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authorJes Sorensen <jes@sgi.com>2009-04-09 16:38:14 +0200
committerAvi Kivity <avi@redhat.com>2009-04-22 13:52:09 +0300
commitd24d2c1cc4156102f9df9cd0425d58cabf955519 (patch)
tree8d487aa14b570e7d7fcebb566ab785850d28dd4b /arch/ia64/kvm
parent99894a799f09cf9e28296bb16e75bd5830fd2c4e (diff)
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 <jes@sgi.com> Acked-by: Xiantao Zhang <xiantao.zhang@intel.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch/ia64/kvm')
-rw-r--r--arch/ia64/kvm/kvm-ia64.c14
1 files changed, 8 insertions, 6 deletions
diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
index 28af6a731bb8..d20a5db4c4dd 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();