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Daniel P. Berrange 8ed5372874 trace: don't abort qemu if ftrace can't be initialized
If the ftrace backend is compiled into QEMU, any attempt
to start QEMU while non-root will fail due to the
inability to open /sys/kernel/debug/tracing/tracing_on.

Add a fallback into the code so that it connects up the
trace_marker_fd variable to /dev/null when getting
EACCES on the 'trace_on' file. This allows QEMU to
run, with ftrace turned into a no-op.

[Fixed s/setting/getting/ and s/EACCESS/EACCES/ errors pointed out by
Eric Blake <eblake@redhat.com>.
--Stefan]

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1475588159-30598-13-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-10-12 09:35:54 +02:00
audio trace-events: fix first line comment in trace-events 2016-08-12 10:36:01 +01:00
backends msmouse: Fix segfault caused by free the chr before chardev cleanup. 2016-09-22 20:20:53 +02:00
block dmg: Move libbz2 code to dmg-bz2.so 2016-10-07 14:14:06 +02:00
bsd-user bsd-user: fix FreeBSD build after d148d90e 2016-10-07 15:17:53 +01:00
contrib Clean up ill-advised or unusual header guards 2016-07-12 16:20:46 +02:00
crypto crypto: Switch to QEMU UUID API 2016-09-23 11:42:52 +08:00
default-configs STM32F2xx: Add the SPI device 2016-10-04 13:28:07 +01:00
disas disas/arm.c: Remove unused macro definitions 2016-09-22 18:13:09 +01:00
docs Block layer patches 2016-10-10 15:19:20 +01:00
dtc@65cc4d2748
fpu fpu: add mechanism to check for invalid long double formats 2016-09-15 12:43:18 +01:00
fsdev 9pfs: drop useless v9fs_string_null() function 2016-09-16 08:56:15 +02:00
gdb-xml target-ppc: gdbstub: Add VSX support 2016-01-30 23:37:38 +11:00
hw virtio, pc: fixes and features 2016-10-10 16:23:40 +01:00
include virtio, pc: fixes and features 2016-10-10 16:23:40 +01:00
io trace: move util/buffer.c trace points into correct file 2016-09-28 19:17:54 +01:00
libdecnumber libdecnumber: Clean up includes 2016-02-16 14:29:27 +00:00
linux-headers linux-headers: update 2016-09-05 15:15:16 +02:00
linux-user trivial patches for 2016-10-08 2016-10-10 13:01:43 +01:00
migration migration: sync all address spaces 2016-09-27 11:57:29 +02:00
nbd nbd-server: Use a separate BlockBackend 2016-09-05 19:06:47 +02:00
net trace: move colo trace events to net/ sub-directory 2016-10-12 09:35:53 +02:00
pc-bios rules.mak: quiet-command: Split command name and args to print 2016-10-06 12:11:51 +01:00
pixman@87eea99e44
po rules.mak: quiet-command: Split command name and args to print 2016-10-06 12:11:51 +01:00
qapi Block layer patches 2016-10-10 15:19:20 +01:00
qga * Thread Sanitizer fixes (Alex) 2016-10-10 10:39:29 +01:00
qobject json-streamer: fix double-free on exiting during a parse 2016-07-12 18:31:27 +02:00
qom cpu: atomically modify cpu->exit_request 2016-10-04 10:00:26 +02:00
replay replay: allow replay stopping and restarting 2016-09-27 11:57:30 +02:00
roms Update OpenBIOS images to c5542f2 built from submodule. 2016-09-12 08:14:50 +01:00
scripts trace: emit name <-> ID mapping in simpletrace header 2016-10-12 09:35:54 +02:00
slirp hw: replace most use of qemu_chr_fe_write with qemu_chr_fe_write_all 2016-09-13 19:09:42 +02:00
stubs trace: remove global 'uint16 dstate[]' array 2016-10-12 09:35:54 +02:00
