swh:1:snp:49cd9498d6cccc5e78252c27dcb645bcf7bf0c91
Tip revision: 98d54f81e36ba3bf92172791eba5ca5bd813989b authored by Linus Torvalds on 01 March 2020, 22:38:46 UTC
Linux 5.6-rc4
Linux 5.6-rc4
Tip revision: 98d54f8
arch_timer.c
// 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)
{
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_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;
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 (swait_active(kvm_arch_vcpu_wq(vcpu)))
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_vtimer(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;
}