The most common use of -net tap is to connect a tap device to a bridge. This
requires the use of a script and running qemu as root in order to allocate a
tap device to pass to the script.
This model is great for portability and flexibility but it's incredibly
difficult to eliminate the need to run qemu as root. The only really viable
mechanism is to use tunctl to create a tap device, attach it to a bridge as
root, and then hand that tap device to qemu. The problem with this mechanism
is that it requires administrator intervention whenever a user wants to create
a guest.
By essentially writing a helper that implements the most common qemu-ifup
script that can be safely given cap_net_admin, we can dramatically simplify
things for non-privileged users. We still support existing -net tap options
as a mechanism for advanced users and backwards compatibility.
Currently, this is very Linux centric but there's really no reason why it
couldn't be extended for other Unixes.
A typical invocation would be similar to one of the following:
qemu linux.img -net bridge -net nic,model=virtio
qemu linux.img -net tap,helper="/usr/local/libexec/qemu-bridge-helper"
-net nic,model=virtio
qemu linux.img -netdev bridge,id=hn0
-device virtio-net-pci,netdev=hn0,id=nic1
qemu linux.img -netdev tap,helper="/usr/local/libexec/qemu-bridge-helper",id=hn0
-device virtio-net-pci,netdev=hn0,id=nic1
The default bridge that we attach to is br0. The thinking is that a distro
could preconfigure such an interface to allow out-of-the-box bridged networking.
Alternatively, if a user wants to use a different bridge, a typical invocation
would be simliar to one of the following:
qemu linux.img -net bridge,br=qemubr0 -net nic,model=virtio
qemu linux.img -net tap,helper="/usr/local/libexec/qemu-bridge-helper --br=qemubr0"
-net nic,model=virtio
qemu linux.img -netdev bridge,br=qemubr0,id=hn0
-device virtio-net-pci,netdev=hn0,id=nic1
qemu linux.img -netdev tap,helper="/usr/local/libexec/qemu-bridge-helper --br=qemubr0",id=hn0
-device virtio-net-pci,netdev=hn0,id=nic1
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Richa Marwaha <rmarwah@linux.vnet.ibm.com>
Signed-off-by: Corey Bryant <coreyb@linux.vnet.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Move the parsing of a filedescriptor into a common function
qemu_parse_fd() so others can use it as well. Have net.c call this
function.
v2:
- moving qemu_parse_fd into cutils.c
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Drop the open-coded MAC assignment from net_init_nic and replace it with
standard qemu_macaddr_default_if_unset which is also used by qdev. That
avoid creating colliding MACs when instantiating NICs via different
mechanisms.
This change requires to store the MAC as MACAddr in NICInfo, and the
remaining nd_table users need to be updated.
Based on suggestion by Peter Maydell.
CC: Markus Armbruster <armbru@redhat.com>
CC: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Include the client type name into the output of 'info network'. The
result looks like this:
(qemu) info network
VLAN 0 devices:
rtl8139.0: type=nic,model=rtl8139,macaddr=52:54:00:12:34:57
Devices not on any VLAN:
virtio-net-pci.0: type=nic,model=virtio-net-pci,macaddr=52:54:00:12:34:56
\ network1: type=tap,fd=5
CC: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Position entries of net_client_types according to the corresponding
values of NET_CLIENT_TYPE_*. The array size is now defined by
NET_CLIENT_TYPE_MAX. This will allow to obtain entries based on type
value in later patches.
At this chance rename NET_CLIENT_TYPE_SLIRP to NET_CLIENT_TYPE_USER for
the sake of consistency.
CC: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Improve the layout when listing non-vlan clients via 'info network'. The
result looks like this:
(qemu) info network
Devices not on any VLAN:
orphan: net=10.0.2.0, restricted=n
virtio-net-pci.0: model=virtio-net-pci,macaddr=52:54:00:12:34:56
\ network2: fd=5
e1000.0: model=e1000,macaddr=52:54:00:12:34:57
\ network1: net=10.0.2.0, restricted=n
rtl8139.0: model=rtl8139,macaddr=52:54:00:12:34:58
ie. peers are grouped, orphans are listed as before.
CC: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
qemu_find_netdev() looks up members of non_vlan_clients by name. It
happily returns the first match. Trouble is the names need not be
unique.
non_vlan_clients contains host parts (netdevs) and guest parts (NICs).
Netdevs have unique names: a netdev's name is a (mandatory)
qemu_netdev_opts ID, and these are unique.
