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[72.80.83.148]) by mx.google.com with ESMTPS id ko19sm9732814veb.1.2013.01.16.09.59.19 (version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 16 Jan 2013 09:59:19 -0800 (PST) Subject: [PATCH v6 14/15] KVM: ARM: Power State Coordination Interface implementation To: kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu From: Christoffer Dall Date: Wed, 16 Jan 2013 12:59:18 -0500 Message-ID: <20130116175918.29147.318.stgit@ubuntu> In-Reply-To: <20130116175716.29147.15348.stgit@ubuntu> References: <20130116175716.29147.15348.stgit@ubuntu> User-Agent: StGit/0.15 MIME-Version: 1.0 X-Gm-Message-State: ALoCoQmZXKMf5lSrJrj+Pn3XYiM8Vo0m4pSA/PRlv2T807q2lqBCYmDhYAjShasE81bnPRdhIc9o X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130116_125922_405441_D0F86A53 X-CRM114-Status: GOOD ( 27.79 ) 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 [209.85.212.41 listed in list.dnswl.org] -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: Marc Zyngier , Will Deacon 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 Implement the PSCI specification (ARM DEN 0022A) to control virtual CPUs being "powered" on or off. PSCI/KVM is detected using the KVM_CAP_ARM_PSCI capability. A virtual CPU can now be initialized in a "powered off" state, using the KVM_ARM_VCPU_POWER_OFF feature flag. The guest can use either SMC or HVC to execute a PSCI function. Reviewed-by: Will Deacon Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall --- Documentation/virtual/kvm/api.txt | 4 + arch/arm/include/asm/kvm_emulate.h | 5 ++ arch/arm/include/asm/kvm_host.h | 5 +- arch/arm/include/asm/kvm_psci.h | 23 ++++++++ arch/arm/include/uapi/asm/kvm.h | 16 +++++ arch/arm/kvm/Makefile | 2 - arch/arm/kvm/arm.c | 28 +++++++++- arch/arm/kvm/psci.c | 105 ++++++++++++++++++++++++++++++++++++ include/uapi/linux/kvm.h | 1 9 files changed, 184 insertions(+), 5 deletions(-) create mode 100644 arch/arm/include/asm/kvm_psci.h create mode 100644 arch/arm/kvm/psci.c diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 38066a7a..c25439a 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -2185,6 +2185,10 @@ return ENOEXEC for that vcpu. Note that because some registers reflect machine topology, all vcpus should be created before this ioctl is invoked. +Possible features: + - KVM_ARM_VCPU_POWER_OFF: Starts the CPU in a power-off state. + Depends on KVM_CAP_ARM_PSCI. + 4.78 KVM_GET_REG_LIST diff --git a/arch/arm/include/asm/kvm_emulate.h b/arch/arm/include/asm/kvm_emulate.h index 4c1a073..ba07de9 100644 --- a/arch/arm/include/asm/kvm_emulate.h +++ b/arch/arm/include/asm/kvm_emulate.h @@ -32,6 +32,11 @@ void kvm_inject_undefined(struct kvm_vcpu *vcpu); void kvm_inject_dabt(struct kvm_vcpu *vcpu, unsigned long addr); void kvm_inject_pabt(struct kvm_vcpu *vcpu, unsigned long addr); +static inline bool vcpu_mode_is_32bit(struct kvm_vcpu *vcpu) +{ + return 1; +} + static inline u32 *vcpu_pc(struct kvm_vcpu *vcpu) { return (u32 *)&vcpu->arch.regs.usr_regs.ARM_pc; diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index e65fc96..c9ba918 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -30,7 +30,7 @@ #define KVM_COALESCED_MMIO_PAGE_OFFSET 1 #define KVM_HAVE_ONE_REG -#define KVM_VCPU_MAX_FEATURES 