Misc 2.1 fixes regarding character/serial devices and SCSI.

# gpg: Signature made Mon 14 Jul 2014 16:26:08 BST using RSA key ID 9B4D86F2
# gpg: Can't check signature: public key not found

* remotes/bonzini/tags/for-upstream:
  serial-pci: remove memory regions from BAR before destroying them
  virtio-scsi: fix with -M pc-i440fx-2.0
  serial: change retry logic to avoid concurrency
  qemu-char: fix deadlock with "-monitor pty"
  scsi: Report error when lun number is in use
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Otherwise, hot-unplug of pci-serial-2x trips the assertion
in memory_region_destroy:

    (qemu) device_del gg
    (qemu) qemu-system-x86_64: /work/armbru/tmp/qemu/memory.c:1021: memory_region_destroy: Assertion `((&mr->subregions)->tqh_first == ((void *)0))' failed.
    Aborted (core dumped)
Reported-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Right now starting a machine with virtio-scsi and a <= 2.0 machine type
fails with:

    qemu-system-x86_64: -device virtio-scsi-pci: Property .any_layout not found

This is because the any_layout bit was actually never set after
virtio-scsi was changed to support arbitrary layout for virtio buffers.

(This was just a cleanup and a preparation for virtio 1.0; no guest
actually checks the bit, but the new request parsing algorithms are
tested even with old guest).
Reported-by: NDavid Gilbert <dgilbert@redhat.com>
Reviewed-by: NDavid Gilbert <dgilbert@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Whenever serial_xmit fails to transmit a byte it adds a watch that would
call it again when the "line" becomes ready. This results in a retry
chain:
  serial_xmit -> add_watch -> serial_xmit
Each chain is able to transmit one character, and for every character
passed to serial by the guest driver a new chain is spawned.

The problem lays with the fact that a new chain is spawned even when
there is one already waiting on the watch. So there can be several retry
chains waiting concurrently on one "line". Every chain tries to transmit
current character, so character order is not messed up. But also every
chain increases retry counter (tsr_retry). If there are enough
concurrent chains this counter will hit MAX_XMIT_RETRY value and
the character will be dropped.

To reproduce this bug you need to feed serial output to some program
consuming it slowly enough. A python script from bug #1335444
description is an example of such program.

This commit changes retry logic in the following way to avoid
concurrency: instead of spawning a new chain for each character being
transmitted spawn only one and make it transmit characters until FIFO is
empty.

The change consists of two parts:
 - add a do {} while () loop in serial_xmit (diff is a bit erratic
   for this part, diff -w will show actual change),
 - do not call serial_xmit from serial_ioport_write if there is one
   waiting on the watch already.

This should fix another issue causing bug #1335444.
Signed-off-by: NKirill Batuzov <batuzovk@ispras.ru>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

qemu_chr_be_generic_open cannot be called with the write lock taken,
because it calls client code that may call qemu_chr_fe_write.  This
actually happens for the monitor:

    0x00007ffff27dbf79 in __GI_raise (sig=sig@entry=6)
    0x00007ffff27df388 in __GI_abort ()
    0x00005555555ef489 in error_exit (err=<optimized out>, msg=msg@entry=0x5555559796d0 <__func__.5959> "qemu_mutex_lock")
    0x00005555558f9080 in qemu_mutex_lock (mutex=mutex@entry=0x555556248a30)
    0x0000555555713936 in qemu_chr_fe_write (s=0x555556248a30, buf=buf@entry=0x5555563d8870 "QEMU 2.0.90 monitor - type 'help' for more information\r\n", len=56)
    0x00005555556217fd in monitor_flush_locked (mon=mon@entry=0x555556251fd0)
    0x0000555555621a12 in monitor_flush_locked (mon=0x555556251fd0)
    monitor_puts (mon=mon@entry=0x555556251fd0, str=0x55555634bfa7 "", str@entry=0x55555634bf70 "QEMU 2.0.90 monitor - type 'help' for more information\n")
    0x0000555555624359 in monitor_vprintf (mon=0x555556251fd0, fmt=<optimized out>, ap=<optimized out>)
    0x0000555555624414 in monitor_printf (mon=<optimized out>, fmt=fmt@entry=0x5555559105a0 "QEMU %s monitor - type 'help' for more information\n")
    0x0000555555629806 in monitor_event (opaque=0x555556251fd0, event=<optimized out>)
    0x000055555571343c in qemu_chr_be_generic_open (s=0x555556248a30)

To avoid this, defer the call to an idle callback, which will be
called as soon as the main loop is re-entered.  In order to simplify
the cleanup and do it in one place only, change pty_chr_close to
call pty_chr_state.

