From 7275acdfe29ba03ad2f6e150386900c4e2d43fb1 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 14 May 2013 14:31:01 +0100 Subject: ARM: KVM: move GIC/timer code to a common location As KVM/arm64 is looming on the horizon, it makes sense to move some of the common code to a single location in order to reduce duplication. The code could live anywhere. Actually, most of KVM is already built with a bunch of ugly ../../.. hacks in the various Makefiles, so we're not exactly talking about style here. But maybe it is time to start moving into a less ugly direction. The include files must be in a "public" location, as they are accessed from non-KVM files (arch/arm/kernel/asm-offsets.c). For this purpose, introduce two new locations: - virt/kvm/arm/ : x86 and ia64 already share the ioapic code in virt/kvm, so this could be seen as a (very ugly) precedent. - include/kvm/ : there is already an include/xen, and while the intent is slightly different, this seems as good a location as any Eventually, we should probably have independant Makefiles at every levels (just like everywhere else in the kernel), but this is just the first step. Signed-off-by: Marc Zyngier Signed-off-by: Gleb Natapov --- virt/kvm/arm/arch_timer.c | 272 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 272 insertions(+) create mode 100644 virt/kvm/arm/arch_timer.c (limited to 'virt/kvm/arm/arch_timer.c') diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c new file mode 100644 index 000000000000..2d00b2925780 --- /dev/null +++ b/virt/kvm/arm/arch_timer.c @@ -0,0 +1,272 @@ +/* + * Copyright (C) 2012 ARM Ltd. + * Author: Marc Zyngier + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include +#include +#include +#include +#include + +#include +#include + +#include +#include + +static struct timecounter *timecounter; +static struct workqueue_struct *wqueue; +static struct kvm_irq_level timer_irq = { + .level = 1, +}; + +static cycle_t kvm_phys_timer_read(void) +{ + return timecounter->cc->read(timecounter->cc); +} + +static bool timer_is_armed(struct arch_timer_cpu *timer) +{ + return timer->armed; +} + +/* timer_arm: as in "arm the timer", not as in ARM the company */ +static void timer_arm(struct arch_timer_cpu *timer, u64 ns) +{ + timer->armed = true; + hrtimer_start(&timer->timer, ktime_add_ns(ktime_get(), ns), + HRTIMER_MODE_ABS); +} + +static void timer_disarm(struct arch_timer_cpu *timer) +{ + if (timer_is_armed(timer)) { + hrtimer_cancel(&timer->timer); + cancel_work_sync(&timer->expired); + timer->armed = false; + } +} + +static void kvm_timer_inject_irq(struct kvm_vcpu *vcpu) +{ + struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; + + timer->cntv_ctl |= ARCH_TIMER_CTRL_IT_MASK; + kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id, + vcpu->arch.timer_cpu.irq->irq, + vcpu->arch.timer_cpu.irq->level); +} + +static irqreturn_t kvm_arch_timer_handler(int irq, void *dev_id) +{ + struct kvm_vcpu *vcpu = *(struct kvm_vcpu **)dev_id; + + /* + * We disable the timer in the world switch and let it be + * handled by kvm_timer_sync_hwstate(). Getting a timer + * interrupt at this point is a sure sign of some major + * breakage. + */ + pr_warn("Unexpected interrupt %d on vcpu %p\n", irq, vcpu); + return IRQ_HANDLED; +} + +static void kvm_timer_inject_irq_work(struct work_struct *work) +{ + struct kvm_vcpu *vcpu; + + vcpu = container_of(work, struct kvm_vcpu, arch.timer_cpu.expired); + vcpu->arch.timer_cpu.armed = false; + kvm_timer_inject_irq(vcpu); +} + +static enum hrtimer_restart