From patchwork Thu Aug 9 06:38:19 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bharat Bhushan X-Patchwork-Id: 176004 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 73DEF2C0095 for ; Thu, 9 Aug 2012 16:39:12 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755062Ab2HIGjE (ORCPT ); Thu, 9 Aug 2012 02:39:04 -0400 Received: from co1ehsobe003.messaging.microsoft.com ([216.32.180.186]:47677 "EHLO co1outboundpool.messaging.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755034Ab2HIGi7 (ORCPT ); Thu, 9 Aug 2012 02:38:59 -0400 Received: from mail90-co1-R.bigfish.com (10.243.78.253) by CO1EHSOBE005.bigfish.com (10.243.66.68) with Microsoft SMTP Server id 14.1.225.23; Thu, 9 Aug 2012 06:38:59 +0000 Received: from mail90-co1 (localhost [127.0.0.1]) by mail90-co1-R.bigfish.com (Postfix) with ESMTP id 2308554047A; Thu, 9 Aug 2012 06:38:59 +0000 (UTC) X-Forefront-Antispam-Report: CIP:70.37.183.190; KIP:(null); UIP:(null); IPV:NLI; H:mail.freescale.net; RD:none; EFVD:NLI X-SpamScore: 3 X-BigFish: VS3(zzzz1202h1082kzz8275bhz2dh2a8h668h839he5bhf0ah) Received: from mail90-co1 (localhost.localdomain [127.0.0.1]) by mail90-co1 (MessageSwitch) id 134449432670245_15062; Thu, 9 Aug 2012 06:38:46 +0000 (UTC) Received: from CO1EHSMHS007.bigfish.com (unknown [10.243.78.245]) by mail90-co1.bigfish.com (Postfix) with ESMTP id 0F104DC0058; Thu, 9 Aug 2012 06:38:46 +0000 (UTC) Received: from mail.freescale.net (70.37.183.190) by CO1EHSMHS007.bigfish.com (10.243.66.17) with Microsoft SMTP Server (TLS) id 14.1.225.23; Thu, 9 Aug 2012 06:38:45 +0000 Received: from az84smr01.freescale.net (10.64.34.197) by 039-SN1MMR1-002.039d.mgd.msft.net (10.84.1.15) with Microsoft SMTP Server (TLS) id 14.2.298.5; Thu, 9 Aug 2012 01:38:44 -0500 Received: from freescale.com ([10.232.15.72]) by az84smr01.freescale.net (8.14.3/8.14.0) with SMTP id q796ceqi020259; Wed, 8 Aug 2012 23:38:41 -0700 Received: by freescale.com (sSMTP sendmail emulation); Thu, 09 Aug 2012 12:08:27 +0530 From: Bharat Bhushan To: , , CC: Bharat Bhushan Subject: [PATCH 2/4] KVM: PPC: booke: Add watchdog emulation Date: Thu, 9 Aug 2012 12:08:19 +0530 Message-ID: <1344494301-29612-2-git-send-email-Bharat.Bhushan@freescale.com> X-Mailer: git-send-email 1.7.0.4 In-Reply-To: <1344494301-29612-1-git-send-email-Bharat.Bhushan@freescale.com> References: <1344494301-29612-1-git-send-email-Bharat.Bhushan@freescale.com> MIME-Version: 1.0 X-OriginatorOrg: freescale.com Sender: kvm-ppc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm-ppc@vger.kernel.org This patch adds the watchdog emulation in KVM. The watchdog emulation is enabled by KVM_ENABLE_CAP(KVM_CAP_PPC_BOOKE_WATCHDOG) 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 Signed-off-by: Scott Wood [bharat.bhushan@freescale.com: reworked patch] Signed-off-by: Bharat Bhushan --- v8: - clear REQ_WATCHDOG moved to arm_next_watchdog(); - Using common request handler v7: - kvmppc_core_dequeue_watchdog() and kvmppc_core_enque_watchdog() are made staic - Clear the KVM_REQ_WATCHDOG request when TSR_ENW | ENW_WIS cleared rather than checking these bits on handling the request. v6: - Added kvmppc_subarch_vcpu_unit/uninit() for subarch specific initialization - Using spin_lock_irqsave() - Using del_timer_sync(). v5: - Checking that TSR_ENW/TSR_WIS are still set on KVM_EXIT_WATCHDOG. - Moved watchdog_next_timeout() in lock. arch/powerpc/include/asm/kvm_host.h | 3 + arch/powerpc/include/asm/kvm_ppc.h | 2 + arch/powerpc/include/asm/reg_booke.h | 7 ++ arch/powerpc/kvm/book3s.c | 9 ++ arch/powerpc/kvm/booke.c | 157 +++++++++++++++++++++++++++++++++- arch/powerpc/kvm/booke_emulate.c | 8 ++ arch/powerpc/kvm/powerpc.c | 14 +++- include/linux/kvm.h | 2 + include/linux/kvm_host.h | 1 + 9 files changed, 200 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h index 572ad01..873ec11 100644 --- a/arch/powerpc/include/asm/kvm_host.h +++ b/arch/powerpc/include/asm/kvm_host.h @@ -469,6 +469,8 @@ 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; @@ -484,6 +486,7 @@ 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..1438a5e 