[libvirt] [PATCH v2 2/4] libxl: channels support
Jim Fehlig
jfehlig at suse.com
Fri Sep 23 22:12:00 UTC 2016
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.
> +
> + 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?
> 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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