[PATCH v5 2/4] ARM: KVM: arch_timers: Add guest timer core support
Christoffer Dall
c.dall at virtualopensystems.com
Mon Jan 14 14:19:58 EST 2013
On Mon, Jan 14, 2013 at 10:18 AM, Will Deacon <will.deacon at arm.com> wrote:
> On Tue, Jan 08, 2013 at 06:43:20PM +0000, Christoffer Dall wrote:
>> From: Marc Zyngier <marc.zyngier at arm.com>
>>
>> Add some the architected timer related infrastructure, and support timer
>> interrupt injection, which can happen as a resultof three possible
>> events:
>>
>> - The virtual timer interrupt has fired while we were still
>> executing the guest
>> - The timer interrupt hasn't fired, but it expired while we
>> were doing the world switch
>> - A hrtimer we programmed earlier has fired
>
> [...]
>
>> +void kvm_timer_sync_to_cpu(struct kvm_vcpu *vcpu)
>> +{
>> + struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
>> +
>> + /*
>> + * We're about to run this vcpu again, so there is no need to
>> + * keep the background timer running, as we're about to
>> + * populate the CPU timer again.
>> + */
>> + timer_disarm(timer);
>> +}
>> +
>> +void kvm_timer_sync_from_cpu(struct kvm_vcpu *vcpu)
>> +{
>> + struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
>> + cycle_t cval, now;
>> + u64 ns;
>> +
>> + /* Check if the timer is enabled and unmasked first */
>> + if ((timer->cntv_ctl & 3) != 1)
>> + return;
>> +
>> + cval = timer->cntv_cval;
>> + now = kvm_phys_timer_read() - vcpu->kvm->arch.timer.cntvoff;
>> +
>> + BUG_ON(timer_is_armed(timer));
>> +
>> + if (cval <= now) {
>> + /*
>> + * Timer has already expired while we were not
>> + * looking. Inject the interrupt and carry on.
>> + */
>> + kvm_timer_inject_irq(vcpu);
>> + return;
>> + }
>> +
>> + ns = cyclecounter_cyc2ns(timecounter->cc, cval - now);
>> + timer_arm(timer, ns);
>> +}
>
> Please use flush/sync terminology to match the rest of arch/arm/.
>
ok, the following fixes this for both timers and the vgic:
commit 1b68f39459dbc797f6766c103edf2c1053984161
Author: Christoffer Dall <c.dall at virtualopensystems.com>
Date: Mon Jan 14 14:16:31 2013 -0500
KVM: ARM: vgic: use sync/flush terminology
Use sync/flush for saving state to/from CPUs to be consistent with
other uses in arch/arm.
Cc: Will Deacon <will.deacon at arm.com>
Signed-off-by: Christoffer Dall <c.dall at virtualopensystems.com>
diff --git a/arch/arm/include/asm/kvm_vgic.h b/arch/arm/include/asm/kvm_vgic.h
index 5e81e28..f5f270b 100644
--- a/arch/arm/include/asm/kvm_vgic.h
+++ b/arch/arm/include/asm/kvm_vgic.h
@@ -149,8 +149,8 @@ int kvm_vgic_hyp_init(void);
int kvm_vgic_init(struct kvm *kvm);
int kvm_vgic_create(struct kvm *kvm);
int kvm_vgic_vcpu_init(struct kvm_vcpu *vcpu);
-void kvm_vgic_sync_to_cpu(struct kvm_vcpu *vcpu);
-void kvm_vgic_sync_from_cpu(struct kvm_vcpu *vcpu);
+void kvm_vgic_flush(struct kvm_vcpu *vcpu);
+void kvm_vgic_sync(struct kvm_vcpu *vcpu);
int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int irq_num,
bool level);
int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu);
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index f986718..7921bc4 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -714,7 +714,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu,
struct kvm_run *run)
update_vttbr(vcpu->kvm);
- kvm_vgic_sync_to_cpu(vcpu);
+ kvm_vgic_flush(vcpu);
kvm_timer_flush(vcpu);
local_irq_disable();
@@ -730,7 +730,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu,
struct kvm_run *run)
if (ret <= 0 || need_new_vmid_gen(vcpu->kvm)) {
local_irq_enable();
kvm_timer_sync(vcpu);
- kvm_vgic_sync_from_cpu(vcpu);
+ kvm_vgic_sync(vcpu);
continue;
}
@@ -770,7 +770,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu,
struct kvm_run *run)
*************************************************************/
kvm_timer_sync(vcpu);
- kvm_vgic_sync_from_cpu(vcpu);
+ kvm_vgic_sync(vcpu);
ret = handle_exit(vcpu, run, ret);
}
diff --git a/arch/arm/kvm/vgic.c b/arch/arm/kvm/vgic.c
index 7eb94fa..25daa07 100644
--- a/arch/arm/kvm/vgic.c
+++ b/arch/arm/kvm/vgic.c
@@ -946,7 +946,7 @@ static bool vgic_queue_hwirq(struct kvm_vcpu *vcpu, int irq)
* Fill the list registers with pending interrupts before running the
* guest.
*/
-static void __kvm_vgic_sync_to_cpu(struct kvm_vcpu *vcpu)
+static void __kvm_vgic_flush(struct kvm_vcpu *vcpu)
{
struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
@@ -1009,7 +1009,7 @@ static bool vgic_process_maintenance(struct
kvm_vcpu *vcpu)
* We do not need to take the distributor lock here, since the only
* action we perform is clearing the irq_active_bit for an EOIed
* level interrupt. There is a potential race with
- * the queuing of an interrupt in __kvm_sync_to_cpu(), where we check
+ * the queuing of an interrupt in __kvm_vgic_flush(), where we check
* if the interrupt is already active. Two possibilities:
*
* - The queuing is occurring on the same vcpu: cannot happen,
@@ -1055,7 +1055,7 @@ static bool vgic_process_maintenance(struct
kvm_vcpu *vcpu)
* the distributor here (the irq_pending_on_cpu bit is safe to set),
* so there is no need for taking its lock.