100644 --- a/arch/powerpc/include/asm/kvm_ppc.h +++ b/arch/powerpc/include/asm/kvm_ppc.h @@ -68,6 +68,8 @@ 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 int kvmppc_sanity_check(struct kvm_vcpu *vcpu); +extern int kvmppc_subarch_vcpu_init(struct kvm_vcpu *vcpu); +extern void kvmppc_subarch_vcpu_uninit(struct kvm_vcpu *vcpu); /* Core-specific hooks */ 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/book3s.c b/arch/powerpc/kvm/book3s.c index 3f2a836..e946665 100644 --- a/arch/powerpc/kvm/book3s.c +++ b/arch/powerpc/kvm/book3s.c @@ -411,6 +411,15 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu) return 0; } +int kvmppc_subarch_vcpu_init(struct kvm_vcpu *vcpu) +{ + return 0; +} + +void kvmppc_subarch_vcpu_uninit(struct kvm_vcpu *vcpu) +{ +} + int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs) { int i; diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c index 6ebff80..4c61f04 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); } +static void kvmppc_core_queue_watchdog(struct kvm_vcpu *vcpu) +{ + kvmppc_booke_queue_irqprio(vcpu, BOOKE_IRQPRIO_WATCHDOG); +} + +static 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 +415,121 @@ 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; + unsigned long flags; + + /* + * If TSR_ENW and TSR_WIS are not set then no need to exit to + * userspace, so clear the KVM_REQ_WATCHDOG request. + */ + if ((vcpu->arch.tsr & (TSR_ENW | TSR_WIS)) != (TSR_ENW | TSR_WIS)) + clear_bit(KVM_REQ_WATCHDOG, &vcpu->requests); + + spin_lock_irqsave(&vcpu->arch.wdt_lock, flags); + 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_irqrestore(&vcpu->arch.wdt_lock, flags); +} + +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); } /* @@ -428,6 +548,11 @@ static int kvmppc_handle_requests(struct kvm_vcpu *vcpu) update_timer_ints(vcpu); } + if (kvm_check_request(KVM_REQ_WATCHDOG, vcpu)) { + vcpu->run->exit_reason = KVM_EXIT_WATCHDOG; + ret = 1; + } + return ret; } @@ -1032,6 +1157,21 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu) return r; } +int kvmppc_subarch_vcpu_init(struct kvm_vcpu *vcpu) +{ + /* setup watchdog timer once */ + spin_lock_init(&vcpu->arch.wdt_lock); + setup_timer(&vcpu->arch.wdt_timer, kvmppc_watchdog_func, + (unsigned long)vcpu); + + return 0; +} + +void kvmppc_subarch_vcpu_uninit(struct kvm_vcpu *vcpu) +{ + del_timer_sync(&vcpu->arch.wdt_timer); +} + int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs) { int i; @@ -1127,7 +1267,13 @@ static int set_sregs_base(struct kvm_vcpu *vcpu, } if (sregs->u.e.update_special & KVM_SREGS_E_UPDATE_TSR) { - vcpu->arch.tsr = sregs->u.e.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); } @@ -1288,6 +1434,7 @@ 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); } @@ -1302,6 +1449,14 @@ 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 a69ca4a..da484a6 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -224,6 +224,7 @@ 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: @@ -382,6 +383,8 @@ enum hrtimer_restart kvmppc_decrementer_wakeup(struct hrtimer *timer) int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu) { + int ret; + hrtimer_init(&vcpu->arch.dec_timer, CLOCK_REALTIME, HRTIMER_MODE_ABS); tasklet_init(&vcpu->arch.tasklet, kvmppc_decrementer_func, (ulong)vcpu); vcpu->arch.dec_timer.function = kvmppc_decrementer_wakeup; @@ -390,13 +393,14 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu) #ifdef CONFIG_KVM_EXIT_TIMING mutex_init(&vcpu->arch.exit_timing_lock); #endif - - return 0; + ret = kvmppc_subarch_vcpu_init(vcpu); + return ret; } void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) { kvmppc_mmu_destroy(vcpu); + kvmppc_subarch_vcpu_uninit(vcpu); } void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) @@ -641,6 +645,12 @@ 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 c03e59e..f4f5be8 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 @@ -620,6 +621,7 @@ 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 dbc65f9..b38adc2 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