On 07/20/2012 12:00 AM, Bharat Bhushan wrote:
> This patch adds the watchdog emulation in KVM. The watchdog
> emulation is enabled by KVM_ENABLE_CAP(KVM_CAP_PPC_WDT) ioctl.
> The kernel timer are used for watchdog emulation and emulates
> h/w watchdog state machine. On watchdog timer expiry, it exit to QEMU
> if TCR.WRC is non ZERO. QEMU can reset/shutdown etc depending upon how
> it is configured.
>
> Signed-off-by: Liu Yu <yu.liu@xxxxxxxxxxxxx>
> Signed-off-by: Scott Wood <scottwood@xxxxxxxxxxxxx>
> Signed-off-by: Bharat Bhushan <bharat.bhushan@xxxxxxxxxxxxx>
> [bharat.bhushan@xxxxxxxxxxxxx: reworked patch]
Typically the [] note goes immediately before your signoff (but after
the others).
> +static void arm_next_watchdog(struct kvm_vcpu *vcpu)
> +{
> + unsigned long nr_jiffies;
> +
> + spin_lock(&vcpu->arch.wdt_lock);
> + nr_jiffies = watchdog_next_timeout(vcpu);
> + /*
> + * If the number of jiffies of watchdog timer >= NEXT_TIMER_MAX_DELTA
> + * then do not run the watchdog timer as this can break timer APIs.
> + */
> + if (nr_jiffies < NEXT_TIMER_MAX_DELTA)
> + mod_timer(&vcpu->arch.wdt_timer, jiffies + nr_jiffies);
> + else
> + del_timer(&vcpu->arch.wdt_timer);
> + spin_unlock(&vcpu->arch.wdt_lock);
> +}
This needs to be an irqsave lock.
> @@ -386,13 +387,23 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
> #ifdef CONFIG_KVM_EXIT_TIMING
> mutex_init(&vcpu->arch.exit_timing_lock);
> #endif
> -
> +#ifdef CONFIG_BOOKE
> + spin_lock_init(&vcpu->arch.wdt_lock);
> + /* setup watchdog timer once */
> + setup_timer(&vcpu->arch.wdt_timer, kvmppc_watchdog_func,
> + (unsigned long)vcpu);
> +#endif
> return 0;
> }
Can you do this in kvmppc_booke_init()?
>
> void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
> {
> kvmppc_mmu_destroy(vcpu);
> +#ifdef CONFIG_BOOKE
> + spin_lock(&vcpu->arch.wdt_lock);
> + del_timer(&vcpu->arch.wdt_timer);
> + spin_unlock(&vcpu->arch.wdt_lock);
> +#endif
> }
Don't acquire the lock here, but use del_timer_sync().
-Scott
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