diff options
Diffstat (limited to 'arch/arm64/kvm/arch_timer.c')
| -rw-r--r-- | arch/arm64/kvm/arch_timer.c | 1171 |
1 files changed, 1171 insertions, 0 deletions
diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c new file mode 100644 index 000000000000..a1fe0ea3254e --- /dev/null +++ b/arch/arm64/kvm/arch_timer.c @@ -0,0 +1,1171 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2012 ARM Ltd. + * Author: Marc Zyngier <marc.zyngier@arm.com> + */ + +#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_emulate.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 unsigned int host_ptimer_irq; +static u32 host_vtimer_irq_flags; +static u32 host_ptimer_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); +static void kvm_arm_timer_write(struct kvm_vcpu *vcpu, + struct arch_timer_context *timer, + enum kvm_arch_timer_regs treg, + u64 val); +static u64 kvm_arm_timer_read(struct kvm_vcpu *vcpu, + struct arch_timer_context *timer, + enum kvm_arch_timer_regs treg); + +u64 kvm_phys_timer_read(void) +{ + return timecounter->cc->read(timecounter->cc); +} + +static void get_timer_map(struct kvm_vcpu *vcpu, struct timer_map *map) +{ + if (has_vhe()) { + map->direct_vtimer = vcpu_vtimer(vcpu); + map->direct_ptimer = vcpu_ptimer(vcpu); + map->emul_ptimer = NULL; + } else { + map->direct_vtimer = vcpu_vtimer(vcpu); + map->direct_ptimer = NULL; + map->emul_ptimer = vcpu_ptimer(vcpu); + } + + trace_kvm_get_timer_map(vcpu->vcpu_id, map); +} + +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_HARD); +} + +static void soft_timer_cancel(struct hrtimer *hrt) +{ + hrtimer_cancel(hrt); +} + +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 *ctx; + struct timer_map map; + + /* + * 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 timer_save_state(), the hardware interrupt + * signal may not have been retired from the interrupt controller yet. + */ + if (!vcpu) + return IRQ_HANDLED; + + get_timer_map(vcpu, &map); + + if (irq == host_vtimer_irq) + ctx = map.direct_vtimer; + else + ctx = map.direct_ptimer; + + if (kvm_timer_should_fire(ctx)) + kvm_timer_update_irq(vcpu, true, ctx); + + if (userspace_irqchip(vcpu->kvm) && + !static_branch_unlikely(&has_gic_active_state)) + disable_percpu_irq(host_vtimer_irq); + + return IRQ_HANDLED; +} + +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) +{ + WARN_ON(timer_ctx && timer_ctx->loaded); + return timer_ctx && + !(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_delta = ULLONG_MAX; + int i; + + for (i = 0; i < NR_KVM_TIMERS; i++) { + struct arch_timer_context *ctx = &vcpu->arch.timer_cpu.timers[i]; + + WARN(ctx->loaded, "timer %d loaded\n", i); + if (kvm_timer_irq_can_fire(ctx)) + min_delta = min(min_delta, kvm_timer_compute_delta(ctx)); + } + + /* If none of timers can fire, then return 0 */ + if (min_delta == ULLONG_MAX) + return 0; + + return min_delta; +} + +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; + } + + kvm_vcpu_wake_up(vcpu); + return HRTIMER_NORESTART; +} + +static enum hrtimer_restart kvm_hrtimer_expire(struct hrtimer *hrt) +{ + struct arch_timer_context *ctx; + struct kvm_vcpu *vcpu; + u64 ns; + + ctx = container_of(hrt, struct arch_timer_context, hrtimer); + vcpu = ctx->vcpu; + + trace_kvm_timer_hrtimer_expire(ctx); + + /* + * 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(ctx); + if (unlikely(ns)) { + hrtimer_forward_now(hrt, ns_to_ktime(ns)); + return HRTIMER_RESTART; + } + + kvm_timer_update_irq(vcpu, true, ctx); + return