diff options
Diffstat (limited to 'virt/kvm/arm/arch_timer.c')
| -rw-r--r-- | virt/kvm/arm/arch_timer.c | 966 |
1 files changed, 966 insertions, 0 deletions
diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c new file mode 100644 index 000000000..17cecc96f --- /dev/null +++ b/virt/kvm/arm/arch_timer.c @@ -0,0 +1,966 @@ +/* + * Copyright (C) 2012 ARM Ltd. + * Author: Marc Zyngier <marc.zyngier@arm.com> + * + * 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 <linux/cpu.h> +#include <linux/kvm.h> +#include <linux/kvm_host.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/uaccess.h> + +#include <clocksource/arm_arch_timer.h> +#include <asm/arch_timer.h> +#include <asm/kvm_hyp.h> + +#include <kvm/arm_vgic.h> +#include <kvm/arm_arch_timer.h> + +#include "trace.h" + +static struct timecounter *timecounter; +static unsigned int host_vtimer_irq; +static u32 host_vtimer_irq_flags; + +static DEFINE_STATIC_KEY_FALSE(has_gic_active_state); + +static const struct kvm_irq_level default_ptimer_irq = { + .irq = 30, + .level = 1, +}; + +static const struct kvm_irq_level default_vtimer_irq = { + .irq = 27, + .level = 1, +}; + +static bool kvm_timer_irq_can_fire(struct arch_timer_context *timer_ctx); +static void kvm_timer_update_irq(struct kvm_vcpu *vcpu, bool new_level, + struct arch_timer_context *timer_ctx); +static bool kvm_timer_should_fire(struct arch_timer_context *timer_ctx); + +u64 kvm_phys_timer_read(void) +{ + return timecounter->cc->read(timecounter->cc); +} + +static inline bool userspace_irqchip(struct kvm *kvm) +{ + return static_branch_unlikely(&userspace_irqchip_in_use) && + unlikely(!irqchip_in_kernel(kvm)); +} + +static void soft_timer_start(struct hrtimer *hrt, u64 ns) +{ + hrtimer_start(hrt, ktime_add_ns(ktime_get(), ns), + HRTIMER_MODE_ABS); +} + +static void soft_timer_cancel(struct hrtimer *hrt, struct work_struct *work) +{ + hrtimer_cancel(hrt); + if (work) + cancel_work_sync(work); +} + +static irqreturn_t kvm_arch_timer_handler(int irq, void *dev_id) +{ + struct kvm_vcpu *vcpu = *(struct kvm_vcpu **)dev_id; + struct arch_timer_context *vtimer; + + /* + * We may see a timer interrupt after vcpu_put() has been called which + * sets the CPU's vcpu pointer to NULL, because even though the timer + * has been disabled in vtimer_save_state(), the hardware interrupt + * signal may not have been retired from the interrupt controller yet. + */ + if (!vcpu) + return IRQ_HANDLED; + + vtimer = vcpu_vtimer(vcpu); + if (kvm_timer_should_fire(vtimer)) + kvm_timer_update_irq(vcpu, true, vtimer); + + if (userspace_irqchip(vcpu->kvm) && + !static_branch_unlikely(&has_gic_active_state)) + disable_percpu_irq(host_vtimer_irq); + + return IRQ_HANDLED; +} + +/* + * Work function for handling the backup timer that we schedule when a vcpu is + * no longer running, but had a timer programmed to fire in the future. + */ +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); + + /* + * If the vcpu is blocked we want to wake it up so that it will see + * the timer has expired when entering the guest. + */ + kvm_vcpu_wake_up(vcpu); +} + +static u64 kvm_timer_compute_delta(struct arch_timer_context *timer_ctx) +{ + u64 cval, now; + + cval = timer_ctx->cnt_cval; + now = kvm_phys_timer_read() - timer_ctx->cntvoff; + + if (now < cval) { + u64 ns; + + ns = cyclecounter_cyc2ns(timecounter->cc, + cval - now, + timecounter->mask, + &timecounter->frac); + return ns; + } + + return 0; +} + +static bool kvm_timer_irq_can_fire(struct arch_timer_context *timer_ctx) +{ + return !