target-alpha target-alpha: Generate fence op 2016-09-16 08:12:12 -07:00
target-arm target-arm: Correctly handle 'sub pc, pc, 1' for ARMv6 2016-10-04 13:28:10 +01:00
target-cris qemu-tech: document lazy condition code evaluation in cpu.h 2016-10-07 10:05:22 +02:00
target-i386 * Thread Sanitizer fixes (Alex) 2016-10-10 10:39:29 +01:00
target-lm32 target-*: Clean up cpu.h header guards 2016-07-12 16:19:16 +02:00
target-m68k qemu-tech: document lazy condition code evaluation in cpu.h 2016-10-07 10:05:22 +02:00
target-microblaze target-*: Clean up cpu.h header guards 2016-07-12 16:19:16 +02:00
target-mips target-mips: generate fences 2016-09-23 07:07:30 +01:00
target-moxie target-*: Clean up cpu.h header guards 2016-07-12 16:19:16 +02:00
target-openrisc Clean up header guards that don't match their file name 2016-07-12 16:19:16 +02:00
target-ppc target-ppc: fix vmx instruction type/type2 2016-10-05 11:05:28 +11:00
target-s390x * Thread Sanitizer fixes (Alex) 2016-10-10 10:39:29 +01:00
target-sh4 sh4: fix broken link to documentation 2016-09-15 15:32:22 +03:00
target-sparc qemu-tech: document lazy condition code evaluation in cpu.h 2016-10-07 10:05:22 +02:00
target-tilegx Clean up header guards that don't match their file name 2016-07-12 16:19:16 +02:00
target-tricore Clean up decorations and whitespace around header guards 2016-07-12 16:20:46 +02:00
target-unicore32 target-*: Clean up cpu.h header guards 2016-07-12 16:19:16 +02:00
target-xtensa Clean up header guards that don't match their file name 2016-07-12 16:19:16 +02:00
tcg qemu-tech: move text from qemu-tech to tcg/README 2016-10-07 10:05:18 +02:00
tests virtio, pc: fixes and features 2016-10-10 16:23:40 +01:00
trace trace: don't abort qemu if ftrace can't be initialized 2016-10-12 09:35:54 +02:00
ui qemu-doc: merge qemu-tech and qemu-doc 2016-10-07 10:05:54 +02:00
util Block layer patches 2016-10-10 15:19:20 +01:00
.dir-locals.el
.exrc
.gitignore trivial patches for 2016-10-08 2016-10-10 13:01:43 +01:00
.gitmodules
.mailmap
.travis.yml .travis.yml: add gcc sanitizer build 2016-10-04 10:00:26 +02:00
accel.c accel: make configure_accelerator return void 2016-05-18 15:04:27 +03:00
aio-posix.c aio-posix: avoid unnecessary aio_epoll_enabled() calls 2016-09-28 11:21:46 +01:00
aio-win32.c aio-posix: remove useless parameter 2016-07-18 15:10:52 +01:00
arch_init.c util: Add UUID API 2016-09-23 11:42:52 +08:00
async.c async: add aio_bh_schedule_oneshot 2016-10-07 13:34:07 +02:00
balloon.c all: Clean up includes 2016-02-04 17:41:30 +00:00
block.c block: Add qdev ID to DEVICE_TRAY_MOVED 2016-10-07 13:34:22 +02:00
blockdev-nbd.c nbd-server: Allow node name for nbd-server-add 2016-09-05 19:06:47 +02:00
blockdev.c block: Remove qemu_root_bds_opts 2016-09-29 14:13:39 +02:00
blockjob.c block: use aio_bh_schedule_oneshot 2016-10-07 13:34:07 +02:00
bootdevice.c error: Remove NULL checks on error_propagate() calls 2016-06-20 16:38:13 +02:00
bt-host.c all: Clean up includes 2016-02-04 17:41:30 +00:00
bt-vhci.c all: Clean up includes 2016-02-04 17:41:30 +00:00
Changelog
CODING_STYLE CODING_STYLE: Fix a typo ("have" vs. "has") 2016-10-08 11:25:29 +03:00
configure oslib-posix: add a configure switch to debug stack usage 2016-09-29 14:13:39 +02:00
COPYING
COPYING.LIB
