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Eric Blake a89ef0c357 nbd: don't request FUA on FLUSH
The NBD protocol does not clearly document what will happen
if a client sends NBD_CMD_FLAG_FUA on NBD_CMD_FLUSH.
Historically, both the qemu and upstream NBD servers silently
ignored that flag, but that feels a bit risky.  Meanwhile, the
qemu NBD client unconditionally sends the flag (without even
bothering to check whether the caller cares; at least with
NBD_CMD_WRITE the client only sends FUA if requested by a
higher layer).

There is ongoing discussion on the NBD list to fix the
protocol documentation to require that the server MUST ignore
the flag (unless the kernel folks can better explain what FUA
means for a flush), but until those doc improvements land, the
current nbd.git master was recently changed to reject the flag
with EINVAL (see nbd commit ab22e082), which now makes it
impossible for a qemu client to use FLUSH with an upstream NBD
server.

We should not send FUA with flush unless the upstream protocol
documents what it will do, and even then, it should be something
that the caller can opt into, rather than being unconditional.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1459526902-32561-1-git-send-email-eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-04-05 11:46:52 +02:00
audio util: move declarations out of qemu-common.h 2016-03-22 22:20:17 +01:00
backends Replaced get_tick_per_sec() by NANOSECONDS_PER_SECOND 2016-03-22 22:20:17 +01:00
block nbd: don't request FUA on FLUSH 2016-04-05 11:46:52 +02:00
bsd-user util: move declarations out of qemu-common.h 2016-03-22 22:20:17 +01:00
contrib * Log filtering from Alex and Peter 2016-03-24 21:42:40 +00:00
crypto crypto: do an explicit check for nettle pbkdf functions 2016-03-30 14:55:11 +01:00
default-configs hw/gpio: Add the emulation of gpio_key 2016-03-30 17:27:22 +01:00
disas * Log filtering from Alex and Peter 2016-03-24 21:42:40 +00:00
docs doc/memory: update MMIO section 2016-04-05 11:46:52 +02:00
dtc@65cc4d2748 dtc: Update dtc / libfdt submodule to version 1.4.0 2015-06-03 23:56:49 +02:00
fpu target-tricore: Add FPU infrastructure 2016-03-23 09:22:48 +01:00
fsdev module: Rename machine_init() to opts_init() 2016-03-16 15:54:23 -03:00
gdb-xml target-ppc: gdbstub: Add VSX support 2016-01-30 23:37:38 +11:00
hw block: m25p80: at25128a/at25256a models 2016-03-30 17:27:24 +01:00
include update Linux headers to 4.6 2016-04-05 11:46:52 +02:00
io include/qemu/osdep.h: Don't include qapi/error.h 2016-03-22 22:20:15 +01:00
libdecnumber libdecnumber: Clean up includes 2016-02-16 14:29:27 +00:00
linux-headers update Linux headers to 4.6 2016-04-05 11:46:52 +02:00
linux-user util: move declarations out of qemu-common.h 2016-03-22 22:20:17 +01:00
migration util: move declarations out of qemu-common.h 2016-03-22 22:20:17 +01:00
nbd include/qemu/osdep.h: Don't include qapi/error.h 2016-03-22 22:20:15 +01:00
net Fix ipv6 options according to documentation 2016-03-31 01:08:29 +02:00
pc-bios * Log filtering from Alex and Peter 2016-03-24 21:42:40 +00:00
pixman@87eea99e44 pixman: update internal copy to pixman-0.32.6 2014-09-15 08:14:19 +02:00
po Update language files for QEMU 2.5.0 2015-12-10 13:50:45 +00:00
qapi block: add generic full disk encryption driver 2016-03-30 12:11:26 +02:00
qga * Log filtering from Alex and Peter 2016-03-24 21:42:40 +00:00
qobject util: move declarations out of qemu-common.h 2016-03-22 22:20:17 +01:00
qom util: move declarations out of qemu-common.h 2016-03-22 22:20:17 +01:00
