KVM: ia64: Don't hold slots_lock in guest mode
Reorder locking to avoid holding the slots_lock when entering
the guest.
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 3bf0a34..f127fb7 100644
--- a/arch/ia64/kvm/kvm-ia64.c
+++ b/arch/ia64/kvm/kvm-ia64.c
@@ -632,34 +632,22 @@
vti_set_rr6(vcpu->arch.vmm_rr);
return kvm_insert_vmm_mapping(vcpu);
}
+
static void kvm_vcpu_post_transition(struct kvm_vcpu *vcpu)
{
kvm_purge_vmm_mapping(vcpu);
vti_set_rr6(vcpu->arch.host_rr6);
}
-static int vti_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
+static int __vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
union context *host_ctx, *guest_ctx;
int r;
- /*Get host and guest context with guest address space.*/
- host_ctx = kvm_get_host_context(vcpu);
- guest_ctx = kvm_get_guest_context(vcpu);
-
- r = kvm_vcpu_pre_transition(vcpu);
- if (r < 0)
- goto out;
- kvm_vmm_info->tramp_entry(host_ctx, guest_ctx);
- kvm_vcpu_post_transition(vcpu);
- r = 0;
-out:
- return r;
-}
-
-static int __vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
-{
- int r;
+ /*
+ * down_read() may sleep and return with interrupts enabled
+ */
+ down_read(&vcpu->kvm->slots_lock);
again:
if (signal_pending(current)) {
@@ -668,23 +656,28 @@
goto out;
}
- /*
- * down_read() may sleep and return with interrupts enabled
- */
- down_read(&vcpu->kvm->slots_lock);
-
preempt_disable();
local_irq_disable();
+ /*Get host and guest context with guest address space.*/
+ host_ctx = kvm_get_host_context(vcpu);
+ guest_ctx = kvm_get_guest_context(vcpu);
+
vcpu->guest_mode = 1;
+
+ r = kvm_vcpu_pre_transition(vcpu);
+ if (r < 0)
+ goto vcpu_run_fail;
+
+ up_read(&vcpu->kvm->slots_lock);
kvm_guest_enter();
- r = vti_vcpu_run(vcpu, kvm_run);
- if (r < 0) {
- local_irq_enable();
- preempt_enable();
- kvm_run->exit_reason = KVM_EXIT_FAIL_ENTRY;
- goto out;
- }
+
+ /*
+ * Transition to the guest
+ */
+ kvm_vmm_info->tramp_entry(host_ctx, guest_ctx);
+
+ kvm_vcpu_post_transition(vcpu);
vcpu->arch.launched = 1;
vcpu->guest_mode = 0;
@@ -698,9 +691,10 @@
*/
barrier();
kvm_guest_exit();
- up_read(&vcpu->kvm->slots_lock);
preempt_enable();
+ down_read(&vcpu->kvm->slots_lock);
+
r = kvm_handle_exit(kvm_run, vcpu);
if (r > 0) {
@@ -709,12 +703,20 @@
}
out:
+ up_read(&vcpu->kvm->slots_lock);
if (r > 0) {
kvm_resched(vcpu);
+ down_read(&vcpu->kvm->slots_lock);
goto again;
}
return r;
+
+vcpu_run_fail:
+ local_irq_enable();
+ preempt_enable();
+ kvm_run->exit_reason = KVM_EXIT_FAIL_ENTRY;
+ goto out;
}
static void kvm_set_mmio_data(struct kvm_vcpu *vcpu)