10:02 a.m.
Future patches will tweak and reuse the function in different places so
move it separately first.
---
Notes:
v2:
- fixed two typos
src/qemu/qemu_domain.c | 84 +++++++++++++++++++++++++++++++++++++++++++++++++
src/qemu/qemu_domain.h | 2 ++
src/qemu/qemu_process.c | 76 ++------------------------------------------
3 files changed, 88 insertions(+), 74 deletions(-)
diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index 1df1b74..5ddf048 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -4280,3 +4280,87 @@ qemuDomainGetVcpuPid(virDomainObjPtr vm,
return priv->vcpupids[vcpu];
}
+
+
+/**
+ * qemuDomainDetectVcpuPids:
+ * @driver: qemu driver data
+ * @vm: domain object
+ * @asyncJob: current asynchronous job type
+ *
+ * Updates vCPU thread ids in the private data of @vm.
+ *
+ * Returns 0 on success -1 on error and reports an appropriate error.
+ */
+int
+qemuDomainDetectVcpuPids(virQEMUDriverPtr driver,
+ virDomainObjPtr vm,
+ int asyncJob)
+{
+ pid_t *cpupids = NULL;
+ int ncpupids;
+ qemuDomainObjPrivatePtr priv = vm->privateData;
+
+ /*
+ * Current QEMU *can* report info about host threads mapped
+ * to vCPUs, but it is not in a manner we can correctly
+ * deal with. The TCG CPU emulation does have a separate vCPU
+ * thread, but it runs every vCPU in that same thread. So it
+ * is impossible to setup different affinity per thread.
+ *
+ * What's more the 'query-cpus' command returns bizarre
+ * data for the threads. It gives the TCG thread for the
+ * vCPU 0, but for vCPUs 1-> N, it actually replies with
+ * the main process thread ID.
+ *
+ * The result is that when we try to set affinity for
+ * vCPU 1, it will actually change the affinity of the
+ * emulator thread :-( When you try to set affinity for
+ * vCPUs 2, 3.... it will fail if the affinity was
+ * different from vCPU 1.
+ *
+ * We *could* allow vcpu pinning with TCG, if we made the
+ * restriction that all vCPUs had the same mask. This would
+ * at least let us separate emulator from vCPUs threads, as
+ * we do for KVM. It would need some changes to our cgroups
+ * CPU layout though, and error reporting for the config
+ * restrictions.
+ *
+ * Just disable CPU pinning with TCG until someone wants
+ * to try to do this hard work.
+ */
+ if (vm->def->virtType == VIR_DOMAIN_VIRT_QEMU) {
+ priv->nvcpupids = 0;
+ priv->vcpupids = NULL;
+ return 0;
+ }
+
+ if (qemuDomainObjEnterMonitorAsync(driver, vm, asyncJob) < 0)
+ return -1;
+ ncpupids = qemuMonitorGetCPUInfo(priv->mon, &cpupids);
+ if (qemuDomainObjExitMonitor(driver, vm) < 0)
+ return -1;
+ /* failure to get the VCPU<-> PID mapping or to execute the query
+ * command will not be treated fatal as some versions of qemu don't
+ * support this command */
+ if (ncpupids <= 0) {
+ virResetLastError();
+
+ priv->nvcpupids = 0;
+ priv->vcpupids = NULL;
+ return 0;
+ }
+
+ if (ncpupids != virDomainDefGetVcpus(vm->def)) {
+ virReportError(VIR_ERR_INTERNAL_ERROR,
+ _("got wrong number of vCPU pids from QEMU monitor. "
+ "got %d, wanted %d"),
+ ncpupids, virDomainDefGetVcpus(vm->def));
+ VIR_FREE(cpupids);
+ return -1;
+ }
+
+ priv->nvcpupids = ncpupids;
+ priv->vcpupids = cpupids;
+ return 0;
+}
diff --git a/src/qemu/qemu_domain.h b/src/qemu/qemu_domain.h
index 7fc4fff..6a8cf70 100644
--- a/src/qemu/qemu_domain.h
+++ b/src/qemu/qemu_domain.h
@@ -508,5 +508,7 @@ int qemuDomainDefValidateMemoryHotplug(const virDomainDef *def,
bool qemuDomainHasVcpuPids(virDomainObjPtr vm);
pid_t qemuDomainGetVcpuPid(virDomainObjPtr vm, unsigned int vcpu);
+int qemuDomainDetectVcpuPids(virQEMUDriverPtr driver, virDomainObjPtr vm,
+ int asyncJob);
#endif /* __QEMU_DOMAIN_H__ */
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index ee94d3f..7b09ba7 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -1992,78 +1992,6 @@ qemuProcessWaitForMonitor(virQEMUDriverPtr driver,
return ret;
}
-static int
-qemuProcessDetectVcpuPIDs(virQEMUDriverPtr driver,
- virDomainObjPtr vm, int asyncJob)
-{
- pid_t *cpupids = NULL;
- int ncpupids;
- qemuDomainObjPrivatePtr priv = vm->privateData;
-
- /*
- * Current QEMU *can* report info about host threads mapped
- * to vCPUs, but it is not in a manner we can correctly
- * deal with. The TCG CPU emulation does have a separate vCPU
- * thread, but it runs every vCPU in that same thread. So it
- * is impossible to setup different affinity per thread.