NIC names are not unique. If a NIC has a qdev ID (which is unique),
that's its name. Else, we make up a name. The made-up names are
unique, but they can clash with qdev IDs. Even if NICs had unique
names, they could still clash with netdev names.
Callers of qemu_find_netdev():
* net_init_nic() wants a netdev. It happens to work because it runs
before NICs get added to non_vlan_clients.
* do_netdev_del() wants a netdev. If it gets a NIC, it complains and
fails. Bug: a netdev with the same name that comes later in
non_vlan_clients can't be deleted:
$ qemu-system-x86_64 -nodefaults -vnc :0 -S -monitor stdio -netdev user,id=hostnet0 -device virtio-net-pci,netdev=hostnet0,id=virtio1
[...]
(qemu) netdev_add user,id=virtio1
(qemu) info network
Devices not on any VLAN:
hostnet0: net=10.0.2.0, restricted=n peer=virtio1
virtio1: model=virtio-net-pci,macaddr=52:54:00:12:34:56 peer=hostnet0
virtio1: net=10.0.2.0, restricted=n
(qemu) netdev_del virtio1
Device 'virtio1' not found
* parse_netdev() wants a netdev. If it gets a NIC, it gets confused.
With the test setup above:
(qemu) device_add virtio-net-pci,netdev=virtio1
Property 'virtio-net-pci.netdev' can't take value 'virtio1', it's in use
You can even connect two NICs to each other:
$ qemu-system-x86_64 -nodefaults -vnc :0 -S -monitor stdio -device virtio-net-pci,id=virtio1 -device e1000,netdev=virtio1
[...]
Devices not on any VLAN:
virtio1: model=virtio-net-pci,macaddr=52:54:00:12:34:56 peer=e1000.0
e1000.0: model=e1000,macaddr=52:54:00:12:34:57 peer=virtio1
(qemu) q
Segmentation fault (core dumped)
* do_set_link() works fine for both netdevs and NICs. Whether it
really makes sense for netdevs is debatable, but that's outside this
patch's scope.
Change qemu_find_netdev() to return only netdevs. This fixes the
netdev_del and device_add/-device bugs demonstrated above.
To avoid changing set_link, make do_set_link() search non_vlan_clients
by hand instead of calling qemu_find_netdev().
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
If a network client doesn't have a name, we make one up, with
assign_name(). assign_name() creates a name MODEL.NUM, where MODEL is
the client's model, and NUM is the number of MODELs that already
exist.
Bug: it misses clients that are not on a VLAN, i.e. netdevs and the
NICs using them:
$ qemu-system-x86_64 -nodefaults -vnc :0 -S -monitor stdio -netdev user,id=hostnet0 -net nic,netdev=hostnet0 -netdev user,id=hostnet1 -net nic,netdev=hostnet1
QEMU 0.14.50 monitor - type 'help' for more information
(qemu) info network
Devices not on any VLAN:
hostnet0: net=10.0.2.0, restricted=n peer=e1000.0
hostnet1: net=10.0.2.0, restricted=n peer=e1000.0
e1000.0: model=e1000,macaddr=52:54:00:12:34:56 peer=hostnet0
e1000.0: model=e1000,macaddr=52:54:00:12:34:57 peer=hostnet1
Fix that.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
error_report() prepends location, and appends a newline. The message
constructed from the arguments should not contain a newline. Fix the
obvious offenders.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Diagnose the case where the user asked for a NIC via "-net nic"
but the board didn't instantiate that NIC (for example where the
user asked for two NICs but the board only supports one). Note
that this diagnostic doesn't apply to NICs created through -device,
because those are always instantiated.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Don't warn about the default network setup that you get if no command line
-net options are specified. There are two cases that we would otherwise
complain about:
(1) board doesn't support a NIC but the implicit "-net nic" requested one
(2) CONFIG_SLIRP not set, so the implicit "-net nic" sets up a nic that
isn't connected to anything
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This reverts commit f68b9d672b.
That attempt at diagnosing unused -net nic options failed to account
for NICs created via -device; back it out cleanly in preparation
for implementing in a different manner.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Improve the warnings we give if the user specified a combination of -net
options which don't make much sense:
* Don't warn about anything if the config is the implicit default
"-net user -net nic" rather than one specified by the user (this will
only kick in for boards with no NIC or if CONFIG_SLIRP is not set)
* Diagnose the case where the user asked for NICs which the board
didn't instantiate (for example where the user asked for two NICs
but the board only supports one)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Benjamin Poirier <benjamin.poirier@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
If any of the clients is not ready to receive (ie it has a can_receive
callback and can_receive() returns false), we don't want to start
sending, else this client may miss/discard the packet.
