Please ignore this as I forget to get [v5] is subject..
Thanks
-Bharat
> -----Original Message-----
> From: Bhushan Bharat-R65777
> Sent: Friday, July 20, 2012 10:29 AM
> To: kvm-ppc@vger.kernel.org; k...@vger.kernel.org; ag...@suse.de
> Cc: Bhushan Bharat-R65777
> Subject: [PATCH 2/2] KVM: PPC: booke: Add watchdog emulation
>
> 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....@freescale.com>
> Signed-off-by: Scott Wood <scottw...@freescale.com>
> Signed-off-by: Bharat Bhushan <bharat.bhus...@freescale.com>
> [bharat.bhus...@freescale.com: reworked patch]
>
> ---
> v5:
> - Checking that TSR_ENW/TSR_WIS are still set on KVM_EXIT_WATCHDOG.
> - Moved watchdog_next_timeout() in lock.
>
> v4:
> - in v3 i forgot to add Scott Wood and Liu Yu signoff
>
> v3:
> - Using KVM_REQ_WATCHDOG for userspace exit.
> - TSR changes left for vcpu thread.
> - Other review comments on v2
>
> arch/powerpc/include/asm/kvm_host.h | 3 +
> arch/powerpc/include/asm/kvm_ppc.h | 3 +
> arch/powerpc/include/asm/reg_booke.h | 7 ++
> arch/powerpc/kvm/booke.c | 140
> ++++++++++++++++++++++++++++++++++
> arch/powerpc/kvm/booke_emulate.c | 8 ++
> arch/powerpc/kvm/powerpc.c | 19 +++++-
> include/linux/kvm.h | 2 +
> include/linux/kvm_host.h | 1 +
> 8 files changed, 182 insertions(+), 1 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/kvm_host.h
> b/arch/powerpc/include/asm/kvm_host.h
> index 50ea12f..43cac48 100644
> --- a/arch/powerpc/include/asm/kvm_host.h
> +++ b/arch/powerpc/include/asm/kvm_host.h
> @@ -467,6 +467,8 @@ struct kvm_vcpu_arch {
> ulong fault_esr;
> ulong queued_dear;
> ulong queued_esr;
> + spinlock_t wdt_lock;
> + struct timer_list wdt_timer;
> u32 tlbcfg[4];
> u32 mmucfg;
> u32 epr;
> @@ -482,6 +484,7 @@ struct kvm_vcpu_arch {
> u8 osi_needed;
> u8 osi_enabled;
> u8 papr_enabled;
> + u8 watchdog_enabled;
> u8 sane;
> u8 cpu_type;
> u8 hcall_needed;
> diff --git a/arch/powerpc/include/asm/kvm_ppc.h
> b/arch/powerpc/include/asm/kvm_ppc.h
> index 0124937..e5cf4b9 100644
> --- a/arch/powerpc/include/asm/kvm_ppc.h
> +++ b/arch/powerpc/include/asm/kvm_ppc.h
> @@ -67,6 +67,7 @@ extern int kvmppc_emulate_mmio(struct kvm_run *run, struct
> kvm_vcpu *vcpu); extern void kvmppc_emulate_dec(struct kvm_vcpu *vcpu);
> extern
> u32 kvmppc_get_dec(struct kvm_vcpu *vcpu, u64 tb); extern void
> kvmppc_decrementer_func(unsigned long data);
> +extern void kvmppc_watchdog_func(unsigned long data);
> extern int kvmppc_sanity_check(struct kvm_vcpu *vcpu);
>
> /* Core-specific hooks */
> @@ -104,6 +105,8 @@ extern void kvmppc_core_queue_external(struct kvm_vcpu
> *vcpu,
> struct kvm_interrupt *irq); extern
> void
> kvmppc_core_dequeue_external(struct kvm_vcpu *vcpu,
