KVM: LAPIC: extract start_sw_period() to handle periodic/oneshot mode

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>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 23b99f3053825d40c6d697cf8c58dfb4ae941208..dad743e3c1f532f431c93da7b43795fb7cc4e3cc 100644 (file)
--- 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);
        }