QEMU With E2K User Support
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Jose Ricardo Ziviani b12a4efb76 Fix a deadlock case in the CPU hotplug flow
We need to set cs->halted to 1 before calling ppc_set_compat. The reason
is that ppc_set_compat kicks up the new thread created to manage the
hotplugged KVM virtual CPU and the code drives directly to KVM_RUN
ioctl. When cs->halted is 1, the code:

int kvm_cpu_exec(CPUState *cpu)
...
     if (kvm_arch_process_async_events(cpu)) {
         atomic_set(&cpu->exit_request, 0);
         return EXCP_HLT;
     }
...

returns before it reaches KVM_RUN, giving time to the main thread to
finish its job. Otherwise we can fall in a deadlock because the KVM
thread will issue the KVM_RUN ioctl while the main thread is setting up
KVM registers. Depending on how these jobs are scheduled we'll end up
freezing QEMU.

The following output shows kvm_vcpu_ioctl sleeping because it cannot get
the mutex and never will.
PS: kvm_vcpu_ioctl was triggered kvm_set_one_reg - compat_pvr.

STATE: TASK_UNINTERRUPTIBLE|TASK_WAKEKILL

PID: 61564  TASK: c000003e981e0780  CPU: 48  COMMAND: "qemu-system-ppc"
 #0 [c000003e982679a0] __schedule at c000000000b10a44
 #1 [c000003e98267a60] schedule at c000000000b113a8
 #2 [c000003e98267a90] schedule_preempt_disabled at c000000000b11910
 #3 [c000003e98267ab0] __mutex_lock at c000000000b132ec
 #4 [c000003e98267bc0] kvm_vcpu_ioctl at c00800000ea03140 [kvm]
 #5 [c000003e98267d20] do_vfs_ioctl at c000000000407d30
 #6 [c000003e98267dc0] ksys_ioctl at c000000000408674
 #7 [c000003e98267e10] sys_ioctl at c0000000004086f8
 #8 [c000003e98267e30] system_call at c00000000000b488

crash> struct -x kvm.vcpus 0xc000003da0000000
vcpus = {0xc000003db4880000, 0xc000003d52b80000, 0xc0000039e9c80000, 0xc000003d0e200000, 0xc000003d58280000, 0x0, 0x0, ...}

crash> struct -x kvm_vcpu.mutex.owner 0xc000003d58280000
  mutex.owner = {
    counter = 0xc000003a23a5c881 <- flag 1: waiters
  },

crash> bt 0xc000003a23a5c880
PID: 61579  TASK: c000003a23a5c880  CPU: 9   COMMAND: "CPU 4/KVM"
(active)

crash> struct -x kvm_vcpu.mutex.wait_list 0xc000003d58280000
  mutex.wait_list = {
    next = 0xc000003e98267b10,
    prev = 0xc000003e98267b10
  },

crash> struct -x mutex_waiter.task 0xc000003e98267b10
  task = 0xc000003e981e0780

The following command-line was used to reproduce the problem (note: gdb
and trace can change the results).

 $ qemu-ppc/build/ppc64-softmmu/qemu-system-ppc64 -cpu host \
     -enable-kvm -m 4096 \
     -smp 4,maxcpus=8,sockets=1,cores=2,threads=4 \
     -display none -nographic \
     -drive file=disk1.qcow2,format=qcow2
 ...
 (qemu) device_add host-spapr-cpu-core,core-id=4
[no interaction is possible after it, only SIGKILL to take the terminal
back]

