[PATCH 11/14] KVM: arm/arm64: timer: Rework data structures for multiple timers

Christoffer Dall
2019-01-24T14:00:29Z

Prepare for having 4 timer data structures (2 for now).

Change loaded to an enum so that we know not just whether *some* state
is loaded on the CPU, but also *which* state is loaded.

Move loaded to the cpu data structure and not the individual timer
structure, in preparation for assigning the EL1 phys timer as well.

Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
---
include/kvm/arm_arch_timer.h | 44 ++++++++++++++-------------
virt/kvm/arm/arch_timer.c | 58 +++++++++++++++++++-----------------
2 files changed, 54 insertions(+), 48 deletions(-)

diff --git a/include/kvm/arm_arch_timer.h b/include/kvm/arm_arch_timer.h
index d26b7fde9935..d40fe57a2d0d 100644
--- a/include/kvm/arm_arch_timer.h
+++ b/include/kvm/arm_arch_timer.h
@@ -36,6 +36,8 @@ enum kvm_arch_timer_regs {
};

struct arch_timer_context {
+ struct kvm_vcpu *vcpu;
+
/* Registers: control register, timer value */
u32 cnt_ctl;
u64 cnt_cval;
@@ -43,32 +45,34 @@ struct arch_timer_context {
/* Timer IRQ */
struct kvm_irq_level irq;

- /*
- * We have multiple paths which can save/restore the timer state
- * onto the hardware, so we need some way of keeping track of
- * where the latest state is.
- *
- * loaded == true: State is loaded on the hardware registers.
- * loaded == false: State is stored in memory.
- */
- bool loaded;
-
/* Virtual offset */
- u64 cntvoff;
+ u64 cntvoff;
+
+ /* Emulated Timer (may be unused) */
+ struct hrtimer hrtimer;
+};
+
+enum loaded_timer_state {
+ TIMER_NOT_LOADED,
+ TIMER_EL1_LOADED,
};

struct arch_timer_cpu {
- struct arch_timer_context vtimer;
- struct arch_timer_context ptimer;
+ struct arch_timer_context timers[NR_KVM_TIMERS];

/* Background timer used when the guest is not running */
struct hrtimer bg_timer;

- /* Physical timer emulation */
- struct hrtimer phys_timer;
-
/* Is the timer enabled */
bool enabled;
+
+ /*
+ * We have multiple paths which can save/restore the timer state
+ * onto the hardware, and for nested virt the EL1 hardware timers can
+ * contain state from either the VM's EL1 timers or EL2 timers, so we
+ * need some way of keeping track of where the latest state is.
+ */
+ enum loaded_timer_state loaded;
};

int kvm_timer_hyp_init(bool);
@@ -98,10 +102,10 @@ void kvm_timer_init_vhe(void);

bool kvm_arch_timer_get_input_level(int vintid);

-#define vcpu_vtimer(v) (&(v)->arch.timer_cpu.vtimer)
-#define vcpu_ptimer(v) (&(v)->arch.timer_cpu.ptimer)
-#define vcpu_get_timer(v,t) \
- (t == TIMER_VTIMER ? vcpu_vtimer(v) : vcpu_ptimer(v))
+#define vcpu_timer(v) (&(v)->arch.timer_cpu)
+#define vcpu_get_timer(v,t) (&vcpu_timer(v)->timers[(t)])
+#define vcpu_vtimer(v) (&(v)->arch.timer_cpu.timers[TIMER_VTIMER])
+#define vcpu_ptimer(v) (&(v)->arch.timer_cpu.timers[TIMER_PTIMER])

u64 kvm_arm_timer_read_sysreg(struct kvm_vcpu *vcpu,
enum kvm_arch_timers tmr,
diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c
index 9502bb91776b..8b0eca5fbad1 100644
--- a/virt/kvm/arm/arch_timer.c
+++ b/virt/kvm/arm/arch_timer.c
@@ -184,13 +184,11 @@ static enum hrtimer_restart kvm_bg_timer_expire(struct hrtimer *hrt)
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);
+ ptimer = container_of(hrt, struct arch_timer_context, hrtimer);
+ vcpu = ptimer->vcpu;

/*
* Check that the timer has really expired from the guest's
@@ -209,9 +207,10 @@ static enum hrtimer_restart kvm_phys_timer_expire(struct hrtimer *hrt)

static bool kvm_timer_should_fire(struct arch_timer_context *timer_ctx)
{
+ struct arch_timer_cpu *timer = vcpu_timer(timer_ctx->vcpu);
u64 cval, now;

- if (timer_ctx->loaded) {
+ if (timer->loaded == TIMER_EL1_LOADED) {
u32 cnt_ctl;

/* Only the virtual timer can be loaded so far */
@@ -280,7 +279,6 @@ static void kvm_timer_update_irq(struct kvm_vcpu *vcpu, bool new_level,
/* 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);

/*
@@ -289,11 +287,11 @@ static void phys_timer_emulate(struct kvm_vcpu *vcpu)
* 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);
+ soft_timer_cancel(&ptimer->hrtimer);
return;
}

- soft_timer_start(&timer->phys_timer, kvm_timer_compute_delta(ptimer));
+ soft_timer_start(&ptimer->hrtimer, kvm_timer_compute_delta(ptimer));
}

