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Re: [Qemu-devel] [RFC PATCH 10/10] cpus: reclaim allocated vCPU objects
From: |
Anshul Makkar |
Subject: |
Re: [Qemu-devel] [RFC PATCH 10/10] cpus: reclaim allocated vCPU objects |
Date: |
Mon, 11 Aug 2014 16:35:26 +0200 |
Hi Gu,
These are APIC IDs.
Taking the example from the previous mail.
Original cpus:0,1 maxcpus:6
(qemu) device_add qemu64-x86_64-cpu,apic-id=3,id=cpu3
(qemu) device_add qemu64-x86_64-cpu,apic-id=5,id=cpu5
cat /proc/cpuinfo shows
processor 0
processor 1
processor 2
processor 3
instead of 3 and 5 cpus 2 and 3 have been added.
Now if I do again
(qemu) device_add qemu64-x86_64-cpu,apic-id=5,id=cpu5
it says cpu already exists but cat /proc/cpuinfo doesn't show me cpu
with apicid 5.
Scenario 2:
Original cpus:0,1 maxcpus:6
(qemu) device_add qemu64-x86_64-cpu,apic-id=2,id=cpu2
(qemu) device_add qemu64-x86_64-cpu,apic-id=3,id=cpu3
(qemu) device_add qemu64-x86_64-cpu,apic-id=4,id=cpu4
cat /proc/cpuinfo
processor 0
processor 1
processor 2
processor 3
processor 4
(qemu) device_del cpu2
(qemu) device_del cpu4
cat /proc/cpuinof
processor 0
processor 1
processor 3
(qemu) device_add qemu64-x86_64-cpu,apic-id=4,id=cpu4
cpu 2 gets added instead of 4 and cat /proc/cpuinfo shows
processor 0
processor 1
processor 2
processor 3
I can just see that random deletion and addition is not possible.
I have put traces in the code to verify the APIC IDs as I couldn't see
APIC IDs in output of "cat /proc/cpuinfo ".
Please let me know if I am missing something .
Thanks
Anshul Makkar
On Fri, Aug 8, 2014 at 7:48 AM, Gu Zheng <address@hidden> wrote:
> Hi Anshul,
> On 08/07/2014 09:31 PM, Anshul Makkar wrote:
>
>> Thanks Gu.. cpu-hotunplug is working fine in my tests.
>
> Thanks for your quick test.
>
>>
>> For cpu-hotplug, I get inconsistent result if I delete arbitrary cpu
>> and not just the last one.
>>
>> for eg
>> list of cpus: 1, 2 ,3
>> device_add cpu 4
>> device_add cpu 5
>> device_add cpu 6
>
> What type id do you use here? apic-id or device id?
>
>>
>> device_del cpu 4
>> device_del cpu 6
>
> Could you please offer the detail reproduce info? the more the better.
>
>>
>> now if I do device_add cpu6, then cpu 4 gets added and now if I try to
>> do add cpu 4 or 6, it says cpu already exist.. Its a kind of vague
>> behaviour.. Do, we follow any protocol here while adding and deleting
>> cpus.
>
> There is not strict restriction here. Does the following routine match
> the condition you mentioned? It works fine in my box.
>
> Original cpus:0,1 maxcpus:6
> (qemu) device_add qemu64-x86_64-cpu,apic-id=2,id=cpu2
> (qemu) device_add qemu64-x86_64-cpu,apic-id=3,id=cpu3
> (qemu) device_add qemu64-x86_64-cpu,apic-id=4,id=cpu4
>
> (qemu) device_del cpu2
> (qemu) device_del cpu4
>
> (qemu) device_add qemu64-x86_64-cpu,apic-id=4,id=cpu4
> (qemu) device_add qemu64-x86_64-cpu,apic-id=2,id=cpu2
>
> Thanks,
> Gu
>
>>
>> Thanks
>> Anshul Makkar
>> www.justkernel.com
>>
>> On Thu, Aug 7, 2014 at 6:54 AM, Gu Zheng <address@hidden> wrote:
>>> After ACPI get a signal to eject a vCPU, the vCPU must be
>>> removed from CPU list,before the vCPU really removed, then
>>> release the all related vCPU objects.
>>> But we do not close KVM vcpu fd, just record it into a list, in
>>> order to reuse it.
