KVM: unify part of generic timer handling

Hide the internals of vcpu awakening / injection from the in-kernel
emulated timers. This makes future changes in this logic easier and
decreases the distance to more generic timer handling.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

diff --git a/arch/x86/kvm/Makefile b/arch/x86/kvm/Makefile
index d3ec292..b43c4ef 100644 (file)
--- a/arch/x86/kvm/Makefile
+++ b/arch/x86/kvm/Makefile
@@ -14,7 +14,7 @@ endif
 EXTRA_CFLAGS += -Ivirt/kvm -Iarch/x86/kvm
 
 kvm-objs := $(common-objs) x86.o mmu.o x86_emulate.o i8259.o irq.o lapic.o \
-       i8254.o
+       i8254.o timer.o
 obj-$(CONFIG_KVM) += kvm.o
 kvm-intel-objs = vmx.o
 obj-$(CONFIG_KVM_INTEL) += kvm-intel.o

diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c
index 09ae841..4e2e3f2 100644 (file)
--- a/arch/x86/kvm/i8254.c
+++ b/arch/x86/kvm/i8254.c
@@ -219,25 +219,6 @@ static void pit_latch_status(struct kvm *kvm, int channel)
        }
 }
 
-static int __pit_timer_fn(struct kvm_kpit_state *ps)
-{
-       struct kvm_vcpu *vcpu0 = ps->pit->kvm->vcpus[0];
-       struct kvm_kpit_timer *pt = &ps->pit_timer;
-
-       if (!atomic_inc_and_test(&pt->pending))
-               set_bit(KVM_REQ_PENDING_TIMER, &vcpu0->requests);
-
-       if (!pt->reinject)
-               atomic_set(&pt->pending, 1);
-
-       if (vcpu0 && waitqueue_active(&vcpu0->wq))
-               wake_up_interruptible(&vcpu0->wq);
-
-       hrtimer_add_expires_ns(&pt->timer, pt->period);
-
-       return (pt->period == 0 ? 0 : 1);
-}
-
 int pit_has_pending_timer(struct kvm_vcpu *vcpu)
 {
        struct kvm_pit *pit = vcpu->kvm->arch.vpit;
@@ -258,21 +239,6 @@ static void kvm_pit_ack_irq(struct kvm_irq_ack_notifier *kian)
        spin_unlock(&ps->inject_lock);
 }
 
-static enum hrtimer_restart pit_timer_fn(struct hrtimer *data)
-{
-       struct kvm_kpit_state *ps;
-       int restart_timer = 0;
-
-       ps = container_of(data, struct kvm_kpit_state, pit_timer.timer);
-
-       restart_timer = __pit_timer_fn(ps);
-
-       if (restart_timer)
-               return HRTIMER_RESTART;
-       else
-               return HRTIMER_NORESTART;
-}
-
 void __kvm_migrate_pit_timer(struct kvm_vcpu *vcpu)
 {
        struct kvm_pit *pit = vcpu->kvm->arch.vpit;
@@ -286,15 +252,26 @@ void __kvm_migrate_pit_timer(struct kvm_vcpu *vcpu)
                hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
 }
 
-static void destroy_pit_timer(struct kvm_kpit_timer *pt)
+static void destroy_pit_timer(struct kvm_timer *pt)
 {
        pr_debug("pit: execute del timer!\n");
        hrtimer_cancel(&pt->timer);
 }
 
