[libvirt] [PATCH 13/34] qemu: Move and rename qemuProcessDetectVcpuPIDs to qemuDomainDetectVcpuPids

[Peter Krempa]

Future patches will tweak and reuse the function in different places so
move it separately first.
---
 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 0fa2dbe..1ea1cd3 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -4257,3 +4257,87 @@ qemuDomainGetVcpuPid(virDomainObjPtr vm,

     return priv->vcpupids[vcpu];
 }
+
+
+/**
+ * qemuDomainDetectVcpuPIDs:
+ * @driver: qemu driver data
+ * @vm: domain object
+ * @asyncJob: current asynchronous job type
+ *
+ * Updates vCPU trhead 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 dec4572..a7c3094 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -1962,78 +1962,6 @@ 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,
@@ -4982,7 +4910,7 @@ 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");
@@ -5689,7 +5617,7 @@ 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