[PATCH V3] ARM: KVM: Allow host virtual timer irq number to be different from guest virtual timer irq number
Anup Patel
anup at brainfault.org
Fri Apr 26 10:48:54 EDT 2013
On Fri, Apr 26, 2013 at 7:17 PM, Marc Zyngier <marc.zyngier at arm.com> wrote:
> On 26/04/13 14:27, Anup Patel wrote:
>> The arch_timer irq numbers (or PPI number) are implementation dependent so, the host virtual timer irq number can be different from guest virtual timer irq number.
>>
>> This patch ensures that host virtual timer irq number is read from DTB and guest virtual timer irq is determined based on guest vcpu target type.
>>
>> Signed-off-by: Anup Patel <anup.patel at linaro.org>
>> Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar at linaro.org>
>> ---
>> arch/arm/include/asm/kvm_arch_timer.h | 7 +++++++
>> arch/arm/include/asm/kvm_host.h | 1 +
>> arch/arm/kvm/arch_timer.c | 32 +++++++++++++++++++++++++-------
>> arch/arm/kvm/guest.c | 15 +++++++++++++++
>> arch/arm/kvm/reset.c | 4 +++-
>> 5 files changed, 51 insertions(+), 8 deletions(-)
>>
>> diff --git a/arch/arm/include/asm/kvm_arch_timer.h b/arch/arm/include/asm/kvm_arch_timer.h
>> index 68cb9e1..c5c135b 100644
>> --- a/arch/arm/include/asm/kvm_arch_timer.h
>> +++ b/arch/arm/include/asm/kvm_arch_timer.h
>> @@ -61,6 +61,7 @@ struct arch_timer_cpu {
>> #ifdef CONFIG_KVM_ARM_TIMER
>> int kvm_timer_hyp_init(void);
>> int kvm_timer_init(struct kvm *kvm);
>> +int kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu);
>> void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu);
>> void kvm_timer_flush_hwstate(struct kvm_vcpu *vcpu);
>> void kvm_timer_sync_hwstate(struct kvm_vcpu *vcpu);
>> @@ -76,7 +77,13 @@ static inline int kvm_timer_init(struct kvm *kvm)
>> return 0;
>> }
>>
>> +static int kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu)
>> +{
>> + return 0;
>> +}
>> +
>> static inline void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu) {}
>> +
>> static inline void kvm_timer_flush_hwstate(struct kvm_vcpu *vcpu) {}
>> static inline void kvm_timer_sync_hwstate(struct kvm_vcpu *vcpu) {}
>> static inline void kvm_timer_vcpu_terminate(struct kvm_vcpu *vcpu) {}
>> diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
>> index 57cb786..cdc0551 100644
>> --- a/arch/arm/include/asm/kvm_host.h
>> +++ b/arch/arm/include/asm/kvm_host.h
>> @@ -43,6 +43,7 @@
>> struct kvm_vcpu;
>> u32 *kvm_vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num, u32 mode);
>> int kvm_target_cpu(void);
>> +struct kvm_irq_level *kvm_target_timer_irq(struct kvm_vcpu *vcpu);
>> int kvm_reset_vcpu(struct kvm_vcpu *vcpu);
>> void kvm_reset_coprocs(struct kvm_vcpu *vcpu);
>>
>> diff --git a/arch/arm/kvm/arch_timer.c b/arch/arm/kvm/arch_timer.c
>> index 49a7516..e558115 100644
>> --- a/arch/arm/kvm/arch_timer.c
>> +++ b/arch/arm/kvm/arch_timer.c
>> @@ -30,7 +30,7 @@
>>
>> static struct timecounter *timecounter;
>> static struct workqueue_struct *wqueue;
>> -static struct kvm_irq_level timer_irq = {
>> +static struct kvm_irq_level host_timer_irq = {
>> .level = 1,
>> };
>>
>> @@ -67,8 +67,8 @@ static void kvm_timer_inject_irq(struct kvm_vcpu *vcpu)
>>
>> timer->cntv_ctl |= ARCH_TIMER_CTRL_IT_MASK;
>> kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id,
>> - vcpu->arch.timer_cpu.irq->irq,
>> - vcpu->arch.timer_cpu.irq->level);
>> + timer->irq->irq,
>> + timer->irq->level);
>> }
>>
>> static irqreturn_t kvm_arch_timer_handler(int irq, void *dev_id)
>> @@ -156,6 +156,24 @@ void kvm_timer_sync_hwstate(struct kvm_vcpu *vcpu)
>> timer_arm(timer, ns);
>> }
>>
>> +int kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu)
>
> If you change this function to:
> int kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu, struct kvm_irq_level *irq)
>
> ...
