From 6afae05109fd8a7067d4751810651eb112fefe17 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Tue, 12 Jul 2016 07:41:37 +0200 Subject: [PATCH 04/34] cpu: Add a sync version of cpu_remove() RH-Author: David Gibson Message-id: <1468309320-14859-5-git-send-email-dgibson@redhat.com> Patchwork-id: 71124 O-Subject: [RHEL7.3 qemu-kvm-rhev PATCHv2 04/27] cpu: Add a sync version of cpu_remove() Bugzilla: 1172917 RH-Acked-by: Igor Mammedov RH-Acked-by: Laurent Vivier RH-Acked-by: Thomas Huth From: Bharata B Rao This sync API will be used by the CPU hotplug code to wait for the CPU to completely get removed before flagging the failure to the device_add command. Sync version of this call is needed to correctly recover from CPU realization failures when ->plug() handler fails. Signed-off-by: Bharata B Rao Reviewed-by: David Gibson Acked-by: Paolo Bonzini Signed-off-by: David Gibson (cherry picked from commit 2c579042e3be50bb40a233a6986348b4f40ed026) Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1172917 Signed-off-by: David Gibson Signed-off-by: Miroslav Rezanina --- cpus.c | 12 ++++++++++++ include/qom/cpu.h | 8 ++++++++ 2 files changed, 20 insertions(+) diff --git a/cpus.c b/cpus.c index 25ecf3d..c826954 100644 --- a/cpus.c +++ b/cpus.c @@ -1082,6 +1082,8 @@ static void *qemu_kvm_cpu_thread_fn(void *arg) } while (!cpu->unplug || cpu_can_run(cpu)); qemu_kvm_destroy_vcpu(cpu); + cpu->created = false; + qemu_cond_signal(&qemu_cpu_cond); qemu_mutex_unlock_iothread(); return NULL; } @@ -1182,6 +1184,8 @@ static void *qemu_tcg_cpu_thread_fn(void *arg) } if (remove_cpu) { qemu_tcg_destroy_vcpu(remove_cpu); + cpu->created = false; + qemu_cond_signal(&qemu_cpu_cond); remove_cpu = NULL; } } @@ -1347,6 +1351,14 @@ void cpu_remove(CPUState *cpu) qemu_cpu_kick(cpu); } +void cpu_remove_sync(CPUState *cpu) +{ + cpu_remove(cpu); + while (cpu->created) { + qemu_cond_wait(&qemu_cpu_cond, &qemu_global_mutex); + } +} + /* For temporary buffers for forming a name */ #define VCPU_THREAD_NAME_SIZE 16 diff --git a/include/qom/cpu.h b/include/qom/cpu.h index 911bc9f..9c544f6 100644 --- a/include/qom/cpu.h +++ b/include/qom/cpu.h @@ -763,6 +763,14 @@ void cpu_resume(CPUState *cpu); */ void cpu_remove(CPUState *cpu); + /** + * cpu_remove_sync: + * @cpu: The CPU to remove. + * + * Requests the CPU to be removed and waits till it is removed. + */ +void cpu_remove_sync(CPUState *cpu); + /** * qemu_init_vcpu: * @cpu: The vCPU to initialize. -- 1.8.3.1