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.

upstream-status: backport

Change-Id: Ie2fc19108c3252f8a299b17aba16c14aa8d31ae8
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Yunhong Jiang <yunhong.jiang@linux.intel.com>

diff --git a/kernel/arch/x86/kvm/lapic.c b/kernel/arch/x86/kvm/lapic.c
index 20d9e9f..1e1e7eb 100644 (file)
--- a/kernel/arch/x86/kvm/lapic.c
+++ b/kernel/arch/x86/kvm/lapic.c
@@ -1258,6 +1258,36 @@ 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;
@@ -1304,32 +1334,7 @@ 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);
-               } else
-                       apic_timer_expired(apic);
-
-               local_irq_restore(flags);
+               start_sw_tscdeadline(apic);
        }
 }