replay replay: introduce block devices record/replay 2016-03-30 12:15:57 +02:00
roms seabios: update to 1.9.1 stable release 2016-03-01 09:37:07 +01:00
scripts checkpatch: add target_ulong to typelist 2016-04-05 11:46:52 +02:00
slirp slirp updates 2016-03-29 18:25:27 +01:00
stubs replay: introduce block devices record/replay 2016-03-30 12:15:57 +02:00
target-alpha include/qemu/osdep.h: Don't include qapi/error.h 2016-03-22 22:20:15 +01:00
target-arm arm: implement query-gic-capabilities 2016-03-30 17:27:24 +01:00
target-cris include/qemu/osdep.h: Don't include qapi/error.h 2016-03-22 22:20:15 +01:00
target-i386 target-i386: assert that KVM_GET/SET_MSRS can set all requested MSRs 2016-04-05 11:46:52 +02:00
target-lm32 include/qemu/osdep.h: Don't include qapi/error.h 2016-03-22 22:20:15 +01:00
target-m68k include/qemu/osdep.h: Don't include qapi/error.h 2016-03-22 22:20:15 +01:00
target-microblaze include/qemu/osdep.h: Don't include qapi/error.h 2016-03-22 22:20:15 +01:00
target-mips target-mips: add MAAR, MAARI register 2016-03-30 09:14:00 +01:00
target-moxie include/qemu/osdep.h: Don't include qapi/error.h 2016-03-22 22:20:15 +01:00
target-openrisc include/qemu/osdep.h: Don't include qapi/error.h 2016-03-22 22:20:15 +01:00
target-ppc * Log filtering from Alex and Peter 2016-03-24 21:42:40 +00:00
target-s390x util: move declarations out of qemu-common.h 2016-03-22 22:20:17 +01:00
target-sh4 include/qemu/osdep.h: Don't include qapi/error.h 2016-03-22 22:20:15 +01:00
target-sparc include/qemu/osdep.h: Don't include qapi/error.h 2016-03-22 22:20:15 +01:00
target-tilegx include/qemu/osdep.h: Don't include qapi/error.h 2016-03-22 22:20:15 +01:00
target-tricore * Log filtering from Alex and Peter 2016-03-24 21:42:40 +00:00
target-unicore32 include/qemu/osdep.h: Don't include qapi/error.h 2016-03-22 22:20:15 +01:00
target-xtensa include/qemu/osdep.h: Don't include qapi/error.h 2016-03-22 22:20:15 +01:00
tcg qemu-log: dfilter-ise exec, out_asm, op and opt_op 2016-03-22 22:20:18 +01:00
tests util: retry getaddrinfo if getting EAI_BADFLAGS with AI_V4MAPPED 2016-04-05 11:46:52 +02:00
trace util: move declarations out of qemu-common.h 2016-03-22 22:20:17 +01:00
ui * Log filtering from Alex and Peter 2016-03-24 21:42:40 +00:00
util util: retry getaddrinfo if getting EAI_BADFLAGS with AI_V4MAPPED 2016-04-05 11:46:52 +02:00
.dir-locals.el Add .dir-locals.el file to configure emacs coding style 2015-10-08 19:46:01 +03:00
.exrc qemu: add .exrc 2012-09-07 09:02:44 +03:00
.gitignore maint: Ignore ivshmem binaries 2015-11-06 15:42:38 +03:00
.gitmodules PPC: Add u-boot firmware for e500 2014-06-16 13:24:35 +02:00
.mailmap Update mailmap 2013-09-05 09:40:31 -05:00
.travis.yml .travis.yml: reduce the test matrix a little 2016-02-08 18:50:25 +00:00
accel.c all: Clean up includes 2016-02-04 17:41:30 +00:00
aio-posix.c aio-posix: Change CONFIG_EPOLL to CONFIG_EPOLL_CREATE1 2016-03-17 09:50:14 +00:00
aio-win32.c all: Clean up includes 2016-02-04 17:41:30 +00:00
arch_init.c util: move declarations out of qemu-common.h 2016-03-22 22:20:17 +01:00
async.c include/qemu/osdep.h: Don't include qapi/error.h 2016-03-22 22:20:15 +01:00
balloon.c all: Clean up includes 2016-02-04 17:41:30 +00:00
block.c block: Remove bdrv_(set_)enable_write_cache() 2016-03-30 12:16:03 +02:00
blockdev-nbd.c nbd: enable use of TLS with nbd-server-start command 2016-02-16 17:17:49 +01:00
blockdev.c block: Remove BDRV_O_CACHE_WB 2016-03-30 12:16:03 +02:00
blockjob.c blockjob: Fix hang in block_job_finish_sync 2016-02-09 13:52:26 +00:00
bootdevice.c include/qemu/osdep.h: Don't include qapi/error.h 2016-03-22 22:20:15 +01:00