Signed-off-by: Jose Ricardo Ziviani <joserz@linux.ibm.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-09-03 11:46:43 +10:00
accel KVM: cleanup unnecessary #ifdef KVM_CAP_... 2018-08-23 18:46:25 +02:00
audio audio: add audio timer trace points 2018-07-03 11:46:47 +02:00
backends hostmem-file: add the 'pmem' option 2018-08-10 13:29:39 +03:00
block Block layer patches: 2018-08-15 22:11:08 +01:00
bsd-user bsd-user: Use the IEC binary prefix definitions 2018-07-02 15:41:18 +02:00
capstone@22ead3e0bf
chardev qemu-char: check errno together with ret < 0 2018-07-06 18:39:19 +02:00
contrib vhost-blk: turn on pre-defined RO feature bit 2018-06-01 19:20:38 +03:00
crypto crypto: Implement TLS Pre-Shared Keys (PSK). 2018-07-03 13:04:38 +01:00
default-configs ppc: Remove deprecated ppcemb target 2018-08-28 11:31:23 +10:00
disas fix "Missing break in switch" coverity reports 2018-08-23 13:32:50 +02:00
docs QObject patches for 2018-08-24 2018-08-25 10:11:54 +01:00
dtc@e54388015a
fpu softfloat: Add scaling float-to-int routines 2018-08-24 13:17:30 +01:00
fsdev fsdev: fix compilation with VIRTIO but not VIRTIO_9P 2018-08-22 12:21:13 +02:00
gdb-xml
hw Fix a deadlock case in the CPU hotplug flow 2018-09-03 11:46:43 +10:00
include uninorth: add ofw-addr property to allow correct fw path generation 2018-08-30 10:42:18 +10:00
io Delete AF_UNIX socket after close 2018-06-28 13:36:59 +01:00
libdecnumber
linux-headers linux-headers: update 2018-08-20 14:18:49 +02:00
linux-user elf: Don't check FCR31_NAN2008 bit for nanoMIPS 2018-08-24 17:51:59 +02:00
migration VFIO fixes 2018-08-23 2018-08-25 10:59:06 +01:00
nbd nbd/server: fix nbd_co_send_block_status 2018-07-07 20:30:09 -05:00
net tap: fix memory leak on success to create a tap device 2018-07-20 08:30:49 +08:00
pc-bios * x86 TCG fixes for 64-bit call gates (Andrew) 2018-08-23 19:03:54 +01:00
po po: Don't include comments with location 2018-07-23 10:50:54 +01:00
qapi ppc: Remove deprecated ppcemb target 2018-08-28 11:31:23 +10:00
qga json: Clean up headers 2018-08-24 20:26:37 +02:00
qobject json: Update references to RFC 7159 to RFC 8259 2018-08-24 20:27:14 +02:00
qom qom/object: Add a new function object_initialize_child() 2018-07-17 13:12:49 +01:00
replay
roms pseries: Update SLOF firmware image 2018-08-21 14:28:45 +10:00
scripts qemu-guest-agent: freeze-hook to ignore dpkg files as well 2018-08-23 18:46:25 +02:00
scsi qemu-pr-helper: Fix build on CentOS 7 2018-08-23 13:32:50 +02:00
slirp slirp: Correct size check in m_inc() 2018-08-07 14:13:22 +01:00
stubs qsp: track BQL callers explicitly 2018-08-23 18:46:25 +02:00
target ppc: Remove deprecated ppcemb target 2018-08-28 11:31:23 +10:00
tcg tcg/optimize: Do not skip default processing of dup_vec 2018-08-06 14:57:48 +01:00
tests ppc: Remove deprecated ppcemb target 2018-08-28 11:31:23 +10:00
trace tracing: Use double-dash spelling for trace option 2018-07-19 13:09:04 +01:00
ui util: promote qemu_egl_rendernode_open() to libqemuutil 2018-08-27 10:51:44 +02:00
util ui: misc fixes which piled up during 3.0 release freeze 2018-08-27 12:30:51 +01:00
.dir-locals.el
.editorconfig
.exrc
.gdbinit
.gitignore .gitignore: add .gcov files 2018-07-05 15:59:41 +01:00
.gitmodules vgabios: remove submodule and build rules. 2018-07-02 17:20:54 +02:00
.gitpublish
.mailmap MAINTAINERS: Update target/mips maintainer's email addresses 2018-08-16 19:18:45 +02:00
.shippable.yml shippable: Remove Debian 8 libfdt kludge 2018-05-11 14:33:40 +02:00
.travis.yml travis: add gcovr summary for GCOV build 2018-07-05 15:59:41 +01:00
arch_init.c arch_init: sort architectures 2018-06-01 19:20:38 +03:00
balloon.c balloon: Allow multiple inhibit users 2018-08-17 09:27:15 -06:00
block.c qjson: Have qobject_from_json() & friends reject empty and blank 2018-08-24 20:26:37 +02:00
blockdev-nbd.c qapi: new qmp command nbd-server-add-bitmap 2018-06-21 09:23:59 -05:00
blockdev.c block: Remove dead deprecation warning code 2018-08-15 12:50:39 +02:00
blockjob.c block: Really pause block jobs on drain 2018-06-18 15:03:25 +02:00
bootdevice.c fw_cfg: ignore suffixes in the bootdevice list dependent on machine class 2018-08-16 22:27:43 -03:00
bt-host.c
bt-vhci.c
Changelog
CODING_STYLE CODING_STYLE: Define our preferred form for multiline comments 2018-06-15 15:23:34 +01:00