HRTIMER_NORESTART; +} + +static bool kvm_timer_should_fire(struct arch_timer_context *timer_ctx) +{ + enum kvm_arch_timers index; + u64 cval, now; + + if (!timer_ctx) + return false; + + index = arch_timer_ctx_index(timer_ctx); + + if (timer_ctx->loaded) { + u32 cnt_ctl = 0; + + switch (index) { + case TIMER_VTIMER: + cnt_ctl = read_sysreg_el0(SYS_CNTV_CTL); + break; + case TIMER_PTIMER: + cnt_ctl = read_sysreg_el0(SYS_CNTP_CTL); + break; + case NR_KVM_TIMERS: + /* GCC is braindead */ + cnt_ctl = 0; + break; + } + + 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 timer_map map; + + get_timer_map(vcpu, &map); + + return kvm_timer_should_fire(map.direct_vtimer) || + kvm_timer_should_fire(map.direct_ptimer) || + kvm_timer_should_fire(map.emul_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); + } +} + +/* Only called for a fully emulated timer */ +static void timer_emulate(struct arch_timer_context *ctx) +{ + bool should_fire = kvm_timer_should_fire(ctx); + + trace_kvm_timer_emulate(ctx, should_fire); + + if (should_fire != ctx->irq.level) { + kvm_timer_update_irq(ctx->vcpu, should_fire, ctx); + return; + } + + /* + * 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_irq_can_fire(ctx)) { + soft_timer_cancel(&ctx->hrtimer); + return; + } + + soft_timer_start(&ctx->hrtimer, kvm_timer_compute_delta(ctx)); +} + +static void timer_save_state(struct arch_timer_context *ctx) +{ + struct arch_timer_cpu *timer = vcpu_timer(ctx->vcpu); + enum kvm_arch_timers index = arch_timer_ctx_index(ctx); + unsigned long flags; + + if (!timer->enabled) + return; + + local_irq_save(flags); + + if (!ctx->loaded) + goto out; + + switch (index) { + case TIMER_VTIMER: + ctx->cnt_ctl = read_sysreg_el0(SYS_CNTV_CTL); + ctx->cnt_cval = read_sysreg_el0(SYS_CNTV_CVAL); + + /* Disable the timer */ + write_sysreg_el0(0, SYS_CNTV_CTL); + isb(); + + break; + case TIMER_PTIMER: + ctx->cnt_ctl = read_sysreg_el0(SYS_CNTP_CTL); + ctx->cnt_cval = read_sysreg_el0(SYS_CNTP_CVAL); + + /* Disable the timer */ + write_sysreg_el0(0, SYS_CNTP_CTL); + isb(); + + break; + case NR_KVM_TIMERS: + BUG(); + } + + trace_kvm_timer_save_state(ctx); + + ctx->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. + */ +static void kvm_timer_blocking(struct kvm_vcpu *vcpu) +{ + struct arch_timer_cpu *timer = vcpu_timer(vcpu); + struct timer_map map; + + get_timer_map(vcpu, &map); + + /* + * If no timers are capable of raising interrupts (disabled or + * masked), then there's no more work for us to do. + */ + if (!kvm_timer_irq_can_fire(map.direct_vtimer) && + !kvm_timer_irq_can_fire(map.direct_ptimer) && + !kvm_timer_irq_can_fire(map.emul_ptimer)) + return; + + /* + * At least one guest time will expire. 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 kvm_timer_unblocking(struct kvm_vcpu *vcpu) +{ + struct arch_timer_cpu *timer = vcpu_timer(vcpu); + + soft_timer_cancel(&timer->bg_timer); +} + +static void timer_restore_state(struct arch_timer_context *ctx) +{ + struct arch_timer_cpu *timer = vcpu_timer(ctx->vcpu); + enum kvm_arch_timers index = arch_timer_ctx_index(ctx); + unsigned long flags; + + if (!timer->enabled) + return; + + local_irq_save(flags); + + if (ctx->loaded) + goto out; + + switch (index) { + case TIMER_VTIMER: + write_sysreg_el0(ctx->cnt_cval, SYS_CNTV_CVAL); + isb(); + write_sysreg_el0(ctx->cnt_ctl, SYS_CNTV_CTL); + break; + case TIMER_PTIMER: + write_sysreg_el0(ctx->cnt_cval, SYS_CNTP_CVAL); + isb(); + write_sysreg_el0(ctx->cnt_ctl, SYS_CNTP_CTL); + break; + case