KVM: ia64: fix locking order entering guest (d24d2c1c) · Commits · 戴 / test

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:

Jes Sorensen <jes@sgi.com> Acked-by:

Xiantao Zhang <xiantao.zhang@intel.com> Signed-off-by:

Avi Kivity <avi@redhat.com>

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();

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