>>>
>>> Signed-off-by: Chen Fan <address@hidden>
>>> Signed-off-by: Gu Zheng <address@hidden>
>>> ---
>>> cpus.c | 37 ++++++++++++++++++++++++++++++++
>>> include/sysemu/kvm.h | 1 +
>>> kvm-all.c | 57
>>> +++++++++++++++++++++++++++++++++++++++++++++++++-
>>> 3 files changed, 94 insertions(+), 1 deletions(-)
>>>
>>> diff --git a/cpus.c b/cpus.c
>>> index 4dfb889..9a73407 100644
>>> --- a/cpus.c
>>> +++ b/cpus.c
>>> @@ -786,6 +786,24 @@ void async_run_on_cpu(CPUState *cpu, void (*func)(void
>>> *data), void *data)
>>> qemu_cpu_kick(cpu);
>>> }
>>>
>>> +static void qemu_kvm_destroy_vcpu(CPUState *cpu)
>>> +{
>>> + CPU_REMOVE(cpu);
>>> +
>>> + if (kvm_destroy_vcpu(cpu) < 0) {
>>> + fprintf(stderr, "kvm_destroy_vcpu failed.\n");
>>> + exit(1);
>>> + }
>>> +
>>> + object_unparent(OBJECT(cpu));
>>> +}
>>> +
>>> +static void qemu_tcg_destroy_vcpu(CPUState *cpu)
>>> +{
>>> + CPU_REMOVE(cpu);
>>> + object_unparent(OBJECT(cpu));
>>> +}
>>> +
>>> static void flush_queued_work(CPUState *cpu)
>>> {
>>> struct qemu_work_item *wi;
>>> @@ -877,6 +895,11 @@ static void *qemu_kvm_cpu_thread_fn(void *arg)
>>> }
>>> }
>>> qemu_kvm_wait_io_event(cpu);
>>> + if (cpu->exit && !cpu_can_run(cpu)) {
>>> + qemu_kvm_destroy_vcpu(cpu);
>>> + qemu_mutex_unlock(&qemu_global_mutex);
>>> + return NULL;
>>> + }
>>> }
>>>
>>> return NULL;
>>> @@ -929,6 +952,7 @@ static void tcg_exec_all(void);
>>> static void *qemu_tcg_cpu_thread_fn(void *arg)
>>> {
>>> CPUState *cpu = arg;
>>> + CPUState *remove_cpu = NULL;
>>>
>>> qemu_tcg_init_cpu_signals();
>>> qemu_thread_get_self(cpu->thread);
>>> @@ -961,6 +985,16 @@ static void *qemu_tcg_cpu_thread_fn(void *arg)
>>> }
>>> }
>>> qemu_tcg_wait_io_event();
>>> + CPU_FOREACH(cpu) {
>>> + if (cpu->exit && !cpu_can_run(cpu)) {
>>> + remove_cpu = cpu;
>>> + break;
>>> + }
>>> + }
>>> + if (remove_cpu) {
>>> + qemu_tcg_destroy_vcpu(remove_cpu);
>>> + remove_cpu = NULL;
>>> + }
>>> }
>>>
>>> return NULL;
>>> @@ -1316,6 +1350,9 @@ static void tcg_exec_all(void)
>>> break;
>>> }
>>> } else if (cpu->stop || cpu->stopped) {
>>> + if (cpu->exit) {
>>> + next_cpu = CPU_NEXT(cpu);
>>> + }
>>> break;
>>> }
>>> }
>>> diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
>>> index 174ea36..88e2403 100644
>>> --- a/include/sysemu/kvm.h
>>> +++ b/include/sysemu/kvm.h
>>> @@ -178,6 +178,7 @@ int kvm_has_intx_set_mask(void);
>>>
>>> int kvm_init_vcpu(CPUState *cpu);
>>> int kvm_cpu_exec(CPUState *cpu);
>>> +int kvm_destroy_vcpu(CPUState *cpu);
>>>
>>> #ifdef NEED_CPU_H
>>>
>>> diff --git a/kvm-all.c b/kvm-all.c
>>> index 1402f4f..d0caeff 100644
>>> --- a/kvm-all.c
>>> +++ b/kvm-all.c
>>> @@ -74,6 +74,12 @@ typedef struct KVMSlot
>>>
>>> typedef struct kvm_dirty_log KVMDirtyLog;
>>>
>>> +struct KVMParkedVcpu {
>>> + unsigned long vcpu_id;
>>> + int kvm_fd;
>>> + QLIST_ENTRY(KVMParkedVcpu) node;
>>> +};
>>> +
>>> struct KVMState
>>> {
>>> KVMSlot *slots;
>>> @@ -108,6 +114,7 @@ struct KVMState
>>> QTAILQ_HEAD(msi_hashtab, KVMMSIRoute)
>>> msi_hashtab[KVM_MSI_HASHTAB_SIZE];
>>> bool direct_msi;
>>> #endif
>>> + QLIST_HEAD(, KVMParkedVcpu) kvm_parked_vcpus;
