Commit Graph

154 Commits

Author SHA1 Message Date
Clément Léger
9996a35c64 net/tap: Use qemu_close_all_open_fd()
Instead of using a slow implementation to close all open fd after
forking, use qemu_close_all_open_fd().

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20240802145423.3232974-6-cleger@rivosinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2024-08-05 08:33:36 +10:00
Clément Léger
a9b5d6e536 net/tap: Factorize fd closing after forking
The same code is used twice to actually close all open file descriptors
after forking. Factorize it in a single place.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20240802145423.3232974-4-cleger@rivosinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2024-08-05 08:06:08 +10:00
Akihiko Odaki
77db537995 tap: Shrink zeroed virtio-net header
tap prepends a zeroed virtio-net header when writing a packet to a
tap with virtio-net header enabled but not in use. This only happens
when s->host_vnet_hdr_len == sizeof(struct virtio_net_hdr).

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2024-06-04 15:14:26 +08:00
Akihiko Odaki
336a058b26 tap: Call tap_receive_iov() from tap_receive()
This will save duplicate logic found in both of tap_receive_iov() and
tap_receive().

Suggested-by: "Zhang, Chen" <chen.zhang@intel.com>
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2024-06-04 15:14:26 +08:00
Akihiko Odaki
b9ad513e18 net: Remove receive_raw()
While netmap implements virtio-net header, it does not implement
receive_raw(). Instead of implementing receive_raw for netmap, add
virtio-net headers in the common code and use receive_iov()/receive()
instead. This also fixes the buffer size for the virtio-net header.

Fixes: fbbdbddec0 ("tap: allow extended virtio header with hash info")
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2024-06-04 15:14:26 +08:00
Akihiko Odaki
a67753710d net: Move virtio-net header length assertion
The virtio-net header length assertion should happen for any clients.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2024-06-04 15:14:26 +08:00
Akihiko Odaki
4b52d63249 tap: Remove qemu_using_vnet_hdr()
Since qemu_set_vnet_hdr_len() is always called when
qemu_using_vnet_hdr() is called, we can merge them and save some code.

For consistency, express that the virtio-net header is not in use by
returning 0 with qemu_get_vnet_hdr_len() instead of having a dedicated
function, qemu_get_using_vnet_hdr().

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2024-06-04 15:14:25 +08:00
Akihiko Odaki
52a7ff5269 tap: Remove tap_probe_vnet_hdr_len()
It was necessary since an Linux older than 2.6.35 may implement the
virtio-net header but may not allow to change its length. Remove it
since such an old Linux is no longer supported.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2024-06-04 15:14:25 +08:00
Akihiko Odaki
d9b33018a0 Revert "tap: setting error appropriately when calling net_init_tap_one()"
This reverts commit 46d4d36d0b.

The reverted commit changed to emit warnings instead of errors when
vhost is requested but vhost initialization fails if vhostforce option
is not set.

However, vhostforce is not meant to ignore vhost errors. It was once
introduced as an option to commit 5430a28fe4 ("vhost: force vhost off
for non-MSI guests") to force enabling vhost for non-MSI guests, which
will have worse performance with vhost. The option was deprecated with
commit 1e7398a140 ("vhost: enable vhost without without MSI-X") and
changed to behave identical with the vhost option for compatibility.

Worse, commit bf769f742c ("virtio: del net client if net_init_tap_one
failed") changed to delete the client when vhost fails even when the
failure only results in a warning. The leads to an assertion failure
for the -netdev command line option.

The reverted commit was intended to avoid that the vhost initialization
failure won't result in a corrupted netdev. This problem should have
been fixed by deleting netdev when the initialization fails instead of
ignoring the failure with an arbitrary option. Fortunately, commit
bf769f742c ("virtio: del net client if net_init_tap_one failed"),
mentioned earlier, implements this behavior.

Restore the correct semantics and fix the assertion failure for the
-netdev command line option by reverting the problematic commit.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2024-03-29 14:59:07 +08:00
Stefan Hajnoczi
0b2675c473 Rename "QEMU global mutex" to "BQL" in comments and docs
The term "QEMU global mutex" is identical to the more widely used Big
QEMU Lock ("BQL"). Update the code comments and documentation to use
"BQL" instead of "QEMU global mutex".

