From patchwork Wed Jul 18 09:36:14 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bharat Bhushan X-Patchwork-Id: 171616 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 7406C2C035A for ; Wed, 18 Jul 2012 19:34:10 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752821Ab2GRJeJ (ORCPT ); Wed, 18 Jul 2012 05:34:09 -0400 Received: from am1ehsobe005.messaging.microsoft.com ([213.199.154.208]:19666 "EHLO am1outboundpool.messaging.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750850Ab2GRJeH (ORCPT ); Wed, 18 Jul 2012 05:34:07 -0400 Received: from mail47-am1-R.bigfish.com (10.3.201.248) by AM1EHSOBE008.bigfish.com (10.3.204.28) with Microsoft SMTP Server id 14.1.225.23; Wed, 18 Jul 2012 09:34:05 +0000 Received: from mail47-am1 (localhost [127.0.0.1]) by mail47-am1-R.bigfish.com (Postfix) with ESMTP id 2793420250; Wed, 18 Jul 2012 09:34:05 +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 mail47-am1 (localhost.localdomain [127.0.0.1]) by mail47-am1 (MessageSwitch) id 134260404452252_31733; Wed, 18 Jul 2012 09:34:04 +0000 (UTC) Received: from AM1EHSMHS013.bigfish.com (unknown [10.3.201.233]) by mail47-am1.bigfish.com (Postfix) with ESMTP id 08ADD240078; Wed, 18 Jul 2012 09:34:04 +0000 (UTC) Received: from mail.freescale.net (70.37.183.190) by AM1EHSMHS013.bigfish.com (10.3.207.151) with Microsoft SMTP Server (TLS) id 14.1.225.23; Wed, 18 Jul 2012 09:34:04 +0000 Received: from tx30smr01.am.freescale.net (10.81.153.31) by 039-SN1MMR1-001.039d.mgd.msft.net (10.84.1.13) with Microsoft SMTP Server (TLS) id 14.2.298.5; Wed, 18 Jul 2012 04:34:01 -0500 Received: from freescale.com ([10.232.15.72]) by tx30smr01.am.freescale.net (8.14.3/8.14.0) with SMTP id q6I9XvNr028339; Wed, 18 Jul 2012 02:33:58 -0700 Received: by freescale.com (sSMTP sendmail emulation); Wed, 18 Jul 2012 15:06:15 +0530 From: Bharat Bhushan To: , , CC: Bharat Bhushan , Bharat Bhushan Subject: [PATCH 2/2 v3] KVM: PPC: booke: Add watchdog emulation Date: Wed, 18 Jul 2012 15:06:14 +0530 Message-ID: <1342604174-22534-1-git-send-email-Bharat.Bhushan@freescale.com> X-Mailer: git-send-email 1.7.0.4 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_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: Bharat Bhushan --- 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 | 27 ++++++- include/linux/kvm.h | 2 + include/linux/kvm_host.h | 1 + 8 files changed, 187 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h index 50ea12f..01047f4 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_enable; 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..9682506 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 +415,112 @@ 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; + + nr_jiffies = watchdog_next_timeout(vcpu); + spin_lock(&vcpu->arch.wdt_lock); + /* + * 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)) { + 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 +627,13 @@ 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.watchdog_enable) { + kvm_run->exit_reason = KVM_EXIT_WATCHDOG; + ret = 0; + goto out; + } + kvm_guest_enter(); #ifdef CONFIG_PPC_FPU @@ -978,6 +1096,12 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu, } } + if (kvm_check_request(KVM_REQ_WATCHDOG, vcpu) && + vcpu->arch.watchdog_enable) { + run->exit_reason = KVM_EXIT_WATCHDOG; + r = RESUME_HOST | (r & RESUME_FLAG_NV); + } + return r; } @@ -1106,7 +1230,14 @@ 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 | TCR_WRC_MASK)) + 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 | TCR_WRC_MASK)) + 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..3c50b81 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -38,9 +38,11 @@ int kvm_arch_vcpu_runnable(struct kvm_vcpu *v) { - return !(v->arch.shared->msr & MSR_WE) || - !!(v->arch.pending_exceptions) || - v->requests; + bool ret = !(v->arch.shared->msr & MSR_WE) || + !!(v->arch.pending_exceptions) || + v->requests; + + return ret; } int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu) @@ -237,6 +239,7 @@ int kvm_dev_ioctl_check_extension(long ext) case KVM_CAP_PPC_GET_PVINFO: #if defined(CONFIG_KVM_E500V2) || defined(CONFIG_KVM_E500MC) case KVM_CAP_SW_TLB: + case KVM_CAP_PPC_WDT: #endif r = 1; break; @@ -386,13 +389,23 @@ 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 +650,12 @@ 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_WDT: + r = 0; + vcpu->arch.watchdog_enable = 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..07dcab3 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_WDT 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