+static bool kpit_is_periodic(struct kvm_timer *ktimer)
+{
+       struct kvm_kpit_state *ps = container_of(ktimer, struct kvm_kpit_state,
+                                                pit_timer);
+       return ps->is_periodic;
+}
+
+struct kvm_timer_ops kpit_ops = {
+       .is_periodic = kpit_is_periodic,
+};
+
 static void create_pit_timer(struct kvm_kpit_state *ps, u32 val, int is_period)
 {
-       struct kvm_kpit_timer *pt = &ps->pit_timer;
+       struct kvm_timer *pt = &ps->pit_timer;
        s64 interval;
 
        interval = muldiv64(val, NSEC_PER_SEC, KVM_PIT_FREQ);
@@ -304,7 +281,13 @@ static void create_pit_timer(struct kvm_kpit_state *ps, u32 val, int is_period)
        /* TODO The new value only affected after the retriggered */
        hrtimer_cancel(&pt->timer);
        pt->period = (is_period == 0) ? 0 : interval;
-       pt->timer.function = pit_timer_fn;
+       ps->is_periodic = is_period;
+
+       pt->timer.function = kvm_timer_fn;
+       pt->t_ops = &kpit_ops;
+       pt->kvm = ps->pit->kvm;
+       pt->vcpu_id = 0;
+
        atomic_set(&pt->pending, 0);
        ps->irq_ack = 1;
 

diff --git a/arch/x86/kvm/i8254.h b/arch/x86/kvm/i8254.h
index 521accf..bbd863f 100644 (file)
--- a/arch/x86/kvm/i8254.h
+++ b/arch/x86/kvm/i8254.h
@@ -3,14 +3,6 @@
 
 #include "iodev.h"
 
-struct kvm_kpit_timer {
-       struct hrtimer timer;
-       int irq;
-       s64 period; /* unit: ns */
-       atomic_t pending;
-       bool reinject;
-};
-
 struct kvm_kpit_channel_state {
        u32 count; /* can be 65536 */
        u16 latched_count;
@@ -29,7 +21,8 @@ struct kvm_kpit_channel_state {
 
 struct kvm_kpit_state {
        struct kvm_kpit_channel_state channels[3];
-       struct kvm_kpit_timer pit_timer;
+       struct kvm_timer pit_timer;
+       bool is_periodic;
        u32    speaker_data_on;
        struct mutex lock;
        struct kvm_pit *pit;

diff --git a/arch/x86/kvm/kvm_timer.h b/arch/x86/kvm/kvm_timer.h
new file mode 100644 (file)
index 0000000..26bd6ba
--- /dev/null
+++ b/arch/x86/kvm/kvm_timer.h
@@ -0,0 +1,18 @@
+
+struct kvm_timer {
+       struct hrtimer timer;
+       s64 period;                             /* unit: ns */
+       atomic_t pending;                       /* accumulated triggered timers */
+       bool reinject;
+       struct kvm_timer_ops *t_ops;
+       struct kvm *kvm;
+       int vcpu_id;
+};
+
+struct kvm_timer_ops {
+        bool (*is_periodic)(struct kvm_timer *);
+};
+
+
+enum hrtimer_restart kvm_timer_fn(struct hrtimer *data);
+

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index afc59b2..27ca43e 100644 (file)
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -528,12 +528,13 @@ static u32 apic_get_tmcct(struct kvm_lapic *apic)
        if (apic_get_reg(apic, APIC_TMICT) == 0)
                return 0;
 
-       remaining = hrtimer_expires_remaining(&apic->timer.dev);
+       remaining = hrtimer_expires_remaining(&apic->lapic_timer.timer);
        if (ktime_to_ns(remaining) < 0)
                remaining = ktime_set(0, 0);
 
-       ns = mod_64(ktime_to_ns(remaining), apic->timer.period);
-       tmcct = div64_u64(ns, (APIC_BUS_CYCLE_NS * apic->timer.divide_count));
+       ns = mod_64(ktime_to_ns(remaining), apic->lapic_timer.period);
+       tmcct = div64_u64(ns,
+                        (APIC_BUS_CYCLE_NS * apic->divide_count));
 
        return tmcct;
 }
@@ -620,25 +621,25 @@ static void update_divide_count(struct kvm_lapic *apic)
        tdcr = apic_get_reg(apic, APIC_TDCR);
        tmp1 = tdcr & 0xf;
        tmp2 = ((tmp1 & 0x3) | ((tmp1 & 0x8) >> 1)) + 1;
-       apic->timer.divide_count = 0x1 << (tmp2 & 0x7);
+       apic->divide_count = 0x1 << (tmp2 & 0x7);
 
        apic_debug("timer divide count is 0x%x\n",
-                                  apic->timer.divide_count);
+                                  apic->lapic_timer.divide_count);
 }
 
 static void start_apic_timer(struct kvm_lapic *apic)
 {
-       ktime_t now = apic->timer.dev.base->get_time();
+       ktime_t now = apic->lapic_timer.timer.base->get_time();
 
