[2/2,v5] KVM: PPC: booke: Add watchdog emulation

Message ID	1342760428-10858-1-git-send-email-Bharat.Bhushan@freescale.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <kvm-owner@vger.kernel.org> From: Bharat Bhushan <r65777@freescale.com> To: <kvm-ppc@vger.kernel.org>, <kvm@vger.kernel.org>, <agraf@suse.de> CC: Bharat Bhushan <Bharat.Bhushan@freescale.com> Subject: [PATCH 2/2 v5] KVM: PPC: booke: Add watchdog emulation Date: Fri, 20 Jul 2012 10:30:28 +0530 Message-ID: <1342760428-10858-1-git-send-email-Bharat.Bhushan@freescale.com> MIME-Version: 1.0 Content-Type: text/plain Sender: kvm-owner@vger.kernel.org Precedence: bulk

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

[2/2,v5] KVM: PPC: booke: Add watchdog emulation

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