cpu-exec-common.c cpu-exec: Rename cpu_resume_from_signal() to cpu_loop_exit_noexc() 2016-06-09 15:55:02 +01:00
cpu-exec.c cpu: atomically modify cpu->exit_request 2016-10-04 10:00:26 +02:00
cpus-common.c cpus-common: lock-free fast path for cpu_exec_start/end 2016-09-27 11:57:30 +02:00
cpus.c qemu: use bdrv_flush_all for vm_stop et al 2016-09-29 14:13:37 +02:00
cputlb.c tcg: Merge GETPC and GETRA 2016-09-16 08:12:11 -07:00
device_tree.c qemu-common: stop including qemu/bswap.h from qemu-common.h 2016-05-19 16:42:28 +02:00
device-hotplug.c blockdev: Split monitor reference from BB creation 2016-03-17 15:47:56 +01:00
disas.c Remove remainders of HPPA backend 2016-09-15 15:32:22 +03:00
dma-helpers.c dma-helpers: dma_blk_io() cancel support 2016-06-28 13:08:31 +01:00
dump.c error: Remove NULL checks on error_propagate() calls 2016-06-20 16:38:13 +02:00
exec.c exec: remove unused compacted argument 2016-10-08 11:25:29 +03:00
gdbstub.c hw: replace most use of qemu_chr_fe_write with qemu_chr_fe_write_all 2016-09-13 19:09:42 +02:00
HACKING Disable warn about left shifts of negative values 2016-08-09 22:57:36 +02:00
hmp-commands-info.hx intc: make HMP 'info irq' and 'info pic' commands available on all targets 2016-10-04 10:00:25 +02:00
hmp-commands.hx monitor: remove mhandler.cmd_new 2016-09-19 17:32:22 +02:00
hmp.c virtio, pc: fixes and features 2016-10-10 16:23:40 +01:00
hmp.h intc: make HMP 'info irq' and 'info pic' commands use InterruptStatsProvider interface 2016-10-04 10:00:25 +02:00
iohandler.c iohandler: Introduce iohandler_get_aio_context 2016-04-22 16:43:42 +02:00
ioport.c hw: remove pio_addr_t 2016-05-19 16:42:30 +02:00
iothread.c iothread: check iothread->ctx before aio_context_unref to avoid assertion 2016-09-28 11:21:46 +01:00
kvm-all.c kvm-all: Pass requester ID to MSI routing functions 2016-10-04 13:28:09 +01:00
kvm-stub.c kvm-all: Pass requester ID to MSI routing functions 2016-10-04 13:28:09 +01:00
LICENSE
main-loop.c main-loop: check return value before using pointer 2016-07-12 18:31:27 +02:00
MAINTAINERS trivial patches for 2016-10-08 2016-10-10 13:01:43 +01:00
Makefile * Thread Sanitizer fixes (Alex) 2016-10-10 10:39:29 +01:00
Makefile.objs -----BEGIN PGP SIGNATURE----- 2016-09-29 00:34:20 +01:00
Makefile.target rules.mak: quiet-command: Split command name and args to print 2016-10-06 12:11:51 +01:00
memory_mapping.c all: Remove unnecessary glib.h includes 2016-06-07 18:19:24 +03:00
memory.c migration: sync all address spaces 2016-09-27 11:57:29 +02:00
module-common.c all: Clean up includes 2016-02-04 17:41:30 +00:00
monitor.c trace: convert code to use event iterators 2016-10-12 09:35:54 +02:00
numa.c numa: reduce code duplication by adding helper numa_get_node_for_cpu() 2016-10-10 01:16:57 +03:00
os-posix.c use g_path_get_dirname instead of dirname 2016-07-17 09:59:21 +02:00
os-win32.c all: Clean up includes 2016-02-04 17:41:30 +00:00
page_cache.c coccinelle: Remove unnecessary variables for function return value 2016-06-20 16:38:13 +02:00
qapi-schema.json qapi: make the json schema files more regular. 2016-10-08 11:25:29 +03:00
qdev-monitor.c qdev-monitor: Add blk_by_qdev_id() 2016-09-23 13:36:10 +02:00
qdict-test-data.txt
qemu-bridge-helper.c all: Remove unnecessary glib.h includes 2016-06-07 18:19:24 +03:00
qemu-char.c virtio, pc: fixes and features 2016-10-10 16:23:40 +01:00
