[libvirt] [PATCH 3/4] qemu: Implement the qemu driver fetch for IOThreads

[John Ferlan]

Make necessary checks for active domain and IOThread capability before
calling the monitor to fetch IOThread data for a domain. If there are
threads, then also return the processor affinity maps - this is similar
to existing GetVcpuPin, GetVcpuInfo, and GetEmulatorPin fetches of the
processor affinity. Having a separate GetIOThreadsPin seemed to be waste
if it could be done in one API.

Signed-off-by: John Ferlan <jferlan at redhat.com>
---
 src/qemu/qemu_driver.c | 114 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 114 insertions(+)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 709f468..ea61015 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -5541,6 +5541,119 @@ qemuDomainGetMaxVcpus(virDomainPtr dom)
                                          VIR_DOMAIN_VCPU_MAXIMUM));
 }
 
+static int
+qemuDomainGetIOThreadsInfo(virDomainPtr dom,
+                           virDomainIOThreadsInfoPtr **info,
+                           unsigned int flags)
+{
+    virQEMUDriverPtr driver = dom->conn->privateData;
+    virDomainObjPtr vm;
+    qemuDomainObjPrivatePtr priv;
+    qemuMonitorIOThreadsInfoPtr *iothreads = NULL;
+    virDomainIOThreadsInfoPtr *info_ret = NULL;
+    int niothreads = 0;
+    int maxcpu, hostcpus, maplen;
+    int ret = -1;
+    size_t i;
+
+    virCheckFlags(0, -1);
+
+    if (!(vm = qemuDomObjFromDomain(dom)))
+        goto cleanup;
+
+    if (virDomainGetIOThreadsInfoEnsureACL(dom->conn, vm->def) < 0)
+        goto cleanup;
+
+    if (qemuDomainObjBeginJob(driver, vm, QEMU_JOB_QUERY) < 0)
+        goto cleanup;
+
+    if (!virDomainObjIsActive(vm)) {
+        virReportError(VIR_ERR_OPERATION_INVALID, "%s",
+                       _("cannot list IOThreads for an inactive domain"));
+        goto endjob;
+    }
+
+    priv = vm->privateData;
+    if (!virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_OBJECT_IOTHREAD)) {
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                       _("IOThreads not supported with this binary"));
+        goto endjob;
+    }
+
+    if (qemuDomainObjEnterMonitorAsync(driver, vm, QEMU_ASYNC_JOB_NONE) < 0)
+        goto endjob;
+    niothreads = qemuMonitorGetIOThreads(priv->mon, &iothreads);
+    if (qemuDomainObjExitMonitor(driver, vm) < 0)
+        goto endjob;
+    if (niothreads < 0)
+        goto endjob;
+
+    /* Nothing to do */
+    if (niothreads == 0) {
+        ret = 0;
+        goto endjob;
+    }
+
+    if ((hostcpus = nodeGetCPUCount()) < 0)
+        goto endjob;
+
+    maplen = VIR_CPU_MAPLEN(hostcpus);
+    maxcpu = maplen * 8;
+    if (maxcpu > hostcpus)
+        maxcpu = hostcpus;
+
+    if (VIR_ALLOC_N(info_ret, niothreads) < 0)
+        goto endjob;
+
+    for (i = 0; i < niothreads; i++) {
+        virBitmapPtr map = NULL;
+        unsigned char *tmpmap = NULL;
+        int tmpmaplen = 0;
+
+        if (VIR_ALLOC(info_ret[i]) < 0)
+            goto endjob;
+
+        if (virStrToLong_ui(iothreads[i]->name + strlen("iothread"), NULL, 10,
+                            &info_ret[i]->iothread_id) < 0)
+            goto endjob;
+        info_ret[i]->thread_id = iothreads[i]->thread_id;
+
+        if (VIR_ALLOC_N(info_ret[i]->cpumap, maplen) < 0)
+            goto endjob;
+
+        if (virProcessGetAffinity(iothreads[i]->thread_id, &map, maxcpu) < 0)
+            goto endjob;
+
+        virBitmapToData(map, &tmpmap, &tmpmaplen);
+        if (tmpmaplen > maplen)
+            tmpmaplen = maplen;
+        memcpy(info_ret[i]->cpumap, tmpmap, tmpmaplen);
+        info_ret[i]->cpumaplen = tmpmaplen;
+
+        VIR_FREE(tmpmap);
+        virBitmapFree(map);
+    }
+
+    *info = info_ret;
+    info_ret = NULL;
+    ret = niothreads;
+
+ endjob:
+    qemuDomainObjEndJob(driver, vm);
+
+ cleanup:
+    qemuDomObjEndAPI(&vm);
+
+    if (info_ret) {
+        for (i = 0; i < niothreads; i++)
+            virDomainIOThreadsInfoFree(info_ret[i]);
+        VIR_FREE(info_ret);
+    }
+    return ret;
+
+}
+
+
 static int qemuDomainGetSecurityLabel(virDomainPtr dom, virSecurityLabelPtr seclabel)
 {
     virQEMUDriverPtr driver = dom->conn->privateData;
@@ -19141,6 +19254,7 @@ static virHypervisorDriver qemuHypervisorDriver = {
     .domainGetEmulatorPinInfo = qemuDomainGetEmulatorPinInfo, /* 0.10.0 */
     .domainGetVcpus = qemuDomainGetVcpus, /* 0.4.4 */
     .domainGetMaxVcpus = qemuDomainGetMaxVcpus, /* 0.4.4 */
+    .domainGetIOThreadsInfo = qemuDomainGetIOThreadsInfo, /* 1.2.13 */
     .domainGetSecurityLabel = qemuDomainGetSecurityLabel, /* 0.6.1 */
     .domainGetSecurityLabelList = qemuDomainGetSecurityLabelList, /* 0.10.0 */
     .nodeGetSecurityModel = qemuNodeGetSecurityModel, /* 0.6.1 */
-- 
2.1.0