kvm_timer_expire(struct hrtimer *hrt) +{ + struct arch_timer_cpu *timer; + timer = container_of(hrt, struct arch_timer_cpu, timer); + queue_work(wqueue, &timer->expired); + return HRTIMER_NORESTART; +} + +/** + * kvm_timer_flush_hwstate - prepare to move the virt timer to the cpu + * @vcpu: The vcpu pointer + * + * Disarm any pending soft timers, since the world-switch code will write the + * virtual timer state back to the physical CPU. + */ +void kvm_timer_flush_hwstate(struct kvm_vcpu *vcpu) +{ + struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; + + /* + * We're about to run this vcpu again, so there is no need to + * keep the background timer running, as we're about to + * populate the CPU timer again. + */ + timer_disarm(timer); +} + +/** + * kvm_timer_sync_hwstate - sync timer state from cpu + * @vcpu: The vcpu pointer + * + * Check if the virtual timer was armed and either schedule a corresponding + * soft timer or inject directly if already expired. + */ +void kvm_timer_sync_hwstate(struct kvm_vcpu *vcpu) +{ + struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; + cycle_t cval, now; + u64 ns; + + if ((timer->cntv_ctl & ARCH_TIMER_CTRL_IT_MASK) || + !(timer->cntv_ctl & ARCH_TIMER_CTRL_ENABLE)) + return; + + cval = timer->cntv_cval; + now = kvm_phys_timer_read() - vcpu->kvm->arch.timer.cntvoff; + + BUG_ON(timer_is_armed(timer)); + + if (cval <= now) { + /* + * Timer has already expired while we were not + * looking. Inject the interrupt and carry on. + */ + kvm_timer_inject_irq(vcpu); + return; + } + + ns = cyclecounter_cyc2ns(timecounter->cc, cval - now); + timer_arm(timer, ns); +} + +void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu) +{ + struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; + + INIT_WORK(&timer->expired, kvm_timer_inject_irq_work); + hrtimer_init(&timer->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); + timer->timer.function = kvm_timer_expire; + timer->irq = &timer_irq; +} + +static void kvm_timer_init_interrupt(void *info) +{ + enable_percpu_irq(timer_irq.irq, 0); +} + + +static int kvm_timer_cpu_notify(struct notifier_block *self, + unsigned long action, void *cpu) +{ + switch (action) { + case CPU_STARTING: + case CPU_STARTING_FROZEN: + kvm_timer_init_interrupt(NULL); + break; + case CPU_DYING: + case CPU_DYING_FROZEN: + disable_percpu_irq(timer_irq.irq); + break; + } + + return NOTIFY_OK; +} + +static struct notifier_block kvm_timer_cpu_nb = { + .notifier_call = kvm_timer_cpu_notify, +}; + +static const struct of_device_id arch_timer_of_match[] = { + { .compatible = "arm,armv7-timer", }, + {}, +}; + +int kvm_timer_hyp_init(void) +{ + struct device_node *np; + unsigned int ppi; + int err; + + timecounter = arch_timer_get_timecounter(); + if (!timecounter) + return -ENODEV; + + np = of_find_matching_node(NULL, arch_timer_of_match); + if (!np) { + kvm_err("kvm_arch_timer: can't find DT node\n"); + return -ENODEV; + } + + ppi = irq_of_parse_and_map(np, 2); + if (!ppi) { + kvm_err("kvm_arch_timer: no virtual timer interrupt\n"); + err = -EINVAL; + goto out; + } + + err = request_percpu_irq(ppi, kvm_arch_timer_handler, + "kvm guest timer", kvm_get_running_vcpus()); + if (err) { + kvm_err("kvm_arch_timer: can't request interrupt %d (%d)\n", + ppi, err); + goto out; + } + + timer_irq.irq = ppi; + + err = register_cpu_notifier(&kvm_timer_cpu_nb); + if (err) { + kvm_err("Cannot register timer CPU notifier\n"); + goto out_free; + } + + wqueue = create_singlethread_workqueue("kvm_arch_timer"); + if (!wqueue) { + err = -ENOMEM; + goto