0 +#define KVM_VCPU_MAX_FEATURES 1 /* We don't currently support large pages. */ #define KVM_HPAGE_GFN_SHIFT(x) 0 @@ -100,6 +100,9 @@ struct kvm_vcpu_arch { int last_pcpu; cpumask_t require_dcache_flush; + /* Don't run the guest: see copy_current_insn() */ + bool pause; + /* IO related fields */ struct kvm_decode mmio_decode; diff --git a/arch/arm/include/asm/kvm_psci.h b/arch/arm/include/asm/kvm_psci.h new file mode 100644 index 0000000..9a83d98 --- /dev/null +++ b/arch/arm/include/asm/kvm_psci.h @@ -0,0 +1,23 @@ +/* + * 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, see . + */ + +#ifndef __ARM_KVM_PSCI_H__ +#define __ARM_KVM_PSCI_H__ + +bool kvm_psci_call(struct kvm_vcpu *vcpu); + +#endif /* __ARM_KVM_PSCI_H__ */ diff --git a/arch/arm/include/uapi/asm/kvm.h b/arch/arm/include/uapi/asm/kvm.h index bbb6b23..3303ff5 100644 --- a/arch/arm/include/uapi/asm/kvm.h +++ b/arch/arm/include/uapi/asm/kvm.h @@ -65,6 +65,8 @@ struct kvm_regs { #define KVM_ARM_TARGET_CORTEX_A15 0 #define KVM_ARM_NUM_TARGETS 1 +#define KVM_ARM_VCPU_POWER_OFF 0 /* CPU is started in OFF state */ + struct kvm_vcpu_init { __u32 target; __u32 features[7]; @@ -145,4 +147,18 @@ struct kvm_arch_memory_slot { /* Highest supported SPI, from VGIC_NR_IRQS */ #define KVM_ARM_IRQ_GIC_MAX 127 +/* PSCI interface */ +#define KVM_PSCI_FN_BASE 0x95c1ba5e +#define KVM_PSCI_FN(n) (KVM_PSCI_FN_BASE + (n)) + +#define KVM_PSCI_FN_CPU_SUSPEND KVM_PSCI_FN(0) +#define KVM_PSCI_FN_CPU_OFF KVM_PSCI_FN(1) +#define KVM_PSCI_FN_CPU_ON KVM_PSCI_FN(2) +#define KVM_PSCI_FN_MIGRATE KVM_PSCI_FN(3) + +#define KVM_PSCI_RET_SUCCESS 0 +#define KVM_PSCI_RET_NI ((unsigned long)-1) +#define KVM_PSCI_RET_INVAL ((unsigned long)-2) +#define KVM_PSCI_RET_DENIED ((unsigned long)-3) + #endif /* __ARM_KVM_H__ */ diff --git a/arch/arm/kvm/Makefile b/arch/arm/kvm/Makefile index 1e45cd9..ea27987 100644 --- a/arch/arm/kvm/Makefile +++ b/arch/arm/kvm/Makefile @@ -18,4 +18,4 @@ kvm-arm-y = $(addprefix ../../../virt/kvm/, kvm_main.o coalesced_mmio.o) obj-y += kvm-arm.o init.o interrupts.o obj-y += arm.o guest.o mmu.o emulate.o reset.o -obj-y += coproc.o coproc_a15.o mmio.o +obj-y += coproc.o coproc_a15.o mmio.o psci.o diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index 3168b9d..6ff5337 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -43,6 +43,7 @@ #include #include #include +#include #include #ifdef REQUIRES_VIRT @@ -160,6 +161,7 @@ int kvm_dev_ioctl_check_extension(long ext) case KVM_CAP_SYNC_MMU: case KVM_CAP_DESTROY_MEMORY_REGION_WORKS: case KVM_CAP_ONE_REG: + case KVM_CAP_ARM_PSCI: r = 1; break; case KVM_CAP_COALESCED_MMIO: @@ -443,13 +445,17 @@ static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run) trace_kvm_hvc(*vcpu_pc(vcpu), *vcpu_reg(vcpu, 0), vcpu->arch.hsr & HSR_HVC_IMM_MASK); + if (kvm_psci_call(vcpu)) + return 1; + return 1; } static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run) { - /* We don't support SMC; don't do that. */ - kvm_debug("smc: at %08x", *vcpu_pc(vcpu)); + if (!kvm_psci_call(vcpu)) + return 1; + kvm_inject_undefined(vcpu); return 1; } @@ -588,6 +594,16 @@ static int kvm_vcpu_first_run_init(struct kvm_vcpu *vcpu) return 0; vcpu->arch.has_run_once = true; + + /* + * Handle the "start in power-off" case by calling into the + * PSCI code. + */ + if (test_and_clear_bit(KVM_ARM_VCPU_POWER_OFF, vcpu->arch.features)) { + *vcpu_reg(vcpu, 0) = KVM_PSCI_FN_CPU_OFF; + kvm_psci_call(vcpu); + } + return 0; } @@ -656,7 +672,13 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) kvm_guest_enter(); vcpu->mode = IN_GUEST_MODE; - ret = kvm_call_hyp(__kvm_vcpu_run, vcpu); + smp_mb(); /* set mode before reading vcpu->arch.pause */ + if (unlikely(vcpu->arch.pause)) { + /* This means ignore, try again. */ + ret = ARM_EXCEPTION_IRQ; + } else { + ret = kvm_call_hyp(__kvm_vcpu_run, vcpu); + } vcpu->mode = OUTSIDE_GUEST_MODE; vcpu->arch.last_pcpu = smp_processor_id(); diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c new file mode 100644 index 0000000..6be3687 --- /dev/null +++ b/arch/arm/kvm/psci.c @@ -0,0 +1,105 @@ +/* + * 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, see . + */ + +#include +#include + +#include +#include + +/* + * This is an implementation of the Power State Coordination Interface + * as described in ARM document number ARM DEN 0022A. + */ + +static void kvm_psci_vcpu_off(struct kvm_vcpu *vcpu) +{ + wait_queue_head_t *wq = kvm_arch_vcpu_wq(vcpu); + + vcpu->arch.pause = true; + + wait_event_interruptible(*wq, !vcpu->arch.pause); +} + +static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) +{ + struct kvm *kvm = source_vcpu->kvm; + struct kvm_vcpu *vcpu; + wait_queue_head_t *wq; + unsigned long cpu_id; + phys_addr_t target_pc; + + cpu_id = *vcpu_reg(source_vcpu, 1); + if (vcpu_mode_is_32bit(source_vcpu)) + cpu_id &= ~((u32) 0); + + if (cpu_id >= atomic_read(&kvm->online_vcpus)) + return KVM_PSCI_RET_INVAL; + + target_pc = *vcpu_reg(source_vcpu, 2); + + vcpu = kvm_get_vcpu(kvm, cpu_id); + + wq = kvm_arch_vcpu_wq(vcpu); + if (!waitqueue_active(wq)) + return KVM_PSCI_RET_INVAL; + + kvm_reset_vcpu(vcpu); + *vcpu_pc(vcpu) = target_pc; + vcpu->arch.pause = false; + smp_mb(); /* Make sure the above is visible */ + + wake_up_interruptible(wq); + + return KVM_PSCI_RET_SUCCESS; +} + +/** + * kvm_psci_call - handle PSCI call if r0 value is in range + * @vcpu: Pointer to the VCPU struct + * + * Handle PSCI calls from guests through traps from HVC or SMC instructions. + * The calling convention is similar to SMC calls to the secure world where + * the function number is placed in r0 and this function returns true if the + * function number specified in r0 is withing the PSCI range, and false + * otherwise. + */ +bool kvm_psci_call(struct kvm_vcpu *vcpu) +{ + unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0); + unsigned long val; + + switch (psci_fn) { + case KVM_PSCI_FN_CPU_OFF: + kvm_psci_vcpu_off(vcpu); + val = KVM_PSCI_RET_SUCCESS; + break; + case KVM_PSCI_FN_CPU_ON: + val = kvm_psci_vcpu_on(vcpu); + break; + case KVM_PSCI_FN_CPU_SUSPEND: + case KVM_PSCI_FN_MIGRATE: + val = KVM_PSCI_RET_NI; + break; + + default: + return false; + } + + *vcpu_reg(vcpu, 0) = val; + return true; +} diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index dc63665..500acda 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -636,6 +636,7 @@ struct kvm_ppc_smmu_info { #define KVM_CAP_IRQFD_RESAMPLE 82 #define KVM_CAP_PPC_BOOKE_WATCHDOG 83 #define KVM_CAP_PPC_HTAB_FD 84 +#define KVM_CAP_ARM_PSCI 86 #ifdef KVM_CAP_IRQ_ROUTING