(timer_ctx->cnt_ctl & ARCH_TIMER_CTRL_IT_MASK) && + (timer_ctx->cnt_ctl & ARCH_TIMER_CTRL_ENABLE); +} + +/* + * Returns the earliest expiration time in ns among guest timers. + * Note that it will return 0 if none of timers can fire. + */ +static u64 kvm_timer_earliest_exp(struct kvm_vcpu *vcpu) +{ + u64 min_virt = ULLONG_MAX, min_phys = ULLONG_MAX; + struct arch_timer_context *vtimer = vcpu_vtimer(vcpu); + struct arch_timer_context *ptimer = vcpu_ptimer(vcpu); + + if (kvm_timer_irq_can_fire(vtimer)) + min_virt = kvm_timer_compute_delta(vtimer); + + if (kvm_timer_irq_can_fire(ptimer)) + min_phys = kvm_timer_compute_delta(ptimer); + + /* If none of timers can fire, then return 0 */ + if ((min_virt == ULLONG_MAX) && (min_phys == ULLONG_MAX)) + return 0; + + return min(min_virt, min_phys); +} + +static enum hrtimer_restart kvm_bg_timer_expire(struct hrtimer *hrt) +{ + struct arch_timer_cpu *timer; + struct kvm_vcpu *vcpu; + u64 ns; + + timer = container_of(hrt, struct arch_timer_cpu, bg_timer); + vcpu = container_of(timer, struct kvm_vcpu, arch.timer_cpu); + + /* + * Check that the timer has really expired from the guest's + * PoV (NTP on the host may have forced it to expire + * early). If we should have slept longer, restart it. + */ + ns = kvm_timer_earliest_exp(vcpu); + if (unlikely(ns)) { + hrtimer_forward_now(hrt, ns_to_ktime(ns)); + return HRTIMER_RESTART; + } + + schedule_work(&timer->expired); + return HRTIMER_NORESTART; +} + +static enum hrtimer_restart kvm_phys_timer_expire(struct hrtimer *hrt) +{ + struct arch_timer_context *ptimer; + struct arch_timer_cpu *timer; + struct kvm_vcpu *vcpu; + u64 ns; + + timer = container_of(hrt, struct arch_timer_cpu, phys_timer); + vcpu = container_of(timer, struct kvm_vcpu, arch.timer_cpu); + ptimer = vcpu_ptimer(vcpu); + + /* + * Check that the timer has really expired from the guest's + * PoV (NTP on the host may have forced it to expire + * early). If not ready, schedule for a later time. + */ + ns = kvm_timer_compute_delta(ptimer); + if (unlikely(ns)) { + hrtimer_forward_now(hrt, ns_to_ktime(ns)); + return HRTIMER_RESTART; + } + + kvm_timer_update_irq(vcpu, true, ptimer); + return HRTIMER_NORESTART; +} + +static bool kvm_timer_should_fire(struct arch_timer_context *timer_ctx) +{ + u64 cval, now; + + if (timer_ctx->loaded) { + u32 cnt_ctl; + + /* Only the virtual timer can be loaded so far */ + cnt_ctl = read_sysreg_el0(cntv_ctl); + return (cnt_ctl & ARCH_TIMER_CTRL_ENABLE) && + (cnt_ctl & ARCH_TIMER_CTRL_IT_STAT) && + !(cnt_ctl & ARCH_TIMER_CTRL_IT_MASK); + } + + if (!kvm_timer_irq_can_fire(timer_ctx)) + return false; + + cval = timer_ctx->cnt_cval; + now = kvm_phys_timer_read() - timer_ctx->cntvoff; + + return cval <= now; +} + +bool kvm_timer_is_pending(struct kvm_vcpu *vcpu) +{ + struct arch_timer_context *vtimer = vcpu_vtimer(vcpu); + struct arch_timer_context *ptimer = vcpu_ptimer(vcpu); + + if (kvm_timer_should_fire(vtimer)) + return true; + + return kvm_timer_should_fire(ptimer); +} + +/* + * Reflect the timer output level into the kvm_run structure + */ +void