[libvirt] [PATCH 5/8] cputune: support cputune for qemu driver

[Osier Yang]

When domain startup, setting cpu affinity and cpu shares according
to the cputune xml specified in domain xml.

Modify "qemudDomainPinVcpu" to update domain config for vcpupin,
and modify "qemuSetSchedulerParameters" to update domain config
for cpu shares.

* src/qemu/qemu_cgroup.c
* src/qemu/qemu_driver.c
* src/qemu/qemu_process.c
---
 src/qemu/qemu_cgroup.c  |   15 +++++++++
 src/qemu/qemu_driver.c  |    8 +++++
 src/qemu/qemu_process.c |   79 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 102 insertions(+), 0 deletions(-)

diff --git a/src/qemu/qemu_cgroup.c b/src/qemu/qemu_cgroup.c
index 935517f..8cf45da 100644
--- a/src/qemu/qemu_cgroup.c
+++ b/src/qemu/qemu_cgroup.c
@@ -343,6 +343,21 @@ int qemuSetupCgroup(struct qemud_driver *driver,
                  vm->def->name);
     }

+    if (qemuCgroupControllerActive(driver, VIR_CGROUP_CONTROLLER_CPU)) {
+        if (vm->def->cputune.shares != 0) {
+            rc = virCgroupSetCpuShares(cgroup, vm->def->cputune.shares);
+            if(rc != 0) {
+                virReportSystemError(-rc,
+                                     _("Unable to set io cpu shares for domain %s"),
+                                     vm->def->name);
+                goto cleanup;
+            }
+        }
+    } else {
+        qemuReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                        _("CPU tuning is not available on this host"));
+    }
+
 done:
     virCgroupFree(&cgroup);
     return 0;
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index e97c1d9..28a5298 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -2681,6 +2681,12 @@ qemudDomainPinVcpu(virDomainPtr dom,
     }
     ret = 0;

+    if (virDomainVcpupinAdd(vm->def, cpumap, maplen, vcpu) < 0) {
+        qemuReportError(VIR_ERR_INTERNAL_ERROR,
+                        "%s", _("failed to update or add vcpupin xml"));
+        goto cleanup;
+    }
+
 cleanup:
     if (vm)
         virDomainObjUnlock(vm);
@@ -4644,6 +4650,8 @@ static int qemuSetSchedulerParameters(virDomainPtr dom,
                                      _("unable to set cpu shares tunable"));
                 goto cleanup;
             }
+
+            vm->def->cputune.shares = params[i].value.ul;
         } else {
             qemuReportError(VIR_ERR_INVALID_ARG,
                             _("Invalid parameter `%s'"), param->field);
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index 209c8cf..e974a67 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -1143,6 +1143,81 @@ qemuProcessInitCpuAffinity(virDomainObjPtr vm)
     return 0;
 }

+/* Set CPU affinites for vcpus if vcpupin xml provided. */
+static int
+qemuProcessSetVcpuAffinites(virConnectPtr conn,
+                            virDomainObjPtr vm)
+{
+    qemuDomainObjPrivatePtr priv = vm->privateData;
+    virDomainDefPtr def = vm->def;
+    virNodeInfo nodeinfo;
+    pid_t vcpupid;
+    unsigned char *cpumask;
+    int vcpu, cpumaplen, hostcpus, maxcpu;
+
+    if (virNodeGetInfo(conn, &nodeinfo) != 0) {
+        return  -1;
+    }
+
+    if (!def->cputune.nvcpupin)
+        return 0;
+
+    if (priv->vcpupids == NULL) {
+        qemuReportError(VIR_ERR_NO_SUPPORT,
+                        "%s", _("cpu affinity is not supported"));
+        return -1;
+    }
+
+    hostcpus = VIR_NODEINFO_MAXCPUS(nodeinfo);
+    cpumaplen = VIR_CPU_MAPLEN(hostcpus);
+    maxcpu = cpumaplen * 8;
+
+    if (maxcpu > hostcpus)
+        maxcpu = hostcpus;
+
+    for (vcpu = 0; vcpu < def->cputune.nvcpupin; vcpu++) {
+        if (vcpu != def->cputune.vcpupin[vcpu]->vcpuid)
+            continue;
+
+        int i;
+        unsigned char *cpumap = NULL;
+
+        if (VIR_ALLOC_VAR(cpumap, char, cpumaplen) < 0) {
+            virReportOOMError();
+            return -1;
+        }
+
+        /* Initialize cpumap to all 0s. */
+        for (i = 0; i < cpumaplen; i++)
+            cpumap[i] = 0;
+
+        cpumask = (unsigned char *)def->cputune.vcpupin[vcpu]->cpumask;
+        vcpupid = priv->vcpupids[vcpu];
+
+        /* Convert cpumask to bitmap here. */
+        for (i = 0; i < VIR_DOMAIN_CPUMASK_LEN; i++) {
+            int cur = 0;
+            int mod = 0;
+
+            if (i) {
+                cur = i / 8;
+                mod = i % 8;
+            }
+
+            if (cpumask[i])
+                cpumap[cur] |= 1 << mod;
+        }
+
+        if (virProcessInfoSetAffinity(vcpupid,
+                                      cpumap,
+                                      cpumaplen,
+                                      maxcpu) < 0) {
+            return -1;
+        }
+    }
+
+    return 0;
+}

 static int
 qemuProcessInitPasswords(virConnectPtr conn,
@@ -2217,6 +2292,10 @@ int qemuProcessStart(virConnectPtr conn,
     if (qemuProcessDetectVcpuPIDs(driver, vm) < 0)
         goto cleanup;

+    VIR_DEBUG0("Setting VCPU affinities");
+    if (qemuProcessSetVcpuAffinites(conn, vm) < 0)
+        goto cleanup;
+
     VIR_DEBUG0("Setting any required VM passwords");
     if (qemuProcessInitPasswords(conn, driver, vm, qemuCaps) < 0)
         goto cleanup;
--
1.7.4