On Wed, 9 Jan 2013 00:21:04 -0500, Christoffer Dall
<c.dall@xxxxxxxxxxxxxxxxxxxxxx> wrote:
> On Mon, Jan 7, 2013 at 1:19 PM, Marc Zyngier <marc.zyngier@xxxxxxx>
wrote:
>> Implement the PSCI specification (ARM DEN 0022A) to control
>> virtual CPUs being "powered" on or off.
>>
>> The 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.
>>
>> Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
>> ---
>> arch/arm/include/asm/kvm_emulate.h | 5 ++
>> arch/arm/include/asm/kvm_host.h | 2 +-
>> 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 | 13 +++++
>> arch/arm/kvm/handle_exit.c | 16 +++---
>> arch/arm/kvm/psci.c | 103
>> +++++++++++++++++++++++++++++++++++++
>> include/uapi/linux/kvm.h | 1 +
>> 9 files changed, 170 insertions(+), 11 deletions(-)
>> create mode 100644 arch/arm/include/asm/kvm_psci.h
>> create mode 100644 arch/arm/kvm/psci.c
>>
>> diff --git a/arch/arm/include/asm/kvm_emulate.h
>> b/arch/arm/include/asm/kvm_emulate.h
>> index d52cb81..b6ed67b 100644
>> --- a/arch/arm/include/asm/kvm_emulate.h
>> +++ b/arch/arm/include/asm/kvm_emulate.h
>> @@ -35,6 +35,11 @@ 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;
>> +}
>> +
>
> this looks premature
Keeping ones sanity is rarely premature... ;-)
I already sit on an irritatingly large set of patches reworking the
existing code to fit arm64. Adding more patches to adapt new code that has
been written with arm64 in mind is not something I want to do.
>
>> static inline unsigned long *vcpu_pc(struct kvm_vcpu *vcpu)
>> {
>> return &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 fe8153a..39fc844 100644
>> --- a/arch/arm/include/asm/kvm_host.h
>> +++ b/arch/arm/include/asm/kvm_host.h
>> @@ -31,7 +31,7 @@
>> #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
>> diff --git a/arch/arm/include/asm/kvm_psci.h
>> b/arch/arm/include/asm/kvm_psci.h
>> new file mode 100644
>> index 0000000..992d7f1
>> --- /dev/null
>> +++ b/arch/arm/include/asm/kvm_psci.h
>> @@ -0,0 +1,23 @@
>> +/*
>> + * Copyright (C) 2012 - ARM Ltd
>> + * Author: Marc Zyngier <marc.zyngier@xxxxxxx>
>> + *
>> + * 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
<http://www.gnu.org/licenses/>.
>> + */
>> +
>> +#ifndef __ARM_KVM_PSCI_H__
>> +#define __ARM_KVM_PSCI_H__
>> +
>> +int 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 974f8b0..3c9663c 100644
>> --- a/arch/arm/include/uapi/asm/kvm.h
>> +++ b/arch/arm/include/uapi/asm/kvm.h
>> @@ -81,6 +81,8 @@ struct kvm_regs {
>> #define KVM_VGIC_V2_DIST_SIZE 0x1000
>> #define KVM_VGIC_V2_CPU_SIZE 0x2000
>>
>> +#define KVM_ARM_VCPU_POWER_OFF 0 /* CPU is started in OFF
state
>> */
>> +
>> struct kvm_vcpu_init {
>> __u32 target;
>> __u32 features[7];
>> @@ -161,4 +163,18 @@ 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 81823c1..1974ba0 100644
>> --- a/arch/arm/kvm/Makefile
>> +++ b/arch/arm/kvm/Makefile
>> @@ -18,6 +18,6 @@ kvm-arm-y = $(addprefix ../../../virt/kvm/,
kvm_main.o
>> coalesced_mmio.o)
>>
>> obj-y += kvm-arm.o init.o interrupts.o
>> obj-y += arm.o handle_exit.o guest.o mmu.o emulate.o reset.o
>> -obj-y += coproc.o coproc_a15.o mmio.o decode.o
>> +obj-y += coproc.o coproc_a15.o mmio.o decode.o psci.o
>> obj-$(CONFIG_KVM_ARM_VGIC) += vgic.o
>> obj-$(CONFIG_KVM_ARM_TIMER) += arch_timer.o
>> diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
>> index d16712d..15e1700 100644
>> --- a/arch/arm/kvm/arm.c
>> +++ b/arch/arm/kvm/arm.c
>> @@ -41,6 +41,7 @@
>> #include <asm/kvm_mmu.h>
>> #include <asm/kvm_emulate.h>
>> #include <asm/kvm_coproc.h>
>> +#include <asm/kvm_psci.h>
>>
>> #ifdef REQUIRES_VIRT
>> __asm__(".arch_extension virt");
>> @@ -189,6 +190,7 @@ 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:
>> @@ -504,6 +506,17 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu,
>> struct kvm_run *run)
>> return ret;
>> }
>>
>> + /*
>> + * Handle the "start in power-off" case by calling into the
>> + * PSCI code. This only happens once in the lifetime of a
>> + * vcpu.
