From patchwork Mon Oct 22 06:53:29 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoffer Dall X-Patchwork-Id: 1624261 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork2.kernel.org (Postfix) with ESMTP id 528EFE00A6 for ; Mon, 22 Oct 2012 07:10:34 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1TQC6H-0002b0-4q; Mon, 22 Oct 2012 07:07:01 +0000 Received: from mail-vb0-f49.google.com ([209.85.212.49]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1TQBt1-0000DD-VK for linux-arm-kernel@lists.infradead.org; Mon, 22 Oct 2012 06:53:25 +0000 Received: by mail-vb0-f49.google.com with SMTP id fo1so2547461vbb.36 for ; Sun, 21 Oct 2012 23:53:19 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=subject:to:from:cc:date:message-id:in-reply-to:references :user-agent:mime-version:content-type:content-transfer-encoding :x-gm-message-state; bh=4JS+ex/Vmm0y7+D7PULgKEroHpC0J3gnc1wbYHDYtRU=; b=BA0+wJgt/u0Sxh2vFfNoRf033nY/gnYcUxxRz0ZwFBxf8apnuWglwheD5NVKW4D9C/ D93zJH0U1D6ELYCwOzGR0X89onuWBi+sHn9d4uaYFH3PjROlketRftbUWmR9jiXmnJYH ijyfFZfoMVdIYMPZmyq4L/hwm0N+dHeNcpTZlWTpPGKPgyj6Djg7H9xxI7MMUgFrJtNK GwxwEF7zjzoDVZnblpWvbkqCa6iEHhMfc4xsEHzR8KJSQoWvhfFr39Bk78YvyxE41Lxp sxxt826YxpAhBx2neooW0f/zp6kpeYVhsYnRqdXQe/N2rksy/gm6pzNgLPbegPetvR8b jIUQ== Received: by 10.52.65.133 with SMTP id x5mr10603616vds.57.1350888799624; Sun, 21 Oct 2012 23:53:19 -0700 (PDT) Received: from [127.0.1.1] (pool-72-80-83-148.nycmny.fios.verizon.net. [72.80.83.148]) by mx.google.com with ESMTPS id w17sm9488416vdf.16.2012.10.21.23.53.18 (version=TLSv1/SSLv3 cipher=OTHER); Sun, 21 Oct 2012 23:53:19 -0700 (PDT) Subject: [PATCH v3 3/5] ARM: KVM: arch_timers: Add guest timer core support To: kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu From: Christoffer Dall Date: Mon, 22 Oct 2012 02:53:29 -0400 Message-ID: <20121022065329.18883.31451.stgit@ubuntu> In-Reply-To: <20121022065301.18883.35308.stgit@ubuntu> References: <20121022065301.18883.35308.stgit@ubuntu> User-Agent: StGit/0.15 MIME-Version: 1.0 X-Gm-Message-State: ALoCoQnnJyaZ+Ux1hn2ZvrSvYJXfS2JENf/vq2nTwNpNSbDG8zMKm/24gcDpt80F2gsHpEEk9o8g X-Spam-Note: CRM114 invocation failed X-Spam-Score: -2.6 (--) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-2.6 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [209.85.212.49 listed in list.dnswl.org] -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: Marc Zyngier X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org From: Marc Zyngier We can inject a timer interrupt into the guest as a result of three possible events: - The virtual timer interrupt has fired while we were still executing the guest - The timer interrupt hasn't fired, but it expired while we were doing the world switch - A hrtimer we programmed earlier has fired Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall --- arch/arm/include/asm/kvm_arch_timer.h | 57 +++++++++ arch/arm/kvm/reset.c | 9 + arch/arm/kvm/timer.c | 204 +++++++++++++++++++++++++++++++++ 3 files changed, 269 insertions(+), 1 deletion(-) create mode 100644 arch/arm/kvm/timer.c diff --git a/arch/arm/include/asm/kvm_arch_timer.h b/arch/arm/include/asm/kvm_arch_timer.h index 513b852..bd5e501 100644 --- a/arch/arm/include/asm/kvm_arch_timer.h +++ b/arch/arm/include/asm/kvm_arch_timer.h @@ -19,13 +19,68 @@ #ifndef __ASM_ARM_KVM_ARCH_TIMER_H #define __ASM_ARM_KVM_ARCH_TIMER_H +#include +#include +#include + struct arch_timer_kvm { +#ifdef CONFIG_KVM_ARM_TIMER + /* Is the timer enabled */ + bool enabled; + + /* + * Virtual offset (kernel access it through cntvoff, HYP code + * access it as two 32bit values). + */ + union { + cycle_t cntvoff; + struct { + u32 low; /* Restored only */ + u32 high; /* Restored only */ + } cntvoff32; + }; +#endif }; struct arch_timer_cpu { +#ifdef CONFIG_KVM_ARM_TIMER + /* Registers: control register, timer value */ + u32 cntv_ctl; /* Saved/restored */ + union { + cycle_t cntv_cval; + struct { + u32 low; /* Saved/restored */ + u32 high; /* Saved/restored */ + } cntv_cval32; + }; + + /* + * Anything that is not used directly from assembly code goes + * here. + */ + + /* Background timer used when the guest is not running */ + struct hrtimer timer; + + /* Work queued with the above timer expires */ + struct work_struct expired; + + /* Background timer active */ + bool armed; + + /* Timer IRQ */ + const struct kvm_irq_level *irq; +#endif }; -#ifndef CONFIG_KVM_ARM_TIMER +#ifdef CONFIG_KVM_ARM_TIMER +int kvm_timer_hyp_init(void); +int kvm_timer_init(struct kvm *kvm); +void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu); +void kvm_timer_sync_to_cpu(struct kvm_vcpu *vcpu); +void kvm_timer_sync_from_cpu(struct kvm_vcpu *vcpu); +void kvm_timer_vcpu_terminate(struct kvm_vcpu *vcpu); +#else static inline int kvm_timer_hyp_init(void) { return 0; diff --git a/arch/arm/kvm/reset.c b/arch/arm/kvm/reset.c index 290a13d..bb17def 100644 --- a/arch/arm/kvm/reset.c +++ b/arch/arm/kvm/reset.c @@ -37,6 +37,12 @@ static struct kvm_regs a15_regs_reset = { .cpsr = SVC_MODE | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT, }; +#ifdef CONFIG_KVM_ARM_TIMER +static const struct kvm_irq_level a15_virt_timer_ppi = { + .irq = 27, /* A7/A15 specific */ + .level = 1, +}; +#endif /******************************************************************************* * Exported reset function @@ -59,6 +65,9 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu) return -EINVAL; cpu_reset = &a15_regs_reset; vcpu->arch.midr = read_cpuid_id(); +#ifdef CONFIG_KVM_ARM_TIMER + vcpu->arch.timer_cpu.irq = &a15_virt_timer_ppi; +#endif break; default: return -ENODEV; diff --git a/arch/arm/kvm/timer.c b/arch/arm/kvm/timer.c new file mode 100644 index 0000000..a241298 --- /dev/null +++ b/arch/arm/kvm/timer.c @@ -0,0 +1,204 @@ +/* + * Copyright (C) 2012 ARM Ltd. + * Author: Marc Zyngier + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include +#include +#include +#include + +#include + +#include +#include + +static struct timecounter *timecounter; +static struct workqueue_struct *wqueue; + +static cycle_t kvm_phys_timer_read(void) +{ + return timecounter->cc->read(timecounter->cc); +} + +static void kvm_timer_inject_irq(struct kvm_vcpu *vcpu) +{ + struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; + + timer->cntv_ctl |= 1 << 1; /* Mask the interrupt in the guest */ + kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id, + vcpu->arch.timer_cpu.irq->irq, + vcpu->arch.timer_cpu.irq->level); +} + +static irqreturn_t kvm_arch_timer_handler(int irq, void *dev_id) +{ + struct kvm_vcpu *vcpu = *(struct kvm_vcpu **)dev_id; + + /* + * We disable the timer in the world switch and let it be + * handled by kvm_timer_sync_from_cpu(). Getting a timer + * interrupt at this point is a sure sign of some major + * breakage. + */ + pr_warn("Unexpected interrupt %d on vcpu %p\n", irq, vcpu); + return IRQ_HANDLED; +} + +static