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 Use qemu-project.org domain name 2013-10-11 09:34:56 -07:00
CODING_STYLE CODING_STYLE: update mixed declaration rules 2015-09-09 15:34:54 +02:00
configure crypto: do an explicit check for nettle pbkdf functions 2016-03-30 14:55:11 +01:00
COPYING
COPYING.LIB
cpu-exec-common.c exec: Clean up includes 2016-01-29 15:07:22 +00:00
cpu-exec.c qemu-log: dfilter-ise exec, out_asm, op and opt_op 2016-03-22 22:20:18 +01:00
cpus.c Replaced get_tick_per_sec() by NANOSECONDS_PER_SECOND 2016-03-22 22:20:17 +01:00
cputlb.c cputlb: modernise the debug support 2016-03-22 22:20:18 +01:00
device_tree.c include/qemu/osdep.h: Don't include qapi/error.h 2016-03-22 22:20:15 +01:00
device-hotplug.c blockdev: Split monitor reference from BB creation 2016-03-17 15:47:56 +01:00
disas.c all: Clean up includes 2016-02-04 17:41:30 +00:00
dma-helpers.c all: Clean up includes 2016-02-04 17:41:30 +00:00
dump.c util: move declarations out of qemu-common.h 2016-03-22 22:20:17 +01:00
exec.c memory: fix segv on qemu_ram_free(block=0x0) 2016-04-05 11:46:52 +02:00
gdbstub.c util: move declarations out of qemu-common.h 2016-03-22 22:20:17 +01:00
HACKING HACKING: Add a section on error handling and reporting 2016-02-09 13:19:49 +01:00
hmp-commands-info.hx Dump: add hmp command "info dump" 2016-02-22 18:40:28 +01:00
hmp-commands.hx hmp: 'drive_add -n' for creating a node without BB 2016-03-14 16:46:43 +01:00
hmp.c util: move declarations out of qemu-common.h 2016-03-22 22:20:17 +01:00
hmp.h Dump: add hmp command "info dump" 2016-02-22 18:40:28 +01:00
iohandler.c include/qemu/osdep.h: Don't include qapi/error.h 2016-03-22 22:20:15 +01:00
ioport.c all: Clean up includes 2016-02-04 17:41:30 +00:00
iothread.c all: Clean up includes 2016-02-04 17:41:30 +00:00
kvm-all.c kvm: add kvm_device_supported() helper function 2016-03-30 17:27:24 +01:00
kvm-stub.c all: Clean up includes 2016-02-04 17:41:30 +00:00
LICENSE vfio: move hw/misc/vfio.c to hw/vfio/pci.c Move vfio.h into include/hw/vfio 2014-12-19 15:24:06 -07:00
main-loop.c util: move declarations out of qemu-common.h 2016-03-22 22:20:17 +01:00
MAINTAINERS MAINTAINERS: Fix typo, block/stream.h -> block/stream.c 2016-03-16 13:25:29 -04:00
Makefile osdep: add wrappers for socket functions 2016-03-10 17:19:07 +00:00
Makefile.objs crypto: add cryptographic random byte source 2016-03-17 09:49:01 +00:00
Makefile.target io: add abstract QIOChannel classes 2015-12-18 12:18:05 +00:00
memory_mapping.c include/qemu/osdep.h: Don't include qapi/error.h 2016-03-22 22:20:15 +01:00
memory.c include/qemu/osdep.h: Don't include qapi/error.h 2016-03-22 22:20:15 +01:00
module-common.c all: Clean up includes 2016-02-04 17:41:30 +00:00
monitor.c arm: qmp: add query-gic-capabilities interface 2016-03-30 17:27:24 +01:00
numa.c qapi: Don't special-case simple union wrappers 2016-03-18 10:29:26 +01:00
os-posix.c util: move declarations out of qemu-common.h 2016-03-22 22:20:17 +01:00
os-win32.c all: Clean up includes 2016-02-04 17:41:30 +00:00
page_cache.c all: Clean up includes 2016-02-04 17:41:30 +00:00
qapi-schema.json arm: qmp: add query-gic-capabilities interface 2016-03-30 17:27:24 +01:00
qdev-monitor.c util: move declarations out of qemu-common.h 2016-03-22 22:20:17 +01:00
qdict-test-data.txt Introduce QDict test data file 2009-09-04 09:37:34 -05:00
qemu-bridge-helper.c all: Clean up includes 2016-02-04 17:41:30 +00:00
qemu-char.c char: ensure all clients are in non-blocking mode 2016-04-05 11:46:52 +02:00