I got this behaviour with the following setup :
the emulated machine is using an USB-ethernet adapter, it is connected
to the network using SLIRP and I'm dumping the traffic in a .pcap file.
As per the following command line :
-net nic,model=usb,vlan=1 -net user,vlan=1 -net dump,vlan=1,file=/tmp/pkt.pcap
Every time that two packets are coming in a row from the host, the
usb-net code will receive the first one, then returns 0 to can_receive
call since it has a 1 packet long queue. But as the dump code is always
ready to receive, qemu_can_send_packet will return true and the next
packet will discard the previous one in the usb-net code.
Signed-off-by: Vincent Palatin <vpalatin@chromium.org>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
qemu makes it possible to disable link at tap which is not communicated
to the guest but causes all packets to be dropped.
This works for virtio userspace, as qemu stops giving it packets, but
not for virtio-net connected to vhost-net as that does not get notified
about this change.
Notify peer when this happens, which will then be used by the follow-up
patch to stop/start vhost-net.
Note: it might be a good idea to make peer link status match tap in this
case, so the guest gets an event and updates the carrier state. For now
stay bug for bug compatible with what we used to have in userspace.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reported-by: pradeep <psuriset@linux.vnet.ibm.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Add an option to specify the host IP to send multicast packets from,
when using a multicast socket for networking. The option takes an IP
address and sets the IP_MULTICAST_IF socket option, which causes the
packets to use that IP's interface as an egress.
This is useful if the host machine has several interfaces with several
virtual networks across disparate interfaces.
Signed-off-by: Mike Ryan <mikeryan@ISI.EDU>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
When hanlding fd/vhostfd form command line through net_handle_fd_param(),
we need to check mon and return value of strtol() otherwise we could
get segmentation fault or invalid fd when user type an illegal fd/vhostfd.
This patch is based on the suggestions from
Luiz Capitulino <lcapitulino@redhat.com>.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
With -netdev, virtio devices present offload
features to guest, depending on the backend used.
Thus, removing host netdev peer while guest is
active leads to guest-visible inconsistency and/or crashes.
As a solution, while guest (NIC) peer device exists,
we prevent the host peer from being deleted.
This patch does this by adding peer_deleted flag in nic state:
if host device is going away while guest device
is around, set this flag and keep a shell of
the host device around for as long as guest device exists.
The link is put down so all packets will get discarded.
At the moment, management can detect that device deletion
is delayed by doing info net. As a next step, we shall add
commands that control hotplug/unplug without
removing the device, and an event to report that
guest has responded to the hotplug event.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Switch tree to lookup-by-name using qemu_find_opts().
Also hook up virtfs options so qemu_find_opts works for them too.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This fixes the following scenario using QMP.
First, put a bogus argument "foo" to "type", which results in an error.
{"execute": "netdev_add", "arguments": { "type": "foo", "id": "netdev1" } }
Then, call it again with correct argument "user".
{"execute": "netdev_add", "arguments": { "type": "user", "id": "netdev1" } }
This results in "DuplicatedId" error.
Because the first command was invalid, it should be able to reuse the
same "id", and the second command should work.
Reported-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Yoshiaki Tamura <tamura.yoshiaki@lab.ntt.co.jp>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Commit 50e32ea8f3 changed the behaviour
for the return type of net_client_init() when a nic type with no init
method was specified. 'none' is one such nic type. Instead of returning
0, which gets interpreted as an index into the nd_table[] array, we
switched to returning -1, which signifies an error as well.
That broke VM start with '-net none'. Testing was only done with the
monitor command 'pci_add', which doesn't fail.
The correct fix would still be to return 0+ values from
net_client_init() only when the return value can be used as an index to
refer to an entry in nd_table[]. With the current code, callers can
erroneously poke into nd_table[0] when -net nic is used, which can lead
to badness.
However, this commit just returns to the previous behaviour before the
offending commit.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
To hot-unplug guest and host part of a network device, you do:
device_del NIC-ID
netdev_del NETDEV-ID
For PCI devices, device_del merely tells ACPI to unplug the device.
The device goes away for real only after the guest processed the ACPI
unplug event.
You have to wait until then (e.g. by polling info pci) before you can
unplug the netdev. Not good.