out_free; + } + + kvm_info("%s IRQ%d\n", np->name, ppi); + on_each_cpu(kvm_timer_init_interrupt, NULL, 1); + + goto out; +out_free: + free_percpu_irq(ppi, kvm_get_running_vcpus()); +out: + of_node_put(np); + return err; +} + +void kvm_timer_vcpu_terminate(struct kvm_vcpu *vcpu) +{ + struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; + + timer_disarm(timer); +} + +int kvm_timer_init(struct kvm *kvm) +{ + if (timecounter && wqueue) { + kvm->arch.timer.cntvoff = kvm_phys_timer_read(); + kvm->arch.timer.enabled = 1; + } + + return 0; +} -- cgit v1.2.1 From 5ae7f87a56fab10b8f9b135a8377c144397293ca Mon Sep 17 00:00:00 2001 From: Anup Patel Date: Tue, 30 Apr 2013 12:02:15 +0530 Subject: ARM: KVM: Allow host virt timer irq to be different from guest timer virt irq The arch_timer irq numbers (or PPI numbers) are implementation dependent, so the host virtual timer irq number can be different from guest virtual timer irq number. This patch ensures that host virtual timer irq number is read from DTB and guest virtual timer irq is determined based on vcpu target type. Signed-off-by: Anup Patel Signed-off-by: Pranavkumar Sawargaonkar Signed-off-by: Christoffer Dall --- virt/kvm/arm/arch_timer.c | 29 ++++++++++++++++++++--------- 1 file changed, 20 insertions(+), 9 deletions(-) (limited to 'virt/kvm/arm/arch_timer.c') diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c index 2d00b2925780..af4583e2c185 100644 --- a/virt/kvm/arm/arch_timer.c +++ b/virt/kvm/arm/arch_timer.c @@ -30,9 +30,7 @@ static struct timecounter *timecounter; static struct workqueue_struct *wqueue; -static struct kvm_irq_level timer_irq = { - .level = 1, -}; +static unsigned int host_vtimer_irq; static cycle_t kvm_phys_timer_read(void) { @@ -67,8 +65,8 @@ static void kvm_timer_inject_irq(struct kvm_vcpu *vcpu) timer->cntv_ctl |= ARCH_TIMER_CTRL_IT_MASK; kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id, - vcpu->arch.timer_cpu.irq->irq, - vcpu->arch.timer_cpu.irq->level); + timer->irq->irq, + timer->irq->level); } static irqreturn_t kvm_arch_timer_handler(int irq, void *dev_id) @@ -156,6 +154,20 @@ void kvm_timer_sync_hwstate(struct kvm_vcpu *vcpu) timer_arm(timer, ns); } +void kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu, + const struct kvm_irq_level *irq) +{ + struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; + + /* + * The vcpu timer irq number cannot be determined in + * kvm_timer_vcpu_init() because it is called much before + * kvm_vcpu_set_target(). To handle this, we determine + * vcpu timer irq number when the vcpu is reset. + */ + timer->irq = irq; +} + void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu) { struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; @@ -163,12 +175,11 @@ void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu) INIT_WORK(&timer->expired, kvm_timer_inject_irq_work); hrtimer_init(&timer->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); timer->timer.function = kvm_timer_expire; - timer->irq = &timer_irq; } static void kvm_timer_init_interrupt(void *info) { - enable_percpu_irq(timer_irq.irq, 0); + enable_percpu_irq(host_vtimer_irq, 0); } @@ -182,7 +193,7 @@ static int kvm_timer_cpu_notify(struct notifier_block *self, break; case CPU_DYING: case CPU_DYING_FROZEN: - disable_percpu_irq(timer_irq.irq); + disable_percpu_irq(host_vtimer_irq); break; } @@ -229,7 +240,7 @@ int kvm_timer_hyp_init(void) goto out; } - timer_irq.irq = ppi; + host_vtimer_irq = ppi; err = register_cpu_notifier(&kvm_timer_cpu_nb); if (err) { -- cgit v1.2.1