configure ppc: Remove deprecated ppcemb target 2018-08-28 11:31:23 +10:00
COPYING
COPYING.LIB
cpus-common.c qom: convert the CPU list to RCU 2018-08-23 18:46:25 +02:00
cpus.c ppc: Remove deprecated ppcemb target 2018-08-28 11:31:23 +10:00
device_tree.c device_tree: Add qemu_fdt_node_unit_path 2018-06-29 15:11:01 +01:00
device-hotplug.c block: Remove deprecated -drive option addr 2018-08-15 12:50:39 +02:00
disas.c
dma-helpers.c
dump.c fw_cfg: import & use linux/qemu_fw_cfg.h 2018-08-23 18:46:25 +02:00
exec.c pc: fixes 2018-08-21 10:23:53 +01:00
gdbstub.c gdbstub: Prevent fd leakage 2018-06-01 15:14:31 +02:00
HACKING HACKING: document preference for g_new instead of g_malloc 2018-05-20 08:32:09 +03:00
hmp-commands-info.hx hmp-commands-info: add sync-profile 2018-08-23 18:46:25 +02:00
hmp-commands.hx hmp-commands: add sync-profile 2018-08-23 18:46:25 +02:00
hmp.c migration/next for 20180822 2018-08-24 16:31:53 +01:00
hmp.h hmp-commands: add sync-profile 2018-08-23 18:46:25 +02:00
ioport.c
iothread.c
job-qmp.c job: Add error message for failing jobs 2018-05-30 13:31:01 +02:00
job.c block: for jobs, do not clear user_paused until after the resume 2018-08-21 14:59:30 -04:00
LICENSE
MAINTAINERS ui: misc fixes which piled up during 3.0 release freeze 2018-08-27 12:30:51 +01:00
Makefile configure: We don't want to clean configuration files 2018-08-27 11:27:06 +02:00
Makefile.objs hw/watchdog/cmsdk_apb_watchdog: Implement CMSDK APB watchdog module 2018-08-20 11:24:33 +01:00
Makefile.target dump: add Windows dump format to dump-guest-memory 2018-06-29 13:02:48 +02:00
memory_ldst.inc.c exec: Fix MAP_RAM for cached access 2018-06-28 19:05:30 +02:00
memory_mapping.c
memory.c pc: fixes 2018-08-21 10:23:53 +01:00
module-common.c
monitor.c json: Clean up headers 2018-08-24 20:26:37 +02:00
numa.c memory, exec: switch file ram allocation functions to 'flags' parameters 2018-08-10 13:29:39 +03:00
os-posix.c qemu-options: Bail out on unsupported options instead of silently ignoring them 2018-05-09 00:13:39 +02:00
os-win32.c qemu-options: Bail out on unsupported options instead of silently ignoring them 2018-05-09 00:13:39 +02:00
qdev-monitor.c
qdict-test-data.txt
qemu-bridge-helper.c
qemu-deprecated.texi ppc: Remove deprecated ppcemb target 2018-08-28 11:31:23 +10:00
qemu-doc.texi doc: switch to modern syntax for VNC TLS setup 2018-08-24 08:40:11 +02:00
qemu-ga.texi
qemu-img-cmds.hx qemu-img: Add -C option for convert with copy offloading 2018-07-30 15:35:37 +02:00
qemu-img.c qemu-img: fix regression copying secrets during convert 2018-08-15 12:50:39 +02:00
qemu-img.texi qemu-img: Add -C option for convert with copy offloading 2018-07-30 15:35:37 +02:00
qemu-io-cmds.c qemu-io: Let command functions return error code 2018-06-11 16:18:45 +02:00
qemu-io.c qemu-io: Exit with error when a command failed 2018-06-11 16:18:45 +02:00
qemu-keymap.c ui: use enum to string helpers 2018-08-24 08:40:10 +02:00
qemu-nbd.c block: Cancel job in bdrv_close_all() callers 2018-05-23 14:30:51 +02:00
qemu-nbd.texi
qemu-option-trace.texi qemu-option-trace: -trace enable= is a pattern, not a file 2018-05-20 08:29:01 +03:00
qemu-options-wrapper.h qemu-img: remove references to GEN_DOCS 2018-05-20 08:35:54 +03:00
qemu-options.h
qemu-options.hx ui: misc fixes which piled up during 3.0 release freeze 2018-08-27 12:30:51 +01:00
qemu-seccomp.c seccomp: set the seccomp filter to all threads 2018-08-23 16:45:44 +02:00
qemu-tech.texi cli qmp: Mark --preconfig, exit-preconfig experimental 2018-07-16 15:38:19 +02:00
qemu.nsi
qemu.sasl
qmp.c cli qmp: Mark --preconfig, exit-preconfig experimental 2018-07-16 15:38:19 +02:00
qtest.c qtest: Use cpu address space instead of system memory 2018-07-06 18:39:19 +02:00
README
replication.c
replication.h
rules.mak tests/docker/Makefile.include: handle empty TARGET_LIST 2018-06-04 14:39:18 +08:00
thunk.c
tpm.c
trace-events job: Add lifecycle QMP commands 2018-05-23 14:30:51 +02:00
VERSION Open 3.1 development tree 2018-08-14 17:10:49 +01:00
version.rc
vl.c kvm: add call to qemu_add_opts() for -overcommit option 2018-08-23 18:46:25 +02:00
win_dump.c dump: add Windows live system dump 2018-06-29 13:02:50 +02:00
win_dump.h dump: add Windows live system dump 2018-06-29 13:02:50 +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:

