lkml.org 
[lkml]   [2016]   [Oct]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 1/5] KVM: LAPIC: extract start_sw_period() to handle periodic/oneshot mode
Date
From: Wanpeng Li <wanpeng.li@hotmail.com>

Extract start_sw_period() to handle periodic/oneshot mode, it will be
used by later patch.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Yunhong Jiang <yunhong.jiang@intel.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
---
arch/x86/kvm/lapic.c | 89 +++++++++++++++++++++++++++-------------------------
1 file changed, 47 insertions(+), 42 deletions(-)

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 23b99f3..dad743e 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1347,6 +1347,50 @@ static void start_sw_tscdeadline(struct kvm_lapic *apic)
local_irq_restore(flags);
}

+static void start_sw_period(struct kvm_lapic *apic)
+{
+ ktime_t now;
+
+ /* lapic timer in oneshot or periodic mode */
+ now = apic->lapic_timer.timer.base->get_time();
+ apic->lapic_timer.period = (u64)kvm_lapic_get_reg(apic, APIC_TMICT)
+ * APIC_BUS_CYCLE_NS * apic->divide_count;
+
+ if (!apic->lapic_timer.period)
+ return;
+ /*
+ * Do not allow the guest to program periodic timers with small
+ * interval, since the hrtimers are not throttled by the host
+ * scheduler.
+ */
+ if (apic_lvtt_period(apic)) {
+ s64 min_period = min_timer_period_us * 1000LL;
+
+ if (apic->lapic_timer.period < min_period) {
+ pr_info_ratelimited(
+ "kvm: vcpu %i: requested %lld ns "
+ "lapic timer period limited to %lld ns\n",
+ apic->vcpu->vcpu_id,
+ apic->lapic_timer.period, min_period);
+ apic->lapic_timer.period = min_period;
+ }
+ }
+
+ hrtimer_start(&apic->lapic_timer.timer,
+ ktime_add_ns(now, apic->lapic_timer.period),
+ HRTIMER_MODE_ABS_PINNED);
+
+ apic_debug("%s: bus cycle is %" PRId64 "ns, now 0x%016"
+ PRIx64 ", "
+ "timer initial count 0x%x, period %lldns, "
+ "expire @ 0x%016" PRIx64 ".\n", __func__,
+ APIC_BUS_CYCLE_NS, ktime_to_ns(now),
+ kvm_lapic_get_reg(apic, APIC_TMICT),
+ apic->lapic_timer.period,
+ ktime_to_ns(ktime_add_ns(now,
+ apic->lapic_timer.period)));
+}
+
bool kvm_lapic_hv_timer_in_use(struct kvm_vcpu *vcpu)
{
if (!lapic_in_kernel(vcpu))
@@ -1424,50 +1468,11 @@ EXPORT_SYMBOL_GPL(kvm_lapic_switch_to_sw_timer);

static void start_apic_timer(struct kvm_lapic *apic)
{
- ktime_t now;
-
atomic_set(&apic->lapic_timer.pending, 0);

- if (apic_lvtt_period(apic) || apic_lvtt_oneshot(apic)) {
- /* lapic timer in oneshot or periodic mode */
- now = apic->lapic_timer.timer.base->get_time();
- apic->lapic_timer.period = (u64)kvm_lapic_get_reg(apic, APIC_TMICT)
- * APIC_BUS_CYCLE_NS * apic->divide_count;
-
- if (!apic->lapic_timer.period)
- return;
- /*
- * Do not allow the guest to program periodic timers with small
- * interval, since the hrtimers are not throttled by the host
- * scheduler.
- */
- if (apic_lvtt_period(apic)) {
- s64 min_period = min_timer_period_us * 1000LL;
-
- if (apic->lapic_timer.period < min_period) {
- pr_info_ratelimited(
- "kvm: vcpu %i: requested %lld ns "
- "lapic timer period limited to %lld ns\n",
- apic->vcpu->vcpu_id,
- apic->lapic_timer.period, min_period);
- apic->lapic_timer.period = min_period;
- }
- }
-
- hrtimer_start(&apic->lapic_timer.timer,
- ktime_add_ns(now, apic->lapic_timer.period),
- HRTIMER_MODE_ABS_PINNED);
-
- apic_debug("%s: bus cycle is %" PRId64 "ns, now 0x%016"
- PRIx64 ", "
- "timer initial count 0x%x, period %lldns, "
- "expire @ 0x%016" PRIx64 ".\n", __func__,
- APIC_BUS_CYCLE_NS, ktime_to_ns(now),
- kvm_lapic_get_reg(apic, APIC_TMICT),
- apic->lapic_timer.period,
- ktime_to_ns(ktime_add_ns(now,
- apic->lapic_timer.period)));
- } else if (apic_lvtt_tscdeadline(apic)) {
+ if (apic_lvtt_period(apic) || apic_lvtt_oneshot(apic))
+ start_sw_period(apic);
+ else if (apic_lvtt_tscdeadline(apic)) {
if (!(kvm_x86_ops->set_hv_timer && start_hv_tscdeadline(apic)))
start_sw_tscdeadline(apic);
}
--
1.9.1
\
 
 \ /
  Last update: 2016-10-17 09:47    [W:0.061 / U:3.348 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site