From 6afae05109fd8a7067d4751810651eb112fefe17 Mon Sep 17 00:00:00 2001
From: David Gibson <dgibson@redhat.com>
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 <dgibson@redhat.com>
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 <imammedo@redhat.com>
RH-Acked-by: Laurent Vivier <lvivier@redhat.com>
RH-Acked-by: Thomas Huth <thuth@redhat.com>
From: Bharata B Rao <bharata@linux.vnet.ibm.com>
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 <bharata@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
(cherry picked from commit 2c579042e3be50bb40a233a6986348b4f40ed026)
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1172917
Signed-off-by: David Gibson <dgibson@redhat.com>
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
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