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path: root/net/tap.c
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2012-02-01Add support for net bridgeCorey Bryant1-3/+201
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>
2011-12-15network scripts: don't block SIGCHLD before forkingMichael Roth1-6/+0
This patch fixes a bug where child processes of launch_script() can misbehave due to SIGCHLD being blocked. In the case of `sudo`, this causes a permanent hang. Previously a SIGCHLD handler was added to reap fork_exec()'d zombie processes by calling waitpid(-1, ...). This required other fork()/waitpid() callers to temporarilly block SIGCHILD to avoid having the final wait status being intercepted by the SIGCHLD handler: 7c3370d4fe3fa6cda8655f109e4659afc8ca4269 Since then, the qemu_add_child_watch() interface was added to allow registration of such processes and reap only from that specific set of PIDs: 4d54ec7898bd951007cb6122d5315584bd41d0c4 As a result, we can now avoid blocking SIGCHLD in launch_script(), so drop that behavior. Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-06-08Fix compilation warning due to missing header for sigaction (followup)Alexandre Raymond1-1/+0
This patch removes all references to signal.h when qemu-common.h is included as they become redundant. Signed-off-by: Alexandre Raymond <cerbere@gmail.com> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-02-01vhost: force vhost off for non-MSI guestsmst@redhat.com1-2/+4
When MSI is off, each interrupt needs to be bounced through the io thread when it's set/cleared, so vhost-net causes more context switches and higher CPU utilization than userspace virtio which handles networking in the same thread. We'll need to fix this by adding level irq support in kvm irqfd, for now disable vhost-net in these configurations. Added a vhostforce flag to force vhost-net back on. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-11-16tap: make set_offload a nop after netdev cleanupMichael S. Tsirkin1-1/+5
virtio-net expects set_offload to succeed after peer cleanup. Since we don't have an open fd anymore, make it so. Fixes warning about the failure of offload setting. Reported-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2010-11-16tap: clear vhost_net backend on cleanupMichael S. Tsirkin1-0/+1
Frontends calling tap_get_vhost_net get an invalid pointer after the peer backend has been deleted. Jason Wang <jasowang@redhat.com> reports this leading to a crash in ack_features when we remove the vhost-net bakend of a virtio nic. The fix is simply to clear the backend pointer. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2010-09-07tap: add APIs for vnet header lengthMichael S. Tsirkin1-0/+21
Add APIs to control host header length. First user will be vhost-net. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2010-09-07tap: generalize code for different vnet header lenMichael S. Tsirkin1-14/+14
Make host vnet header length a structure field in preparation for using this support in linux kernel. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2010-04-25Remove dead assignments in various common files, spotted by clang analyzerBlue Swirl1-1/+1
Value stored is never read. Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2010-04-01tap: add API to retrieve vhost net headerMichael S. Tsirkin1-0/+7
will be used by virtio-net for vhost net support Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-04-01tap: add vhost/vhostfd optionsMichael S. Tsirkin1-0/+29
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>
2010-04-01tap: add interface to get device fdMichael S. Tsirkin1-0/+7
Will be used by vhost to attach/detach to backend. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-03-21Revert "tap: invoke downscript when we exit abnormally"Anthony Liguori1-16/+0
This reverts commit 8af8ce4d6116e3d46ad298ca8fe50d3b515b1aac.
2010-03-19tap: invoke downscript when we exit abnormallyAnthony Liguori1-0/+16
Right now, downscript is not invoked reliably. If you execute 'quit' from the monitor, it won't be invoked. This fixes that by converting tap to use an exit_notifier to execute the downscript. In this case, allowing an exit notifier to include state is critically important for the conversion. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-03-16error: Replace qemu_error() by error_report()Markus Armbruster1-1/+1
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.