*/
-static void __kvm_vgic_sync_from_cpu(struct kvm_vcpu *vcpu)
+static void __kvm_vgic_sync(struct kvm_vcpu *vcpu)
{
struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
@@ -1085,7 +1085,7 @@ static void __kvm_vgic_sync_from_cpu(struct
kvm_vcpu *vcpu)
set_bit(vcpu->vcpu_id, &dist->irq_pending_on_cpu);
}
-void kvm_vgic_sync_to_cpu(struct kvm_vcpu *vcpu)
+void kvm_vgic_flush(struct kvm_vcpu *vcpu)
{
struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
@@ -1093,16 +1093,16 @@ void kvm_vgic_sync_to_cpu(struct kvm_vcpu *vcpu)
return;
spin_lock(&dist->lock);
- __kvm_vgic_sync_to_cpu(vcpu);
+ __kvm_vgic_flush(vcpu);
spin_unlock(&dist->lock);
}
-void kvm_vgic_sync_from_cpu(struct kvm_vcpu *vcpu)
+void kvm_vgic_sync(struct kvm_vcpu *vcpu)
{
if (!irqchip_in_kernel(vcpu->kvm))
return;
- __kvm_vgic_sync_from_cpu(vcpu);
+ __kvm_vgic_sync(vcpu);
}
int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu)
--
commit b9e08fdd32b7f3da3ad0b287c4da575b3b6c23d7
Author: Christoffer Dall <c.dall at virtualopensystems.com>
Date: Mon Jan 14 14:15:31 2013 -0500
KVM: ARM: timers: use sync/flush terminology
Use sync/flush for saving state to/from CPUs to be consistent with other
uses in arch/arm.
Cc: Will Deacon <will.deacon at arm.com>
Signed-off-by: Christoffer Dall <c.dall at virtualopensystems.com>
diff --git a/arch/arm/include/asm/kvm_arch_timer.h
b/arch/arm/include/asm/kvm_arch_timer.h
index aed1c42..2af5096 100644
--- a/arch/arm/include/asm/kvm_arch_timer.h
+++ b/arch/arm/include/asm/kvm_arch_timer.h
@@ -62,8 +62,8 @@ struct arch_timer_cpu {
int kvm_timer_hyp_init(void);
int kvm_timer_init(struct kvm *kvm);
void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu);
-void kvm_timer_sync_to_cpu(struct kvm_vcpu *vcpu);
-void kvm_timer_sync_from_cpu(struct kvm_vcpu *vcpu);
+void kvm_timer_flush(struct kvm_vcpu *vcpu);
+void kvm_timer_sync(struct kvm_vcpu *vcpu);
void kvm_timer_vcpu_terminate(struct kvm_vcpu *vcpu);
#else
static inline int kvm_timer_hyp_init(void)
diff --git a/arch/arm/kvm/arch_timer.c b/arch/arm/kvm/arch_timer.c
index 6cb9aa3..3f2580f 100644
--- a/arch/arm/kvm/arch_timer.c
+++ b/arch/arm/kvm/arch_timer.c
@@ -101,7 +101,14 @@ static enum hrtimer_restart
kvm_timer_expire(struct hrtimer *hrt)
return HRTIMER_NORESTART;
}
-void kvm_timer_sync_to_cpu(struct kvm_vcpu *vcpu)
+/**
+ * kvm_timer_flush - prepare to move the virt timer to the cpu
+ * @vcpu: The vcpu pointer
+ *
+ * Disarm any pending soft timers, since the world-switch code will write the
+ * virtual timer state back to the physical CPU.
+ */
+void kvm_timer_flush(struct kvm_vcpu *vcpu)
{
struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
@@ -113,7 +120,14 @@ void kvm_timer_sync_to_cpu(struct kvm_vcpu *vcpu)
timer_disarm(timer);
}
-void kvm_timer_sync_from_cpu(struct kvm_vcpu *vcpu)
+/**
+ * kvm_timer_sync - sync timer state from cpu
+ * @vcpu: The vcpu pointer
+ *
+ * Check if the virtual timer was armed and either schedule a corresponding
+ * soft timer or inject directly if already expired.
+ */
+void kvm_timer_sync(struct kvm_vcpu *vcpu)
{
struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
cycle_t cval, now;
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index fdd4a7c..f986718 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -715,7 +715,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu,
struct kvm_run *run)
update_vttbr(vcpu->kvm);
kvm_vgic_sync_to_cpu(vcpu);
- kvm_timer_sync_to_cpu(vcpu);
+ kvm_timer_flush(vcpu);
local_irq_disable();
@@ -729,7 +729,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu,
struct kvm_run *run)
if (ret <= 0 || need_new_vmid_gen(vcpu->kvm)) {
local_irq_enable();
- kvm_timer_sync_from_cpu(vcpu);
+ kvm_timer_sync(vcpu);
kvm_vgic_sync_from_cpu(vcpu);
continue;
}
@@ -769,7 +769,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu,
struct kvm_run *run)
* Back from guest
*************************************************************/
- kvm_timer_sync_from_cpu(vcpu);
+ kvm_timer_sync(vcpu);
kvm_vgic_sync_from_cpu(vcpu);
ret = handle_exit(vcpu, run, ret);
--
Thanks,
-Christoffer
More information about the linux-arm-kernel
mailing list