[PATCH V3] ARM: KVM: Allow host virt timer irq to be different from guest timer virt irq

[Christoffer Dall]

On Mon, Apr 29, 2013 at 11:32 PM, Anup Patel <anup.patel at linaro.org> wrote:
> The arch_timer irq numbers (or PPI numbers) 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 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 |    4 ++++
>  arch/arm/kvm/arch_timer.c             |   29 ++++++++++++++++++++---------
>  arch/arm/kvm/reset.c                  |   11 +++++++++++
>  3 files changed, 35 insertions(+), 9 deletions(-)
>
> diff --git a/arch/arm/include/asm/kvm_arch_timer.h b/arch/arm/include/asm/kvm_arch_timer.h
> index 68cb9e1..eeb2a3f 100644
> --- a/arch/arm/include/asm/kvm_arch_timer.h
> +++ b/arch/arm/include/asm/kvm_arch_timer.h
> @@ -61,6 +61,8 @@ struct arch_timer_cpu {
>  #ifdef CONFIG_KVM_ARM_TIMER
>  int kvm_timer_hyp_init(void);
>  int kvm_timer_init(struct kvm *kvm);
> +void kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu,
> +                         const struct kvm_irq_level *irq);
>  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);
> @@ -76,6 +78,8 @@ static inline int kvm_timer_init(struct kvm *kvm)
>         return 0;
>  }
>
> +static inline void kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu,
> +                                       const struct kvm_irq_level *irq) {}
>  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) {}
> diff --git a/arch/arm/kvm/arch_timer.c b/arch/arm/kvm/arch_timer.c
> index 49a7516..5826437 100644
> --- a/arch/arm/kvm/arch_timer.c
> +++ b/arch/arm/kvm/arch_timer.c
> @@ -30,9 +30,7 @@
>
>  static struct timecounter *timecounter;
>  static struct workqueue_struct *wqueue;
> -static struct kvm_irq_level timer_irq = {
> -       .level  = 1,
> -};
> +static unsigned int host_vtimer_irq;
>
>  static cycle_t kvm_phys_timer_read(void)
>  {
> @@ -67,8 +65,8 @@ 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 +154,20 @@ void kvm_timer_sync_hwstate(struct kvm_vcpu *vcpu)
>         timer_arm(timer, ns);
>  }
>
> +void kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu,
> +                         const 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 reset.
> +        */
> +       timer->irq = irq;
> +}
> +
>  void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu)
>  {
>         struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
> @@ -163,12 +175,11 @@ 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;
>  }
>
>  static void kvm_timer_init_interrupt(void *info)
>  {
> -       enable_percpu_irq(timer_irq.irq, 0);
> +       enable_percpu_irq(host_vtimer_irq, 0);
>  }
>
>
> @@ -182,7 +193,7 @@ 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_vtimer_irq);
>                 break;
>         }
>
> @@ -230,7 +241,7 @@ int kvm_timer_hyp_init(void)
>                 goto out;
>         }
>
> -       timer_irq.irq = ppi;
> +       host_vtimer_irq = ppi;
>
>         err = register_cpu_notifier(&kvm_timer_cpu_nb);
>         if (err) {
> diff --git a/arch/arm/kvm/reset.c b/arch/arm/kvm/reset.c
> index b80256b..0b49ad7 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
> @@ -37,6 +38,11 @@ static struct kvm_regs a15_regs_reset = {
>         .usr_regs.ARM_cpsr = SVC_MODE | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT,
>  };
>
> +static const struct kvm_irq_level a15_vtimer_irq = {
> +       .irq = 27,
> +       .level = 1,
> +};
> +
>
>  /*******************************************************************************
>   * Exported reset function
> @@ -52,6 +58,7 @@ static struct kvm_regs a15_regs_reset = {
>  int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
>  {
>         struct kvm_regs *cpu_reset;
> +       const struct kvm_irq_level *cpu_vtimer_irq;
>
>         switch (vcpu->arch.target) {
>         case KVM_ARM_TARGET_CORTEX_A15:
> @@ -59,6 +66,7 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
>                         return -EINVAL;
>                 cpu_reset = &a15_regs_reset;
>                 vcpu->arch.midr = read_cpuid_id();
> +               cpu_vtimer_irq = &a15_vtimer_irq;
>                 break;
>         default:
>                 return -ENODEV;
> @@ -70,5 +78,8 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
>         /* Reset CP15 registers */
>         kvm_reset_coprocs(vcpu);
>
> +       /* Reset arch_timer context */
> +       kvm_timer_vcpu_reset(vcpu, cpu_vtimer_irq);
> +
>         return 0;
>  }
> --
> 1.7.9.5
>
applied (minus the trailing white space - please adjust your editor or
run checkpatch), thanks

-Christoffer