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Paul Durrant <paul@xen.org>
Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Message-id: 20240102153529.486531-6-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2024-01-08 10:45:43 -05:00
Peter Maydell
6d7a53e9f1 net/tap: Avoid variable-length array
Use a heap allocation instead of a variable length array in
tap_receive_iov().

The codebase has very few VLAs, and if we can get rid of them all we
can make the compiler error on new additions.  This is a defensive
measure against security bugs where an on-stack dynamic allocation
isn't correctly size-checked (e.g.  CVE-2021-3527).

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Francisco Iglesias <frasse.iglesias@gmail.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2023-09-18 14:36:13 +08:00
Yuri Benditovich
f03e0cf63b tap: Add check for USO features
Tap indicates support for USO features according to
capabilities of current kernel module.

Signed-off-by: Yuri Benditovich <yuri.benditovich@daynix.com>
Signed-off-by: Andrew Melnychecnko <andrew@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2023-09-18 14:36:13 +08:00
Andrew Melnychenko
2ab0ec3121 tap: Add USO support to tap device.
Passing additional parameters (USOv4 and USOv6 offloads) when
setting TAP offloads

Signed-off-by: Yuri Benditovich <yuri.benditovich@daynix.com>
Signed-off-by: Andrew Melnychenko <andrew@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2023-09-18 14:36:13 +08:00
Akihiko Odaki
481c52320a net: Strip virtio-net header when dumping
filter-dump specifiees Ethernet as PCAP LinkType, which does not expect
virtio-net header. Having virtio-net header in such PCAP file breaks
PCAP unconsumable. Unfortunately currently there is no LinkType for
virtio-net so for now strip virtio-net header to convert the output to
Ethernet.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2023-03-10 15:35:38 +08:00
Nikita Ivanov
37b0b24e93 error handling: Use RETRY_ON_EINTR() macro where applicable
There is a defined RETRY_ON_EINTR() macro in qemu/osdep.h
which handles the same while loop.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/415
Signed-off-by: Nikita Ivanov <nivanov@cloudlinux.com>
Message-Id: <20221023090422.242617-3-nivanov@cloudlinux.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
[thuth: Dropped the hunk that changed socket_accept() in libqtest.c]
Signed-off-by: Thomas Huth <thuth@redhat.com>
2023-01-09 13:50:47 +01:00
Nikita Ivanov
8b6aa69365 Refactoring: refactor TFR() macro to RETRY_ON_EINTR()
Rename macro name to more transparent one and refactor
it to expression.

Signed-off-by: Nikita Ivanov <nivanov@cloudlinux.com>
Message-Id: <20221023090422.242617-2-nivanov@cloudlinux.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2023-01-09 13:50:47 +01:00
Markus Armbruster
7480874a69 qapi net: Elide redundant has_FOO in generated C
The has_FOO for pointer-valued FOO are redundant, except for arrays.
They are also a nuisance to work with.  Recent commit "qapi: Start to
elide redundant has_FOO in generated C" provided the means to elide
them step by step.  This is the step for qapi/net.json.

Said commit explains the transformation in more detail.  The invariant
violations mentioned there do not occur here.

Cc: Jason Wang <jasowang@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20221104160712.3005652-19-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
[Fixes for MacOS squashed in]
2022-12-14 20:04:47 +01:00
Laurent Vivier
53b85d9574 net: introduce qemu_set_info_str() function
Embed the setting of info_str in a function.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2022-10-28 13:28:52 +08:00
lu zhipeng
bf769f742c virtio: del net client if net_init_tap_one failed
If the net tap initializes successful, but failed during
network card hot-plugging, the net-tap will remains,
so cleanup.

Signed-off-by: lu zhipeng <luzhipeng@cestc.cn>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2022-09-27 15:14:37 +08:00
Marc-André Lureau
a8208626ba net: replace qemu_set_nonblock()
Those calls are POSIX-specific. Use the dedicated GLib
API. (qemu_set_nonblock() is for socket-like)

(this is a preliminary patch before renaming qemu_set_nonblock())

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
2022-05-03 15:52:47 +04:00
Marc-André Lureau
0f9668e0c1 Remove qemu-common.h include from most units
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220323155743.1585078-33-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-06 14:31:55 +02:00
Peter Foley
41bcea7b2c net/tap: Set return code on failure
Match the other error handling in this function.

