This patch provides a way for virtio-net to notify the
backend about the host MTU set by the user.
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Aaron Conole <aconole@redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Unused function declarations were found using a simple gcc plugin and
manually verified by grepping the sources.
Signed-off-by: Ladi Prosek <lprosek@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
is_netdev is only used as a bool, so make it one.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1468468228-27827-14-git-send-email-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
This is a mostly-mechanical conversion that creates a new flat
union 'Netdev' QAPI type that covers all the branches of the
former 'NetClientOptions' simple union, where the branches are
now listed in a new 'NetClientDriver' enum rather than generated
from the simple union. The existence of a flat union has no
change to the command line syntax accepted for new code, and
will make it possible for a future patch to switch the QMP
command to parse a boxed union for no change to valid QMP; but
it does have some ripple effect on the C code when dealing with
the new types.
While making the conversion, note that the 'NetLegacy' type
remains unchanged: it applies only to legacy command line options,
and will not be ported to QMP, so it should remain a wrapper
around a simple union; to avoid confusion, the type named
'NetClientOptions' is now gone, and we introduce 'NetLegacyOptions'
in its place. Then, in the C code, we convert from NetLegacy to
Netdev as soon as possible, so that the bulk of the net stack
only has to deal with one QAPI type, not two. Note that since
the old legacy code always rejected 'hubport', we can just omit
that branch from the new 'NetLegacyOptions' simple union.
Based on an idea originally by Zoltán Kővágó <DirtY.iCE.hu@gmail.com>:
Message-Id: <01a527fbf1a5de880091f98cf011616a78adeeee.1441627176.git.DirtY.iCE.hu@gmail.com>
although the sed script in that patch no longer applies due to
other changes in the tree since then, and I also did some manual
cleanups (such as fixing whitespace to keep checkpatch happy).
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1468468228-27827-13-git-send-email-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Fixup from Eric squashed in]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
This patch add the capability of basic vhost net busy polling which is
supported by recent kernel. User could configure the maximum number of
us that could be spent on busy polling through a new property of tap
"poll-us".
Cc: Greg Kurz <groug@kaod.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
A driver may change the vring enable state at run time but vhost-user
backend may not be present (a contrived example is when the backend is
disconnected and the device is reconfigured after driver rebinding)
Restore the vring state when the vhost-user backend is started, so it
can process the ring.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Tested-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Victor Kaplansky <victork@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The initial vhost-user connection sets the features to be negotiated
with the driver. Renegotiation isn't possible without device reset.
To handle reconnection of vhost-user backend, ensure the same set of
features are provided, and reuse already acked features.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Tested-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Victor Kaplansky <victork@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This patch extends the TX/RX packet abstractions with features that will
be used by the e1000e device implementation.
Changes are:
1. Support iovec lists for RX buffers
2. Deeper RX packets parsing
3. Loopback option for TX packets
4. Extended VLAN headers handling
5. RSS processing for RX packets
Signed-off-by: Dmitry Fleytman <dmitry.fleytman@ravellosystems.com>
Signed-off-by: Leonid Bloch <leonid.bloch@ravellosystems.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Dmitry Fleytman <dmitry.fleytman@ravellosystems.com>
Signed-off-by: Leonid Bloch <leonid.bloch@ravellosystems.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
These macros will be used by future commits introducing
e1000e device emulation and by vmxnet3 tracing code.
Signed-off-by: Dmitry Fleytman <dmitry.fleytman@ravellosystems.com>
Signed-off-by: Leonid Bloch <leonid.bloch@ravellosystems.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Dmitry Fleytman <dmitry.fleytman@ravellosystems.com>
Signed-off-by: Leonid Bloch <leonid.bloch@ravellosystems.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
This function is from net/socket.c, move it to net.c and net.h.