  https://qemu.org/Hosts/Linux
  https://qemu.org/Hosts/Mac
  https://qemu.org/Hosts/W32


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

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

   git clone git://git.qemu.org/qemu.git

When submitting patches, one common 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

  https://qemu.org/Contribute/SubmitAPatch
  https://qemu.org/Contribute/TrivialPatches

The QEMU website is also maintained under source control.

  git clone git://git.qemu.org/qemu-web.git
  https://www.qemu.org/2017/02/04/the-new-qemu-website-is-up/

A 'git-publish' utility was created to make above process less
cumbersome, and is highly recommended for making regular contributions,
or even just for sending consecutive patch series revisions. It also
requires a working 'git send-email' setup, and by default doesn't
automate everything, so you may want to go through the above steps
manually for once.

For installation instructions, please go to

  https://github.com/stefanha/git-publish

The workflow with 'git-publish' is:

  $ git checkout master -b my-feature
  $ # work on new commits, add your 'Signed-off-by' lines to each
  $ git publish

Your patch series will be sent and tagged as my-feature-v1 if you need to refer
back to it in the future.

Sending v2:

  $ git checkout my-feature # same topic branch
  $ # making changes to the commits (using 'git rebase', for example)
  $ git publish

Your patch series will be sent with 'v2' tag in the subject and the git tip
will be tagged as my-feature-v2.

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:

  https://qemu.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
   https://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:

  https://qemu.org/Contribute/StartHere

-- End