Fixes: e7b347d0bf ("net: detect errors from probing vnet hdr flag for TAP devices")

Reviewed-by: Patrick Venture <venture@google.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Peter Foley <pefoley@google.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2022-02-14 11:50:44 +08:00
Jason Wang
6a756d1495 vhost_net: do not assume nvqs is always 2
This patch switches to initialize dev.nvqs from the VhostNetOptions
instead of assuming it was 2. This is useful for implementing control
virtqueue support which will be a single vhost_net structure with a
single cvq.

Note that nvqs is still set to 2 for all users and this patch does not
change functionality.

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Eli Cohen <elic@nvidia.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20210903091031.47303-6-jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-09-04 17:34:05 -04:00
Andrew Melnychenko
8f364e344c net: Added SetSteeringEBPF method for NetClientState.
For now, that method supported only by Linux TAP.
Linux TAP uses TUNSETSTEERINGEBPF ioctl.

Signed-off-by: Andrew Melnychenko <andrew@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2021-06-04 15:25:46 +08:00
Jason Wang
bc38e31b4e net: check the existence of peer before trying to pad
There could be case that peer is NULL. This can happen when during
network device hot-add where net device needs to be added first. So
the patch check the existence of peer before trying to do the pad.

Fixes: 969e50b61a ("net: Pad short frames to minimum size before sending from SLiRP/TAP")
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Stefan Weil <sw@weilnetz.de>
Message-id: 20210423031803.1479-1-jasowang@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2021-04-23 11:11:28 +01:00
Jason Wang
f9bb0c1f98 Revert "qapi: net: Add query-netdev command"
Several issues has been reported for query-netdev series. Consider
it's late in the rc, this reverts commit
d32ad10a14.

Signed-off-by: Jason Wang <jasowang@redhat.com>
2021-04-08 17:33:59 +08:00
Jason Wang
56e6f594bf Revert "net: Move NetClientState.info_str to dynamic allocations"
Several issues has been reported for query-netdev info
series. Consider it's late in the rc, this reverts commit
commit 59b5437eb7.

Signed-off-by: Jason Wang <jasowang@redhat.com>
2021-04-08 17:33:59 +08:00
Jason Wang
d89b4f839f Revert "net: Do not fill legacy info_str for backends"
Several issues has been reported for query-netdev info
series. Consider it's late in the rc, this reverts commit
f2e8319d45.

Signed-off-by: Jason Wang <jasowang@redhat.com>
2021-04-08 17:33:59 +08:00
Bin Meng
969e50b61a net: Pad short frames to minimum size before sending from SLiRP/TAP
The minimum Ethernet frame length is 60 bytes. For short frames with
smaller length like ARP packets (only 42 bytes), on a real world NIC
it can choose either padding its length to the minimum required 60
bytes, or sending it out directly to the wire. Such behavior can be
hardcoded or controled by a register bit. Similarly on the receive
path, NICs can choose either dropping such short frames directly or
handing them over to software to handle.

On the other hand, for the network backends like SLiRP/TAP, they
don't expose a way to control the short frame behavior. As of today
they just send/receive data from/to the other end connected to them,
which means any sized packet is acceptable. So they can send and
receive short frames without any problem. It is observed that ARP
packets sent from SLiRP/TAP are 42 bytes, and SLiRP/TAP just send
these ARP packets to the other end which might be a NIC model that
does not allow short frames to pass through.

To provide better compatibility, for packets sent from QEMU network
backends like SLiRP/TAP, we change to pad short frames before sending
it out to the other end, if the other end does not forbid it via the
nc->do_not_pad flag. This ensures a backend as an Ethernet sender
does not violate the spec. But with this change, the behavior of
dropping short frames from SLiRP/TAP interfaces in the NIC model
cannot be emulated because it always receives a packet that is spec
complaint. The capability of sending short frames from NIC models is
still supported and short frames can still pass through SLiRP/TAP.

This commit should be able to fix the issue as reported with some
NIC models before, that ARP requests get dropped, preventing the
guest from becoming visible on the network. It was workarounded in
these NIC models on the receive path, that when a short frame is
received, it is padded up to 60 bytes.