/*
@@ -303,7 +301,7 @@ static void phys_timer_emulate(struct kvm_vcpu *vcpu)
*/
static void kvm_timer_update_state(struct kvm_vcpu *vcpu)
{
- struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
+ struct arch_timer_cpu *timer = vcpu_timer(vcpu);
struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
struct arch_timer_context *ptimer = vcpu_ptimer(vcpu);
bool level;
@@ -329,13 +327,13 @@ static void kvm_timer_update_state(struct kvm_vcpu *vcpu)

static void vtimer_save_state(struct kvm_vcpu *vcpu)
{
- struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
+ struct arch_timer_cpu *timer = vcpu_timer(vcpu);
struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
unsigned long flags;

local_irq_save(flags);

- if (!vtimer->loaded)
+ if (timer->loaded == TIMER_NOT_LOADED)
goto out;

if (timer->enabled) {
@@ -347,7 +345,7 @@ static void vtimer_save_state(struct kvm_vcpu *vcpu)
write_sysreg_el0(0, cntv_ctl);
isb();

- vtimer->loaded = false;
+ timer->loaded = TIMER_NOT_LOADED;
out:
local_irq_restore(flags);
}
@@ -359,7 +357,7 @@ static void vtimer_save_state(struct kvm_vcpu *vcpu)
*/
static void kvm_timer_blocking(struct kvm_vcpu *vcpu)
{
- struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
+ struct arch_timer_cpu *timer = vcpu_timer(vcpu);
struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
struct arch_timer_context *ptimer = vcpu_ptimer(vcpu);

@@ -379,20 +377,20 @@ static void kvm_timer_blocking(struct kvm_vcpu *vcpu)

static void kvm_timer_unblocking(struct kvm_vcpu *vcpu)
{
- struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
+ struct arch_timer_cpu *timer = vcpu_timer(vcpu);

soft_timer_cancel(&timer->bg_timer);
}

static void vtimer_restore_state(struct kvm_vcpu *vcpu)
{
- struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
+ struct arch_timer_cpu *timer = vcpu_timer(vcpu);
struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
unsigned long flags;

local_irq_save(flags);

- if (vtimer->loaded)
+ if (timer->loaded == TIMER_EL1_LOADED)
goto out;

if (timer->enabled) {
@@ -401,7 +399,7 @@ static void vtimer_restore_state(struct kvm_vcpu *vcpu)
write_sysreg_el0(vtimer->cnt_ctl, cntv_ctl);
}

- vtimer->loaded = true;
+ timer->loaded = TIMER_EL1_LOADED;
out:
local_irq_restore(flags);
}
@@ -462,7 +460,7 @@ static void kvm_timer_vcpu_load_nogic(struct kvm_vcpu *vcpu)

void kvm_timer_vcpu_load(struct kvm_vcpu *vcpu)
{
- struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
+ struct arch_timer_cpu *timer = vcpu_timer(vcpu);
struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
struct arch_timer_context *ptimer = vcpu_ptimer(vcpu);

@@ -507,7 +505,8 @@ bool kvm_timer_should_notify_user(struct kvm_vcpu *vcpu)

void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu)
{
- struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
+ struct arch_timer_cpu *timer = vcpu_timer(vcpu);
+ struct arch_timer_context *ptimer = vcpu_ptimer(vcpu);

if (unlikely(!timer->enabled))
return;
@@ -523,7 +522,7 @@ void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu)
* 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);
+ soft_timer_cancel(&ptimer->hrtimer);

if (swait_active(kvm_arch_vcpu_wq(vcpu)))
kvm_timer_blocking(vcpu);
@@ -559,7 +558,7 @@ static void unmask_vtimer_irq_user(struct kvm_vcpu *vcpu)

void kvm_timer_sync_hwstate(struct kvm_vcpu *vcpu)
{
- struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
+ struct arch_timer_cpu *timer = vcpu_timer(vcpu);

if (unlikely(!timer->enabled))
return;
@@ -570,7 +569,7 @@ void kvm_timer_sync_hwstate(struct kvm_vcpu *vcpu)

int kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu)
{
- struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
+ struct arch_timer_cpu *timer = vcpu_timer(vcpu);
struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
struct arch_timer_context *ptimer = vcpu_ptimer(vcpu);

@@ -611,22 +610,25 @@ static void update_vtimer_cntvoff(struct kvm_vcpu *vcpu, u64 cntvoff)

void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu)
{
- struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
+ 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());
- vcpu_ptimer(vcpu)->cntvoff = 0;
+ ptimer->cntvoff = 0;

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;
+ hrtimer_init(&ptimer->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+ ptimer->hrtimer.function = kvm_phys_timer_expire;

vtimer->irq.irq = default_vtimer_irq.irq;
ptimer->irq.irq = default_ptimer_irq.irq;
+
+ vtimer->vcpu = vcpu;
+ ptimer->vcpu = vcpu;
}

static void kvm_timer_init_interrupt(void *info)
@@ -859,7 +861,7 @@ int kvm_timer_hyp_init(bool has_gic)

void kvm_timer_vcpu_terminate(struct kvm_vcpu *vcpu)
{
- struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
+ struct arch_timer_cpu *timer = vcpu_timer(vcpu);

soft_timer_cancel(&timer->bg_timer);
}
@@ -903,7 +905,7 @@ bool kvm_arch_timer_get_input_level(int vintid)

int kvm_timer_enable(struct kvm_vcpu *vcpu)
{
- struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
+ struct arch_timer_cpu *timer = vcpu_timer(vcpu);
struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
int ret;

--
2.18.0