To reproduce, run with "-monitor pty", then try to read from the
slave /dev/pts/FOO that it creates.

Fixes: 9005b2a7Reported-by: NLi Liang <liangx.z.li@intel.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Block patches for 2.1.0-rc2 (v2)

# gpg: Signature made Mon 14 Jul 2014 11:04:12 BST using RSA key ID C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"

* remotes/kevin/tags/for-upstream: (22 commits)
  ide: Treat read/write beyond end as invalid
  virtio-blk: Treat read/write beyond end as invalid
  virtio-blk: Bypass error action and I/O accounting on invalid r/w
  virtio-blk: Factor common checks out of virtio_blk_handle_read/write()
  dma-helpers: Fix too long qiov
  qtest: fix vhost-user-test compilation with old GLib
  tests: Fix unterminated string output visitor enum human string
  AioContext: do not rely on aio_poll(ctx, true) result to end a loop
  virtio-blk: embed VirtQueueElement in VirtIOBlockReq
  virtio-blk: avoid g_slice_new0() for VirtIOBlockReq and VirtQueueElement
  dataplane: do not free VirtQueueElement in vring_push()
  virtio-blk: avoid dataplane VirtIOBlockReq early free
  block: Assert qiov length matches request length
  qed: Make qiov match request size until backing file EOF
  qcow2: Make qiov match request size until backing file EOF
  block: Make qiov match the request size until EOF
  AioContext: speed up aio_notify
  test-aio: fix GSource-based timer test
  block: drop aio functions that operate on the main AioContext
  block: prefer aio_poll to qemu_aio_wait
  ...
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

A s390x/kvm bugfix for missing floating point register synchronization.

# gpg: Signature made Mon 14 Jul 2014 08:21:54 BST using RSA key ID C6F02FAF
# gpg: Can't check signature: public key not found

* remotes/cohuck/tags/s390x-20140714:
  s390x/kvm: synchronize guest floating point registers
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

The block layer fails such reads and writes just fine.  However, they
then get treated like valid operations that fail: the error action
gets executed.  Unwanted; reporting the error to the guest is the only
sensible action.

Reject them before passing them to the block layer.  This bypasses the
error action and I/O accounting.  Not quite correct for DMA, because
DMA can fail after some success, and when that happens, the part that
succeeded isn't counted.  Tolerable, because I/O accounting is an
inconsistent mess anyway.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

The block layer fails such reads and writes just fine.  However, they
then get treated like valid operations that fail: the error action
gets executed.  Unwanted; reporting the error to the guest is the only
sensible action.

Reject them before passing them to the block layer.  This bypasses the
error action and I/O accounting.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

When a device model's I/O operation fails, we execute the error
action.  This lets layers above QEMU implement thin provisioning, or
attempt to correct errors before they reach the guest.  But when the
I/O operation fails because it's invalid, reporting the error to the
guest is the only sensible action.

If the guest's read or write asks for an invalid sector range, fail
the request right away, without considering the error action.  No
change with error action BDRV_ACTION_REPORT.

Furthermore, bypass I/O accounting, because we want to track only I/O
that actually reaches the block layer.

The next commit will extend "invalid sector range" to cover attempts
to read/write beyond the end of the medium.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

If the size of the scatter/gather list isn't a multiple of 512, the
number of sectors for the block layer request is rounded down, resulting
in a qiov that doesn't match the request length. Truncate the qiov to the
new length of the request.

