[libvirt] [PATCH v2 2/4] libxl: channels support
Joao Martins
joao.m.martins at oracle.com
Sun Sep 25 18:55:26 UTC 2016
On 09/24/2016 12:15 AM, Joao Martins wrote:
> 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.
Hmm, I can just avoid passing driver and have cfg->channelDir added as an
argument. I just noticed that I am unnecessarily doing libxlDriverConfigGet
twice and perhaps if a third argument is added in the future then probably
consider having driver be passed as an argument?
Joao
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