The following 2 commits seem to be the one to workaround this issue
in e1000 and vmxenet3 before, and should probably be reverted.

  commit 78aeb23ede ("e1000: Pad short frames to minimum size (60 bytes)")
  commit 40a87c6c9b ("vmxnet3: Pad short frames to minimum size (60 bytes)")

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2021-03-22 17:34:31 +08:00
Alexey Kirillov
f2e8319d45 net: Do not fill legacy info_str for backends
As we use QAPI NetClientState->stored_config to store and get information
about backend network devices, we can drop fill of legacy field info_str
for them.

We still use info_str field for NIC and hubports, so we can not completely
remove it.

Signed-off-by: Alexey Kirillov <lekiravi@yandex-team.ru>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2021-03-15 16:41:22 +08:00
Alexey Kirillov
59b5437eb7 net: Move NetClientState.info_str to dynamic allocations
The info_str field of the NetClientState structure is static and has a size
of 256 bytes. This amount is often unclaimed, and the field itself is used
exclusively for HMP "info network".

The patch translates info_str to dynamic memory allocation.

This action is also allows us to painlessly discard usage of this field
for backend devices.

Signed-off-by: Alexey Kirillov <lekiravi@yandex-team.ru>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2021-03-15 16:41:22 +08:00
Alexey Kirillov
d32ad10a14 qapi: net: Add query-netdev command
The query-netdev command is used to get the configuration of the current
network device backends (netdevs).
This is the QMP analog of the HMP command "info network" but only for
netdevs (i.e. excluding NIC and hubports).

The query-netdev command returns an array of objects of the NetdevInfo
type, which are an extension of Netdev type. It means that response can
be used for netdev-add after small modification. This can be useful for
recreate the same netdev configuration.

Information about the network device is filled in when it is created or
modified and is available through the NetClientState->stored_config.

Signed-off-by: Alexey Kirillov <lekiravi@yandex-team.ru>
Acked-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2021-03-15 16:41:22 +08:00
Keqian Zhu
9925990d01 net: Use correct default-path macro for downscript
Fixes: 63c4db4c2e (net: relocate paths to helpers and scripts)
Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2020-11-24 10:40:17 +08:00
yuanjungong
f012bec890 tap: fix a memory leak
Close fd before returning.

Buglink: https://bugs.launchpad.net/qemu/+bug/1904486

Signed-off-by: yuanjungong <ruc_gongyuanjun@163.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2020-11-24 10:40:17 +08:00
Kevin Wolf
947e47448d monitor: Use getter/setter functions for cur_mon
cur_mon really needs to be coroutine-local as soon as we move monitor
command handlers to coroutines and let them yield. As a first step, just
remove all direct accesses to cur_mon so that we can implement this in
the getter function later.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20201005155855.256490-4-kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-10-09 07:08:19 +02:00
Paolo Bonzini
63c4db4c2e net: relocate paths to helpers and scripts
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-09-30 19:11:36 +02:00
Daniel P. Berrange
e7b347d0bf net: detect errors from probing vnet hdr flag for TAP devices
When QEMU sets up a tap based network device backend, it mostly ignores errors
reported from various ioctl() calls it makes, assuming the TAP file descriptor
is valid. This assumption can easily be violated when the user is passing in a
pre-opened file descriptor. At best, the ioctls may fail with a -EBADF, but if
the user passes in a bogus FD number that happens to clash with a FD number that
QEMU has opened internally for another reason, a wide variety of errnos may
result, as the TUNGETIFF ioctl number may map to a completely different command
on a different type of file.

By ignoring all these errors, QEMU sets up a zombie network backend that will
never pass any data. Even worse, when QEMU shuts down, or that network backend
is hot-removed, it will close this bogus file descriptor, which could belong to
another QEMU device backend.

There's no obvious guaranteed reliable way to detect that a FD genuinely is a
TAP device, as opposed to a UNIX socket, or pipe, or something else. Checking
the errno from probing vnet hdr flag though, does catch the big common cases.
ie calling TUNGETIFF will return EBADF for an invalid FD, and ENOTTY when FD is
a UNIX socket, or pipe which catches accidental collisions with FDs used for
stdio, or monitor socket.

