Re: [libvirt] [PATCH] 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. Since the

introdution of netprefix (commit a040ba9), ifnames with a registered

prefix will be freed on virDomain{Obj,Def}Format*, thus eliminating the migration issues observed with the reverted commit d2e5538 whereas source and destination would have the same ifname. 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(a)oracle.com&gt; --- Changes since d2e5538: - Check net->ifname beforehand, preventing a crash on the migration failure path. - Use LIBXL_GENERATED_PREFIX_XEN as opposed to hardcoding "vif" - Bump from 1.3.0 to 1.3.2 - Change commit message to mention the migration issue and netprefix. --- src/libxl/libxl_domain.c | 39 ++++++++++++++++++++++++++++++++++++ src/libxl/libxl_driver.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 91 insertions(+) diff --git a/src/libxl/libxl_domain.c b/src/libxl/libxl_domain.c index 50f7eed..9d0da68 100644 --- a/src/libxl/libxl_domain.c +++ b/src/libxl/libxl_domain.c @@ -762,6 +762,18 @@ 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 (net->ifname && + STRPREFIX(net->ifname, LIBXL_GENERATED_PREFIX_XEN)) + 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); @@ -929,6 +941,32 @@ 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, + LIBXL_GENERATED_PREFIX_XEN "%d.%d%s", + def->id, x_nic->devid, suffix)); + } +} + /* * Start a domain through libxenlight. @@ -1073,6 +1111,7 @@ 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, cfg->caps, 0)) == NULL) goto cleanup_dom; diff --git a/src/libxl/libxl_driver.c b/src/libxl/libxl_driver.c index 404016e..5479441 100644 --- 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 @@ -4662,6 +4663,56 @@ libxlDomainIsUpdated(virDomainPtr dom) } static int +libxlDomainInterfaceStats(virDomainPtr dom, + const char *path, + virDomainInterfaceStatsPtr stats) +{ + libxlDriverPrivatePtr driver = dom->conn->privateData; + virDomainObjPtr vm; + ssize_t i;