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2020-07-15net: detect errors from probing vnet hdr flag for TAP devicesDaniel P. Berrange
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>
2019-08-16Clean up inclusion of sysemu/sysemu.hMarkus Armbruster
In my "build everything" tree, changing sysemu/sysemu.h triggers a recompile of some 5400 out of 6600 objects (not counting tests and objects that don't depend on qemu/osdep.h). Almost a third of its inclusions are actually superfluous. Delete them. Downgrade two more to qapi/qapi-types-run-state.h, and move one from char/serial.h to char/serial.c. hw/semihosting/config.c, monitor/monitor.c, qdev-monitor.c, and stubs/semihost.c define variables declared in sysemu/sysemu.h without including it. The compiler is cool with that, but include it anyway. This doesn't reduce actual use much, as it's still included into widely included headers. The next commit will tackle that. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Message-Id: <20190812052359.30071-27-armbru@redhat.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
2019-06-12Include qemu-common.h exactly where neededMarkus Armbruster
No header includes qemu-common.h after this commit, as prescribed by qemu-common.h's file comment. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20190523143508.25387-5-armbru@redhat.com> [Rebased with conflicts resolved automatically, except for include/hw/arm/xlnx-zynqmp.h hw/arm/nrf51_soc.c hw/arm/msf2-soc.c block/qcow2-refcount.c block/qcow2-cluster.c block/qcow2-cache.c target/arm/cpu.h target/lm32/cpu.h target/m68k/cpu.h target/mips/cpu.h target/moxie/cpu.h target/nios2/cpu.h target/openrisc/cpu.h target/riscv/cpu.h target/tilegx/cpu.h target/tricore/cpu.h target/unicore32/cpu.h target/xtensa/cpu.h; bsd-user/main.c and net/tap-bsd.c fixed up]
2017-07-13Convert error_report() to warn_report()Alistair Francis
Convert all uses of error_report("warning:"... to use warn_report() instead. This helps standardise on a single method of printing warnings to the user. All of the warnings were changed using these two commands: find ./* -type f -exec sed -i \ 's|error_report(".*warning[,:] |warn_report("|Ig' {} + Indentation fixed up manually afterwards. The test-qdev-global-props test case was manually updated to ensure that this patch passes make check (as the test cases are case sensitive). Signed-off-by: Alistair Francis <alistair.francis@xilinx.com> Suggested-by: Thomas Huth <thuth@redhat.com> Cc: Jeff Cody <jcody@redhat.com> Cc: Kevin Wolf <kwolf@redhat.com> Cc: Max Reitz <mreitz@redhat.com> Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Lieven <pl@kamp.de> Cc: Josh Durgin <jdurgin@redhat.com> Cc: "Richard W.M. Jones" <rjones@redhat.com> Cc: Markus Armbruster <armbru@redhat.com> Cc: Peter Crosthwaite <crosthwaite.peter@gmail.com> Cc: Richard Henderson <rth@twiddle.net> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Greg Kurz <groug@kaod.org> Cc: Rob Herring <robh@kernel.org> Cc: Peter Maydell <peter.maydell@linaro.org> Cc: Peter Chubb <peter.chubb@nicta.com.au> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Marcel Apfelbaum <marcel@redhat.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: Alexander Graf <agraf@suse.de> Cc: Gerd Hoffmann <kraxel@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Cornelia Huck <cohuck@redhat.com> Cc: Stefan Hajnoczi <stefanha@redhat.com> Acked-by: David Gibson <david@gibson.dropbear.id.au> Acked-by: Greg Kurz <groug@kaod.org> Acked-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed by: Peter Chubb <peter.chubb@data61.csiro.au> Acked-by: Max Reitz <mreitz@redhat.com> Acked-by: Marcel Apfelbaum <marcel@redhat.com> Message-Id: <e1cfa2cd47087c248dd24caca9c33d9af0c499b0.1499866456.git.alistair.francis@xilinx.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-03-22util: move declarations out of qemu-common.hVeronia Bahaa
Move declarations out of qemu-common.h for functions declared in utils/ files: e.g. include/qemu/path.h for utils/path.c. Move inline functions out of qemu-common.h and into new files (e.g. include/qemu/bcd.h) Signed-off-by: Veronia Bahaa <veroniabahaa@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22include/qemu/osdep.h: Don't include qapi/error.hMarkus Armbruster
Commit 57cb38b included qapi/error.h into qemu/osdep.h to get the Error typedef. Since then, we've moved to include qemu/osdep.h everywhere. Its file comment explains: "To avoid getting into possible circular include dependencies, this file should not include any other QEMU headers, with the exceptions of config-host.h, compiler.h, os-posix.h and os-win32.h, all of which are doing a similar job to this file and are under similar constraints." qapi/error.h doesn't do a similar job, and it doesn't adhere to similar constraints: it includes qapi-types.h. That's in excess of 100KiB of crap most .c files don't actually need. Add the typedef to qemu/typedefs.h, and include that instead of qapi/error.h. Include qapi/error.h in .c files that need it and don't get it now. Include qapi-types.h in qom/object.h for uint16List. Update scripts/clean-includes accordingly. Update it further to match reality: replace config.h by config-target.h, add sysemu/os-posix.h, sysemu/os-win32.h. Update the list of includes in the qemu/osdep.h comment quoted above similarly. This reduces the number of objects depending on qapi/error.h from "all of them" to less than a third. Unfortunately, the number depending on qapi-types.h shrinks only a little. More work is needed for that one. Signed-off-by: Markus Armbruster <armbru@redhat.com> [Fix compilation without the spice devel packages. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-04net: Clean up includesPeter Maydell
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. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-id: 1454089805-5470-11-git-send-email-peter.maydell@linaro.org
2015-09-11trivial: remove trailing newline from error_reportJohn Snow
Minor cleanup. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Gonglei <arei.gonglei@huawei.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2015-06-17tap: add VNET_LE/VNET_BE operationsGreg Kurz
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>
2015-05-27tap-linux: Convert tap_open() to ErrorMarkus Armbruster
Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 1431691143-1015-12-git-send-email-armbru@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2015-05-27tap: Permit incremental conversion of tap_open() to ErrorMarkus Armbruster
Convert the trivial ones immediately: tap-aix and tap-haiku. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 1431691143-1015-11-git-send-email-armbru@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2015-05-27tap: Convert tap_set_sndbuf() to ErrorMarkus Armbruster
Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 1431691143-1015-8-git-send-email-armbru@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-01-27tap-linux: Get features once and use it many timesKusanagi Kouichi
Signed-off-by: Kusanagi Kouichi <slash@ac.auone-net.jp> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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>