kvm_timer_update_run(struct kvm_vcpu *vcpu) +{ + struct arch_timer_context *vtimer = vcpu_vtimer(vcpu); + struct arch_timer_context *ptimer = vcpu_ptimer(vcpu); + struct kvm_sync_regs *regs = &vcpu->run->s.regs; + + /* Populate the device bitmap with the timer states */ + regs->device_irq_level &= ~(KVM_ARM_DEV_EL1_VTIMER | + KVM_ARM_DEV_EL1_PTIMER); + if (kvm_timer_should_fire(vtimer)) + regs->device_irq_level |= KVM_ARM_DEV_EL1_VTIMER; + if (kvm_timer_should_fire(ptimer)) + regs->device_irq_level |= KVM_ARM_DEV_EL1_PTIMER; +} + +static void kvm_timer_update_irq(struct kvm_vcpu *vcpu, bool new_level, + struct arch_timer_context *timer_ctx) +{ + int ret; + + timer_ctx->irq.level = new_level; + trace_kvm_timer_update_irq(vcpu->vcpu_id, timer_ctx->irq.irq, + timer_ctx->irq.level); + + if (!userspace_irqchip(vcpu->kvm)) { + ret = kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id, + timer_ctx->irq.irq, + timer_ctx->irq.level, + timer_ctx); + WARN_ON(ret); + } +} + +/* Schedule the background timer for the emulated timer. */ +static void phys_timer_emulate(struct kvm_vcpu *vcpu) +{ + struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; + struct arch_timer_context *ptimer = vcpu_ptimer(vcpu); + + /* + * If the timer can fire now, we don't need to have a soft timer + * scheduled for the future. If the timer cannot fire at all, + * then we also don't need a soft timer. + */ + if (kvm_timer_should_fire(ptimer) || !kvm_timer_irq_can_fire(ptimer)) { + soft_timer_cancel(&timer->phys_timer, NULL); + return; + } + + soft_timer_start(&timer->phys_timer, kvm_timer_compute_delta(ptimer)); +} + +/* + * Check if there was a change in the timer state, so that we should either + * raise or lower the line level to the GIC or schedule a background timer to + * emulate the physical timer. + */ +static void kvm_timer_update_state(struct kvm_vcpu *vcpu) +{ + struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; + struct arch_timer_context *vtimer = vcpu_vtimer(vcpu); + struct arch_timer_context *ptimer = vcpu_ptimer(vcpu); + bool level; + + if (unlikely(!timer->enabled)) + return; + + /* + * The vtimer virtual interrupt is a 'mapped' interrupt, meaning part + * of its lifecycle is offloaded to the hardware, and we therefore may + * not have lowered the irq.level value before having to signal a new + * interrupt, but have to signal an interrupt every time the level is + * asserted. + */ + level = kvm_timer_should_fire(vtimer); + kvm_timer_update_irq(vcpu, level, vtimer); + + phys_timer_emulate(vcpu); + + if (kvm_timer_should_fire(ptimer) != ptimer->irq.level) + kvm_timer_update_irq(vcpu, !ptimer->irq.level, ptimer); +} + +static void vtimer_save_state(struct kvm_vcpu *vcpu) +{ + struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; + struct arch_timer_context *vtimer = vcpu_vtimer(vcpu); + unsigned long flags; + + local_irq_save(flags); + + if (!vtimer->loaded) + goto out; + + if (timer->enabled) { + vtimer->cnt_ctl = read_sysreg_el0(cntv_ctl); + vtimer->cnt_cval = read_sysreg_el0(cntv_cval); + } + + /* Disable the virtual timer */ + write_sysreg_el0(0, cntv_ctl); + isb(); + + vtimer->loaded = false; +out: + local_irq_restore(flags); +} + +/* + * Schedule the background timer before calling kvm_vcpu_block, so that this + * thread is removed