void kvm_timer_inject_irq_work(struct work_struct *work) +{ + struct kvm_vcpu *vcpu; + + vcpu = container_of(work, struct kvm_vcpu, arch.timer_cpu.expired); + vcpu->arch.timer_cpu.armed = false; + kvm_timer_inject_irq(vcpu); +} + +static enum hrtimer_restart kvm_timer_expire(struct hrtimer *hrt) +{ + struct arch_timer_cpu *timer; + timer = container_of(hrt, struct arch_timer_cpu, timer); + queue_work(wqueue, &timer->expired); + return HRTIMER_NORESTART; +} + +void kvm_timer_sync_to_cpu(struct kvm_vcpu *vcpu) +{ + struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; + + /* + * We're about to run this vcpu again, so there is no need to + * keep the background timer running, as we're about to + * populate the CPU timer again. + */ + if (timer->armed) { + hrtimer_cancel(&timer->timer); + cancel_work_sync(&timer->expired); + timer->armed = false; + } +} + +void kvm_timer_sync_from_cpu(struct kvm_vcpu *vcpu) +{ + struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; + cycle_t cval, now; + u64 ns; + + /* Check if the timer is enabled and unmasked first */ + if ((timer->cntv_ctl & 3) != 1) + return; + + cval = timer->cntv_cval; + now = kvm_phys_timer_read() - vcpu->kvm->arch.timer.cntvoff; + + BUG_ON(timer->armed); + + if (cval <= now) { + /* + * Timer has already expired while we were not + * looking. Inject the interrupt and carry on. + */ + kvm_timer_inject_irq(vcpu); + return; + } + + timer->armed = true; + ns = cyclecounter_cyc2ns(timecounter->cc, cval - now); + hrtimer_start(&timer->timer, ktime_add_ns(ktime_get(), ns), + HRTIMER_MODE_ABS); +} + +void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu) +{ + struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; + + INIT_WORK(&timer->expired, kvm_timer_inject_irq_work); + hrtimer_init(&timer->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); + timer->timer.function = kvm_timer_expire; +} + +static void kvm_timer_init_interrupt(void *info) +{ + unsigned int *irqp = info; + + enable_percpu_irq(*irqp, 0); +} + + +static const struct of_device_id arch_timer_of_match[] = { + { .compatible = "arm,armv7-timer", }, + {}, +}; + +int kvm_timer_hyp_init(void) +{ + struct device_node *np; + unsigned int ppi; + int err; + + timecounter = arch_timer_get_timecounter(); + if (!timecounter) + return -ENODEV; + + np = of_find_matching_node(NULL, arch_timer_of_match); + if (!np) { + kvm_err("kvm_arch_timer: can't find DT node\n"); + return -ENODEV; + } + + ppi = irq_of_parse_and_map(np, 2); + if (!ppi) { + kvm_err("kvm_arch_timer: no virtual timer interrupt\n"); + return -EINVAL; + } + + err = request_percpu_irq(ppi, kvm_arch_timer_handler, + "kvm guest timer", kvm_get_running_vcpus()); + if (err) { + kvm_err("kvm_arch_timer: can't request interrupt %d (%d)\n", + ppi, err); + return err; + } + + wqueue = create_singlethread_workqueue("kvm_arch_timer"); + if (!wqueue) { + free_percpu_irq(ppi, kvm_get_running_vcpus()); + return -ENOMEM; + } + + kvm_info("%s IRQ%d\n", np->name, ppi); + on_each_cpu(kvm_timer_init_interrupt, &ppi, 1); + + return 0; +} + +void kvm_timer_vcpu_terminate(struct kvm_vcpu *vcpu) +{ + struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; + + hrtimer_cancel(&timer->timer); + cancel_work_sync(&timer->expired); +} + +int kvm_timer_init(struct kvm *kvm) +{ + if (timecounter && wqueue) { + kvm->arch.timer.cntvoff = kvm_phys_timer_read(); + kvm->arch.timer.enabled = 1; + } + + return 0; +}