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2013-02-27tap: set IFF_ONE_QUEUE per defaultPeter Lieven
historically the kernel queues packets two times. once at the device and second in qdisc. this is believed to cause interface stalls if one of these queues overruns. setting IFF_ONE_QUEUE is the default in kernels >= 3.8. the flag is ignored since then. see kernel commit 5d097109257c03a71845729f8db6b5770c4bbedc Signed-off-by: Peter Lieven <pl@kamp.de> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-02-01tap: multiqueue supportJason Wang
Recently, linux support multiqueue tap which could let userspace call TUNSETIFF for a signle device many times to create multiple file descriptors as independent queues. User could also enable/disabe a specific queue through TUNSETQUEUE. The patch adds the generic infrastructure to create multiqueue taps. To achieve this a new parameter "queues" were introduced to specify how many queues were expected to be created for tap by qemu itself. Alternatively, management could also pass multiple pre-created tap file descriptors separated with ':' through a new parameter fds like -netdev tap,id=hn0,fds="X:Y:..:Z". Multiple vhost file descriptors could also be passed in this way. Each TAPState were still associated to a tap fd, which mean multiple TAPStates were created when user needs multiqueue taps. Since each TAPState contains one NetClientState, with the multiqueue nic support, an N peers of NetClientState were built up. A new parameter, mq_required were introduce in tap_open() to create multiqueue tap fds. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-02-01tap: introduce a helper to get the name of an interfaceJason Wang
This patch introduces a helper tap_get_ifname() to get the device name of tap device. This is needed when ifname is unspecified in the command line and qemu were asked to create tap device by itself. In this situation, the name were allocated by kernel, so if multiqueue is asked, we need to fetch its name after creating the first queue. Only linux has this support since it's the only platform that supports multiqueue tap. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-02-01tap: add Linux multiqueue supportJason Wang
This patch add basic multiqueue support for Linux. When multiqueue is needed, we will first check whether kernel support multiqueue tap before creating more queues. Two new functions tap_fd_enable() and tap_fd_disable() were introduced to enable and disable a specific queue. Since the multiqueue is only supported in Linux, return error on other platforms. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-02-01net: tap: use abort() instead of assert(0)Jason Wang
Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-12-19softmmu: move include files to include/sysemu/Paolo Bonzini
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19misc: move include files to include/qemu/Paolo Bonzini
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19net: reorganize headersPaolo Bonzini
Move public headers to include/net, and leave private headers in net/. Put the virtio headers in include/net/tap.h, removing the multiple copies that existed. Leave include/net/tap.h as the interface for NICs, and net/tap_int.h as the interface for OS-specific parts of the tap backend. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-12tap: reset vnet header size on openMichael S. Tsirkin
For tap, we currently assume the vnet header size is 10 (the default value) but that might not be the case if tap is persistent and has been used by qemu previously. To fix, set vnet header size correctly on open. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2012-07-23convert net_init_tap() to NetClientOptionsLaszlo Ersek
Signed-off-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-11-01net: tap-linux: Fix unhelpful error messageLuiz Capitulino
I'm getting: could not configure /dev/net/tun (tap%d): Operation not permitted When the ioctl() fails, ifr.ifr_name will most likely not be overwritten. So we better only use it when ifname contains a string. Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-02-01tap: safe sndbuf defaultMichael S. Tsirkin
With current sndbuf default value, a blocked target guest can prevent another guest from transmitting any packets. While current sndbuf value (1M) is reported to help some UDP based workloads, the default should be safe (0). Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-09-07tap: add APIs for vnet header lengthMichael S. Tsirkin
Add APIs to control host header length. First user will be vhost-net. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2010-06-22give some useful error messages when tap openMichael Tokarev
In net/tap-linux.c, when manipulation of /dev/net/tun fails, it prints (with fprintf) something like this: warning: could not open /dev/net/tun: no virtual network emulation this has 2 issues: 1) it is not a warning really, it's a fatal error (kvm exits after that), 2) there's no indication as of what's actually wrong: printing errno there is helpful. The patch below removes the "warning" prefix, uses %m (since it's linux, %m is available as format modifier), and changes fprintf() to %qemu_error(). Now it prints something like this instead: could not configure /dev/net/tun: Device or resource busy (there are 2 messages like that in the same function) This fixes Debian bug #578154, see http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=578154 Signed-off-by: Michael Tokarev <mjt@tls.msk.ru> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-03-16error: Replace qemu_error() by error_report()Markus Armbruster
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 Armbruster
2009-12-03net: check for TUNSETOFFLOAD support before trying to enable offload featuresPierre Riteau
This avoids the "TUNSETOFFLOAD ioctl() failed: Invalid argument" message on kernels without TUNSETOFFLOAD support. Signed-off-by: Pierre Riteau <Pierre.Riteau@irisa.fr> Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-12-03net: fix TAP networking on host kernels without IFF_VNET_HDR supportPierre Riteau
vnet_hdr is initialized at 1 by default. We need to reset it to 0 if the kernel doesn't support IFF_VNET_HDR. Signed-off-by: Pierre Riteau <Pierre.Riteau@irisa.fr> Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-30net: move UFO support detection to tap-linux.cMark McLoughlin
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 McLoughlin
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 McLoughlin
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 McLoughlin
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 McLoughlin
Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
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