused random crashes on the Altix as the timer interrupt tried
to read a memory mapped clock source, for which the TLB had not yet been
reinstated in the exit, before ipsr was retored.

Signed-off-by: default avatarJes Sorensen <jes@sgi.com>
Acked-by: default avatarXiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 99894a79

arch/ia64/kvm/kvm-ia64.c

+8 −6
Original line number Diff line number Diff line
@@ -610,20 +610,22 @@ static int __vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 
	int r;



again:

	preempt_disable();

	local_irq_disable();



	if (signal_pending(current)) {

		local_irq_enable();

		preempt_enable();

		r = -EINTR;

		kvm_run->exit_reason = KVM_EXIT_INTR;

		goto out;

	}



	/*

	 * down_read() may sleep and return with interrupts enabled

	 */

	down_read(&vcpu->kvm->slots_lock);



	preempt_disable();

	local_irq_disable();



	vcpu->guest_mode = 1;

	kvm_guest_enter();

	down_read(&vcpu->kvm->slots_lock);

	r = vti_vcpu_run(vcpu, kvm_run);

	if (r < 0) {

		local_irq_enable();