qemu-doc.texi qemu-doc: merge qemu-tech and qemu-doc 2016-10-07 10:05:54 +02:00
qemu-ga.texi
qemu-img-cmds.hx qemu-img: add skip option to dd 2016-09-20 22:10:57 +02:00
qemu-img.c qemu-img: add skip option to dd 2016-09-20 22:10:57 +02:00
qemu-img.texi qemu-img: add skip option to dd 2016-09-20 22:10:57 +02:00
qemu-io-cmds.c block: switch blk_write_compressed() to byte-based interface 2016-09-05 19:06:47 +02:00
qemu-io.c trace: enable tracing in qemu-io 2016-06-28 21:14:12 +01:00
qemu-nbd.c qemu-nbd: Shrink image size by specified offset 2016-10-06 18:04:13 +02:00
qemu-nbd.texi trace: enable tracing in qemu-nbd 2016-06-28 21:14:12 +01:00
qemu-option-trace.texi doc: move text describing --trace to specific .texi file 2016-06-28 21:14:12 +01:00
qemu-options-wrapper.h
qemu-options.h Clean up ill-advised or unusual header guards 2016-07-12 16:20:46 +02:00
qemu-options.hx qemu-options.hx: fix -chardev ringbuf typos 2016-10-08 09:02:19 +03:00
qemu-seccomp.c seccomp: adding getrusage to the whitelist 2016-09-21 11:26:02 +02:00
qemu-tech.texi qemu-doc: merge qemu-tech and qemu-doc 2016-10-07 10:05:54 +02:00
qemu-timer.c timer: set vm_clock disabled default 2016-08-09 22:57:36 +02:00
qemu.nsi qemu-doc: merge qemu-tech and qemu-doc 2016-10-07 10:05:54 +02:00
qemu.sasl
qmp.c qmp: fix object-add assert() without props 2016-10-06 14:47:41 +02:00
qtest.c tests: add RTAS command in the protocol 2016-09-23 10:29:40 +10:00
README qemu-doc: drop installation and compilation notes 2016-10-07 10:05:15 +02:00
replication.c replication: Introduce new APIs to do replication operation 2016-09-13 11:00:56 +01:00
replication.h replication: Introduce new APIs to do replication operation 2016-09-13 11:00:56 +01:00
rules.mak build-sys: fix find-in-path 2016-10-08 11:25:29 +03:00
softmmu_template.h tcg: Merge GETPC and GETRA 2016-09-16 08:12:11 -07:00
spice-qemu-char.c qapi: Don't special-case simple union wrappers 2016-03-18 10:29:26 +01:00
tcg-runtime.c all: Clean up includes 2016-02-04 17:41:30 +00:00
tci.c tcg/tci: Add support for fence 2016-09-16 08:12:12 -07:00
thread-pool.c coroutine: move entry argument to qemu_coroutine_create 2016-07-13 13:26:02 +02:00
thunk.c thunk: Rename args and fields in host-target bitmask conversion code 2016-06-07 18:19:24 +03:00
tpm.c qapi: Don't special-case simple union wrappers 2016-03-18 10:29:26 +01:00
trace-events trace: move colo trace events to net/ sub-directory 2016-10-12 09:35:53 +02:00
translate-all.c tcg: Make tb_flush() thread safe 2016-09-27 11:57:30 +02:00
translate-all.h trace: Add per-vCPU tracing states for events with the 'vcpu' property 2016-07-18 18:23:12 +01:00
translate-common.c include: move CPU-related definitions out of qemu-common.h 2016-05-19 13:08:04 +02:00
user-exec.c tcg: Merge GETPC and GETRA 2016-09-16 08:12:11 -07:00
VERSION Open 2.8 development tree 2016-09-05 11:38:54 +01:00
version.rc
vl.c Block layer patches 2016-10-10 15:19:20 +01:00
xen-common-stub.c
xen-common.c xen: drop XenXC and associated interface wrappers 2016-02-10 12:01:24 +00:00
xen-hvm-stub.c fix MSI injection on Xen 2016-02-06 20:44:10 +02:00
xen-hvm.c xen: handle inbound migration of VMs without ioreq server pages 2016-08-12 16:38:30 -07:00
xen-mapcache.c os-posix: include sys/mman.h 2016-06-16 18:39:03 +02:00

