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qemu_opt_set() is a wrapper around qemu_opt_set() that reports the
error with qerror_report_err().
Most of its users assume the function can't fail. Make them use
qemu_opt_set_err() with &error_abort, so that should the assumption
ever break, it'll break noisily.
Just two users remain, in util/qemu-config.c. Switch them to
qemu_opt_set_err() as well, then rename qemu_opt_set_err() to
qemu_opt_set().
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
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Return the Error object instead of reporting it with
qerror_report_err().
Change callers that assume the function can't fail to pass
&error_abort, so that should the assumption ever break, it'll break
noisily.
Turns out all callers outside its unit test assume that. We could
drop the Error ** argument, but that would make the interface less
regular, so don't.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
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into staging
Clean up around error_get_pretty(), qerror_report_err()
# gpg: Signature made Wed Feb 18 10:10:07 2015 GMT using RSA key ID EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg: aka "Markus Armbruster <armbru@pond.sub.org>"
* remotes/armbru/tags/pull-error-2015-02-18:
qemu-char: Avoid qerror_report_err() outside QMP command handlers
qemu-img: Avoid qerror_report_err() outside QMP command handlers
vl: Avoid qerror_report_err() outside QMP command handlers
tpm: Avoid qerror_report_err() outside QMP command handlers
numa: Avoid qerror_report_err() outside QMP command handlers
net: Avoid qerror_report_err() outside QMP command handlers
monitor: Avoid qerror_report_err() outside QMP command handlers
monitor: Clean up around monitor_handle_fd_param()
error: Use error_report_err() where appropriate
error: New convenience function error_report_err()
vhost-scsi: Improve error reporting for invalid vhostfd
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
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Some are called do_info_SUBCOMMAND() (old ones, usually), some
hmp_info_SUBCOMMAND(), some SUBCOMMAND_info(), sometimes SUBCOMMAND
pointlessly differs in spelling.
Normalize to hmp_info_SUBCOMMAND(), where SUBCOMMAND is exactly the
subcommand name with '-' replaced by '_'.
Exceptions:
* sun4m_irq_info(), sun4m_pic_info() renamed to sun4m_hmp_info_irq(),
sun4m_hmp_info_pic().
* lm32_irq_info(), lm32_pic_info() renamed to lm32_hmp_info_irq(),
lm32_hmp_info_pic().
Signed-off-by: Markus Armbruster <armbru@redhat.com>
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Some are called do_COMMAND() (old ones, usually), some hmp_COMMAND(),
and sometimes COMMAND pointlessly differs in spelling.
Normalize to hmp_COMMAND(), where COMMAND is exactly the command name
with '-' replaced by '_'.
Exceptions:
* do_device_add() and client_migrate_info() *not* renamed to
hmp_device_add(), hmp_client_migrate_info(), because they're also
QMP handlers. They still need to be converted to QAPI.
* do_memory_dump(), do_physical_memory_dump(), do_ioport_read(),
do_ioport_write() renamed do hmp_* instead of hmp_x(), hmp_xp(),
hmp_i(), hmp_o(), because those names are too cryptic for my taste.
* do_info_help() renamed to hmp_info_help() instead of hmp_info(),
because it only covers help.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
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qerror_report_err() is a transitional interface to help with
converting existing monitor commands to QMP. It should not be used
elsewhere. Replace by error_report_err() in HMP command handler
hmp_host_net_add() and initial startup helpers net_init_client(),
net_init_netdev(). Keep it in QMP command handler qmp_netdev_add().
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
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monitor_handle_fd_param() is a wrapper around
monitor_handle_fd_param2() that feeds errors to qerror_report_err()
instead of returning them. qerror_report_err() is inappropriate in
many contexts. monitor_handle_fd_param() looks simpler than
monitor_handle_fd_param2(), which tempts use. Remove the temptation:
drop the wrapper and open-code the (trivial) error handling instead.
Replace the open-coded qerror_report_err() by error_report_err() in
places that already use error_report(). Turns out that's everywhere.
While there, rename monitor_handle_fd_param2() to monitor_fd_param().
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
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We should del hub port when peer is deleted since it will not be reused
and will only be freed during exit.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Message-id: 1422860798-17495-3-git-send-email-jasowang@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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Not only nic could be the one to peer.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Message-id: 1422860798-17495-2-git-send-email-jasowang@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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Signed-off-by: Jason Wang <jasowang@redhat.com>
Message-id: 1422860798-17495-1-git-send-email-jasowang@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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g_new(T, n) is neater than g_malloc(sizeof(T) * n). It's also safer,
for two reasons. One, it catches multiplication overflowing size_t.