from its waitqueue and made runnable when there's a timer + * interrupt to handle. + */ +void kvm_timer_schedule(struct kvm_vcpu *vcpu) +{ + struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; + struct arch_timer_context *vtimer = vcpu_vtimer(vcpu); + struct arch_timer_context *ptimer = vcpu_ptimer(vcpu); + + vtimer_save_state(vcpu); + + /* + * No need to schedule a background timer if any guest timer has + * already expired, because kvm_vcpu_block will return before putting + * the thread to sleep. + */ + if (kvm_timer_should_fire(vtimer) || kvm_timer_should_fire(ptimer)) + return; + + /* + * If both timers are not capable of raising interrupts (disabled or + * masked), then there's no more work for us to do. + */ + if (!kvm_timer_irq_can_fire(vtimer) && !kvm_timer_irq_can_fire(ptimer)) + return; + + /* + * The guest timers have not yet expired, schedule a background timer. + * Set the earliest expiration time among the guest timers. + */ + soft_timer_start(&timer->bg_timer, kvm_timer_earliest_exp(vcpu)); +} + +static void vtimer_restore_state(struct kvm_vcpu *vcpu) +{ + struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; + struct arch_timer_context *vtimer = vcpu_vtimer(vcpu); + unsigned long flags; + + local_irq_save(flags); + + if (vtimer->loaded) + goto out; + + if (timer->enabled) { + write_sysreg_el0(vtimer->cnt_cval, cntv_cval); + isb(); + write_sysreg_el0(vtimer->cnt_ctl, cntv_ctl); + } + + vtimer->loaded = true; +out: + local_irq_restore(flags); +} + +void kvm_timer_unschedule(struct kvm_vcpu *vcpu) +{ + struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; + + vtimer_restore_state(vcpu); + + soft_timer_cancel(&timer->bg_timer, &timer->expired); +} + +static void set_cntvoff(u64 cntvoff) +{ + u32 low = lower_32_bits(cntvoff); + u32 high = upper_32_bits(cntvoff); + + /* + * Since kvm_call_hyp doesn't fully support the ARM PCS especially on + * 32-bit systems, but rather passes register by register shifted one + * place (we put the function address in r0/x0), we cannot simply pass + * a 64-bit value as an argument, but have to split the value in two + * 32-bit halves. + */ + kvm_call_hyp(__kvm_timer_set_cntvoff, low, high); +} + +static inline void set_vtimer_irq_phys_active(struct kvm_vcpu *vcpu, bool active) +{ + int r; + r = irq_set_irqchip_state(host_vtimer_irq, IRQCHIP_STATE_ACTIVE, active); + WARN_ON(r); +} + +static void kvm_timer_vcpu_load_gic(struct kvm_vcpu *vcpu) +{ + struct arch_timer_context *vtimer = vcpu_vtimer(vcpu); + bool phys_active; + + if (irqchip_in_kernel(vcpu->kvm)) + phys_active = kvm_vgic_map_is_active(vcpu, vtimer->irq.irq); + else + phys_active = vtimer->irq.level; + set_vtimer_irq_phys_active(vcpu, phys_active); +} + +static void kvm_timer_vcpu_load_nogic(struct kvm_vcpu *vcpu) +{ + struct arch_timer_context *vtimer = vcpu_vtimer(vcpu); + + /* + * When using a userspace irqchip with the architected timers and a + * host interrupt controller that doesn't support an active state, we + * must still prevent continuously exiting from the guest, and + * therefore mask the physical interrupt by disabling it on the host + * interrupt controller when the virtual level is high, such that the + * guest can make forward progress. Once we detect the output level + * being de-asserted, we unmask