From d24d2c1cc4156102f9df9cd0425d58cabf955519 Mon Sep 17 00:00:00 2001 From: Jes Sorensen Date: Thu, 9 Apr 2009 16:38:14 +0200 Subject: [PATCH] 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: Jes Sorensen Acked-by: Xiantao Zhang Signed-off-by: Avi Kivity --- arch/ia64/kvm/kvm-ia64.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c index 28af6a731bb..d20a5db4c4d 100644 --- a/arch/ia64/kvm/kvm-ia64.c +++ b/arch/ia64/kvm/kvm-ia64.c @@ -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(); -- 2.39.3