KVM: Move apic timer migration away from critical section

Migrating the apic timer in the critical section is not very nice, and is
absolutely horrible with the real-time port.  Move migration to the regular
vcpu execution path, triggered by a new bitflag.

Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index f0493e7dcf0c..8f94a0b89dff 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2518,13 +2518,16 @@ again:
         if (unlikely(r))
                 goto out;
 
-        if (vcpu->requests)
+        if (vcpu->requests) {
+                if (test_and_clear_bit(KVM_REQ_MIGRATE_TIMER, &vcpu->requests))
+                        __kvm_migrate_apic_timer(vcpu);
                 if (test_and_clear_bit(KVM_REQ_REPORT_TPR_ACCESS,
                                        &vcpu->requests)) {
                         kvm_run->exit_reason = KVM_EXIT_TPR_ACCESS;
                         r = 0;
                         goto out;
                 }
+        }
 
         kvm_inject_pending_timer_irqs(vcpu);