NR_KVM_TIMERS: + BUG(); + } + + trace_kvm_timer_restore_state(ctx); + + ctx->loaded = true; +out: + local_irq_restore(flags); +} + +static void set_cntvoff(u64 cntvoff) +{ + kvm_call_hyp(__kvm_timer_set_cntvoff, cntvoff); +} + +static inline void set_timer_irq_phys_active(struct arch_timer_context *ctx, bool active) +{ + int r; + r = irq_set_irqchip_state(ctx->host_timer_irq, IRQCHIP_STATE_ACTIVE, active); + WARN_ON(r); +} + +static void kvm_timer_vcpu_load_gic(struct arch_timer_context *ctx) +{ + struct kvm_vcpu *vcpu = ctx->vcpu; + bool phys_active = false; + + /* + * Update the timer output so that it is likely to match the + * state we're about to restore. If the timer expires between + * this point and the register restoration, we'll take the + * interrupt anyway. + */ + kvm_timer_update_irq(ctx->vcpu, kvm_timer_should_fire(ctx), ctx); + + if (irqchip_in_kernel(vcpu->kvm)) + phys_active = kvm_vgic_map_is_active(vcpu, ctx->irq.irq); + + phys_active |= ctx->irq.level; + + set_timer_irq_phys_active(ctx, phys_active); +} + +static void kvm_timer_vcpu_load_nogic(struct kvm_vcpu *vcpu) +{ + struct arch_timer_context *vtimer = vcpu_vtimer(vcpu); + + /* + * Update the timer output so that it is likely to match the + * state we're about to restore. If the timer expires between + * this point and the register restoration, we'll take the + * interrupt anyway. + */ + kvm_timer_update_irq(vcpu, kvm_timer_should_fire(vtimer), vtimer); + + /* + * 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_timer(vcpu); + struct timer_map map; + + if (unlikely(!timer->enabled)) + return; + + get_timer_map(vcpu, &map); + + if (static_branch_likely(&has_gic_active_state)) { + kvm_timer_vcpu_load_gic(map.direct_vtimer); + if (map.direct_ptimer) + kvm_timer_vcpu_load_gic(map.direct_ptimer); + } else { + kvm_timer_vcpu_load_nogic(vcpu); + } + + set_cntvoff(map.direct_vtimer->cntvoff); + + kvm_timer_unblocking(vcpu); + + timer_restore_state(map.direct_vtimer); + if (map.direct_ptimer) + timer_restore_state(map.direct_ptimer); + + if (map.emul_ptimer) + timer_emulate(map.emul_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_timer(vcpu); + struct timer_map map; + struct rcuwait *wait = kvm_arch_vcpu_get_wait(vcpu); + + if (unlikely(!timer->enabled)) + return; + + get_timer_map(vcpu, &map); + + timer_save_state(map.direct_vtimer); + if (map.direct_ptimer) + timer_save_state(map.direct_ptimer); + + /* + * Cancel soft 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(). + */ + if (map.emul_ptimer) + soft_timer_cancel(&map.emul_ptimer->hrtimer); + + if (rcuwait_active(wait)) + kvm_timer_blocking(vcpu); + + /* + * 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. + */ + 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_timer_irq_phys_active(vtimer, 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_timer(vcpu); + + 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_timer(vcpu); + struct timer_map map; + + get_timer_map(vcpu, &map); + + /* + * 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. + */ + vcpu_vtimer(vcpu)->cnt_ctl = 0; + vcpu_ptimer(vcpu)->cnt_ctl = 0; + + if (timer->enabled) { + kvm_timer_update_irq(vcpu, false, vcpu_vtimer(vcpu)); + kvm_timer_update_irq(vcpu, false, vcpu_ptimer(vcpu)); + + if (irqchip_in_kernel(vcpu->kvm)) { + kvm_vgic_reset_mapped_irq(vcpu, map.direct_vtimer->irq.irq); + if (map.direct_ptimer) + kvm_vgic_reset_mapped_irq(vcpu, map.direct_ptimer->irq.irq); + } + } + + if (map.emul_ptimer) + soft_timer_cancel(&map.emul_ptimer->hrtimer); + + 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_timer(vcpu); + 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()); + ptimer->cntvoff = 0; + + hrtimer_init(&timer->bg_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD); + timer->bg_timer.function = kvm_bg_timer_expire; + + hrtimer_init(&vtimer->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD); + hrtimer_init(&ptimer->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD); + vtimer->hrtimer.function = kvm_hrtimer_expire; + ptimer->hrtimer.function = kvm_hrtimer_expire; + + vtimer->irq.irq = default_vtimer_irq.irq; + ptimer->irq.irq = default_ptimer_irq.irq; + + vtimer->host_timer_irq = host_vtimer_irq; + ptimer->host_timer_irq = host_ptimer_irq; + + vtimer->host_timer_irq_flags = host_vtimer_irq_flags; + ptimer->host_timer_irq_flags = host_ptimer_irq_flags; + + vtimer->vcpu = vcpu; + ptimer->vcpu = vcpu; +} + +static void kvm_timer_init_interrupt(void *info) +{ + enable_percpu_irq(host_vtimer_irq, host_vtimer_irq_flags); + enable_percpu_irq(host_ptimer_irq, host_ptimer_irq_flags); +} + +int kvm_arm_timer_set_reg(struct kvm_vcpu *vcpu, u64 regid, u64 value) +{ + struct arch_timer_context *timer; + + switch (regid) { + case KVM_REG_ARM_TIMER_CTL: + timer = vcpu_vtimer(vcpu); + kvm_arm_timer_write(vcpu, timer, TIMER_REG_CTL, value); + break; + case KVM_REG_ARM_TIMER_CNT: + timer = vcpu_vtimer(vcpu); + update_vtimer_cntvoff(vcpu, kvm_phys_timer_read() - value); + break; + case KVM_REG_ARM_TIMER_CVAL: + timer = vcpu_vtimer(vcpu); + kvm_arm_timer_write(vcpu, timer, TIMER_REG_CVAL, value); + break; + case KVM_REG_ARM_PTIMER_CTL: + timer = vcpu_ptimer(vcpu); + kvm_arm_timer_write(vcpu, timer, TIMER_REG_CTL, value); + break; + case KVM_REG_ARM_PTIMER_CVAL: + timer = vcpu_ptimer(vcpu); + kvm_arm_timer_write(vcpu, timer, TIMER_REG_CVAL, value); + break; + + default: + return -1; + } + + 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) +{ + switch (regid) { + case KVM_REG_ARM_TIMER_CTL: + return kvm_arm_timer_read(vcpu, + vcpu_vtimer(vcpu), TIMER_REG_CTL); + case KVM_REG_ARM_TIMER_CNT: + return kvm_arm_timer_read(vcpu, + vcpu_vtimer(vcpu), TIMER_REG_CNT); + case KVM_REG_ARM_TIMER_CVAL: + return kvm_arm_timer_read(vcpu, + vcpu_vtimer(vcpu), TIMER_REG_CVAL); + case KVM_REG_ARM_PTIMER_CTL: + return kvm_arm_timer_read(vcpu, + vcpu_ptimer(vcpu), TIMER_REG_CTL); + case KVM_REG_ARM_PTIMER_CNT: + return kvm_arm_timer_read(vcpu, + vcpu_ptimer(vcpu), TIMER_REG_CNT); + case KVM_REG_ARM_PTIMER_CVAL: + return kvm_arm_timer_read(vcpu, + vcpu_ptimer(vcpu), TIMER_REG_CVAL); + } + return (u64)-1; +} + +static u64 kvm_arm_timer_read(struct kvm_vcpu *vcpu, + struct arch_timer_context *timer, + enum kvm_arch_timer_regs treg) +{ + u64 val; + + switch (treg) { + case TIMER_REG_TVAL: + val = timer->cnt_cval - kvm_phys_timer_read() + timer->cntvoff; + val &= lower_32_bits(val); + break; + + case TIMER_REG_CTL: + val = read_timer_ctl(timer); + break; + + case TIMER_REG_CVAL: + val = timer->cnt_cval; + break; + + case TIMER_REG_CNT: + val = kvm_phys_timer_read() - timer->cntvoff; + break; + + default: + BUG(); + } + + return val; +} + +u64 kvm_arm_timer_read_sysreg(struct kvm_vcpu *vcpu, + enum kvm_arch_timers tmr, + enum kvm_arch_timer_regs treg) +{ + u64 val; + + preempt_disable(); + kvm_timer_vcpu_put(vcpu); + + val = kvm_arm_timer_read(vcpu, vcpu_get_timer(vcpu, tmr), treg); + + kvm_timer_vcpu_load(vcpu); + preempt_enable(); + + return