-       apic->timer.period = apic_get_reg(apic, APIC_TMICT) *
-                   APIC_BUS_CYCLE_NS * apic->timer.divide_count;
-       atomic_set(&apic->timer.pending, 0);
+       apic->lapic_timer.period = apic_get_reg(apic, APIC_TMICT) *
+                   APIC_BUS_CYCLE_NS * apic->divide_count;
+       atomic_set(&apic->lapic_timer.pending, 0);
 
-       if (!apic->timer.period)
+       if (!apic->lapic_timer.period)
                return;
 
-       hrtimer_start(&apic->timer.dev,
-                     ktime_add_ns(now, apic->timer.period),
+       hrtimer_start(&apic->lapic_timer.timer,
+                     ktime_add_ns(now, apic->lapic_timer.period),
                      HRTIMER_MODE_ABS);
 
        apic_debug("%s: bus cycle is %" PRId64 "ns, now 0x%016"
@@ -647,9 +648,9 @@ static void start_apic_timer(struct kvm_lapic *apic)
                           "expire @ 0x%016" PRIx64 ".\n", __func__,
                           APIC_BUS_CYCLE_NS, ktime_to_ns(now),
                           apic_get_reg(apic, APIC_TMICT),
-                          apic->timer.period,
+                          apic->lapic_timer.period,
                           ktime_to_ns(ktime_add_ns(now,
-                                       apic->timer.period)));
+                                       apic->lapic_timer.period)));
 }
 
 static void apic_manage_nmi_watchdog(struct kvm_lapic *apic, u32 lvt0_val)
@@ -731,7 +732,7 @@ static void apic_mmio_write(struct kvm_io_device *this,
                                apic_set_reg(apic, APIC_LVTT + 0x10 * i,
                                             lvt_val | APIC_LVT_MASKED);
                        }
-                       atomic_set(&apic->timer.pending, 0);
+                       atomic_set(&apic->lapic_timer.pending, 0);
 
                }
                break;
@@ -763,7 +764,7 @@ static void apic_mmio_write(struct kvm_io_device *this,
                break;
 
        case APIC_TMICT:
-               hrtimer_cancel(&apic->timer.dev);
+               hrtimer_cancel(&apic->lapic_timer.timer);
                apic_set_reg(apic, APIC_TMICT, val);
                start_apic_timer(apic);
                return;
@@ -803,7 +804,7 @@ void kvm_free_lapic(struct kvm_vcpu *vcpu)
        if (!vcpu->arch.apic)
                return;
 
-       hrtimer_cancel(&vcpu->arch.apic->timer.dev);
+       hrtimer_cancel(&vcpu->arch.apic->lapic_timer.timer);
 
        if (vcpu->arch.apic->regs_page)
                __free_page(vcpu->arch.apic->regs_page);
@@ -881,7 +882,7 @@ void kvm_lapic_reset(struct kvm_vcpu *vcpu)
        ASSERT(apic != NULL);
 
