kvm: lapic: separate start_sw_tscdeadline from start_apic_timer

The function to start the tsc deadline timer virtualization will be used
also by the pre_block hook when we use the preemption timer; change it
to a separate function. No logic changes.

Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 31 insertions, 26 deletions

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index bbb5b283ff63..f1cf8a5ede11 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1313,6 +1313,36 @@ void wait_lapic_expire(struct kvm_vcpu *vcpu)
                 __delay(tsc_deadline - guest_tsc);
 }
 
+static void start_sw_tscdeadline(struct kvm_lapic *apic)
+{
+        u64 guest_tsc, tscdeadline = apic->lapic_timer.tscdeadline;
+        u64 ns = 0;
+        ktime_t expire;
+        struct kvm_vcpu *vcpu = apic->vcpu;
+        unsigned long this_tsc_khz = vcpu->arch.virtual_tsc_khz;
+        unsigned long flags;
+        ktime_t now;
+
+        if (unlikely(!tscdeadline || !this_tsc_khz))
+                return;
+
+        local_irq_save(flags);
+
+        now = apic->lapic_timer.timer.base->get_time();
+        guest_tsc = kvm_read_l1_tsc(vcpu, rdtsc());
+        if (likely(tscdeadline > guest_tsc)) {
+                ns = (tscdeadline - guest_tsc) * 1000000ULL;
+                do_div(ns, this_tsc_khz);
+                expire = ktime_add_ns(now, ns);
+                expire = ktime_sub_ns(expire, lapic_timer_advance_ns);
+                hrtimer_start(&apic->lapic_timer.timer,
+                                expire, HRTIMER_MODE_ABS_PINNED);
+        } else
+                apic_timer_expired(apic);
+
+        local_irq_restore(flags);
+}
+
 static void start_apic_timer(struct kvm_lapic *apic)
 {
         ktime_t now;
@@ -1359,32 +1389,7 @@ static void start_apic_timer(struct kvm_lapic *apic)
                            ktime_to_ns(ktime_add_ns(now,
                                         apic->lapic_timer.period)));
         } else if (apic_lvtt_tscdeadline(apic)) {
-                /* lapic timer in tsc deadline mode */
-                u64 guest_tsc, tscdeadline = apic->lapic_timer.tscdeadline;
-                u64 ns = 0;
-                ktime_t expire;
-                struct kvm_vcpu *vcpu = apic->vcpu;
-                unsigned long this_tsc_khz = vcpu->arch.virtual_tsc_khz;
-                unsigned long flags;
-
-                if (unlikely(!tscdeadline || !this_tsc_khz))
-                        return;
-
-                local_irq_save(flags);
-
-                now = apic->lapic_timer.timer.base->get_time();
-                guest_tsc = kvm_read_l1_tsc(vcpu, rdtsc());
-                if (likely(tscdeadline > guest_tsc)) {
-                        ns = (tscdeadline - guest_tsc) * 1000000ULL;
-                        do_div(ns, this_tsc_khz);
-                        expire = ktime_add_ns(now, ns);
-                        expire = ktime_sub_ns(expire, lapic_timer_advance_ns);
-                        hrtimer_start(&apic->lapic_timer.timer,
-                                      expire, HRTIMER_MODE_ABS_PINNED);
-                } else
-                        apic_timer_expired(apic);
-
-                local_irq_restore(flags);
+                start_sw_tscdeadline(apic);
         }
 }