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>
diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
index d8f43e4..112b402 100644
--- a/arch/ia64/kvm/kvm-ia64.c
+++ b/arch/ia64/kvm/kvm-ia64.c
@@ -662,20 +662,22 @@
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();
