Re: [libvirt] [PATCH v2 2/4] libxl: channels support

On September 23, 2016 11:12:00 PM GMT+01:00, Jim Fehlig <jfehlig(a)suse.com&gt; wrote: > On 09/22/2016 01:53 PM, Joao Martins wrote: >> 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 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. >> * Remove the switch case from target type xen and rework the function > structure >> a bit. >> --- >> src/libxl/libxl_conf.c | 120 > ++++++++++++++++++++++++++++++++++++++++++++++- >> src/libxl/libxl_conf.h | 4 +- >> src/libxl/libxl_domain.c | 44 ++++++++++++++++- >> src/libxl/libxl_driver.c | 7 +++ >> 4 files changed, 171 insertions(+), 4 deletions(-) >> >> diff --git a/src/libxl/libxl_conf.c b/src/libxl/libxl_conf.c >> index 306e441..824f2d2 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); >> } >> >> @@ -1339,6 +1340,8 @@ 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; >> @@ -1490,6 +1493,114 @@ 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) >> +{ >> + int ret = -1; > > Similar to the other libxlMake* functions, ret could be dropped simply > return -1 > when encountering failure. Ok, will change that. >> + >> + 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 ret; >> + } >> + >> + 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 ret; >> + 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 ret; >> + } >> + >> + if (VIR_STRDUP(x_channel->name, l_channel->target.name) < 0) >> + return ret; >> + >> + return 0; >> +} >> + >> +static int >> +libxlMakeChannelList(libxlDriverPrivatePtr driver, >> + virDomainDefPtr def, >> + libxl_domain_config *d_config) >> +{ >> + virDomainChrDefPtr *l_channels = def->channels; >> + size_t nchannels = def->nchannels; >> + libxl_device_channel *x_channels; >> + libxlDriverConfigPtr cfg; >> + size_t i, nvchannels = 0; >> + >> + if (VIR_ALLOC_N(x_channels, nchannels) < 0) >> + return -1; >> + >> + cfg = libxlDriverConfigGet(driver); >> + >> + for (i = 0; i < nchannels; i++) { >> + if (l_channels[i]->deviceType != > VIR_DOMAIN_CHR_DEVICE_TYPE_CHANNEL) >> + continue; >> + >> + if (libxlPrepareChannel(l_channels[i], cfg->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; >> + virObjectUnref(cfg); >> + >> + return 0; >> + >> + error: >> + for (i = 0; i < nchannels; i++) >> + libxl_device_channel_dispose(&x_channels[i]); >> + VIR_FREE(x_channels); >> + virObjectUnref(cfg); >> + return -1; >> +} >> +#endif >> + >> #ifdef LIBXL_HAVE_PVUSB >> int >> libxlMakeUSBController(virDomainControllerDefPtr controller, >> @@ -1828,11 +1939,13 @@ libxlDriverNodeGetInfo(libxlDriverPrivatePtr > driver, virNodeInfoPtr info) >> } >> >> int >> -libxlBuildDomainConfig(virPortAllocatorPtr graphicsports, >> +libxlBuildDomainConfig(libxlDriverPrivatePtr driver, >> virDomainDefPtr def, >> libxl_ctx *ctx, >> libxl_domain_config *d_config) >> { >> + virPortAllocatorPtr graphicsports = > driver->reservedGraphicsPorts; >> + > > Spurious change? This (and the other two below) was intended, as I needed channelDir. and instead of having yet another argument, I passed driver instead as graphics port was using it too. But I could use the macro directly, or add another argument if you prefer.