val; +} + +static void kvm_arm_timer_write(struct kvm_vcpu *vcpu, + struct arch_timer_context *timer, + enum kvm_arch_timer_regs treg, + u64 val) +{ + switch (treg) { + case TIMER_REG_TVAL: + timer->cnt_cval = kvm_phys_timer_read() - timer->cntvoff + (s32)val; + break; + + case TIMER_REG_CTL: + timer->cnt_ctl = val & ~ARCH_TIMER_CTRL_IT_STAT; + break; + + case TIMER_REG_CVAL: + timer->cnt_cval = val; + break; + + default: + BUG(); + } +} + +void kvm_arm_timer_write_sysreg(struct kvm_vcpu *vcpu, + enum kvm_arch_timers tmr, + enum kvm_arch_timer_regs treg, + u64 val) +{ + preempt_disable(); + kvm_timer_vcpu_put(vcpu); + + kvm_arm_timer_write(vcpu, vcpu_get_timer(vcpu, tmr), treg, val); + + kvm_timer_vcpu_load(vcpu); + preempt_enable(); +} + +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; + } + + /* First, do the virtual EL1 timer irq */ + + 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 vtimer 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 vtimer", kvm_get_running_vcpus()); + if (err) { + kvm_err("kvm_arch_timer: can't request vtimer 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); + + /* Now let's do the physical EL1 timer irq */ + + if (info->physical_irq > 0) { + host_ptimer_irq = info->physical_irq; + host_ptimer_irq_flags = irq_get_trigger_type(host_ptimer_irq); + if (host_ptimer_irq_flags != IRQF_TRIGGER_HIGH && + host_ptimer_irq_flags != IRQF_TRIGGER_LOW) { + kvm_err("Invalid trigger for ptimer IRQ%d, assuming level low\n", + host_ptimer_irq); + host_ptimer_irq_flags = IRQF_TRIGGER_LOW; + } + + err = request_percpu_irq(host_ptimer_irq, kvm_arch_timer_handler, + "kvm guest ptimer", kvm_get_running_vcpus()); + if (err) { + kvm_err("kvm_arch_timer: can't request ptimer interrupt %d (%d)\n", + host_ptimer_irq, err); + return err; + } + + if (has_gic) { + err = irq_set_vcpu_affinity(host_ptimer_irq, + kvm_get_running_vcpus()); + if (err) { + kvm_err("kvm_arch_timer: error setting vcpu affinity\n"); + goto out_free_irq; + } + } + + kvm_debug("physical timer IRQ%d\n", host_ptimer_irq); + } else if (has_vhe()) { + kvm_err("kvm_arch_timer: invalid physical timer IRQ: %d\n", + info->physical_irq); + err = -ENODEV; + goto out_free_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_timer(vcpu); + + soft_timer_cancel(&timer->bg_timer); +} + +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_get_running_vcpu(); + struct arch_timer_context *timer; + + if (vintid == vcpu_vtimer(vcpu)->irq.irq) + timer = vcpu_vtimer(vcpu); + else if (vintid == vcpu_ptimer(vcpu)->irq.irq) + timer = vcpu_ptimer(vcpu); + else + BUG(); + + return kvm_timer_should_fire(timer); +} + +int kvm_timer_enable(struct kvm_vcpu *vcpu) +{ + struct arch_timer_cpu *timer = vcpu_timer(vcpu); + struct timer_map map; + 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; + } + + get_timer_map(vcpu, &map); + + ret = kvm_vgic_map_phys_irq(vcpu, + map.direct_vtimer->host_timer_irq, + map.direct_vtimer->irq.irq, + kvm_arch_timer_get_input_level); + if (ret) + return ret; + + if (map.direct_ptimer) { + ret = kvm_vgic_map_phys_irq(vcpu, + map.direct_ptimer->host_timer_irq, + map.direct_ptimer->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 the EL2 timer trap register 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; + + /* + * VHE systems allow the guest direct access to the EL1 physical + * timer/counter. + */ + 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; +} |