> struct kvm_interrupt *irq);
> +extern void kvmppc_core_queue_watchdog(struct kvm_vcpu *vcpu); extern
> +void kvmppc_core_dequeue_watchdog(struct kvm_vcpu *vcpu);
>
> extern int kvmppc_core_emulate_op(struct kvm_run *run, struct kvm_vcpu *vcpu,
> unsigned int op, int *advance); diff --git
> a/arch/powerpc/include/asm/reg_booke.h b/arch/powerpc/include/asm/reg_booke.h
> index 2d916c4..e07e6af 100644
> --- a/arch/powerpc/include/asm/reg_booke.h
> +++ b/arch/powerpc/include/asm/reg_booke.h
> @@ -539,6 +539,13 @@
> #define TCR_FIE 0x00800000 /* FIT Interrupt Enable */
> #define TCR_ARE 0x00400000 /* Auto Reload Enable */
>
> +#ifdef CONFIG_E500
> +#define TCR_GET_WP(tcr) ((((tcr) & 0xC0000000) >> 30) | \
> + (((tcr) & 0x1E0000) >> 15))
> +#else
> +#define TCR_GET_WP(tcr) (((tcr) & 0xC0000000) >> 30) #endif
> +
> /* Bit definitions for the TSR. */
> #define TSR_ENW 0x80000000 /* Enable Next Watchdog */
> #define TSR_WIS 0x40000000 /* WDT Interrupt Status */
> diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c index
> d25a097..71b4ce9 100644
> --- a/arch/powerpc/kvm/booke.c
> +++ b/arch/powerpc/kvm/booke.c
> @@ -206,6 +206,16 @@ void kvmppc_core_dequeue_external(struct kvm_vcpu *vcpu,
> clear_bit(BOOKE_IRQPRIO_EXTERNAL_LEVEL, &vcpu->arch.pending_exceptions);
> }
>
> +void kvmppc_core_queue_watchdog(struct kvm_vcpu *vcpu) {
> + kvmppc_booke_queue_irqprio(vcpu, BOOKE_IRQPRIO_WATCHDOG); }
> +
> +void kvmppc_core_dequeue_watchdog(struct kvm_vcpu *vcpu) {
> + clear_bit(BOOKE_IRQPRIO_WATCHDOG, &vcpu->arch.pending_exceptions); }
> +
> static void set_guest_srr(struct kvm_vcpu *vcpu, unsigned long srr0, u32
> srr1)
> { #ifdef CONFIG_KVM_BOOKE_HV @@ -325,6 +335,7 @@ static int
> kvmppc_booke_irqprio_deliver(struct kvm_vcpu *vcpu,
> msr_mask = MSR_CE | MSR_ME | MSR_DE;
> int_class = INT_CLASS_NONCRIT;
> break;
> + case BOOKE_IRQPRIO_WATCHDOG:
> case BOOKE_IRQPRIO_CRITICAL:
> case BOOKE_IRQPRIO_DBELL_CRIT:
> allowed = vcpu->arch.shared->msr & MSR_CE; @@ -404,12 +415,113
> @@
> static int kvmppc_booke_irqprio_deliver(struct kvm_vcpu *vcpu,
> return allowed;
> }
>
> +/*
> + * Return the number of jiffies until the next timeout. If the timeout
> +is
> + * longer than the NEXT_TIMER_MAX_DELTA, then return
> +NEXT_TIMER_MAX_DELTA
> + * because the larger value can break the timer APIs.
> + */
> +static unsigned long watchdog_next_timeout(struct kvm_vcpu *vcpu) {
> + u64 tb, wdt_tb, wdt_ticks = 0;
> + u64 nr_jiffies = 0;
> + u32 period = TCR_GET_WP(vcpu->arch.tcr);
> +
> + wdt_tb = 1ULL << (63 - period);
> + tb = get_tb();
> + /*
> + * The watchdog timeout will hapeen when TB bit corresponding
> + * to watchdog will toggle from 0 to 1.