This fixes the IDE qtest case /x86_64/ide/bmdma/short_prdt.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

Mising G_TIME_SPAN_SECOND definition breaks the RHEL6 compilation as GLib
version before 2.26 does not have it. In such case just define it.
Reported-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NNikolay Nikolaev <n.nikolaev@virtualopensystems.com>
Tested-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

The buffer was being allocated of size string length plus two.
Around the string two quotes were being added, but no terminating NUL.
It was then compared using g_assert_cmpstr(), resulting in fairly random
assertion failures:

 ERROR:tests/test-string-output-visitor.c:213:test_visitor_out_enum: assertion failed (str == str_human): ("\"value1\"" == "\"value1\"\001EEEEEEEEEEEEEE\0171")

There is no g_assert_cmpnstr() counterpart, so use g_strdup_printf()
for safely assembling the string in the first place.

Cc: Hu Tao <hutao@cn.fujitsu.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Suggested-by: NEric Blake <eblake@redhat.com>
Fixes: b4900c0e tests: add human format test for string output visitor
Signed-off-by: NAndreas Färber <afaerber@suse.de>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Currently, whenever aio_poll(ctx, true) has completed all pending
work it returns true *and* the next call to aio_poll(ctx, true)
will not block.

This invariant has its roots in qemu_aio_flush()'s implementation
as "while (qemu_aio_wait()) {}".  However, qemu_aio_flush() does
not exist anymore and bdrv_drain_all() is implemented differently;
and this invariant is complicated to maintain and subtly different
from the return value of GMainLoop's g_main_context_iteration.

All calls to aio_poll(ctx, true) except one are guarded by a
while() loop checking for a request to be incomplete, or a
BlockDriverState to be idle.  The one remaining call (in
iothread.c) uses this to delay the aio_context_release/acquire
pair until the AioContext is quiescent, however:

- we can do the same just by using non-blocking aio_poll,
  similar to how vl.c invokes main_loop_wait

- it is buggy, because it does not ensure that the AioContext
  is released between an aio_notify and the next time the
  iothread goes to sleep.  This leads to hangs when stopping
  the dataplane thread.

In the end, these semantics are a bad match for the current
users of AioContext.  So modify that one exception in iothread.c,
which also fixes the hangs, as well as the testcase so that
it use the same idiom as the actual QEMU code.
Reported-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Tested-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

The memory allocation between hw/block/virtio-blk.c,
hw/block/dataplane/virtio-blk.c, and hw/virtio/dataplane/vring.c is
messy.  Structs are allocated in different files than they are freed in.
This is risky and makes memory leaks easier.

Embed VirtQueueElement in VirtIOBlockReq to reduce the amount of memory
allocation we need to juggle.  This also makes vring.c and virtio.c
slightly more similar.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

In commit de6c8042 ("virtio-blk: Avoid
zeroing every request structure") we avoided the 40 KB memset when
allocating VirtIOBlockReq.

The memset was reintroduced in commit
671ec3f0 ("virtio-blk: Convert
VirtIOBlockReq.elem to pointer").

It must be fixed again to avoid a performance regression.

Cc: Fam Zheng <famz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

VirtQueueElement is allocated in vring_pop() so it seems to make sense
that vring_push() should free it.  Alas, virtio-blk frees
VirtQueueElement itself in virtio_blk_free_request().

This patch solves a double-free assertion in glib's g_slice_free().

Rename vring_free_element() to vring_unmap_element() since it no longer
frees the VirtQueueElement.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Tested-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

VirtIOBlockReq is freed later by virtio_blk_free_request() in
hw/block/virtio-blk.c.  Remove this extraneous g_slice_free().

This patch fixes the following segfault:

  0x00005555556373af in virtio_blk_rw_complete (opaque=0x5555565ff5e0, ret=0) at hw/block/virtio-blk.c:99
  99          bdrv_acct_done(req->dev->bs, &req->acct);
  (gdb) print req
  $1 = (VirtIOBlockReq *) 0x5555565ff5e0
  (gdb) print req->dev
  $2 = (VirtIOBlock *) 0x0
  (gdb) bt
  #0  0x00005555556373af in virtio_blk_rw_complete (opaque=0x5555565ff5e0, ret=0) at hw/block/virtio-blk.c:99
  #1  0x0000555555840ebe in bdrv_co_em_bh (opaque=0x5555566152d0) at block.c:4675
  #2  0x000055555583de77 in aio_bh_poll (ctx=ctx@entry=0x5555563a8150) at async.c:81
  #3  0x000055555584b7a7 in aio_poll (ctx=0x5555563a8150, blocking=blocking@entry=true) at aio-posix.c:188
  #4  0x00005555556e520e in iothread_run (opaque=0x5555563a7fd8) at iothread.c:41
  #5  0x00007ffff42ba124 in start_thread () from /usr/lib/libpthread.so.0
  #6  0x00007ffff16d14bd in clone () from /usr/lib/libc.so.6
Reported-by: NMax Reitz <mreitz@redhat.com>
Cc: Fam Zheng <famz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Tested-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

