Re: [libvirt] [PATCH v3 2/4] libxl: channels support

And allow libxl to handle channel element which creates a Xen console visible to the guest as a low-bandwitdh communication channel. If type is PTY we also fetch the tty after boot using libxl_channel_getinfo to fetch the tty path. On socket case, we autogenerate a path if not specified in the XML. Path autogenerated is slightly different from qemu driver: qemu stores also on "channels/target" but it creates then a directory per domain with each channel target name. libxl doesn't appear to have a clear definition of private files associated with each domain, so for simplicity we do it slightly different. On qemu each autogenerated channel goes like: channels/target/<domain-name>/<target name> Whereas for libxl: channels/target/<domain-name>-<target name> Should note that if path is not specified it won't persist, existing only on live XML, unless user had initially specified it. Since support for libxl channels only came on Xen >= 4.5 we therefore need to conditionally compile it with LIBXL_HAVE_DEVICE_CHANNEL. After this patch and having a qemu guest agent: $ cat domain.xml | grep -a1 channel | head -n 5 | tail -n 4 <channel type='unix'> <source mode='bind' path='/tmp/channel'/> <target type='xen' name='org.qemu.guest_agent.0'/> </channel> $ virsh create domain.xml $ echo '{"execute":"guest-network-get-interfaces"}' | socat stdio,ignoreeof unix-connect:/tmp/channel {"execute":"guest-network-get-interfaces"} {"return": [{"name": "lo", "ip-addresses": [{"ip-address-type": "ipv4", "ip-address": "127.0.0.1", "prefix": 8}, {"ip-address-type": "ipv6", "ip-address": "::1", "prefix": 128}], "hardware-address": "00:00:00:00:00:00"}, {"name": "eth0", "ip-addresses": [{"ip-address-type": "ipv4", "ip-address": "10.100.0.6", "prefix": 24}, {"ip-address-type": "ipv6", "ip-address": "fe80::216:3eff:fe40:88eb", "prefix": 64}], "hardware-address": "00:16:3e:40:88:eb"}, {"name": "sit0"}]} Signed-off-by: Joao Martins <joao.m.martins(a)oracle.com&gt; --- Since v2: * Remove ret variable and do similar to other make functions. * Have channelDir passed as an argument instead of driver. Since v1: * Autogenerated paths, and updated commit message explaning it the different naming. Despite per domain name being slightly different, parent directory is same across both drivers. --- src/libxl/libxl_conf.c | 110 +++++++++++++++++++++++++++++++++++++++++++++++ src/libxl/libxl_conf.h | 3 ++ src/libxl/libxl_domain.c | 43 +++++++++++++++++- src/libxl/libxl_driver.c | 7 +++ 4 files changed, 162 insertions(+), 1 deletion(-) diff --git a/src/libxl/libxl_conf.c b/src/libxl/libxl_conf.c index 92faa44..4c94d54 100644 --- a/src/libxl/libxl_conf.c +++ b/src/libxl/libxl_conf.c @@ -88,6 +88,7 @@ libxlDriverConfigDispose(void *obj) VIR_FREE(cfg->saveDir); VIR_FREE(cfg->autoDumpDir); VIR_FREE(cfg->lockManagerName); + VIR_FREE(cfg->channelDir); virFirmwareFreeList(cfg->firmwares, cfg->nfirmwares); } @@ -1348,6 +1349,8 @@ libxlDriverConfigNew(void) goto error; if (VIR_STRDUP(cfg->autoDumpDir, LIBXL_DUMP_DIR) < 0) goto error; + if (VIR_STRDUP(cfg->channelDir, LIBXL_CHANNEL_DIR) < 0) + goto error; if (virAsprintf(&log_file, "%s/libxl-driver.log", cfg->logDir) < 0) goto error; @@ -1499,6 +1502,107 @@ int libxlDriverConfigLoadFile(libxlDriverConfigPtr cfg, } +#ifdef LIBXL_HAVE_DEVICE_CHANNEL +static int +libxlPrepareChannel(virDomainChrDefPtr channel, + const char *channelDir, + const char *domainName) +{ + if (channel->targetType == VIR_DOMAIN_CHR_CHANNEL_TARGET_TYPE_XEN && + channel->source.type == VIR_DOMAIN_CHR_TYPE_UNIX && + !channel->source.data.nix.path) { + if (virAsprintf(&channel->source.data.nix.path, + "%s/%s-%s", channelDir, domainName, + channel->target.name ? channel->target.name + : "unknown.sock") < 0) + return -1; + + channel->source.data.nix.listen = true; + } + + return 0; +} + +static int +libxlMakeChannel(virDomainChrDefPtr l_channel, + libxl_device_channel *x_channel) +{ + libxl_device_channel_init(x_channel); + + if (l_channel->targetType != VIR_DOMAIN_CHR_CHANNEL_TARGET_TYPE_XEN) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", + _("channel target type not supported")); + return -1; + } + + switch (l_channel->source.type) { + case VIR_DOMAIN_CHR_TYPE_PTY: + x_channel->connection = LIBXL_CHANNEL_CONNECTION_PTY; + break; + case VIR_DOMAIN_CHR_TYPE_UNIX: + x_channel->connection = LIBXL_CHANNEL_CONNECTION_SOCKET; + if (VIR_STRDUP(x_channel->u.socket.path, + l_channel->source.data.nix.path) < 0) + return -1; + break; + default: + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", + _("channel source type not supported")); + break; + } + + if (!l_channel->target.name) { + virReportError(VIR_ERR_OPERATION_INVALID, "%s", + _("channel target name missing")); + return -1; + } + + if (VIR_STRDUP(x_channel->name, l_channel->target.name) < 0) + return -1; + + return 0; +} + +static int +libxlMakeChannelList(const char *channelDir, + virDomainDefPtr def, + libxl_domain_config *d_config) +{ + virDomainChrDefPtr *l_channels = def->channels; + size_t nchannels = def->nchannels; + libxl_device_channel *x_channels; + size_t i, nvchannels = 0; + + if (VIR_ALLOC_N(x_channels, nchannels) < 0) + return -1; + + for (i = 0; i < nchannels; i++) { + if (l_channels[i]->deviceType != VIR_DOMAIN_CHR_DEVICE_TYPE_CHANNEL) + continue; + + if (libxlPrepareChannel(l_channels[i], channelDir, def->name) < 0) + goto error; + + if (libxlMakeChannel(l_channels[i], &x_channels[nvchannels]) < 0) + goto error; + + nvchannels++; + } + + VIR_SHRINK_N(x_channels, nchannels, nchannels - nvchannels); + d_config->channels = x_channels; + d_config->num_channels = nvchannels; + + return 0; + + error: + for (i = 0; i < nchannels; i++) + libxl_device_channel_dispose(&x_channels[i]); + VIR_FREE(x_channels); + return -1; +} +#endif + #ifdef LIBXL_HAVE_PVUSB int libxlMakeUSBController(virDomainControllerDefPtr controller, @@ -1839,6 +1943,7 @@ libxlDriverNodeGetInfo(libxlDriverPrivatePtr driver, virNodeInfoPtr info) int libxlBuildDomainConfig(virPortAllocatorPtr graphicsports, virDomainDefPtr def, + const char *channelDir, libxl_ctx *ctx, libxl_domain_config *d_config) { @@ -1873,6 +1978,11 @@ libxlBuildDomainConfig(virPortAllocatorPtr graphicsports, return -1; #endif +#ifdef LIBXL_HAVE_DEVICE_CHANNEL + if (libxlMakeChannelList(channelDir, def, d_config) < 0) + return -1; +#endif +