Hi Anshul, On 07/18/2014 12:24 AM, Anshul Makkar wrote: > Are we not going to introduce new command cpu_del for deleting the cpu ? > > I couldn't find any patch for addition of cpu_del command. Is this > intentional and we intend to use device_del (and similarly device_add) > for cpu hot(un)plug or just skipped to be added later. I have the > patch for the same which I can release, if the intent is to add this > command.
The "device_add/device_del" interface is the approved way to support add/del cpu, which is also more common and elegant than "cpu_add/del". <http://wiki.qemu.org/Features/CPUHotplug> so we intend to use device_del rather than the cpu_del. And IMO, the cpu_add will be replaced by "device_add" sooner or later. Thanks, Gu > > Thanks > Anshul Makkar > > On Fri, Jul 11, 2014 at 11:59 AM, Gu Zheng <guz.f...@cn.fujitsu.com> 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 <chen.fan.f...@cn.fujitsu.com> >> Signed-off-by: Gu Zheng <guz.f...@cn.fujitsu.com> >> --- >> 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 3ae30ee..25e2a43 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 >> > . >
