v4.19.13 snapshot.
diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c
new file mode 100644
index 0000000..17cecc9
--- /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;
+}