Two, it returns T * rather than void *, which lets the compiler catch
more type errors.
This commit only touches allocations with size arguments of the form
sizeof(T).
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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[Adjusted doc comment for grammar.
--Stefan]
Signed-off-by: Wangkai <wangkai86@huawei.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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If is_connected parameter is false, the saddr
variable will no initialize. Coverity report:
uninit_use: Using uninitialized value saddr.sin_port.
We don't need add saddr information to nc->info_str
when is_connected is false.
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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commit b412eb61 introduce 'cmd:' target for guestfwd,
and fwd don't be used in this scenario, and will leak
memory in true branch with 'cmd:'. Let's allocate memory
for fwd variable just in else statement.
Cc: Alexander Graf <agraf@suse.de>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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In this false branch, fd will leak when it is zero.
Change the testing condition.
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
[Fix net_l2tpv3_cleanup as well. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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freeaddrinfo(result) does not assign result = NULL, after frees it.
There will be a double free when it goes error case.
It is reported by covertiy.
Reviewed-by: Gonglei <arei.gonglei@huawei.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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The file sharing module should not handle printers, so disable it.
The options 'load printers' and 'printing' have been available since the
beginning (May 1996, commit 0e8fd3398771da2f016d72830179507f3edda51b).
Option 'disable spoolss' is available since Samba 2.0.4, commit
de5f42c9d9172592779fa2504d44544e3b6b1c0d).
Next, "socket address" was reported as deprecated, use a combination of
"interfaces" and "bind interfaces only" instead (available since October
1997, commit 79f4fb52c1ed56fd843f81b4eb0cdd2991d4d0f4).
Override cache directory to avoid writing to a global directory. Option
available since Samba 3.4.0, Jan 2009, commit
19a05bf2f485023b11b41dfae3f6459847d55ef7.
Set "usershare max shared=0" to prevent a global directory from being
used. Option available since Samba 3.0.23, February 2006, commit
5831715049f2d460ce42299963a5defdc160891b.
The last option was introduced with Samba 3.4.0, but previously
"state directory" was already added which exists in Samba 3.4.0. As
unknown parameters are ignored (while printing a warning), it should be
safe to add another option.
Signed-off-by: Peter Wu <peter@lekensteyn.nl>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
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In hotplugging scenario, taking those true branch, the file
handler do not be closed. Let's close them before return.
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
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commit 5193e5fb (tap: factor out common tap initialization)
introduce net_init_tap_one(). But it's inappropriate that
we close fd in net_init_tap_one(), we should lay it in the
caller, becuase some callers needn't to close it if we get
the fd by monitor_handle_fd_param().
On the other hand, in other exceptional branches fd isn't
closed, so that's incomplete anyway.
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
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DEFAULT_NETWORK_SCRIPT and DEFAULT_NETWORK_DOWN_SCRIPT
have been defined in net/net.h included in
tap.c, which is the only C file that using those two macro.
Let's remove the repeating macroinstruction.
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
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It looks like smbd always logs to /var/log/samba/log.$progname
even if config file specifies different logfile -- when it needs
to log something before completing reading the config file. But
if it can't open it for writing, it fails and exits. Tell smbd
to use our temp dir as logbase (-l option) to avoid that.
The same option is used by samba3 and samba4, so there should
be no incompatible changes.
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
Tested-by: Jan Kiszka <jan.kiszka@siemens.com>
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staging
Net patches
# gpg: Signature made Thu 04 Sep 2014 17:32:44 BST using RSA key ID 81AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>"
# gpg: aka "Stefan Hajnoczi <stefanha@gmail.com>"
* remotes/stefanha/tags/net-pull-request:
virtio-net: purge outstanding packets when starting vhost
net: complete all queued packets on VM stop
net: invoke callback when purging queue
virtio: don't call device on !vm_running
virtio-net: don't run bh on vm stopped
net: Forbid dealing with packets when VM is not running
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
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This completes all packets, ensuring that callbacks
will not run when VM is stopped.
Cc: qemu-stable@nongnu.org
Cc: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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devices rely on packet callbacks eventually running,
but we violate this rule whenever we purge the queue.
To fix, invoke callbacks on all packets on purge.
Set length to 0, this way callers can detect that
this happened and re-queue if necessary.
Cc: qemu-stable@nongnu.org
Cc: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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For all NICs(except virtio-net) emulated by qemu,
Such as e1000, rtl8139, pcnet and ne2k_pci,
Qemu can still receive packets when VM is not running.