Add SocketReadState to make others reuse net_fill_rstate().
suggestion from jason.
v4:
- move 'rs->finalize = finalize' to rs_init()
v3:
- remove SocketReadState init callback
- put finalize callback to net_fill_rstate()
v2:
- rename ReadState to SocketReadState
- add SocketReadState init and finalize callback
v1:
- init patch
Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
All handling of defaults (default_* variables) is inside vl.c,
move default_net there too, so we can more easily refactor that
code later.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Re-run scripts/clean-includes to apply the previous commit's
corrections and updates. Besides redundant qemu/typedefs.h, this only
finds a redundant config-host.h include in ui/egl-helpers.c. No idea
how that escaped the previous runs.
Some manual whitespace trimming around dropped includes squashed in.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
With this property, users can control if this filter is 'on'
or 'off'. The default behavior for filter is 'on'.
For some types of filters, they may need to react to status changing,
So here, we introduced status changing callback/notifier for filter class.
We will skip the disabled ('off') filter when delivering packets in net layer.
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Yang Hongyang <hongyang.yang@easystack.cn>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.
This commit was created with scripts/clean-includes.
NB: If this commit breaks compilation for your out-of-tree
patchseries or fork, then you need to make sure you add
#include "qemu/osdep.h" to any new .c files that you have.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
The properties of netfilter object could be changed by 'qom-set'
command, but the output of 'info network' command is not updated,
because it got the old information through nf->info_str, it will
not be updated while we change the value of netfilter's property.
Here we split a helper function that could collect the output
information for filter, and also remove the useless member
'info_str' from struct NetFilterState.
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Eric Blake <eblake@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
Cc: Yang Hongyang <hongyang.yang@easystack.cn>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Previously, if we attach more than one filters for a single netdev,
both ingress and egress traffic will go through net filters in same
order like:
ingress: netdev ->filter1 ->filter2 ->...filter[n] ->emulated device
egress: emulated device ->filter1 ->filter2 ->...filter[n] ->netdev.
This is against the natural feeling and will complicate filters
configuration since in some scenes, we hope filters handle the egress
traffic in a reverse order. For example, in colo-proxy (will be
implemented later), we have a redirector filter and a colo-rewriter
filter, we need the filter behave like:
ingress(->)/egress(<-): chardev<->redirector<->colo-rewriter<->emulated device
Since both buffer filter and dump do not require strict order of
filters, this patch switches to always let egress traffic walk through
net filters in reverse to simplify the possible filters configuration
in the future.
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Reviewed-by: Yang Hongyang <hongyang.yang@easystack.cn>
Signed-off-by: Jason Wang <jasowang@redhat.com>
eth.h and slirp.h both define ETH_ALEN and ETH_P_IP
rtl8139.c and eth.h both define ETH_HLEN
Move the related constant (ETH_P_ARP) from slirp.h to eth.h, and
remove the duplicates; make slirp.h include eth.h
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Jason Wang <jasowang@redhat.com>
A new vhost user message is added to allow QEMU to ask to vhost user backend to
broadcast a fake RARP after live migration for guest without GUEST_ANNOUNCE
capability.
This new message is sent only if the backend supports the new
VHOST_USER_PROTOCOL_F_RARP protocol feature.
The payload of this new message is the MAC address of the guest (not known by
the backend). The MAC address is copied in the first 6 bytes of a u64 to avoid
to create a new payload message type.
This new message has no equivalent ioctl so a new callback is added in the
userOps structure to send the request.
Upon reception of this new message the vhost user backend must generate and
broadcast a fake RARP request to notify the migration is terminated.
Signed-off-by: Thibaut Collet <thibaut.collet@6wind.com>
[Rebased and fixed checkpatch errors - Marc-André]
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Thibaut Collet <thibaut.collet@6wind.com>
This will be used by buffer filter implementation later to
queue packets.
Signed-off-by: Yang Hongyang <yanghy@cn.fujitsu.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
When execute "info network", print filter info also.
add a info_str member to NetFilterState, store specific filters
info.
Signed-off-by: Yang Hongyang <yanghy@cn.fujitsu.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
add an API qemu_netfilter_pass_to_next() to pass the packet
to next filter.
Signed-off-by: Yang Hongyang <yanghy@cn.fujitsu.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
net/queue.c has logic to send/queue/flush packets but a
qemu_deliver_packet_iov() call is hardcoded. Abstract this
func so that we can use our own deliver function in netfilter.