qemu-doc.texi ivshmem: Require master to have ID zero 2016-03-21 21:29:03 +01:00
qemu-ga.texi docs: Style the command and its options in the synopsis 2016-01-26 15:58:11 +01:00
qemu-img-cmds.hx qemu-img: allow specifying image as a set of options args 2016-02-22 09:50:04 +01:00
qemu-img.c qemu-img: Fix preallocation with -S 0 for convert 2016-03-30 12:16:03 +02:00
qemu-img.texi qemu-img: allow specifying image as a set of options args 2016-02-22 09:50:04 +01:00
qemu-io-cmds.c block: Remove BDRV_O_CACHE_WB 2016-03-30 12:16:03 +02:00
qemu-io.c qemu-io: Call blk_set_enable_write_cache() explicitly 2016-03-30 12:16:01 +02:00
qemu-nbd.c qemu-nbd: Call blk_set_enable_write_cache() explicitly 2016-03-30 12:16:00 +02:00
qemu-nbd.texi qemu-nbd: allow specifying image as a set of options args 2016-02-22 09:50:04 +01:00
qemu-options-wrapper.h vl.c: In qemu -h output, only print options for the arch we are running as 2011-12-19 10:27:33 -06:00
qemu-options.h vl.c: Move option generation logic into a wrapper file 2011-12-19 10:27:33 -06:00
qemu-options.hx net/filter-mirror: implement filter-redirector 2016-03-30 08:57:28 +08:00
qemu-seccomp.c all: Clean up includes 2016-02-04 17:41:30 +00:00
qemu-tech.texi tcg: Rename tcg-target.c to tcg-target.inc.c 2016-02-23 08:30:38 -08:00
qemu-timer.c icount: decouple warp calls 2016-03-15 18:23:45 +01:00
qemu.nsi nsis: Add QEMU version information to Windows registry 2015-09-24 20:52:28 +02:00
qemu.sasl sasl: Avoid 'Could not find keytab file' in syslog 2014-03-15 13:54:18 +04:00
qjson.c all: Clean up includes 2016-02-04 17:41:30 +00:00
qmp-commands.hx arm: qmp: add query-gic-capabilities interface 2016-03-30 17:27:24 +01:00
qmp.c util: move declarations out of qemu-common.h 2016-03-22 22:20:17 +01:00
qtest.c include/qemu/osdep.h: Don't include qapi/error.h 2016-03-22 22:20:15 +01:00
README README: fill out some useful quickstart information 2015-10-13 18:48:46 +02:00
rules.mak rules: filter out irrelevant files 2016-02-17 16:59:36 +02:00
softmmu_template.h exec.c: Pass MemTxAttrs to iotlb_to_region so it uses the right AS 2016-01-21 14:15:05 +00:00
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 all: Clean up includes 2016-02-04 17:41:30 +00:00
thread-pool.c all: Clean up includes 2016-02-04 17:41:30 +00:00
thunk.c all: Clean up includes 2016-02-04 17:41:30 +00:00
tpm.c qapi: Don't special-case simple union wrappers 2016-03-18 10:29:26 +01:00
trace-events hw/intc: Add (new) ASPEED VIC device model 2016-03-16 17:42:18 +00:00
translate-all.c qemu-log: dfilter-ise exec, out_asm, op and opt_op 2016-03-22 22:20:18 +01:00
translate-all.h translate-all: remove unnecessary argument to tb_invalidate_phys_range 2015-06-05 17:09:59 +02:00
translate-common.c exec: Clean up includes 2016-01-29 15:07:22 +00:00
user-exec.c all: Clean up includes 2016-02-04 17:41:30 +00:00
VERSION Update version for v2.6.0-rc0 release 2016-03-30 19:25:40 +01:00
version.rc Use qemu-project.org domain name 2013-10-11 09:34:56 -07:00
vl.c net/filter-mirror: implement filter-redirector 2016-03-30 08:57:28 +08:00
xen-common-stub.c xen: Clean up includes 2016-01-29 15:07:23 +00:00
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: Drop __XEN_LATEST_INTERFACE_VERSION__ checks from prior to Xen 4.2 2016-02-10 12:01:32 +00:00
xen-mapcache.c xen: Clean up includes 2016-01-29 15:07:23 +00:00

         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

Complete details of the process for building and configuring QEMU for
all supported host platforms can be found in the qemu-tech.html file.
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