If this happened in *migration's* last PAUSE VM stage, but
before the end of the migration, the new receiving packets will possibly dirty
parts of RAM which has been cached in *iovec*(will be sent asynchronously) and
dirty parts of new RAM which will be missed.
This will lead serious network fault in VM.
To avoid this, we forbid receiving packets in generic net code when
VM is not running.
Bug reproduction steps:
(1) Start a VM which configured at least one NIC
(2) In VM, open several Terminal and do *Ping IP -i 0.1*
(3) Migrate the VM repeatedly between two Hosts
And the *PING* command in VM will very likely fail with message:
'Destination HOST Unreachable', the NIC in VM will stay unavailable unless you
run 'service network restart'
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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The hostfwd_add and hostfwd_remove monitor commands allow the user
to optionally specify a vlan/stack tuple. hostfwd_add honours this,
but hostfwd_remove does not (it looks up the tuple but then ignores
the SlirpState it has looked up and always uses the first stack
in the list anyway). Correct this to honour what the user requested.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
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The current behaviour of tap_open for BSD systems differ greatly from
it's Linux counterpart. Since FreeBSD supports interface renaming and
tap device cloning by opening /dev/tap, implement a FreeBSD specific
version of tap_open that behaves like it's Linux counterpart.
This is specially important for toolstacks that use Qemu (like Xen
libxl), in order to have a unified behaviour across suported
platforms.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
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If the user specified a (vlan ID, slirp stack name) tuple in a monitor
hostfwd_add/remove command and we can't find it, give the user an
error message rather than silently doing nothing.
This brings this error case in slirp_lookup() into line with the
other two.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
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The mmsghdr struct is only introduced in Linux 2.6.32; add a
configure check for it and disable L2TPV3 on hosts which are
too old to provide it, rather than simply failing to compile.
Reported-by: chenliang <chenliang88@huawei.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 1404219488-11196-1-git-send-email-arei.gonglei@huawei.com
[PMM: cleaned up commit message and corrected kernel version number]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
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It indicates the number of elements in ncs field and makes sense to have
int inside NICPeers. Also in parse_netdev we do not need to access
container and work with NICPeers only.
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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This transport allows to connect a QEMU nic to a static Ethernet
over L2TPv3 tunnel. The transport supports all options present
in the Linux kernel implementation. It allows QEMU to connect
to any Linux host running kernel 3.3+, most routers and network
devices as well as other QEMU instances.
[Fixed up net_client_init1() switch statement to support -netdev
--Stefan]
Signed-off-by: Anton Ivanov <antivano@cisco.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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The supplied chardev id will be inspected for supported options. Only
a socket backend, with a set path (i.e. a Unix socket) and optionally
the server parameter set, will be allowed. Other options (nowait, telnet)
will make the chardev unusable and the netdev will not be initialised.
Additional checks for validity:
- requires `-numa node,memdev=..`
- requires `-device virtio-net-*`
The `vhostforce` option is used to force vhost-net when we deal with
non-MSIX guests.
Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
Signed-off-by: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
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Add a new QEMU netdev backend that is intended to invoke vhost_net with the
vhost-user backend. It uses an Unix socket chardev to establish a
communication with the 'slave' (client and server mode supported).
At runtime the netdev will handle OPEN/CLOSE events from the chardev. Upon
disconnection it will set link_down accordingly and notify virtio-net; the
virtio-net interface will go down.
Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
Signed-off-by: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Use vhost_set_backend_type to initialise a proper vhost_ops structure.
In vhost_net_init and vhost_net_start_one call conditionally TAP related
initialisation depending on the vhost backend type.
Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
Signed-off-by: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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vhost_dev_init will replace devfd and devpath with a single opaque argument.
This is initialised with a file descriptor. When TAP is used (through
vhost_net), open /dev/vhost-net and pass the fd as an opaque parameter in
VhostNetOptions. The same applies to vhost-scsi - open /dev/vhost-scsi and
pass the fd.
Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
Signed-off-by: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Signed-off-by: Hani Benhabiles <hani@linux.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
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Make it possible to query all net clients without specifying an ID when calling
qemu_find_net_clients_except().
This also adds the add_completion_option() function which is to be used for
other commands completions as well.