Fix by removing the "in use" check from do_netdev_del(). Deleting a
netdev while it's in use is safe; packets simply get routed to the bit
bucket.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
The correct model type wasn't getting added when hotplugging nics with
pci_add.
Testcase: start VM with default nic type. In the qemu_monitor:
(qemu) pci_add auto nic model=virtio
This results in a nic hot-plug of the same nic type as the default.
This was broken in 5294e2c774
Also changes the behaviour where no .init is defined for a
net_client_type. Previously, 0 was returned, which indicated the init
was successful and that 0 was the index into the nd_tables[] array.
Return -1, indicating unsuccessful init, in such a case.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Previous commit added QMP documentation to the qemu-monitor.hx
file, it's is a copy of this information.
While it's good to keep it near code, maintaining two copies of
the same information is too hard and has little benefit as we
don't expect client writers to consult the code to find how to
use a QMP command.
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Second argument is now "on" or "off" instead of "up" or "down".
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
The conversion is shallow: client type init() methods aren't
converted. Converting them is a big job for relatively little
practical benefit, so leave it for later.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Both functions report errors nicely enough now, no need for additional
messages.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
There are many problems with net_set_boot_mask():
1) It is broken when using the device model instead of "-net nic". Example:
$ qemu-system-x86_64 -device rtl8139,vlan=0,id=net0,mac=52:54:00:82:41:fd,bus=pci.0,addr=0x4 -net user,vlan=0,name=hostnet0 -vnc 0.0.0.0:0 -boot n
Cannot boot from non-existent NIC
$
2) The mask was previously used to set which boot ROMs were supposed to be
loaded, but this was changed long time ago. Now all ROM images are loaded,
and SeaBIOS takes care of jumping to the right boot entry point depending on
the boot settings.
3) Interpretation and validation of the boot parameter letters is done on
the machine type code. Examples: PC accepts only a,b,c,d,n as valid boot
device letters. mac99 accepts only a,b,c,d,e,f.
As a side-effect of this change, qemu-kvm won't abort anymore if using "-boot n"
on a machine with no network devices. Checking if the requested boot device is
valid is now a task for the BIOS or the machine-type code.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Acked-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
It is just set by net_set_boot_mask() and never used. The logic for rom loading
changed a lot since this field was introduced. It is not needed anymore.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Acked-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
This adds vhost binary option to tap, to enable vhost net accelerator.
Default is off for now, we'll be able to make default on long term
when we know it's stable.
vhostfd option can be used by management, to pass in the fd. Assigning
vhostfd implies vhost=on.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
We sometimes permit omitting the first option name, for example
-device foo is short for -device driver=foo. The name to use
("driver" in the example) is passed as argument to qemu_opts_parse().
For each QemuOptsList, we use at most one such name.
Move the name into QemuOptsList, and pass whether to permit the
abbreviation. This ensures continued consistency, and simplifies the
commit after next in this series.
error_report() terminates the message with a newline. Strip it it
from its arguments.
This fixes a few error messages lacking a newline:
net_handle_fd_param()'s "No file descriptor named %s found", and
tap_open()'s "vnet_hdr=1 requested, but no kernel support for
IFF_VNET_HDR available" (all three versions).
There's one place that passes arguments without newlines
intentionally: load_vmstate(). Fix it up.
Guest device and host netdev are peers, i.e. it's a 1:1 relation.
However, we fail to enforce that:
$ qemu -nodefaults --nographic -netdev user,id=net0 -device e1000,netdev=net0 -device virtio-net-pci,netdev=net0 -monitor stdio
QEMU 0.12.50 monitor - type 'help' for more information
(qemu) info network
Devices not on any VLAN:
net0: net=10.0.2.0, restricted=n peer=virtio-net-pci.0
e1000.0: model=e1000,macaddr=52:54:00:12:34:56 peer=net0
virtio-net-pci.0: model=virtio-net-pci,macaddr=52:54:00:12:34:57 peer=net0
It's all downhill from there.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
net.c used a constant to signify no MSI vectors were specified. Extend
that to all qdev devices.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Reported-by: "Michael S. Tsirkin" <mst@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
/src/qemu/net.c: In function `net_check_clients':
/src/qemu/net.c:1287: warning: `has_nic' might be used uninitialized in this function
/src/qemu/net.c:1287: warning: `has_host_dev' might be used uninitialized in this function
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Clients not associated with a VLAN exist since commit d80b9fc6.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Clients not associated with a VLAN exist since commit d80b9fc6.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
