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

Steven Rostedt
2016-07-12T19:55:23Z

[-- Attachment #1: 0001-Revert-KVM-lapic-mark-LAPIC-timer-handler-as-irqsafe.patch --]
[-- Type: text/plain, Size: 3003 bytes --]

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

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

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

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

Signed-off-by: Steven Rostedt <rostedt@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