Signed-off-by: Hani Benhabiles <hani@linux.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
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into staging
trivial patches for 2014-04-28
# gpg: Signature made Mon 28 Apr 2014 05:56:01 BST using RSA key ID A4C3D7DB
# gpg: Good signature from "Michael Tokarev <mjt@tls.msk.ru>"
# gpg: aka "Michael Tokarev <mjt@corpit.ru>"
# gpg: aka "Michael Tokarev <mjt@debian.org>"
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg: There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 6EE1 95D1 886E 8FFB 810D 4324 457C E0A0 8044 65C5
# Subkey fingerprint: 6F67 E18E 7C91 C5B1 5514 66A7 BEE5 9D74 A4C3 D7DB
* remotes/mjt/tags/trivial-patches-2014-04-28:
slirp/smb: Move ncalrpc directory to tmp
po: add proper Language: tags to .po files
po/Makefile: fix $SRC_PATH reference
init_paths: fix minor memory leak
virtfs-proxy-helper: fix call to accept
net/net.c: remove unnecessary semicolon
Add QEMU logo (SVG file)
vl: avoid closing stdout with 'writeconfig'
xilinx: Fix typo in comment (Marvel -> Marvell)
vl: Eliminate a superfluous local variable
vl: Remove useless 'continue'
gitignore: cleanups #2
tests/.gitignore: Ignore test-rfifolock
move test-* from .gitignore to tests/.gitignore
configure: Improve help behavior
vl: convert -m to QemuOpts
qemu-option: introduce qemu_find_opts_singleton
misc: Use cpu_physical_memory_read and cpu_physical_memory_write
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
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The smbd forked by qemu still uses the default ncalrpc directory
in /var/run/samba. This may lead to problems, if /var/run/samba
does not exist (for example if /var/run is a tmpfs and the host
smbd was not started).
This leads to the following error message from samba
and an unworkable smbd:
Failed to create pipe directory /var/run/samba/ncalrpc - No such file or directory
Fix this by pointing smbd to /tmp/qemu-smb.%d.%d/ncalrpc as ncalrpc directory.
Smbd will create the actual ncalrpc subdirectory on its own.
Signed-off-by: Michael Buesch <m@bues.ch>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
(Applying this to -trivial because it _is_ rather trivial
and because Jan does not reply for months)
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Signed-off-by: Igor Ryzhov <iryzhov@arccn.ru>
Reviewed-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
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Using error_is_set(errp) that way can sweep programming errors under
the carpet when we get called incorrectly with an error set.
qmp_query_rx_filter() breaks its loop when it detects an error. It
needs to set another error when the loop completes normally.
Return right away instead of merely breaking the loop.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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With a client name, the QMP command is specified to return a list of
one element. This isn't locally obvious in the code. Make it so.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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Signed-off-by: Igor Ryzhov <iryzhov@arccn.ru>
Reviewed-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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Avoid iterations for fd 0, 1 & 2 when we are closing file fds in child process.
Signed-off-by: Pankaj Gupta <pagupta@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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Also convert nearby monitor_printf() call to error_report().
Signed-off-by: Hani Benhabiles <hani@linux.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
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Signed-off-by: Prasad Joshi <prasadjoshi.linux@gmail.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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staging
Net patches
# gpg: Signature made Wed 12 Mar 2014 13:48:20 GMT using RSA key ID 81AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>"
# gpg: aka "Stefan Hajnoczi <stefanha@gmail.com>"
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg: There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35 775A 9CA4 ABB3 81AB 73C8
* remotes/stefanha/tags/net-pull-request:
tap: avoid deadlocking rx
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
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The net subsystem has a control flow mechanism so peer NetClientStates
can tell each other to stop sending packets. This is used to stop
monitoring the tap file descriptor for incoming packets if the guest rx
ring has no spare buffers.
There is a corner case when tap_can_send() is true at the beginning of
an event loop iteration but becomes false before the tap_send() fd
handler is invoked.
tap_send() will read the packet from the tap file descriptor and attempt
to send it. The net queue will hold on to the packet and return 0,
indicating that further I/O is not possible. tap then stops monitoring
the file descriptor for reads.
This is unlike the normal case where tap_can_send() is the same before
and during the event loop iteration. The event loop would simply not
monitor the file descriptor if tap_can_send() returns true. Upon next
iteration it would check tap_can_send() again and begin monitoring if we
can send.
The deadlock happens because tap_send() explicitly disabled read_poll.
This is done with the expectation that the peer will call
qemu_net_queue_flush(). But hw/net/virtio-net.c does not monitor
vm_running transitions and issue the flush. Hence we're left with a
broken tap device.
Cc: qemu-stable@nongnu.org
Reported-by: Neil Skrypuch <neil@tembosocial.com>
Tested-by: Neil Skrypuch <neil@tembosocial.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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