>>> };
>>>
>>> KVMState *kvm_state;
>>> @@ -226,6 +233,53 @@ static int kvm_set_user_memory_region(KVMState *s,
>>> KVMSlot *slot)
>>> return kvm_vm_ioctl(s, KVM_SET_USER_MEMORY_REGION, &mem);
>>> }
>>>
>>> +int kvm_destroy_vcpu(CPUState *cpu)
>>> +{
>>> + KVMState *s = kvm_state;
>>> + long mmap_size;
>>> + struct KVMParkedVcpu *vcpu = NULL;
>>> + int ret = 0;
>>> +
>>> + DPRINTF("kvm_destroy_vcpu\n");
>>> +
>>> + mmap_size = kvm_ioctl(s, KVM_GET_VCPU_MMAP_SIZE, 0);
>>> + if (mmap_size < 0) {
>>> + ret = mmap_size;
>>> + DPRINTF("KVM_GET_VCPU_MMAP_SIZE failed\n");
>>> + goto err;
>>> + }
>>> +
>>> + ret = munmap(cpu->kvm_run, mmap_size);
>>> + if (ret < 0) {
>>> + goto err;
>>> + }
>>> +
>>> + vcpu = g_malloc0(sizeof(*vcpu));
>>> + vcpu->vcpu_id = kvm_arch_vcpu_id(cpu);
>>> + vcpu->kvm_fd = cpu->kvm_fd;
>>> + QLIST_INSERT_HEAD(&kvm_state->kvm_parked_vcpus, vcpu, node);
>>> +err:
>>> + return ret;
>>> +}
>>> +
>>> +static int kvm_get_vcpu(KVMState *s, unsigned long vcpu_id)
>>> +{
>>> + struct KVMParkedVcpu *cpu;
>>> +
>>> + QLIST_FOREACH(cpu, &s->kvm_parked_vcpus, node) {
>>> + if (cpu->vcpu_id == vcpu_id) {
>>> + int kvm_fd;
>>> +
>>> + QLIST_REMOVE(cpu, node);
>>> + kvm_fd = cpu->kvm_fd;
>>> + g_free(cpu);
>>> + return kvm_fd;
>>> + }
>>> + }
>>> +
>>> + return kvm_vm_ioctl(s, KVM_CREATE_VCPU, (void *)vcpu_id);
>>> +}
>>> +
>>> int kvm_init_vcpu(CPUState *cpu)
>>> {
>>> KVMState *s = kvm_state;
>>> @@ -234,7 +288,7 @@ int kvm_init_vcpu(CPUState *cpu)
>>>
>>> DPRINTF("kvm_init_vcpu\n");
>>>
>>> - ret = kvm_vm_ioctl(s, KVM_CREATE_VCPU, (void *)kvm_arch_vcpu_id(cpu));
>>> + ret = kvm_get_vcpu(s, kvm_arch_vcpu_id(cpu));
>>> if (ret < 0) {
>>> DPRINTF("kvm_create_vcpu failed\n");
>>> goto err;
>>> @@ -1404,6 +1458,7 @@ int kvm_init(MachineClass *mc)
>>> #ifdef KVM_CAP_SET_GUEST_DEBUG
>>> QTAILQ_INIT(&s->kvm_sw_breakpoints);
>>> #endif
>>> + QLIST_INIT(&s->kvm_parked_vcpus);
>>> s->vmfd = -1;
>>> s->fd = qemu_open("/dev/kvm", O_RDWR);
>>> if (s->fd == -1) {
>>> --
>>> 1.7.7
>>>
>> .
>>
>
>
- [Qemu-devel] [RFC PATCH 03/10] cpu: add device_add foo-x86_64-cpu support, (continued)
- [Qemu-devel] [RFC PATCH 03/10] cpu: add device_add foo-x86_64-cpu support, Gu Zheng, 2014/08/07
- [Qemu-devel] [RFC PATCH 04/10] x86: add x86_cpu_unrealizefn() for cpu apic remove, Gu Zheng, 2014/08/07
- [Qemu-devel] [RFC PATCH 05/10] i386: add cpu device_del support, Gu Zheng, 2014/08/07
- [Qemu-devel] [RFC PATCH 06/10] qom cpu: rename variable 'cpu_added_notifier' to 'cpu_hotplug_notifier', Gu Zheng, 2014/08/07
- [Qemu-devel] [RFC PATCH 07/10] qom cpu: add UNPLUG cpu notify support, Gu Zheng, 2014/08/07
- [Qemu-devel] [RFC PATCH 08/10] i386: implement pc interface cpu_common_unrealizefn() in qom/cpu.c, Gu Zheng, 2014/08/07
- [Qemu-devel] [RFC PATCH 09/10] cpu hotplug: implement function cpu_status_write() for vcpu ejection, Gu Zheng, 2014/08/07
- [Qemu-devel] [RFC PATCH 10/10] cpus: reclaim allocated vCPU objects, Gu Zheng, 2014/08/07
Re: [Qemu-devel] [RFC PATCH 00/10] cpu: add device_add foo-x86_64-cpu and i386 cpu hot remove support, Gu Zheng, 2014/08/18