         QEMU README
         ===========

QEMU is a generic and open source machine & userspace emulator and
virtualizer.

QEMU is capable of emulating a complete machine in software without any
need for hardware virtualization support. By using dynamic translation,
it achieves very good performance. QEMU can also integrate with the Xen
and KVM hypervisors to provide emulated hardware while allowing the
hypervisor to manage the CPU. With hypervisor support, QEMU can achieve
near native performance for CPUs. When QEMU emulates CPUs directly it is
capable of running operating systems made for one machine (e.g. an ARMv7
board) on a different machine (e.g. an x86_64 PC board).

QEMU is also capable of providing userspace API virtualization for Linux
and BSD kernel interfaces. This allows binaries compiled against one
architecture ABI (e.g. the Linux PPC64 ABI) to be run on a host using a
different architecture ABI (e.g. the Linux x86_64 ABI). This does not
involve any hardware emulation, simply CPU and syscall emulation.

QEMU aims to fit into a variety of use cases. It can be invoked directly
by users wishing to have full control over its behaviour and settings.
It also aims to facilitate integration into higher level management
layers, by providing a stable command line interface and monitor API.
It is commonly invoked indirectly via the libvirt library when using
open source applications such as oVirt, OpenStack and virt-manager.

QEMU as a whole is released under the GNU General Public License,
version 2. For full licensing details, consult the LICENSE file.


Building
========

QEMU is multi-platform software intended to be buildable on all modern
Linux platforms, OS-X, Win32 (via the Mingw64 toolchain) and a variety
of other UNIX targets. The simple steps to build QEMU are:

  mkdir build
  cd build
  ../configure
  make

Additional information can also be found online via the QEMU website:

  http://qemu-project.org/Hosts/Linux
  http://qemu-project.org/Hosts/W32


Submitting patches
==================

The QEMU source code is maintained under the GIT version control system.

   git clone git://git.qemu-project.org/qemu.git

When submitting patches, the preferred approach is to use 'git
format-patch' and/or 'git send-email' to format & send the mail to the
qemu-devel@nongnu.org mailing list. All patches submitted must contain
a 'Signed-off-by' line from the author. Patches should follow the
guidelines set out in the HACKING and CODING_STYLE files.

Additional information on submitting patches can be found online via
the QEMU website

  http://qemu-project.org/Contribute/SubmitAPatch
  http://qemu-project.org/Contribute/TrivialPatches


Bug reporting
=============

The QEMU project uses Launchpad as its primary upstream bug tracker. Bugs
found when running code built from QEMU git or upstream released sources
should be reported via:

  https://bugs.launchpad.net/qemu/

If using QEMU via an operating system vendor pre-built binary package, it
is preferable to report bugs to the vendor's own bug tracker first. If
the bug is also known to affect latest upstream code, it can also be
reported via launchpad.

For additional information on bug reporting consult:

  http://qemu-project.org/Contribute/ReportABug


Contact
=======

The QEMU community can be contacted in a number of ways, with the two
main methods being email and IRC

 - qemu-devel@nongnu.org
   http://lists.nongnu.org/mailman/listinfo/qemu-devel
 - #qemu on irc.oftc.net

Information on additional methods of contacting the community can be
found online via the QEMU website:

  http://qemu-project.org/Contribute/StartHere

-- End