On Thu, 28 Aug 2014 11:36:42 +0800
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.
An additional question,
Have you checked if migration works after CPU unplug?
>
> 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 eee693b..0608b41 100644
> --- a/cpus.c
> +++ b/cpus.c
> @@ -851,6 +851,24 @@ 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;
> @@ -942,6 +960,11 @@ 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;
> @@ -994,6 +1017,7 @@ 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);
> @@ -1026,6 +1050,16 @@ 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;
> @@ -1383,6 +1417,9 @@ 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) {