>> + */
>> + if (unlikely(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);
>> + }
>> +
>> if (vcpu->sigset_active)
>> sigprocmask(SIG_SETMASK, &vcpu->sigset, &sigsaved);
>>
>> diff --git a/arch/arm/kvm/handle_exit.c b/arch/arm/kvm/handle_exit.c
>> index f2fc5fa..de86710 100644
>> --- a/arch/arm/kvm/handle_exit.c
>> +++ b/arch/arm/kvm/handle_exit.c
>
> this doesn't apply - looks like you sent a patch requiring your cleanup
> patches.
Indeed.
>
>> @@ -21,6 +21,7 @@
>> #include <asm/kvm_emulate.h>
>> #include <asm/kvm_coproc.h>
>> #include <asm/kvm_mmu.h>
>> +#include <asm/kvm_psci.h>
>> #include <trace/events/kvm.h>
>>
>> #include "trace.h"
>> @@ -37,21 +38,18 @@ static int handle_svc_hyp(struct kvm_vcpu *vcpu,
>> struct kvm_run *run)
>>
>> static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run)
>> {
>> - /*
>> - * Guest called HVC instruction:
>> - * Let it know we don't want that by injecting an undefined
>> exception.
>> - */
>> - kvm_debug("hvc: %x (at %08lx)", kvm_vcpu_get_hsr(vcpu) & ((1 <<
>> 16) - 1),
>> - *vcpu_pc(vcpu));
>> - kvm_debug(" HSR: %8x", kvm_vcpu_get_hsr(vcpu));
>> + if (!kvm_psci_call(vcpu))
>> + return 1;
>> +
>> kvm_inject_undefined(vcpu);
>> 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 %08lx", *vcpu_pc(vcpu));
>> + if (!kvm_psci_call(vcpu))
>> + return 1;
>> +
>> kvm_inject_undefined(vcpu);
>> return 1;
>> }
>> diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c
>> new file mode 100644
>> index 0000000..d59f763
>> --- /dev/null
>> +++ b/arch/arm/kvm/psci.c
>> @@ -0,0 +1,103 @@
>> +/*
>> + * Copyright (C) 2012 - ARM Ltd
>> + * Author: Marc Zyngier <marc.zyngier@xxxxxxx>
>> + *
>> + * 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
<http://www.gnu.org/licenses/>.
>> + */
>> +
>> +#include <linux/kvm_host.h>
>> +#include <linux/sched.h>
>> +
>> +#include <asm/kvm_emulate.h>
>> +#include <asm/kvm_psci.h>
>> +
>> +static void kvm_psci_vcpu_off(struct kvm_vcpu *vcpu)
>> +{
>> + DEFINE_WAIT(wait);
>> + wait_queue_head_t *wq = kvm_arch_vcpu_wq(vcpu);
>> +
>> + vcpu->arch.pause = true;
>> +
>> + while (1) {
>> + prepare_to_wait(wq, &wait, TASK_INTERRUPTIBLE);
>> +
>> + if (!vcpu->arch.pause)
>> + break;
>> +
>> + if (signal_pending(current))
>> + break;
>> +
>> + schedule();
>> + };
>> +
>> + finish_wait(wq, &wait);
>> +}
>> +
>> +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;
>> +}
>> +
>> +int kvm_psci_call(struct kvm_vcpu *vcpu)
>> +{
>> + unsigned long psci_fn = *vcpu_reg(vcpu, 0) & 0xffffffff;
>> + 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 -EINVAL;
>> + }
>> +
>> + *vcpu_reg(vcpu, 0) = val;
>> + return 0;
>> +}
>> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
>> index 03248d1..8233566 100644
>> --- a/include/uapi/linux/kvm.h
>> +++ b/include/uapi/linux/kvm.h
>> @@ -637,6 +637,7 @@ struct kvm_ppc_smmu_info {
>> #define KVM_CAP_PPC_BOOKE_WATCHDOG 83
>> #define KVM_CAP_PPC_HTAB_FD 84
>> #define KVM_CAP_SET_DEVICE_ADDR 85
>> +#define KVM_CAP_ARM_PSCI 86
>>
>> #ifdef KVM_CAP_IRQ_ROUTING
>>
>> --
>> 1.8.1
>>
>>
>>
>> _______________________________________________
>> kvmarm mailing list
>> kvmarm@xxxxxxxxxxxxxxxxxxxxx
>> https://lists.cs.columbia.edu/cucslists/listinfo/kvmarm
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