libxl: implement virDomainInterfaceStats

Introduce support for domainInterfaceStats API call for querying
network interface statistics. Consequently it also enables the
use of `virsh domifstat <dom> <interface name>` command plus
seeing the interfaces names instead of "-" when doing
`virsh domiflist <dom>`.

After successful guest creation we fill the network
interfaces names based on domain, device id and append suffix
if it's emulated in the following form: vif<domid>.<devid>[-emu].
We extract the network interfaces info from the libxl_domain_config
object in libxlDomainCreateIfaceNames() to generate ifname. On domain
cleanup we also clear ifname, in case it was set by libvirt (i.e.
being prefixed with "vif"). We also skip these two steps in case the name
of the interface was manually inserted by the adminstrator.

For getting the interface statistics we resort to virNetInterfaceStats
and let libvirt handle the platform specific nits. Note that the latter
is not yet supported in FreeBSD.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>

diff --git a/src/libxl/libxl_domain.c b/src/libxl/libxl_domain.c
index 40dcea171c06746d7e49ae3a73a01e0c3d014c4e..ef929740affdc21ba5245c4fa65f5ceb4190616e 100644 (file)
--- a/src/libxl/libxl_domain.c
+++ b/src/libxl/libxl_domain.c
@@ -728,6 +728,17 @@ libxlDomainCleanup(libxlDriverPrivatePtr driver,
         }
     }
 
+    if ((vm->def->nnets)) {
+        size_t i;
+
+        for (i = 0; i < vm->def->nnets; i++) {
+            virDomainNetDefPtr net = vm->def->nets[i];
+
+            if (STRPREFIX(net->ifname, "vif"))
+                VIR_FREE(net->ifname);
+        }
+    }
+
     if (virAsprintf(&file, "%s/%s.xml", cfg->stateDir, vm->def->name) > 0) {
         if (unlink(file) < 0 && errno != ENOENT && errno != ENOTDIR)
             VIR_DEBUG("Failed to remove domain XML for %s", vm->def->name);
@@ -887,6 +898,31 @@ libxlConsoleCallback(libxl_ctx *ctx, libxl_event *ev, void *for_callback)
     libxl_event_free(ctx, ev);
 }
 
+/*
+ * Create interface names for the network devices in parameter def.
+ * Names are created with the pattern 'vif<domid>.<devid><suffix>'.
+ * devid is extracted from the network devices in the d_config
+ * parameter. User-provided interface names are skipped.
+ */
+static void
+libxlDomainCreateIfaceNames(virDomainDefPtr def, libxl_domain_config *d_config)
+{
+    size_t i;
+
+    for (i = 0; i < def->nnets && i < d_config->num_nics; i++) {
+        virDomainNetDefPtr net = def->nets[i];
+        libxl_device_nic *x_nic = &d_config->nics[i];
+        const char *suffix =
+            x_nic->nictype != LIBXL_NIC_TYPE_VIF ? "-emu" : "";
+
+        if (net->ifname)
+            continue;
+
+        ignore_value(virAsprintf(&net->ifname, "vif%d.%d%s",
+                                 def->id, x_nic->devid, suffix));
+    }
+}
+
 
 /*
  * Start a domain through libxenlight.
@@ -1027,6 +1063,7 @@ libxlDomainStart(libxlDriverPrivatePtr driver, virDomainObjPtr vm,
     if (libxl_evenable_domain_death(cfg->ctx, vm->def->id, 0, &priv->deathW))
         goto cleanup_dom;
 
+    libxlDomainCreateIfaceNames(vm->def, &d_config);
 
     if ((dom_xml = virDomainDefFormat(vm->def, 0)) == NULL)
         goto cleanup_dom;

diff --git a/src/libxl/libxl_driver.c b/src/libxl/libxl_driver.c
index 35d7fae892a60db6519468eddeeb541dc47058ff..05041305a32c878c371cd9676bae16c6a8d7d299 100644 (file)
--- a/src/libxl/libxl_driver.c
+++ b/src/libxl/libxl_driver.c
@@ -58,6 +58,7 @@
 #include "virhostdev.h"
 #include "network/bridge_driver.h"
 #include "locking/domain_lock.h"
+#include "virstats.h"
 
 #define VIR_FROM_THIS VIR_FROM_LIBXL
 
@@ -4642,6 +4643,56 @@ libxlDomainIsUpdated(virDomainPtr dom)
     return ret;
 }
 
+static int
+libxlDomainInterfaceStats(virDomainPtr dom,
+                          const char *path,
+                          virDomainInterfaceStatsPtr stats)
+{
+    libxlDriverPrivatePtr driver = dom->conn->privateData;
+    virDomainObjPtr vm;
+    ssize_t i;
+    int ret = -1;
+
+    if (!(vm = libxlDomObjFromDomain(dom)))
+        goto cleanup;
+
+    if (virDomainInterfaceStatsEnsureACL(dom->conn, vm->def) < 0)
+        goto cleanup;
+
+    if (libxlDomainObjBeginJob(driver, vm, LIBXL_JOB_QUERY) < 0)
+        goto cleanup;
+
+    if (!virDomainObjIsActive(vm)) {
+        virReportError(VIR_ERR_OPERATION_INVALID,
+                       "%s", _("domain is not running"));
+        goto endjob;
+    }
+
+    /* Check the path is one of the domain's network interfaces. */
+    for (i = 0; i < vm->def->nnets; i++) {
+        if (vm->def->nets[i]->ifname &&
+            STREQ(vm->def->nets[i]->ifname, path)) {
+            ret = 0;
+            break;
+        }
+    }
+
+    if (ret == 0)
+        ret = virNetInterfaceStats(path, stats);
+    else
+        virReportError(VIR_ERR_INVALID_ARG,
+                       _("'%s' is not a known interface"), path);
+
+ endjob:
+    if (!libxlDomainObjEndJob(driver, vm))
+        vm = NULL;
+
+ cleanup:
+    if (vm)
+        virObjectUnlock(vm);
+    return ret;
+}
+
 static int
 libxlDomainGetTotalCPUStats(libxlDriverPrivatePtr driver,
                             virDomainObjPtr vm,
@@ -5423,6 +5474,7 @@ static virHypervisorDriver libxlHypervisorDriver = {
     .nodeGetCellsFreeMemory = libxlNodeGetCellsFreeMemory, /* 1.1.1 */
     .domainMemoryStats = libxlDomainMemoryStats, /* 1.3.0 */
     .domainGetCPUStats = libxlDomainGetCPUStats, /* 1.3.0 */
+    .domainInterfaceStats = libxlDomainInterfaceStats, /* 1.3.0 */
     .connectDomainEventRegister = libxlConnectDomainEventRegister, /* 0.9.0 */
     .connectDomainEventDeregister = libxlConnectDomainEventDeregister, /* 0.9.0 */
     .domainManagedSave = libxlDomainManagedSave, /* 0.9.2 */