Previously the example below where bogus fd 9 collides with the FD used for the
chardev saw:

$ ./x86_64-softmmu/qemu-system-x86_64 -netdev tap,id=hostnet0,fd=9 \
  -chardev socket,id=charchannel0,path=/tmp/qga,server,nowait \
  -monitor stdio -vnc :0
qemu-system-x86_64: -netdev tap,id=hostnet0,fd=9: TUNGETIFF ioctl() failed: Inappropriate ioctl for device
TUNSETOFFLOAD ioctl() failed: Bad address
QEMU 2.9.1 monitor - type 'help' for more information
(qemu) Warning: netdev hostnet0 has no peer

which gives a running QEMU with a zombie network backend.

With this change applied we get an error message and QEMU immediately exits
before carrying on and making a bigger disaster:

$ ./x86_64-softmmu/qemu-system-x86_64 -netdev tap,id=hostnet0,fd=9 \
  -chardev socket,id=charchannel0,path=/tmp/qga,server,nowait \
  -monitor stdio -vnc :0
qemu-system-x86_64: -netdev tap,id=hostnet0,vhost=on,fd=9: Unable to query TUNGETIFF on FD 9: Inappropriate ioctl for device

Reported-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Tested-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-id: 20171027085548.3472-1-berrange@redhat.com
[lv: to simplify, don't check on EINVAL with TUNGETIFF as it exists since v2.6.27]
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2020-07-15 21:00:13 +08:00
Laurent Vivier
894022e616 net: check if the file descriptor is valid before using it
qemu_set_nonblock() checks that the file descriptor can be used and, if
not, crashes QEMU. An assert() is used for that. The use of assert() is
used to detect programming error and the coredump will allow to debug
the problem.

But in the case of the tap device, this assert() can be triggered by
a misconfiguration by the user. At startup, it's not a real problem, but it
can also happen during the hot-plug of a new device, and here it's a
problem because we can crash a perfectly healthy system.

For instance:
 # ip link add link virbr0 name macvtap0 type macvtap mode bridge
 # ip link set macvtap0 up
 # TAP=/dev/tap$(ip -o link show macvtap0 | cut -d: -f1)
 # qemu-system-x86_64 -machine q35 -device pcie-root-port,id=pcie-root-port-0 -monitor stdio 9<> $TAP
 (qemu) netdev_add type=tap,id=hostnet0,vhost=on,fd=9
 (qemu) device_add driver=virtio-net-pci,netdev=hostnet0,id=net0,bus=pcie-root-port-0
 (qemu) device_del net0
 (qemu) netdev_del hostnet0
 (qemu) netdev_add type=tap,id=hostnet1,vhost=on,fd=9
 qemu-system-x86_64: .../util/oslib-posix.c:247: qemu_set_nonblock: Assertion `f != -1' failed.
 Aborted (core dumped)

To avoid that, add a function, qemu_try_set_nonblock(), that allows to report the
problem without crashing.

In the same way, we also update the function for vhostfd in net_init_tap_one() and
for fd in net_init_socket() (both descriptors are provided by the user and can
be wrong).

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2020-07-15 21:00:13 +08:00
Markus Armbruster
af175e85f9 error: Eliminate error_propagate() with Coccinelle, part 2
When all we do with an Error we receive into a local variable is
propagating to somewhere else, we can just as well receive it there
right away.  The previous commit did that with a Coccinelle script I
consider fairly trustworthy.  This commit uses the same script with
the matching of return taken out, i.e. we convert

    if (!foo(..., &err)) {
        ...
        error_propagate(errp, err);
        ...
    }

to

    if (!foo(..., errp)) {
        ...
        ...
    }

This is unsound: @err could still be read between afterwards.  I don't
know how to express "no read of @err without an intervening write" in
Coccinelle.  Instead, I manually double-checked for uses of @err.