>
>> +{
>> + struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
>> +
>> + /*
>> + * The vcpu timer irq number cannot be determined in
>> + * kvm_timer_vcpu_init() because it is called much before
>> + * kvm_vcpu_set_target(). To handle this, we determine
>> + * vcpu timer irq number when the vcpu is resetted.
>> + */
>> + timer->irq = kvm_target_timer_irq(vcpu);
>> + if (!timer->irq) {
>> + return -ENODEV;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu)
>> {
>> struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
>> @@ -163,12 +181,12 @@ void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu)
>> INIT_WORK(&timer->expired, kvm_timer_inject_irq_work);
>> hrtimer_init(&timer->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
>> timer->timer.function = kvm_timer_expire;
>> - timer->irq = &timer_irq;
>> + timer->irq = NULL;
>> }
>>
>> static void kvm_timer_init_interrupt(void *info)
>> {
>> - enable_percpu_irq(timer_irq.irq, 0);
>> + enable_percpu_irq(host_timer_irq.irq, 0);
>> }
>>
>>
>> @@ -182,7 +200,7 @@ static int kvm_timer_cpu_notify(struct notifier_block *self,
>> break;
>> case CPU_DYING:
>> case CPU_DYING_FROZEN:
>> - disable_percpu_irq(timer_irq.irq);
>> + disable_percpu_irq(host_timer_irq.irq);
>> break;
>> }
>>
>> @@ -230,7 +248,7 @@ int kvm_timer_hyp_init(void)
>> goto out;
>> }
>>
>> - timer_irq.irq = ppi;
>> + host_timer_irq.irq = ppi;
>>
>> err = register_cpu_notifier(&kvm_timer_cpu_nb);
>> if (err) {
>> diff --git a/arch/arm/kvm/guest.c b/arch/arm/kvm/guest.c
>> index 152d036..6fbc988 100644
>> --- a/arch/arm/kvm/guest.c
>> +++ b/arch/arm/kvm/guest.c
>> @@ -36,6 +36,11 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
>> { NULL }
>> };
>>
>> +static struct kvm_irq_level target_cortex_a15_timer_irq = {
>> + .irq = 27,
>> + .level = 1,
>> +};
>
> ... Move this to reset.c ...
>
>> int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
>> {
>> return 0;
>> @@ -197,6 +202,16 @@ int __attribute_const__ kvm_target_cpu(void)
>> }
>> }
>>
>> +struct kvm_irq_level *kvm_target_timer_irq(struct kvm_vcpu *vcpu)
>> +{
>> + switch (vcpu->arch.target) {
>> + case KVM_ARM_TARGET_CORTEX_A15:
>> + return &target_cortex_a15_timer_irq;
>> + default:
>> + return NULL;
>> + };
>> +}
>
> ... drop this ...
>
>> int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
>> const struct kvm_vcpu_init *init)
>> {
>> diff --git a/arch/arm/kvm/reset.c b/arch/arm/kvm/reset.c
>> index b80256b..655e567 100644
>> --- a/arch/arm/kvm/reset.c
>> +++ b/arch/arm/kvm/reset.c
>> @@ -26,6 +26,7 @@
>> #include <asm/cputype.h>
>> #include <asm/kvm_arm.h>
>> #include <asm/kvm_coproc.h>
>> +#include <asm/kvm_arch_timer.h>
>>
>> /******************************************************************************
>> * Cortex-A15 Reset Values
>> @@ -70,5 +71,6 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
>
> ...
>
> In case KVM_ARM_TARGET_CORTEX_A15:
> [...]
> timer_irq = &target_cortex_a15_timer_irq;
>
> ...
>
>> /* Reset CP15 registers */
>> kvm_reset_coprocs(vcpu);
>>
>> - return 0;
>> + /* Reset arch_timer context */
>> + return kvm_timer_vcpu_reset(vcpu);
>
> ... and call kvm_timer_vcpu_reset(vcpu, timer_irq)
>
> it would look much better.
>
> M.
> --
> Jazz is not dead. It just smells funny...
>
>
> _______________________________________________
> kvmarm mailing list
> kvmarm at lists.cs.columbia.edu
> https://lists.cs.columbia.edu/cucslists/listinfo/kvmarm
Sure, I incorporate all above comments and send revised patch.
Regards,
Anup
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