        /* Stop the timer in case it's a reset to an active apic */
-       hrtimer_cancel(&apic->timer.dev);
+       hrtimer_cancel(&apic->lapic_timer.timer);
 
        apic_set_reg(apic, APIC_ID, vcpu->vcpu_id << 24);
        apic_set_reg(apic, APIC_LVR, APIC_VERSION);
@@ -906,7 +907,7 @@ void kvm_lapic_reset(struct kvm_vcpu *vcpu)
                apic_set_reg(apic, APIC_TMR + 0x10 * i, 0);
        }
        update_divide_count(apic);
-       atomic_set(&apic->timer.pending, 0);
+       atomic_set(&apic->lapic_timer.pending, 0);
        if (vcpu->vcpu_id == 0)
                vcpu->arch.apic_base |= MSR_IA32_APICBASE_BSP;
        apic_update_ppr(apic);
@@ -937,22 +938,11 @@ EXPORT_SYMBOL_GPL(kvm_lapic_enabled);
  *----------------------------------------------------------------------
  */
 
-/* TODO: make sure __apic_timer_fn runs in current pCPU */
-static int __apic_timer_fn(struct kvm_lapic *apic)
+static bool lapic_is_periodic(struct kvm_timer *ktimer)
 {
-       int result = 0;
-       wait_queue_head_t *q = &apic->vcpu->wq;
-
-       if(!atomic_inc_and_test(&apic->timer.pending))
-               set_bit(KVM_REQ_PENDING_TIMER, &apic->vcpu->requests);
-       if (waitqueue_active(q))
-               wake_up_interruptible(q);
-
-       if (apic_lvtt_period(apic)) {
-               result = 1;
-               hrtimer_add_expires_ns(&apic->timer.dev, apic->timer.period);
-       }
-       return result;
+       struct kvm_lapic *apic = container_of(ktimer, struct kvm_lapic,
+                                             lapic_timer);
+       return apic_lvtt_period(apic);
 }
 
 int apic_has_pending_timer(struct kvm_vcpu *vcpu)
@@ -960,7 +950,7 @@ int apic_has_pending_timer(struct kvm_vcpu *vcpu)
        struct kvm_lapic *lapic = vcpu->arch.apic;
 
        if (lapic && apic_enabled(lapic) && apic_lvt_enabled(lapic, APIC_LVTT))
-               return atomic_read(&lapic->timer.pending);
+               return atomic_read(&lapic->lapic_timer.pending);
 
        return 0;
 }
@@ -987,20 +977,9 @@ void kvm_apic_nmi_wd_deliver(struct kvm_vcpu *vcpu)
                kvm_apic_local_deliver(apic, APIC_LVT0);
 }
 
-static enum hrtimer_restart apic_timer_fn(struct hrtimer *data)
-{
-       struct kvm_lapic *apic;
-       int restart_timer = 0;
-
-       apic = container_of(data, struct kvm_lapic, timer.dev);
-
-       restart_timer = __apic_timer_fn(apic);
-
-       if (restart_timer)
-               return HRTIMER_RESTART;
-       else
-               return HRTIMER_NORESTART;
-}
+struct kvm_timer_ops lapic_timer_ops = {
+       .is_periodic = lapic_is_periodic,
+};
 
 int kvm_create_lapic(struct kvm_vcpu *vcpu)
 {
@@ -1025,8 +1004,13 @@ int kvm_create_lapic(struct kvm_vcpu *vcpu)
        memset(apic->regs, 0, PAGE_SIZE);
        apic->vcpu = vcpu;
 
-       hrtimer_init(&apic->timer.dev, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
-       apic->timer.dev.function = apic_timer_fn;
+       hrtimer_init(&apic->lapic_timer.timer, CLOCK_MONOTONIC,
+                    HRTIMER_MODE_ABS);
+       apic->lapic_timer.timer.function = kvm_timer_fn;
+       apic->lapic_timer.t_ops = &lapic_timer_ops;
+       apic->lapic_timer.kvm = vcpu->kvm;
+       apic->lapic_timer.vcpu_id = vcpu->vcpu_id;
+
        apic->base_address = APIC_DEFAULT_PHYS_BASE;
        vcpu->arch.apic_base = APIC_DEFAULT_PHYS_BASE;
 
@@ -1079,9 +1063,9 @@ void kvm_inject_apic_timer_irqs(struct kvm_vcpu *vcpu)
 {
        struct kvm_lapic *apic = vcpu->arch.apic;
 