the interrupt again so that we exit + * from the guest when the timer fires. + */ + if (vtimer->irq.level) + disable_percpu_irq(host_vtimer_irq); + else + enable_percpu_irq(host_vtimer_irq, host_vtimer_irq_flags); +} + +void kvm_timer_vcpu_load(struct kvm_vcpu *vcpu) +{ + struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; + struct arch_timer_context *vtimer = vcpu_vtimer(vcpu); + struct arch_timer_context *ptimer = vcpu_ptimer(vcpu); + + if (unlikely(!timer->enabled)) + return; + + if (static_branch_likely(&has_gic_active_state)) + kvm_timer_vcpu_load_gic(vcpu); + else + kvm_timer_vcpu_load_nogic(vcpu); + + set_cntvoff(vtimer->cntvoff); + + vtimer_restore_state(vcpu); + + /* Set the background timer for the physical timer emulation. */ + phys_timer_emulate(vcpu); + + /* If the timer fired while we weren't running, inject it now */ + if (kvm_timer_should_fire(ptimer) != ptimer->irq.level) + kvm_timer_update_irq(vcpu, !ptimer->irq.level, ptimer); +} + +bool kvm_timer_should_notify_user(struct kvm_vcpu *vcpu) +{ + struct arch_timer_context *vtimer = vcpu_vtimer(vcpu); + struct arch_timer_context *ptimer = vcpu_ptimer(vcpu); + struct kvm_sync_regs *sregs = &vcpu->run->s.regs; + bool vlevel, plevel; + + if (likely(irqchip_in_kernel(vcpu->kvm))) + return false; + + vlevel = sregs->device_irq_level & KVM_ARM_DEV_EL1_VTIMER; + plevel = sregs->device_irq_level & KVM_ARM_DEV_EL1_PTIMER; + + return kvm_timer_should_fire(vtimer) != vlevel || + kvm_timer_should_fire(ptimer) != plevel; +} + +void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu) +{ + struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; + + if (unlikely(!timer->enabled)) + return; + + vtimer_save_state(vcpu); + + /* + * Cancel the physical timer emulation, because the only case where we + * need it after a vcpu_put is in the context of a sleeping VCPU, and + * in that case we already factor in the deadline for the physical + * timer when scheduling the bg_timer. + * + * In any case, we re-schedule the hrtimer for the physical timer when + * coming back to the VCPU thread in kvm_timer_vcpu_load(). + */ + soft_timer_cancel(&timer->phys_timer, NULL); + + /* + * The kernel may decide to run userspace after calling vcpu_put, so + * we reset cntvoff to 0 to ensure a consistent read between user + * accesses to the virtual counter and kernel access to the physical + * counter of non-VHE case. For VHE, the virtual counter uses a fixed + * virtual offset of zero, so no need to zero CNTVOFF_EL2 register. + */ + if (!has_vhe()) + set_cntvoff(0); +} + +/* + * With a userspace irqchip we have to check if the guest de-asserted the + * timer and if so, unmask the timer irq signal on the host interrupt + * controller to ensure that we see future timer signals. + */ +static void unmask_vtimer_irq_user(struct kvm_vcpu *vcpu) +{ + struct arch_timer_context *vtimer = vcpu_vtimer(vcpu); + + if (!kvm_timer_should_fire(vtimer)) { + kvm_timer_update_irq(vcpu, false, vtimer); + if (static_branch_likely(&has_gic_active_state)) + set_vtimer_irq_phys_active(vcpu, false); + else + enable_percpu_irq(host_vtimer_irq, host_vtimer_irq_flags); + } +} + +void kvm_timer_sync_hwstate(struct kvm_vcpu *vcpu) +{ + struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; + + if (unlikely(!timer->enabled)) + return; + + if (unlikely(!irqchip_in_kernel(vcpu->kvm))) + unmask_vtimer_irq_user(vcpu); +} + +int kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu) +{ + struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; + struct arch_timer_context *vtimer = vcpu_vtimer(vcpu); + struct arch_timer_context *ptimer = vcpu_ptimer(vcpu); + + /* + * The bits in CNTV_CTL are architecturally reset to UNKNOWN for ARMv8 + * and to 0 for ARMv7. We provide an implementation that always + * resets the timer to be disabled and unmasked and is compliant with + * the ARMv7 architecture. + */ + vtimer->cnt_ctl = 0; + ptimer->cnt_ctl = 0; + kvm_timer_update_state(vcpu); + + if (timer->enabled && irqchip_in_kernel(vcpu->kvm)) + kvm_vgic_reset_mapped_irq(vcpu, vtimer->irq.irq); + + return 0; +} + +/* Make the updates of cntvoff for all vtimer contexts atomic */ +static void update_vtimer_cntvoff(struct kvm_vcpu *vcpu, u64 cntvoff) +{ + int i; + struct kvm *kvm = vcpu->kvm; + struct kvm_vcpu *tmp; + + mutex_lock(&kvm->lock); + kvm_for_each_vcpu(i, tmp, kvm) + vcpu_vtimer(tmp)->cntvoff = cntvoff; + + /* + * When called from the vcpu create path, the CPU being created is not + * included in the loop above, so we just set it here as well. + */ + vcpu_vtimer(vcpu)->cntvoff = cntvoff; + mutex_unlock(&kvm->lock); +} + +void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu) +{ + struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; + struct arch_timer_context *vtimer = vcpu_vtimer(vcpu); + struct arch_timer_context *ptimer = vcpu_ptimer(vcpu); + + /* Synchronize cntvoff across all vtimers of a VM. */ + update_vtimer_cntvoff(vcpu, kvm_phys_timer_read()); + vcpu_ptimer(vcpu)->cntvoff = 0; + + INIT_WORK(&timer->expired, kvm_timer_inject_irq_work); + hrtimer_init(&timer->bg_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); + timer->bg_timer.function = kvm_bg_timer_expire; + + hrtimer_init(&timer->phys_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); + timer->phys_timer.function = kvm_phys_timer_expire; + + vtimer->irq.irq = default_vtimer_irq.irq; + ptimer->irq.irq = default_ptimer_irq.irq; +} + +static void kvm_timer_init_interrupt(void *info) +{ + enable_percpu_irq(host_vtimer_irq, host_vtimer_irq_flags); +} + +int kvm_arm_timer_set_reg(struct kvm_vcpu *vcpu, u64 regid, u64 value) +{ + struct arch_timer_context *vtimer = vcpu_vtimer(vcpu); + struct arch_timer_context *ptimer = vcpu_ptimer(vcpu); + + switch (regid) { + case KVM_REG_ARM_TIMER_CTL: + vtimer->cnt_ctl = value & ~ARCH_TIMER_CTRL_IT_STAT; + break; + case KVM_REG_ARM_TIMER_CNT: + update_vtimer_cntvoff(vcpu, kvm_phys_timer_read() - value); + break; + case KVM_REG_ARM_TIMER_CVAL: + vtimer->cnt_cval = value; + break; + case KVM_REG_ARM_PTIMER_CTL: + ptimer->cnt_ctl = value & ~ARCH_TIMER_CTRL_IT_STAT; + break; + case KVM_REG_ARM_PTIMER_CVAL: + ptimer->cnt_cval = value; + break; + + default: + return -1; + } + + kvm_timer_update_state(vcpu); + return 0; +} + +static u64 read_timer_ctl(struct arch_timer_context *timer) +{ + /* + * Set ISTATUS bit if it's expired. + * Note that according to ARMv8 ARM Issue A.k, ISTATUS bit is + * UNKNOWN when ENABLE bit is 0, so we chose to set ISTATUS bit + * regardless of ENABLE bit for our implementation convenience. + */ + if (!kvm_timer_compute_delta(timer)) + return