Suboptimal line breaks tweaked manually.  qdev_realize() simplified
further to placate scripts/checkpatch.pl.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-36-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Markus Armbruster
668f62ec62 error: Eliminate error_propagate() with Coccinelle, part 1
When all we do with an Error we receive into a local variable is
propagating to somewhere else, we can just as well receive it there
right away.  Convert

    if (!foo(..., &err)) {
        ...
        error_propagate(errp, err);
        ...
        return ...
    }

to

    if (!foo(..., errp)) {
        ...
        ...
        return ...
    }

where nothing else needs @err.  Coccinelle script:

    @rule1 forall@
    identifier fun, err, errp, lbl;
    expression list args, args2;
    binary operator op;
    constant c1, c2;
    symbol false;
    @@
         if (
    (
    -        fun(args, &err, args2)
    +        fun(args, errp, args2)
    |
    -        !fun(args, &err, args2)
    +        !fun(args, errp, args2)
    |
    -        fun(args, &err, args2) op c1
    +        fun(args, errp, args2) op c1
    )
            )
         {
             ... when != err
                 when != lbl:
                 when strict
    -        error_propagate(errp, err);
             ... when != err
    (
             return;
    |
             return c2;
    |
             return false;
    )
         }

    @rule2 forall@
    identifier fun, err, errp, lbl;
    expression list args, args2;
    expression var;
    binary operator op;
    constant c1, c2;
    symbol false;
    @@
    -    var = fun(args, &err, args2);
    +    var = fun(args, errp, args2);
         ... when != err
         if (
    (
             var
    |
             !var
    |
             var op c1
    )
            )
         {
             ... when != err
                 when != lbl:
                 when strict
    -        error_propagate(errp, err);
             ... when != err
    (
             return;
    |
             return c2;
    |
             return false;
    |
             return var;
    )
         }

    @depends on rule1 || rule2@
    identifier err;
    @@
    -    Error *err = NULL;
         ... when != err

Not exactly elegant, I'm afraid.

The "when != lbl:" is necessary to avoid transforming

         if (fun(args, &err)) {
             goto out
         }
         ...
     out:
         error_propagate(errp, err);

even though other paths to label out still need the error_propagate().
For an actual example, see sclp_realize().

Without the "when strict", Coccinelle transforms vfio_msix_setup(),
incorrectly.  I don't know what exactly "when strict" does, only that
it helps here.

The match of return is narrower than what I want, but I can't figure
out how to express "return where the operand doesn't use @err".  For
an example where it's too narrow, see vfio_intx_enable().

Silently fails to convert hw/arm/armsse.c, because Coccinelle gets
confused by ARMSSE being used both as typedef and function-like macro
there.  Converted manually.

Line breaks tidied up manually.  One nested declaration of @local_err
deleted manually.  Preexisting unwanted blank line dropped in
hw/riscv/sifive_e.c.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-35-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Yuri Benditovich
fbbdbddec0 tap: allow extended virtio header with hash info
Signed-off-by: Yuri Benditovich <yuri.benditovich@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2020-06-18 21:05:50 +08:00
Markus Armbruster
db72581598 Include qemu/main-loop.h less
In my "build everything" tree, changing qemu/main-loop.h triggers a
recompile of some 5600 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h).  It includes block/aio.h,
which in turn includes qemu/event_notifier.h, qemu/notify.h,
qemu/processor.h, qemu/qsp.h, qemu/queue.h, qemu/thread-posix.h,
qemu/thread.h, qemu/timer.h, and a few more.

Include qemu/main-loop.h only where it's needed.  Touching it now
recompiles only some 1700 objects.  For block/aio.h and
qemu/event_notifier.h, these numbers drop from 5600 to 2800.  For the
others, they shrink only slightly.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190812052359.30071-21-armbru@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2019-08-16 13:31:52 +02:00
Prasad J Pandit
389abe1dd1 net: tap: replace snprintf with g_strdup_printf calls
When invoking qemu-bridge-helper in 'net_bridge_run_helper',
instead of using fixed sized buffers, use dynamically allocated
ones initialised and returned by g_strdup_printf().

Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Reviewed-by: Li Qiang <liq3ea@gmail.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2019-07-29 16:29:30 +08:00
Li Qiang
ab79237a15 net: tap: use qemu_set_nonblock
The fcntl will change the flags directly, use qemu_set_nonblock()
instead.

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Li Qiang <liq3ea@gmail.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2019-03-29 15:22:18 +08:00
Yunjian Wang
323e7c1177 tap: fix memory leak on success to create a tap device
The memory leak on success to create a tap device. And the nfds and
nvhosts may not be the same and need to be processed separately.

