[PATCH RT 1/4] Revert: KVM: lapic: mark LAPIC timer handler as irqsafe

[Steven Rostedt]

3.4.112-rt143-rc1 stable review patch.
If anyone has any objections, please let me know.

------------------

From: "Steven Rostedt (Red Hat)" <rost...@goodmis.org>

The whole patch was not backported correctly and causes allmodconfig to
fail.

Signed-off-by: Steven Rostedt <rost...@goodmis.org>
---
 arch/x86/kvm/lapic.c | 42 +++---------------------------------------
 1 file changed, 3 insertions(+), 39 deletions(-)

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index b6dffeacbe92..53454a6775bf 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -683,38 +683,8 @@ static void update_divide_count(struct kvm_lapic *apic)
                                   apic->divide_count);
 }
 
-
-static enum hrtimer_restart apic_timer_fn(struct hrtimer *data);
-
-static void apic_timer_expired(struct hrtimer *data)
-{
-       int ret, i = 0;
-       enum hrtimer_restart r;
-       struct kvm_timer *ktimer = container_of(data, struct kvm_timer, timer);
-
-       r = apic_timer_fn(data);
-
-       if (r == HRTIMER_RESTART) {
-               do {
-                       ret = hrtimer_start_expires(data, HRTIMER_MODE_ABS);
-                       if (ret == -ETIME)
-                               hrtimer_add_expires_ns(&ktimer->timer,
-                                                       ktimer->period);
-                       i++;
-               } while (ret == -ETIME && i < 10);
-
-               if (ret == -ETIME) {
-                       printk_once(KERN_ERR "%s: failed to reprogram timer\n",
-                              __func__);
-                       WARN_ON_ONCE(1);
-               }
-       }
-}
-
-
 static void start_apic_timer(struct kvm_lapic *apic)
 {
-       int ret;
        ktime_t now;
        atomic_set(&apic->lapic_timer.pending, 0);
 
@@ -744,11 +714,9 @@ static void start_apic_timer(struct kvm_lapic *apic)
                        }
                }
 
-               ret = hrtimer_start(&apic->lapic_timer.timer,
+               hrtimer_start(&apic->lapic_timer.timer,
                              ktime_add_ns(now, apic->lapic_timer.period),
                              HRTIMER_MODE_ABS);
-               if (ret == -ETIME)
-                       apic_timer_expired(&apic->lapic_timer.timer);
 
                apic_debug("%s: bus cycle is %" PRId64 "ns, now 0x%016"
                           PRIx64 ", "
@@ -778,10 +746,8 @@ static void start_apic_timer(struct kvm_lapic *apic)
                        ns = (tscdeadline - guest_tsc) * 1000000ULL;
                        do_div(ns, this_tsc_khz);
                }
-               ret = hrtimer_start(&apic->lapic_timer.timer,
+               hrtimer_start(&apic->lapic_timer.timer,
                        ktime_add_ns(now, ns), HRTIMER_MODE_ABS);
-               if (ret == -ETIME)
-                       apic_timer_expired(&apic->lapic_timer.timer);
 
                local_irq_restore(flags);
        }
@@ -1211,7 +1177,6 @@ int kvm_create_lapic(struct kvm_vcpu *vcpu)
        hrtimer_init(&apic->lapic_timer.timer, CLOCK_MONOTONIC,
                     HRTIMER_MODE_ABS);
        apic->lapic_timer.timer.function = kvm_timer_fn;
-       apic->lapic_timer.timer.irqsafe = 1;
        apic->lapic_timer.t_ops = &lapic_timer_ops;
        apic->lapic_timer.kvm = vcpu->kvm;
        apic->lapic_timer.vcpu = vcpu;
@@ -1309,8 +1274,7 @@ void __kvm_migrate_apic_timer(struct kvm_vcpu *vcpu)
 
        timer = &apic->lapic_timer.timer;
        if (hrtimer_cancel(timer))
-               if (hrtimer_start_expires(timer, HRTIMER_MODE_ABS) == -ETIME)
-                       apic_timer_expired(timer);
+               hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
 }
 
 void kvm_lapic_sync_from_vapic(struct kvm_vcpu *vcpu)
-- 
2.8.1