mirror of
https://github.com/torvalds/linux.git
synced 2024-12-23 03:11:46 +00:00
22601127c0
The timer optimization patches inadvertendly changed the logic to always load the timer state as if we have a vgic, even if we don't have a vgic. Fix this by doing the usual irqchip_in_kernel() check and call the appropriate load function. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
944 lines
24 KiB
C
944 lines
24 KiB
C
/*
|
|
* 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 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 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 void kvm_vtimer_update_mask_user(struct kvm_vcpu *vcpu)
|
|
{
|
|
struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
|
|
|
|
/*
|
|
* When using a userspace irqchip with the architected timers, we must
|
|
* 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, 0);
|
|
}
|
|
|
|
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;
|
|
|
|
if (!vcpu) {
|
|
pr_warn_once("Spurious arch timer IRQ on non-VCPU thread\n");
|
|
return IRQ_NONE;
|
|
}
|
|
vtimer = vcpu_vtimer(vcpu);
|
|
|
|
if (!vtimer->irq.level) {
|
|
vtimer->cnt_ctl = read_sysreg_el0(cntv_ctl);
|
|
if (kvm_timer_irq_can_fire(vtimer))
|
|
kvm_timer_update_irq(vcpu, true, vtimer);
|
|
}
|
|
|
|
if (unlikely(!irqchip_in_kernel(vcpu->kvm)))
|
|
kvm_vtimer_update_mask_user(vcpu);
|
|
|
|
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 (!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 (vtimer->irq.level || ptimer->irq.level)
|
|
return true;
|
|
|
|
/*
|
|
* When this is called from withing the wait loop of kvm_vcpu_block(),
|
|
* the software view of the timer state is up to date (timer->loaded
|
|
* is false), and so we can simply check if the timer should fire now.
|
|
*/
|
|
if (!vtimer->loaded && 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 (vtimer->irq.level)
|
|
regs->device_irq_level |= KVM_ARM_DEV_EL1_VTIMER;
|
|
if (ptimer->irq.level)
|
|
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 (likely(irqchip_in_kernel(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 have just raised the IRQ line and 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);
|
|
|
|
if (unlikely(!timer->enabled))
|
|
return;
|
|
|
|
if (kvm_timer_should_fire(vtimer) != vtimer->irq.level)
|
|
kvm_timer_update_irq(vcpu, !vtimer->irq.level, vtimer);
|
|
|
|
if (kvm_timer_should_fire(ptimer) != ptimer->irq.level)
|
|
kvm_timer_update_irq(vcpu, !ptimer->irq.level, ptimer);
|
|
|
|
phys_timer_emulate(vcpu);
|
|
}
|
|
|
|
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);
|
|
|
|
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 void kvm_timer_vcpu_load_vgic(struct kvm_vcpu *vcpu)
|
|
{
|
|
struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
|
|
bool phys_active;
|
|
int ret;
|
|
|
|
phys_active = vtimer->irq.level ||
|
|
kvm_vgic_map_is_active(vcpu, vtimer->irq.irq);
|
|
|
|
ret = irq_set_irqchip_state(host_vtimer_irq,
|
|
IRQCHIP_STATE_ACTIVE,
|
|
phys_active);
|
|
WARN_ON(ret);
|
|
}
|
|
|
|
static void kvm_timer_vcpu_load_user(struct kvm_vcpu *vcpu)
|
|
{
|
|
kvm_vtimer_update_mask_user(vcpu);
|
|
}
|
|
|
|
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);
|
|
|
|
if (unlikely(!timer->enabled))
|
|
return;
|
|
|
|
if (unlikely(!irqchip_in_kernel(vcpu->kvm)))
|
|
kvm_timer_vcpu_load_user(vcpu);
|
|
else
|
|
kvm_timer_vcpu_load_vgic(vcpu);
|
|
|
|
set_cntvoff(vtimer->cntvoff);
|
|
|
|
vtimer_restore_state(vcpu);
|
|
|
|
/* Set the background timer for the physical timer emulation. */
|
|
phys_timer_emulate(vcpu);
|
|
}
|
|
|
|
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 vtimer->irq.level != vlevel ||
|
|
ptimer->irq.level != 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.
|
|
*/
|
|
set_cntvoff(0);
|
|
}
|
|
|
|
static void unmask_vtimer_irq(struct kvm_vcpu *vcpu)
|
|
{
|
|
struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
|
|
|
|
if (unlikely(!irqchip_in_kernel(vcpu->kvm))) {
|
|
kvm_vtimer_update_mask_user(vcpu);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* If the guest disabled the timer without acking the interrupt, then
|
|
* we must make sure the physical and virtual active states are in
|
|
* sync by deactivating the physical interrupt, because otherwise we
|
|
* wouldn't see the next timer interrupt in the host.
|
|
*/
|
|
if (!kvm_vgic_map_is_active(vcpu, vtimer->irq.irq)) {
|
|
int ret;
|
|
ret = irq_set_irqchip_state(host_vtimer_irq,
|
|
IRQCHIP_STATE_ACTIVE,
|
|
false);
|
|
WARN_ON(ret);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* kvm_timer_sync_hwstate - sync timer state from cpu
|
|
* @vcpu: The vcpu pointer
|
|
*
|
|
* Check if any of the timers have expired while we were running in the guest,
|
|
* and inject an interrupt if that was the case.
|
|
*/
|
|
void kvm_timer_sync_hwstate(struct kvm_vcpu *vcpu)
|
|
{
|
|
struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
|
|
|
|
/*
|
|
* If we entered the guest with the vtimer output asserted we have to
|
|
* check if the guest has modified the timer so that we should lower
|
|
* the line at this point.
|
|
*/
|
|
if (vtimer->irq.level) {
|
|
vtimer->cnt_ctl = read_sysreg_el0(cntv_ctl);
|
|
vtimer->cnt_cval = read_sysreg_el0(cntv_cval);
|
|
if (!kvm_timer_should_fire(vtimer)) {
|
|
kvm_timer_update_irq(vcpu, false, vtimer);
|
|
unmask_vtimer_irq(vcpu);
|
|
}
|
|
}
|
|
}
|
|
|
|
int kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu)
|
|
{
|
|
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);
|
|
|
|
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(void)
|
|
{
|
|
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;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
kvm_info("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;
|
|
}
|
|
|
|
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);
|
|
if (ret)
|
|
return ret;
|
|
|
|
no_vgic:
|
|
preempt_disable();
|
|
timer->enabled = 1;
|
|
if (!irqchip_in_kernel(vcpu->kvm))
|
|
kvm_timer_vcpu_load_user(vcpu);
|
|
else
|
|
kvm_timer_vcpu_load_vgic(vcpu);
|
|
preempt_enable();
|
|
|
|
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;
|
|
}
|