Fixes: 07825977 ("tap: fix memory leak on failure to create a multiqueue tap device")
Fixes: 264986e2 ("tap: multiqueue support")
Cc: qemu-stable@nongnu.org
Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2018-07-20 08:30:49 +08:00
Brijesh Singh
d542800d1e tap: set vhostfd passed from qemu cli to non-blocking
A guest boot hangs while probing the network interface when
iommu_platform=on is used.

The following qemu cli hangs without this patch:

# $QEMU \
  -netdev tap,fd=3,id=hostnet0,vhost=on,vhostfd=4 3<>/dev/tap67 4<>/dev/host-net \
  -device virtio-net-pci,netdev=hostnet0,id=net0,iommu_platform=on,disable-legacy=on \
  ...

Commit: c471ad0e9b (vhost_net: device IOTLB support) took care of
setting vhostfd to non-blocking when QEMU opens /dev/host-net but if
the fd is passed from qemu cli then we need to ensure that fd is set
to non-blocking.

Fixes: c471ad0e9b ("vhost_net: device IOTLB support")
Cc: qemu-stable@nongnu.org
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2018-06-15 10:39:53 +08:00
Thomas Huth
442da403ea net: Get rid of 'vlan' terminology and use 'hub' instead in the source files
'vlan' is very confusing since it does not mean something like IEEE
802.1Q, but rather emulated hubs, so let's switch to that terminology
instead.

Buglink: https://bugs.launchpad.net/qemu/+bug/658904
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2018-05-14 15:47:14 +08:00
Jay Zhou
46d4d36d0b tap: setting error appropriately when calling net_init_tap_one()
If netdev_add tap,id=net0,...,vhost=on failed in net_init_tap_one(),
the followed up device_add virtio-net-pci,netdev=net0 will fail
too, prints:

   TUNSETOFFLOAD ioctl() failed: Bad file descriptor TUNSETOFFLOAD
   ioctl() failed: Bad file descriptor

The reason is that the fd of tap is closed when error occured after
calling net_init_tap_one().

The fd should be closed when calling net_init_tap_one failed:
   - if tap_set_sndbuf() failed
   - if tap_set_sndbuf() succeeded but vhost failed to open or
     initialize with vhostforce flag on
   - with wrong vhost command line parameter
The fd should not be closed just because vhost failed to open or
initialize but without vhostforce flag. So the followed up
device_add can fall back to userspace virtio successfully.

Suggested-by: Michael S. Tsirkin <mst@redhat.com>
Suggested-by: Igor Mammedov <imammedo@redhat.com>
Suggested-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Jay Zhou <jianjay.zhou@huawei.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2018-03-05 10:30:16 +08:00
Peter Maydell
db655a9653 -----BEGIN PGP SIGNATURE-----
Version: GnuPG v1
 
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 =gkbh
 -----END PGP SIGNATURE-----

Merge remote-tracking branch 'remotes/jasowang/tags/net-pull-request' into staging

# gpg: Signature made Fri 20 Jan 2017 02:58:57 GMT
# gpg:                using RSA key 0xEF04965B398D6211
# gpg: Good signature from "Jason Wang (Jason Wang on RedHat) <jasowang@redhat.com>"
# gpg: WARNING: This key is not certified with sufficiently trusted signatures!
# gpg:          It is not certain that the signature belongs to the owner.
# Primary key fingerprint: 215D 46F4 8246 689E C77F  3562 EF04 965B 398D 6211

* remotes/jasowang/tags/net-pull-request:
  tap: fix memory leak on failure in net_init_tap()
  hw/pci: use-after-free in pci_nic_init_nofail when nic device fails to initialize
  hw/net/dp8393x: Avoid unintentional sign extensions on addresses
  m68k: QOMify the MCF Fast Ethernet Controller device
  net: optimize checksum computation
  docs: Fix description of the sentence

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-01-20 14:56:40 +00:00
Peter Maydell
fac7d7b1cd tap: fix memory leak on failure in net_init_tap()
Commit 091a6b2ac fixed most of the memory leaks in failure
paths in net_init_tap() reported by Coverity (CID 1356216),
but missed one. Fix it by deferring the allocation of
fds and vhost_fds until after the error check.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2017-01-20 10:58:26 +08:00