- *
- * What's more the 'query-cpus' command returns bizarre
- * data for the threads. It gives the TCG thread for the
- * vCPU 0, but for vCPUs 1-> N, it actually replies with
- * the main process thread ID.
- *
- * The result is that when we try to set affinity for
- * vCPU 1, it will actually change the affinity of the
- * emulator thread :-( When you try to set affinity for
- * vCPUs 2, 3.... it will fail if the affinity was
- * different from vCPU 1.
- *
- * We *could* allow vcpu pinning with TCG, if we made the
- * restriction that all vCPUs had the same mask. This would
- * at least let us separate emulator from vCPUs threads, as
- * we do for KVM. It would need some changes to our cgroups
- * CPU layout though, and error reporting for the config
- * restrictions.
- *
- * Just disable CPU pinning with TCG until someone wants
- * to try to do this hard work.
- */
- if (vm->def->virtType == VIR_DOMAIN_VIRT_QEMU) {
- priv->nvcpupids = 0;
- priv->vcpupids = NULL;
- return 0;
- }
-
- if (qemuDomainObjEnterMonitorAsync(driver, vm, asyncJob) < 0)
- return -1;
- ncpupids = qemuMonitorGetCPUInfo(priv->mon, &cpupids);
- if (qemuDomainObjExitMonitor(driver, vm) < 0)
- return -1;
- /* failure to get the VCPU<-> PID mapping or to execute the query
- * command will not be treated fatal as some versions of qemu don't
- * support this command */
- if (ncpupids <= 0) {
- virResetLastError();
-
- priv->nvcpupids = 0;
- priv->vcpupids = NULL;
- return 0;
- }
-
- if (ncpupids != virDomainDefGetVcpus(vm->def)) {
- virReportError(VIR_ERR_INTERNAL_ERROR,
- _("got wrong number of vCPU pids from QEMU monitor. "
- "got %d, wanted %d"),
- ncpupids, virDomainDefGetVcpus(vm->def));
- VIR_FREE(cpupids);
- return -1;
- }
-
- priv->nvcpupids = ncpupids;
- priv->vcpupids = cpupids;
- return 0;
-}
-
static int
qemuProcessDetectIOThreadPIDs(virQEMUDriverPtr driver,
@@ -5020,7 +4948,7 @@ qemuProcessLaunch(virConnectPtr conn,
goto cleanup;
VIR_DEBUG("Detecting VCPU PIDs");
- if (qemuProcessDetectVcpuPIDs(driver, vm, asyncJob) < 0)
+ if (qemuDomainDetectVcpuPids(driver, vm, asyncJob) < 0)
goto cleanup;
VIR_DEBUG("Detecting IOThread PIDs");
@@ -5727,7 +5655,7 @@ int qemuProcessAttach(virConnectPtr conn ATTRIBUTE_UNUSED,
}
VIR_DEBUG("Detecting VCPU PIDs");
- if (qemuProcessDetectVcpuPIDs(driver, vm, QEMU_ASYNC_JOB_NONE) < 0)
+ if (qemuDomainDetectVcpuPids(driver, vm, QEMU_ASYNC_JOB_NONE) < 0)
goto error;
VIR_DEBUG("Detecting IOThread PIDs");
--
2.6.2