Signed-off-by: Yang Hongyang <yanghy@cn.fujitsu.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
qemu_deliver_packet_iov already have the compat delivery, we
can drop qemu_deliver_packet.
Signed-off-by: Yang Hongyang <yanghy@cn.fujitsu.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Capture packets that will be sent.
Signed-off-by: Yang Hongyang <yanghy@cn.fujitsu.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Add a netfilter object based on QOM.
A netfilter is attached to a netdev, captures all network packets
that pass through the netdev. When we delete the netdev, we also
delete the netfilter object attached to it, because if the netdev is
removed, the filter which attached to it is useless.
Signed-off-by: Yang Hongyang <yanghy@cn.fujitsu.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Add a new message, VHOST_USER_SET_VRING_ENABLE, to enable or disable
a specific virt queue, which is similar to attach/detach queue for
tap device.
virtio driver on guest doesn't have to use max virt queue pair, it
could enable any number of virt queue ranging from 1 to max virt
queue pair.
Signed-off-by: Changchun Ouyang <changchun.ouyang@intel.com>
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Tested-by: Marcel Apfelbaum <marcel@redhat.com>
This is for querying how many queues the backend supports if it has mq
support(when VHOST_USER_PROTOCOL_F_MQ flag is set from the quried
protocol features).
vhost_net_get_max_queues() is the interface to export that value, and
to tell if the backend supports # of queues user requested, which is
done in the following patch.
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Tested-by: Marcel Apfelbaum <marcel@redhat.com>
The traditional QMP command handler interface
int qmp_FOO(Monitor *mon, const QDict *params, QObject **ret_data);
doesn't provide for returning an Error object. Instead, the handler
is expected to stash it in the monitor with qerror_report().
When we rebased QMP on top of QAPI, we didn't change this interface.
Instead, commit 776574d introduced "middle mode" as a temporary aid
for converting existing QMP commands to QAPI one by one. More than
three years later, we're still using it.
Middle mode has two effects:
* Instead of the native input marshallers
static void qmp_marshal_input_FOO(QDict *, QObject **, Error **)
it generates input marshallers conforming to the traditional QMP
command handler interface.
* It suppresses generation of code to register them with
qmp_register_command()
This permits giving them internal linkage.
As long as we need qmp-commands.hx, we can't use the registry behind
qmp_register_command(), so the latter has to stay for now.
The former has to go to get rid of qerror_report(). Changing all QMP
commands to fit the QAPI mold in one go was impractical back when we
started, but by now there are just a few stragglers left:
do_qmp_capabilities(), qmp_qom_set(), qmp_qom_get(), qmp_object_add(),
qmp_netdev_add(), do_device_add().
Switch middle mode to generate native input marshallers, and adapt the
stragglers. Simplifies both the monitor code and the stragglers.
Rename do_qmp_capabilities() to qmp_capabilities(), and
do_device_add() to qmp_device_add, because that's how QMP command
handlers are named today.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
We use vhostforce to enable vhost even if Guests don't have MSI-X
support and we fall back to QEMU virtio-net.
This gives a very small performance gain, but the disadvantage
is that guest now controls which virtio code is running
(qemu or vhost) so our attack surface is doubled.
This patch will enable vhost unconditionally whenever it's requested.
For compatibility, enable vhost when vhostforce is set, as well.
Signed-off-by: Pankaj Gupta <pagupta@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
The linux tap and macvtap backends can be told to parse vnet headers
according to little or big endian. This is done through the TUNSETVNETLE
and TUNSETVNETBE ioctls.
This patch brings all the plumbing for QEMU to use these APIs.
Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Make sure that all vhost interfaces use 64 bit features, as the virtio
core does, and make sure to use ULL everywhere possible to be on the
safe side.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
We can use this in virtio-net code as well as new Rocker driver code, so
up-level this.
Signed-off-by: Scott Feldman <sfeldma@gmail.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1426306173-24884-2-git-send-email-sfeldma@gmail.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Some are called do_info_SUBCOMMAND() (old ones, usually), some
hmp_info_SUBCOMMAND(), some SUBCOMMAND_info(), sometimes SUBCOMMAND
pointlessly differs in spelling.