timer->cnt_ctl | ARCH_TIMER_CTRL_IT_STAT; + else + return timer->cnt_ctl; +} + +u64 kvm_arm_timer_get_reg(struct kvm_vcpu *vcpu, u64 regid) +{ + struct arch_timer_context *ptimer = vcpu_ptimer(vcpu); + struct arch_timer_context *vtimer = vcpu_vtimer(vcpu); + + switch (regid) { + case KVM_REG_ARM_TIMER_CTL: + return read_timer_ctl(vtimer); + case KVM_REG_ARM_TIMER_CNT: + return kvm_phys_timer_read() - vtimer->cntvoff; + case KVM_REG_ARM_TIMER_CVAL: + return vtimer->cnt_cval; + case KVM_REG_ARM_PTIMER_CTL: + return read_timer_ctl(ptimer); + case KVM_REG_ARM_PTIMER_CVAL: + return ptimer->cnt_cval; + case KVM_REG_ARM_PTIMER_CNT: + return kvm_phys_timer_read(); + } + return (u64)-1; +} + +static int kvm_timer_starting_cpu(unsigned int cpu) +{ + kvm_timer_init_interrupt(NULL); + return 0; +} + +static int kvm_timer_dying_cpu(unsigned int cpu) +{ + disable_percpu_irq(host_vtimer_irq); + return 0; +} + +int kvm_timer_hyp_init(bool has_gic) +{ + struct arch_timer_kvm_info *info; + int err; + + info = arch_timer_get_kvm_info(); + timecounter = &info->timecounter; + + if (!timecounter->cc) { + kvm_err("kvm_arch_timer: uninitialized timecounter\n"); + return -ENODEV; + } + + if (info->virtual_irq <= 0) { + kvm_err("kvm_arch_timer: invalid virtual timer IRQ: %d\n", + info->virtual_irq); + return -ENODEV; + } + host_vtimer_irq = info->virtual_irq; + + host_vtimer_irq_flags = irq_get_trigger_type(host_vtimer_irq); + if (host_vtimer_irq_flags != IRQF_TRIGGER_HIGH && + host_vtimer_irq_flags != IRQF_TRIGGER_LOW) { + kvm_err("Invalid trigger for IRQ%d, assuming level low\n", + host_vtimer_irq); + host_vtimer_irq_flags = IRQF_TRIGGER_LOW; + } + + err = request_percpu_irq(host_vtimer_irq, 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", + host_vtimer_irq, err); + return err; + } + + if (has_gic) { + err = irq_set_vcpu_affinity(host_vtimer_irq, + kvm_get_running_vcpus()); + if (err) { + kvm_err("kvm_arch_timer: error setting vcpu affinity\n"); + goto out_free_irq; + } + + static_branch_enable(&has_gic_active_state); + } + + kvm_debug("virtual timer IRQ%d\n", host_vtimer_irq); + + cpuhp_setup_state(CPUHP_AP_KVM_ARM_TIMER_STARTING, + "kvm/arm/timer:starting", kvm_timer_starting_cpu, + kvm_timer_dying_cpu); + return 0; +out_free_irq: + free_percpu_irq(host_vtimer_irq, kvm_get_running_vcpus()); + return err; +} + +void kvm_timer_vcpu_terminate(struct kvm_vcpu *vcpu) +{ + struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; + struct arch_timer_context *vtimer = vcpu_vtimer(vcpu); + + soft_timer_cancel(&timer->bg_timer, &timer->expired); + soft_timer_cancel(&timer->phys_timer, NULL); + kvm_vgic_unmap_phys_irq(vcpu, vtimer->irq.irq); +} + +static bool timer_irqs_are_valid(struct kvm_vcpu *vcpu) +{ + int vtimer_irq, ptimer_irq; + int i, ret; + + vtimer_irq = vcpu_vtimer(vcpu)->irq.irq; + ret = kvm_vgic_set_owner(vcpu, vtimer_irq, vcpu_vtimer(vcpu)); + if (ret) + return false; + + ptimer_irq = vcpu_ptimer(vcpu)->irq.irq; + ret = kvm_vgic_set_owner(vcpu, ptimer_irq, vcpu_ptimer(vcpu)); + if (ret) + return false; + + kvm_for_each_vcpu(i, vcpu, vcpu->kvm) { + if (vcpu_vtimer(vcpu)->irq.irq != vtimer_irq || + vcpu_ptimer(vcpu)->irq.irq != ptimer_irq) + return false; + } + + return true; +} + +bool kvm_arch_timer_get_input_level(int vintid) +{ + struct kvm_vcpu *vcpu = kvm_arm_get_running_vcpu(); + struct arch_timer_context *timer; + + if (vintid == vcpu_vtimer(vcpu)->irq.irq) + timer = vcpu_vtimer(vcpu); + else + BUG(); /* We only map the vtimer so far */ + + return kvm_timer_should_fire(timer); +} + +int kvm_timer_enable(struct kvm_vcpu *vcpu) +{ + struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; + struct arch_timer_context *vtimer = vcpu_vtimer(vcpu); + int ret; + + if (timer->enabled) + return 0; + + /* Without a VGIC we do not map virtual IRQs to physical IRQs */ + if (!irqchip_in_kernel(vcpu->kvm)) + goto no_vgic; + + if (!vgic_initialized(vcpu->kvm)) + return -ENODEV; + + if (!timer_irqs_are_valid(vcpu)) { + kvm_debug("incorrectly configured timer irqs\n"); + return -EINVAL; + } + + ret = kvm_vgic_map_phys_irq(vcpu, host_vtimer_irq, vtimer->irq.irq, + kvm_arch_timer_get_input_level); + if (ret) + return ret; + +no_vgic: + timer->enabled = 1; + return 0; +} + +/* + * On VHE system, we only need to configure trap on physical timer and counter + * accesses in EL0 and EL1 once, not for every world switch. + * The host kernel runs at EL2 with HCR_EL2.TGE == 1, + * and this makes those bits have no effect for the host kernel execution. + */ +void kvm_timer_init_vhe(void) +{ + /* When HCR_EL2.E2H ==1, EL1PCEN and EL1PCTEN are shifted by 10 */ + u32 cnthctl_shift = 10; + u64 val; + + /* + * Disallow physical timer access for the guest. + * Physical counter access is allowed. + */ + val = read_sysreg(cnthctl_el2); + val &= ~(CNTHCTL_EL1PCEN << cnthctl_shift); + val |= (CNTHCTL_EL1PCTEN << cnthctl_shift); + write_sysreg(val, cnthctl_el2); +} + +static void set_timer_irqs(struct kvm *kvm, int vtimer_irq, int ptimer_irq) +{ + struct kvm_vcpu *vcpu; + int i; + + kvm_for_each_vcpu(i, vcpu, kvm) { + vcpu_vtimer(vcpu)->irq.irq = vtimer_irq; + vcpu_ptimer(vcpu)->irq.irq = ptimer_irq; + } +} + +int kvm_arm_timer_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) +{ + int __user *uaddr = (int __user *)(long)attr->addr; + struct arch_timer_context *vtimer = vcpu_vtimer(vcpu); + struct arch_timer_context *ptimer = vcpu_ptimer(vcpu); + int irq; + + if (!irqchip_in_kernel(vcpu->kvm)) + return -EINVAL; + + if (get_user(irq, uaddr)) + return -EFAULT; + + if (!(irq_is_ppi(irq))) + return -EINVAL; + + if (vcpu->arch.timer_cpu.enabled) + return -EBUSY; + + switch (attr->attr) { + case KVM_ARM_VCPU_TIMER_IRQ_VTIMER: + set_timer_irqs(vcpu->kvm, irq, ptimer->irq.irq); + break; + case KVM_ARM_VCPU_TIMER_IRQ_PTIMER: + set_timer_irqs(vcpu->kvm, vtimer->irq.irq, irq); + break; + default: + return -ENXIO; + } + + return 0; +} + +int kvm_arm_timer_get_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) +{ + int __user *uaddr = (int __user *)(long)attr->addr; + struct arch_timer_context *timer; + int irq; + + switch (attr->attr) { + case KVM_ARM_VCPU_TIMER_IRQ_VTIMER: + timer = vcpu_vtimer(vcpu); + break; + case KVM_ARM_VCPU_TIMER_IRQ_PTIMER: + timer = vcpu_ptimer(vcpu); + break; + default: + return -ENXIO; + } + + irq = timer->irq.irq; + return put_user(irq, uaddr); +} + +int kvm_arm_timer_has_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) +{ + switch (attr->attr) { + case KVM_ARM_VCPU_TIMER_IRQ_VTIMER: + case KVM_ARM_VCPU_TIMER_IRQ_PTIMER: + return 0; + } + + return -ENXIO; +} |