4:44 p.m.
Now that qemuDomainDetectVcpuPids is able to refresh the vCPU pid
information it can be reused in the hotplug and hotunplug code paths
rather than open-coding a very similar algorithm.
A slight algorithm change is necessary for unplug since the vCPU needs
to be marked offline prior to calling the thread detector function and
eventually rolled back if something fails.
---
Notes:
v3: correctly handle return values and pointer sanity in the unplug case
src/qemu/qemu_driver.c | 76 +++++++++++++++++---------------------------------
1 file changed, 25 insertions(+), 51 deletions(-)
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 78f177a..af44b0a 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -4770,11 +4770,10 @@ qemuDomainHotplugAddVcpu(virQEMUDriverPtr driver,
int ret = -1;
int rc;
int oldvcpus = virDomainDefGetVcpus(vm->def);
- pid_t *cpupids = NULL;
- int ncpupids = 0;
virCgroupPtr cgroup_vcpu = NULL;
char *mem_mask = NULL;
virDomainNumatuneMemMode mem_mode;
+ pid_t vcpupid;
if (!(vcpuinfo = virDomainDefGetVcpu(vm->def, vcpu)))
return -1;
@@ -4789,9 +4788,6 @@ qemuDomainHotplugAddVcpu(virQEMUDriverPtr driver,
rc = qemuMonitorSetCPU(priv->mon, vcpu, true);
- if (rc == 0)
- ncpupids = qemuMonitorGetCPUInfo(priv->mon, &cpupids);
-
if (qemuDomainObjExitMonitor(driver, vm) < 0)
goto cleanup;
@@ -4802,23 +4798,15 @@ qemuDomainHotplugAddVcpu(virQEMUDriverPtr driver,
vcpuinfo->online = true;
- if (ncpupids < 0)
- goto cleanup;
+ if ((rc = qemuDomainDetectVcpuPids(driver, vm, QEMU_ASYNC_JOB_NONE)) <= 0) {
+ /* vcpu pids were not detected, skip setting of affinity */
+ if (rc == 0)
+ ret = 0;
- /* failure to re-detect vCPU pids after hotplug due to lack of support was
- * historically deemed not fatal. We need to skip the rest of the steps though. */
- if (ncpupids == 0) {
- ret = 0;
goto cleanup;
}
- if (ncpupids != oldvcpus + 1) {
- virReportError(VIR_ERR_INTERNAL_ERROR,
- _("got wrong number of vCPU pids from QEMU monitor. "
- "got %d, wanted %d"),
- ncpupids, oldvcpus + 1);
- goto cleanup;
- }
+ vcpupid = qemuDomainGetVcpuPid(vm, vcpu);
if (virDomainNumatuneGetMode(vm->def->numa, -1, &mem_mode) == 0 &&
mem_mode == VIR_DOMAIN_NUMATUNE_MEM_STRICT &&
@@ -4828,11 +4816,9 @@ qemuDomainHotplugAddVcpu(virQEMUDriverPtr driver,
goto cleanup;
if (priv->cgroup) {
- cgroup_vcpu =
- qemuDomainAddCgroupForThread(priv->cgroup,
- VIR_CGROUP_THREAD_VCPU,
- vcpu, mem_mask,
- cpupids[vcpu]);
+ cgroup_vcpu = qemuDomainAddCgroupForThread(priv->cgroup,
+ VIR_CGROUP_THREAD_VCPU,
+ vcpu, mem_mask, vcpupid);
if (!cgroup_vcpu)
goto cleanup;
}
@@ -4844,26 +4830,20 @@ qemuDomainHotplugAddVcpu(virQEMUDriverPtr driver,
&vm->def->cputune.nvcpupin) < 0)
goto cleanup;
- if (qemuDomainHotplugPinThread(vm->def->cpumask, vcpu, cpupids[vcpu],
+ if (qemuDomainHotplugPinThread(vm->def->cpumask, vcpu, vcpupid,
cgroup_vcpu) < 0) {
goto cleanup;
}
}
- if (qemuProcessSetSchedParams(vcpu, cpupids[vcpu],
+ if (qemuProcessSetSchedParams(vcpu, vcpupid,
vm->def->cputune.nvcpusched,
vm->def->cputune.vcpusched) < 0)
goto cleanup;
- priv->nvcpupids = ncpupids;
- VIR_FREE(priv->vcpupids);
- priv->vcpupids = cpupids;
- cpupids = NULL;
-
ret = 0;
cleanup:
- VIR_FREE(cpupids);
VIR_FREE(mem_mask);
virCgroupFree(&cgroup_vcpu);
return ret;
@@ -4880,8 +4860,6 @@ qemuDomainHotplugDelVcpu(virQEMUDriverPtr driver,
int ret = -1;
int rc;
int oldvcpus = virDomainDefGetVcpus(vm->def);
- pid_t *cpupids = NULL;
- int ncpupids = 0;
if (!(vcpuinfo = virDomainDefGetVcpu(vm->def, vcpu)))
return -1;
@@ -4892,30 +4870,32 @@ qemuDomainHotplugDelVcpu(virQEMUDriverPtr driver,
return -1;
}
+ vcpuinfo->online = false;
+
qemuDomainObjEnterMonitor(driver, vm);
rc = qemuMonitorSetCPU(priv->mon, vcpu, false);
- if (rc == 0)
- ncpupids = qemuMonitorGetCPUInfo(priv->mon, &cpupids);
-
if (qemuDomainObjExitMonitor(driver, vm) < 0)
goto cleanup;
- virDomainAuditVcpu(vm, oldvcpus, oldvcpus - 1, "update",
- rc == 0 && ncpupids == oldvcpus -1);
-
- if (rc < 0 || ncpupids < 0)
+ if (rc < 0) {
+ virDomainAuditVcpu(vm, oldvcpus, oldvcpus - 1, "update", false);
+ vcpuinfo->online = true;
goto cleanup;
+ }
- /* check if hotunplug has failed */
- if (ncpupids != oldvcpus - 1) {
- virReportError(VIR_ERR_OPERATION_UNSUPPORTED,
- _("qemu didn't unplug vCPU '%u' properly"),
vcpu);
+ if ((rc = qemuDomainDetectVcpuPids(driver, vm, QEMU_ASYNC_JOB_NONE)) < 0) {
+ /* rollback only if domain didn't exit */
+ if (rc == -2)
+ goto cleanup;
+
+ virDomainAuditVcpu(vm, oldvcpus, oldvcpus - 1, "update", false);
+ vcpuinfo->online = true;
goto cleanup;
}
- vcpuinfo->online = false;
+ virDomainAuditVcpu(vm, oldvcpus, oldvcpus - 1, "update", true);
if (qemuDomainDelCgroupForThread(priv->cgroup,
VIR_CGROUP_THREAD_VCPU, vcpu) < 0)
@@ -4926,15 +4906,9 @@ qemuDomainHotplugDelVcpu(virQEMUDriverPtr driver,
&vm->def->cputune.nvcpupin,
vcpu);
- priv->nvcpupids = ncpupids;
- VIR_FREE(priv->vcpupids);
- priv->vcpupids = cpupids;
- cpupids = NULL;
-
ret = 0;
cleanup:
- VIR_FREE(cpupids);
return ret;
}
--
2.6.2