Normalize to hmp_info_SUBCOMMAND(), where SUBCOMMAND is exactly the
subcommand name with '-' replaced by '_'.
Exceptions:
* sun4m_irq_info(), sun4m_pic_info() renamed to sun4m_hmp_info_irq(),
sun4m_hmp_info_pic().
* lm32_irq_info(), lm32_pic_info() renamed to lm32_hmp_info_irq(),
lm32_hmp_info_pic().
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Some are called do_COMMAND() (old ones, usually), some hmp_COMMAND(),
and sometimes COMMAND pointlessly differs in spelling.
Normalize to hmp_COMMAND(), where COMMAND is exactly the command name
with '-' replaced by '_'.
Exceptions:
* do_device_add() and client_migrate_info() *not* renamed to
hmp_device_add(), hmp_client_migrate_info(), because they're also
QMP handlers. They still need to be converted to QAPI.
* do_memory_dump(), do_physical_memory_dump(), do_ioport_read(),
do_ioport_write() renamed do hmp_* instead of hmp_x(), hmp_xp(),
hmp_i(), hmp_o(), because those names are too cryptic for my taste.
* do_info_help() renamed to hmp_info_help() instead of hmp_info(),
because it only covers help.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Remove bootindex form qdev property to qom, things will
continue to work just fine, and we can use qom features
which are not supported by qdev property.
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
It indicates the number of elements in ncs field and makes sense to have
int inside NICPeers. Also in parse_netdev we do not need to access
container and work with NICPeers only.
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Add a new QEMU netdev backend that is intended to invoke vhost_net with the
vhost-user backend. It uses an Unix socket chardev to establish a
communication with the 'slave' (client and server mode supported).
At runtime the netdev will handle OPEN/CLOSE events from the chardev. Upon
disconnection it will set link_down accordingly and notify virtio-net; the
virtio-net interface will go down.
Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
Signed-off-by: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Use vhost_set_backend_type to initialise a proper vhost_ops structure.
In vhost_net_init and vhost_net_start_one call conditionally TAP related
initialisation depending on the vhost backend type.
Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
Signed-off-by: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
vhost_dev_init will replace devfd and devpath with a single opaque argument.
This is initialised with a file descriptor. When TAP is used (through
vhost_net), open /dev/vhost-net and pass the fd as an opaque parameter in
VhostNetOptions. The same applies to vhost-scsi - open /dev/vhost-scsi and
pass the fd.
Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
Signed-off-by: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This decouples virtio-net from the TAP netdev backend and allows support
for other backends to be implemented.
Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
Signed-off-by: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The virtio_net offload APIs are used on the NIC's peer (i.e. the tap
device). The API was defined to implicitly use nc->peer, saving the
caller the trouble.
This wasn't ideal because:
1. There are callers who have the peer but not the NIC. Currently they
are forced to bypass the API and access peer->info->... directly.
2. The rest of the net.h API uses nc, not nc->peer, so it is
inconsistent.
This patch pushes nc->peer back up to callers.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Since TAP offloadings are manipulated through a new API, it's
not necessary to export them in include/net/tap.h anymore.
Signed-off-by: Vincenzo Maffione <v.maffione@gmail.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Some new callbacks have been added to generalize the operations done
by virtio-net and vmxnet3 frontends to manipulate TAP offloadings.
Signed-off-by: Vincenzo Maffione <v.maffione@gmail.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
The tap_has_vnet_hdr() and tap_has_vnet_hdr_len() functions used
to return int, even though they only return true/false values.
This patch changes the prototypes to return bool.
Signed-off-by: Vincenzo Maffione <v.maffione@gmail.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
The checksum calculation header exports a function that refers to
struct iov defined in iov.h. Without including the former, build
fails like this:
In file included from hw/net/fsl_etsec/rings.c:24:0:
include/net/checksum.h:51:31: error: ‘struct iovec’ declared inside parameter list [-Werror]
include/net/checksum.h:51:31: error: its scope is only this definition or declaration, which is probably not what you want [-Werror]
Mention struct iovec there.
Reported-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