> + */
> + if (tb & wdt_tb)
> + wdt_ticks = wdt_tb;
> +
> + wdt_ticks += wdt_tb - (tb & (wdt_tb - 1));
> +
> + /* Convert timebase ticks to jiffies */
> + nr_jiffies = wdt_ticks;
> +
> + if (do_div(nr_jiffies, tb_ticks_per_jiffy))
> + nr_jiffies++;
> +
> + return min_t(unsigned long long, nr_jiffies, NEXT_TIMER_MAX_DELTA); }
> +
> +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);
> +}
> +
> +void kvmppc_watchdog_func(unsigned long data) {
> + struct kvm_vcpu *vcpu = (struct kvm_vcpu *)data;
> + u32 tsr, new_tsr;
> + int final;
> +
> + do {
> + new_tsr = tsr = vcpu->arch.tsr;
> + final = 0;
> +
> + /* Time out event */
> + if (tsr & TSR_ENW) {
> + if (tsr & TSR_WIS)
> + final = 1;
> + else
> + new_tsr = tsr | TSR_WIS;
> + } else {
> + new_tsr = tsr | TSR_ENW;
> + }
> + } while (cmpxchg(&vcpu->arch.tsr, tsr, new_tsr) != tsr);
> +
> + if (new_tsr & TSR_WIS) {
> + smp_wmb();
> + kvm_make_request(KVM_REQ_PENDING_TIMER, vcpu);
> + kvm_vcpu_kick(vcpu);
> + }
> +
> + /*
> + * If this is final watchdog expiry and some action is required
> + * then exit to userspace.
> + */
> + if (final && (vcpu->arch.tcr & TCR_WRC_MASK) &&
> + vcpu->arch.watchdog_enabled) {
> + smp_wmb();
> + kvm_make_request(KVM_REQ_WATCHDOG, vcpu);
> + kvm_vcpu_kick(vcpu);
> + }
> +
> + /*
> + * Stop running the watchdog timer after final expiration to
> + * prevent the host from being flooded with timers if the
> + * guest sets a short period.
> + * Timers will resume when TSR/TCR is updated next time.
> + */
> + if (!final)
> + arm_next_watchdog(vcpu);
> +}
> +
> static void update_timer_ints(struct kvm_vcpu *vcpu) {
> if ((vcpu->arch.tcr & TCR_DIE) && (vcpu->arch.tsr & TSR_DIS))
> kvmppc_core_queue_dec(vcpu);
> else
> kvmppc_core_dequeue_dec(vcpu);
> +
> + if ((vcpu->arch.tcr & TCR_WIE) && (vcpu->arch.tsr & TSR_WIS))
> + kvmppc_core_queue_watchdog(vcpu);
> + else
> + kvmppc_core_dequeue_watchdog(vcpu);
> }
>
> static void kvmppc_core_check_exceptions(struct kvm_vcpu *vcpu) @@ -516,6
> +628,13 @@ int kvmppc_vcpu_run(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
> goto out;
> }
>
> + if (kvm_check_request(KVM_REQ_WATCHDOG, vcpu) &&
> + (vcpu->arch.tsr & (TSR_ENW | TSR_WIS))) {
> + kvm_run->exit_reason = KVM_EXIT_WATCHDOG;
> + ret = 0;
> + goto out;
> + }
> +
> kvm_guest_enter();
>
> #ifdef CONFIG_PPC_FPU
> @@ -978,6 +1097,12 @@ int kvmppc_handle_exit(struct kvm_run *run, struct
> kvm_vcpu *vcpu,
> }
> }
>
> + if (kvm_check_request(KVM_REQ_WATCHDOG, vcpu) &&
> + (vcpu->arch.tsr & (TSR_ENW | TSR_WIS))) {
> + run->exit_reason = KVM_EXIT_WATCHDOG;
> + r = RESUME_HOST | (r & RESUME_FLAG_NV);
> + }
> +
> return r;
> }
>
> @@ -1106,7 +1231,13 @@ static int set_sregs_base(struct kvm_vcpu *vcpu,
> }
>
> if (sregs->u.e.update_special & KVM_SREGS_E_UPDATE_TSR) {
> + u32 old_tsr = vcpu->arch.tsr;
> +
> vcpu->arch.tsr = sregs->u.e.tsr;
> +
> + if ((old_tsr ^ vcpu->arch.tsr) & (TSR_ENW | TSR_WIS))
> + arm_next_watchdog(vcpu);
> +
> update_timer_ints(vcpu);
> }
>
> @@ -1267,6 +1398,7 @@ void kvmppc_core_commit_memory_region(struct kvm *kvm,
> void kvmppc_set_tcr(struct kvm_vcpu *vcpu, u32 new_tcr) {
> vcpu->arch.tcr = new_tcr;
> + arm_next_watchdog(vcpu);
> update_timer_ints(vcpu);
> }
>
> @@ -1281,6 +1413,14 @@ void kvmppc_set_tsr_bits(struct kvm_vcpu *vcpu, u32
> tsr_bits) void kvmppc_clr_tsr_bits(struct kvm_vcpu *vcpu, u32 tsr_bits) {
> clear_bits(tsr_bits, &vcpu->arch.tsr);
> +
> + /*
> + * We may have stopped the watchdog due to
> + * being stuck on final expiration.