-       if (apic && atomic_read(&apic->timer.pending) > 0) {
+       if (apic && atomic_read(&apic->lapic_timer.pending) > 0) {
                if (kvm_apic_local_deliver(apic, APIC_LVTT))
-                       atomic_dec(&apic->timer.pending);
+                       atomic_dec(&apic->lapic_timer.pending);
        }
 }
 
@@ -1107,7 +1091,7 @@ void kvm_apic_post_state_restore(struct kvm_vcpu *vcpu)
                             MSR_IA32_APICBASE_BASE;
        apic_set_reg(apic, APIC_LVR, APIC_VERSION);
        apic_update_ppr(apic);
-       hrtimer_cancel(&apic->timer.dev);
+       hrtimer_cancel(&apic->lapic_timer.timer);
        update_divide_count(apic);
        start_apic_timer(apic);
 }
@@ -1120,7 +1104,7 @@ void __kvm_migrate_apic_timer(struct kvm_vcpu *vcpu)
        if (!apic)
                return;
 
-       timer = &apic->timer.dev;
+       timer = &apic->lapic_timer.timer;
        if (hrtimer_cancel(timer))
                hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
 }

diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
index 45ab6ee..2fc0d3c 100644 (file)
--- a/arch/x86/kvm/lapic.h
+++ b/arch/x86/kvm/lapic.h
@@ -2,18 +2,15 @@
 #define __KVM_X86_LAPIC_H
 
 #include "iodev.h"
+#include "kvm_timer.h"
 
 #include <linux/kvm_host.h>
 
 struct kvm_lapic {
        unsigned long base_address;
        struct kvm_io_device dev;
-       struct {
-               atomic_t pending;
-               s64 period;     /* unit: ns */
-               u32 divide_count;
-               struct hrtimer dev;
-       } timer;
+       struct kvm_timer lapic_timer;
+       u32 divide_count;
        struct kvm_vcpu *vcpu;
        struct page *regs_page;
        void *regs;

diff --git a/arch/x86/kvm/timer.c b/arch/x86/kvm/timer.c
new file mode 100644 (file)
index 0000000..86dbac0
--- /dev/null
+++ b/arch/x86/kvm/timer.c
@@ -0,0 +1,46 @@
+#include <linux/kvm_host.h>
+#include <linux/kvm.h>
+#include <linux/hrtimer.h>
+#include <asm/atomic.h>
+#include "kvm_timer.h"
+
+static int __kvm_timer_fn(struct kvm_vcpu *vcpu, struct kvm_timer *ktimer)
+{
+       int restart_timer = 0;
+       wait_queue_head_t *q = &vcpu->wq;
+
+       /* FIXME: this code should not know anything about vcpus */
+       if (!atomic_inc_and_test(&ktimer->pending))
+               set_bit(KVM_REQ_PENDING_TIMER, &vcpu->requests);
+
+       if (!ktimer->reinject)
+               atomic_set(&ktimer->pending, 1);
+
+       if (waitqueue_active(q))
+               wake_up_interruptible(q);
+
+       if (ktimer->t_ops->is_periodic(ktimer)) {
+               hrtimer_add_expires_ns(&ktimer->timer, ktimer->period);
+               restart_timer = 1;
+       }
+
+       return restart_timer;
+}
+
+enum hrtimer_restart kvm_timer_fn(struct hrtimer *data)
+{
+       int restart_timer;
+       struct kvm_vcpu *vcpu;
+       struct kvm_timer *ktimer = container_of(data, struct kvm_timer, timer);
+
+       vcpu = ktimer->kvm->vcpus[ktimer->vcpu_id];
+       if (!vcpu)
+               return HRTIMER_NORESTART;
+
+       restart_timer = __kvm_timer_fn(vcpu, ktimer);
+       if (restart_timer)
+               return HRTIMER_RESTART;
+       else
+               return HRTIMER_NORESTART;
+}
+