[libvirt] [PATCH v2 2/4] libxl: channels support
Joao Martins
joao.m.martins at oracle.com
Fri Sep 23 23:15:14 UTC 2016
On September 23, 2016 11:12:00 PM GMT+01:00, Jim Fehlig <jfehlig at suse.com> 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 at oracle.com>
>> ---
>> 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.
>
>> libxl_domain_config_init(d_config);
>>
>> if (libxlMakeDomCreateInfo(ctx, def, &d_config->c_info) < 0)
>> @@ -1864,6 +1977,11 @@ libxlBuildDomainConfig(virPortAllocatorPtr
>graphicsports,
>> return -1;
>> #endif
>>
>> +#ifdef LIBXL_HAVE_DEVICE_CHANNEL
>> + if (libxlMakeChannelList(driver, def, d_config) < 0)
>> + return -1;
>> +#endif
>> +
>> /*
>> * Now that any potential VFBs are defined, update the build
>info with
>> * the data of the primary display. Some day libxl might
>implicitely do
>> diff --git a/src/libxl/libxl_conf.h b/src/libxl/libxl_conf.h
>> index ed5a3de..56a3d4a 100644
>> --- a/src/libxl/libxl_conf.h
>> +++ b/src/libxl/libxl_conf.h
>> @@ -57,6 +57,7 @@
>> # define LIBXL_LIB_DIR LOCALSTATEDIR "/lib/libvirt/libxl"
>> # define LIBXL_SAVE_DIR LIBXL_LIB_DIR "/save"
>> # define LIBXL_DUMP_DIR LIBXL_LIB_DIR "/dump"
>> +# define LIBXL_CHANNEL_DIR LIBXL_LIB_DIR "/channel/target"
>> # define LIBXL_BOOTLOADER_PATH "pygrub"
>>
>>
>> @@ -98,6 +99,7 @@ struct _libxlDriverConfig {
>> char *libDir;
>> char *saveDir;
>> char *autoDumpDir;
>> + char *channelDir;
>>
>> virFirmwarePtr *firmwares;
>> size_t nfirmwares;
>> @@ -197,7 +199,7 @@ virDomainXMLOptionPtr
>> libxlCreateXMLConf(void);
>>
>> int
>> -libxlBuildDomainConfig(virPortAllocatorPtr graphicsports,
>> +libxlBuildDomainConfig(libxlDriverPrivatePtr driver,
>> virDomainDefPtr def,
>> libxl_ctx *ctx,
>> libxl_domain_config *d_config);
>
>And here.
>
>> diff --git a/src/libxl/libxl_domain.c b/src/libxl/libxl_domain.c
>> index 43f4a7f..0540afb 100644
>> --- a/src/libxl/libxl_domain.c
>> +++ b/src/libxl/libxl_domain.c
>> @@ -1059,6 +1059,42 @@ libxlDomainCreateIfaceNames(virDomainDefPtr
>def, libxl_domain_config *d_config)
>> }
>> }
>>
>> +#ifdef LIBXL_HAVE_DEVICE_CHANNEL
>> +static void
>> +libxlDomainCreateChannelPTY(virDomainDefPtr def, libxl_ctx *ctx)
>> +{
>> + libxl_device_channel *x_channels;
>> + virDomainChrDefPtr chr;
>> + size_t i;
>> + int nchannels;
>> +
>> + x_channels = libxl_device_channel_list(ctx, def->id,
>&nchannels);
>> + if (!x_channels)
>> + return;
>> +
>> + for (i = 0; i < def->nchannels; i++) {
>> + libxl_channelinfo channelinfo;
>> + int ret;
>> +
>> + chr = def->channels[i];
>> + if (chr->source.type != VIR_DOMAIN_CHR_TYPE_PTY)
>> + continue;
>> +
>> + ret = libxl_device_channel_getinfo(ctx, def->id,
>&x_channels[i],
>> + &channelinfo);
>> +
>> + if (!ret && channelinfo.u.pty.path &&
>> + channelinfo.u.pty.path != '\0') {
>> + VIR_FREE(chr->source.data.file.path);
>> + ignore_value(VIR_STRDUP(chr->source.data.file.path,
>> + channelinfo.u.pty.path));
>> + }
>> + }
>> +
>> + for (i = 0; i < nchannels; i++)
>> + libxl_device_channel_dispose(&x_channels[i]);
>> +}
>> +#endif
>>
>> #ifdef LIBXL_HAVE_SRM_V2
>> # define LIBXL_DOMSTART_RESTORE_VER_ATTR /* empty */
>> @@ -1181,8 +1217,7 @@ libxlDomainStart(libxlDriverPrivatePtr driver,
>> if (libxlNetworkPrepareDevices(vm->def) < 0)
>> goto cleanup_dom;
>>
>> - if (libxlBuildDomainConfig(driver->reservedGraphicsPorts,
>vm->def,
>> - cfg->ctx, &d_config) < 0)
>> + if (libxlBuildDomainConfig(driver, vm->def, cfg->ctx, &d_config)
>< 0)
>
>And a final one here?
>
>Regards,
>Jim
>
>> goto cleanup_dom;
>>
>> if (cfg->autoballoon && libxlDomainFreeMem(cfg->ctx, &d_config)
>< 0)
>> @@ -1263,6 +1298,11 @@ libxlDomainStart(libxlDriverPrivatePtr driver,
>>
>> libxlDomainCreateIfaceNames(vm->def, &d_config);
>>
>> +#ifdef LIBXL_HAVE_DEVICE_CHANNEL
>> + if (vm->def->nchannels > 0)
>> + libxlDomainCreateChannelPTY(vm->def, cfg->ctx);
>> +#endif
>> +
>> if ((dom_xml = virDomainDefFormat(vm->def, cfg->caps, 0)) ==
>NULL)
>> goto destroy_dom;
>>
>> diff --git a/src/libxl/libxl_driver.c b/src/libxl/libxl_driver.c
>> index 42fa129..d555202 100644
>> --- a/src/libxl/libxl_driver.c
>> +++ b/src/libxl/libxl_driver.c
>> @@ -718,6 +718,13 @@ libxlStateInitialize(bool privileged,
>> virStrerror(errno, ebuf, sizeof(ebuf)));
>> goto error;
>> }
>> + if (virFileMakePath(cfg->channelDir) < 0) {
>> + virReportError(VIR_ERR_INTERNAL_ERROR,
>> + _("failed to create channel dir '%s': %s"),
>> + cfg->channelDir,
>> + virStrerror(errno, ebuf, sizeof(ebuf)));
>> + goto error;
>> + }
>>
>> if (!(libxl_driver->lockManager =
>> virLockManagerPluginNew(cfg->lockManagerName ?
--
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