> + */
> + if (tsr_bits & (TSR_ENW | TSR_WIS))
> + arm_next_watchdog(vcpu);
> +
> update_timer_ints(vcpu);
> }
>
> diff --git a/arch/powerpc/kvm/booke_emulate.c
> b/arch/powerpc/kvm/booke_emulate.c
> index 12834bb..5a66ade 100644
> --- a/arch/powerpc/kvm/booke_emulate.c
> +++ b/arch/powerpc/kvm/booke_emulate.c
> @@ -145,6 +145,14 @@ int kvmppc_booke_emulate_mtspr(struct kvm_vcpu *vcpu, int
> sprn, ulong spr_val)
> kvmppc_clr_tsr_bits(vcpu, spr_val);
> break;
> case SPRN_TCR:
> + /*
> + * WRC is a 2-bit field that is supposed to preserve its
> + * value once written to non-zero.
> + */
> + if (vcpu->arch.tcr & TCR_WRC_MASK) {
> + spr_val &= ~TCR_WRC_MASK;
> + spr_val |= vcpu->arch.tcr & TCR_WRC_MASK;
> + }
> kvmppc_set_tcr(vcpu, spr_val);
> break;
>
> diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index
> 87f4dc8..63457cb 100644
> --- a/arch/powerpc/kvm/powerpc.c
> +++ b/arch/powerpc/kvm/powerpc.c
> @@ -220,6 +220,7 @@ int kvm_dev_ioctl_check_extension(long ext)
> switch (ext) {
> #ifdef CONFIG_BOOKE
> case KVM_CAP_PPC_BOOKE_SREGS:
> + case KVM_CAP_PPC_BOOKE_WATCHDOG:
> #else
> case KVM_CAP_PPC_SEGSTATE:
> case KVM_CAP_PPC_HIOR:
> @@ -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;
> }
>
> 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
> }
>
> void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) @@ -637,6 +648,12 @@
> static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
> r = 0;
> vcpu->arch.papr_enabled = true;
> break;
> +#ifdef CONFIG_BOOKE
> + case KVM_CAP_PPC_BOOKE_WATCHDOG:
> + r = 0;
> + vcpu->arch.watchdog_enabled = true;
> + break;
> +#endif
> #if defined(CONFIG_KVM_E500V2) || defined(CONFIG_KVM_E500MC)
> case KVM_CAP_SW_TLB: {
> struct kvm_config_tlb cfg;
> diff --git a/include/linux/kvm.h b/include/linux/kvm.h index 2ce09aa..9ff5aa5
> 100644
> --- a/include/linux/kvm.h
> +++ b/include/linux/kvm.h
> @@ -163,6 +163,7 @@ struct kvm_pit_config {
> #define KVM_EXIT_OSI 18
> #define KVM_EXIT_PAPR_HCALL 19
> #define KVM_EXIT_S390_UCONTROL 20
> +#define KVM_EXIT_WATCHDOG 21
>
> /* For KVM_EXIT_INTERNAL_ERROR */
> #define KVM_INTERNAL_ERROR_EMULATION 1
> @@ -618,6 +619,7 @@ struct kvm_ppc_smmu_info { #define
> KVM_CAP_PPC_GET_SMMU_INFO 78 #define KVM_CAP_S390_COW 79 #define
> KVM_CAP_PPC_ALLOC_HTAB 80
> +#define KVM_CAP_PPC_BOOKE_WATCHDOG 81
>
> #ifdef KVM_CAP_IRQ_ROUTING
>
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index
> 27ac8a4..41d32be 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -69,6 +69,7 @@
> #define KVM_REQ_IMMEDIATE_EXIT 15
> #define KVM_REQ_PMU 16
> #define KVM_REQ_PMI 17
> +#define KVM_REQ_WATCHDOG 18
>
> #define KVM_USERSPACE_IRQ_SOURCE_ID 0
>
> --
> 1.7.0.4
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