2010-03-16error: Move qemu_error & friends into their own headerMarkus Armbruster1-0/+1
2010-02-19net: Fix bogus "Warning: vlan 0 with no nics" with -deviceMarkus Armbruster1-4/+0
net_check_clients() prints this when an VLAN has host devices, but no guest devices. It uses VLANState members nb_guest_devs and nb_host_devs to keep track of these devices. However, -device does not update nb_guest_devs, only net_init_nic() does that, for -net nic. Check the VLAN clients directly, and remove the counters. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-01-08net: add API to disable/enable pollingMichael S. Tsirkin1-0/+8
When vhost is bound to a backend device, we need to stop polling it when vhost is started, and restart polling when vhost is stopped. Add an API for that for use by vhost, and implement in tap backend. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-12-03net: initialize vnet_hdr in net_init_tap()Mark McLoughlin1-1/+1
net_tap_init() always sets vnet_hdr using qemu_opt_get_bool(), but initialize it in net_init_tap() just to reduce confusion. Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-12-03net: remove VLANClientState members now in NetClientInfoMark McLoughlin1-3/+3
Add a NetClientInfo pointer to VLANClientState and use that for the typecode and function pointers. Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-12-03net: convert tap to NetClientInfoMark McLoughlin1-37/+45
Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-11-21Avoid segfault on net_tap_init() failureJuergen Lock1-0/+3
Check for fd == -1 there. Signed-off-by: Juergen Lock <nox@jelal.kn-bremen.de> Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2009-11-09tap: drain queue in tap_send()Mark McLoughlin1-13/+16
Okay, let's try re-enabling the drain-entire-queue behaviour, with a difference - before each subsequent packet, use qemu_can_send_packet() to check that we can send it. This is similar to how we check before polling the tap fd and avoids having to drop a packet if the receiver cannot handle it. This patch should be a performance improvement since we no longer have to go through the mainloop for each packet. Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-11-09tap: disable draining queue in one goMark McLoughlin1-16/+13
If qemu_send_packet_async() returns zero, it means the packet has been queued and the sent callback will be invoked once it has been flushed. This is only possible where the NIC's receive() handler returns zero and promises to notify the networking core that room is available in its queue again. In the case where the receive handler does not have this capability (and its queue fills up) it returns -1 and the networking core does not queue up the packet. This condition is indicated by a -1 return from qemu_send_packet_async(). Currently, tap handles this condition simply by dropping the packet. It should do its best to avoid getting into this situation by checking such NIC's have room for a packet before copying the packet from the tap interface. tap_send() used to achieve this by only reading a single packet before returning to the mainloop. That way, tap_can_send() is called before reading each packet. tap_send() was changed to completely drain the tap interface queue without taking into account the situation where the NIC returns an error and the packet is not queued. Let's start fixing this by reverting to the previous behaviour of reading one packet at a time. Reported-by: Scott Tsai <scottt.tw@gmail.com> Tested-by: Sven Rudolph <Sven_Rudolph@drewag.de> Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-30Unbreak tap compilation on OS XAlexander Graf1-0/+1
Currently compiling the tap sources breaks on Mac OS X. This is because of: 1) tap-linux.h requiring Linux includes 2) typos 3) missing #includes This patch adds what's necessary to compile tap happily on Mac OS X. I haven't tested if using tap actually works, but I don't think that's a major issue as that code was probably seriously untested before already. I didn't split the patch, because it's only a few lines of code and splitting is probably not worth the effort here. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-30net: move UFO support detection to tap-linux.cMark McLoughlin1-6/+1
Only supported on Linux Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-30net: move tap_set_offload() code into tap-linux.cMark McLoughlin1-20/+1
TUNSETOFFLOAD is only available on Linux Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-30net: move tap_probe_vnet_hdr() to tap-linux.cMark McLoughlin1-12/+0
Only Linux has support for IFF_VNET_HDR Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-30net: move tap_set_sndbuf() to tap-linux.cMark McLoughlin1-24/+1
TUNSETSNDBUF is only available on linux Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-30net: move linux code into net/tap-linux.cMark McLoughlin1-47/+0
Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-30net: move AIX code into net/tap-aix.cMark McLoughlin1-12/+0
Okay, this makes the tap options available on AIX even though there's no support, but if we want to do it right we should have not compile the tap code at all on AIX using e.g. CONFIG_TAP. Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-30net: move solaris code to net/tap-solaris.cMark McLoughlin1-165/+3
Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-30net: split BSD tap_open() out into net/tap-bsd.cMark McLoughlin1-46/+4
Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-30net: split all the tap code out into net/tap.cMark McLoughlin1-0/+759
Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
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