At least raw-posix relies on this because it can allocate bounce buffers
based on the request length, but access it using all of the qiov entries
later.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>

If a QED image has a shorter backing file and a read request to
unallocated clusters goes across EOF of the backing file, the backing
file sees a shortened request and the rest is filled with zeros.
However, the original too long qiov was used with the shortened request.

This patch makes the qiov size match the request size, avoiding a
potential buffer overflow in raw-posix.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

If a qcow2 image has a shorter backing file and a read request to
unallocated clusters goes across EOF of the backing file, the backing
file sees a shortened request and the rest is filled with zeros.
However, the original too long qiov was used with the shortened request.

This patch makes the qiov size match the request size, avoiding a
potential buffer overflow in raw-posix.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>

If a read request goes across EOF, the block driver sees a shortened
request that stops at EOF (the rest is memsetted in block.c), however
the original qiov was used for this request.

This patch makes the qiov size match the request size, avoiding a
potential buffer overflow in raw-posix.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>

In the case that the lun number is taken by another scsi device, don't
release the existing device siliently, but report an error to user.
Signed-off-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Add code to kvm_arch_get_registers and kvm_arch_put_registers to
save/restore floating point registers. This missing sync was
unnoticed until migration of userspace that uses fprs.
Signed-off-by: NJason J. Herne <jjherne@us.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
[Update patch to latest upstream]
Cc: qemu-stable@nongnu.org
Reviewed-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>

vga: some cirrus fixes.

# gpg: Signature made Fri 11 Jul 2014 10:38:32 BST using RSA key ID D3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>"
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>"
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>"

* remotes/kraxel/tags/pull-vga-20140711-1:
  cirrus: Fix host CPU blits
  cirrus: Fix build of debug code
  cirrus_vga: adding sanity check for vram size
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

mtp: linux guest detection fix

# gpg: Signature made Fri 11 Jul 2014 11:32:20 BST using RSA key ID D3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>"
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>"
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>"

* remotes/kraxel/tags/pull-usb-20140711-1:
  mtp: linux guest detection fix.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

spice: auth fixes

# gpg: Signature made Fri 11 Jul 2014 10:17:15 BST using RSA key ID D3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>"
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>"
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>"

* remotes/spice/tags/pull-spice-20140711-1:
  spice: auth fixes
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

ui/gtk: Restore keyboard focus after Page change

# gpg: Signature made Fri 11 Jul 2014 09:46:21 BST using RSA key ID D3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>"
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>"
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>"

* remotes/kraxel/tags/pull-gtk-20140711-1:
  ui/gtk: Restore keyboard focus after Page change
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Attach a name to the MTP interface (android phones have this too).

With this patch recent linux guests such as fedora 20 happily detect and
use the device.  It shows up in nautilus file manager automatically, and
simple-mtpfs can mount it.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

(Resending for correct email addresses via MAINTAINERS ...)

In the GTK UI, after changing focus to the qemu monitor Notebook Page,
when restoring focus to the virtual machine page, the keyboard focus is lost
to a hidden GTK widget. Focus can only be restored to the virtual machine by
pressing "tab" or any of the four directional arrow keys.

Clicking in the window or grabbing/ungrabbing input does not restore keyboard
focus to the child widget.

This patch adjusts the Notebook page switching callback to automatically
steal keyboard focus on the Page switch event, so that keyboard input
does not appear to break or disappear after tabbing to the QEMU monitor.
Signed-off-by: NJohn Snow <jsnow@redhat.com>
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

Commit b2eb849d
"CVE-2007-1320 - Cirrus LGD-54XX "bitblt" heap overflow" broke
cpu to video blits.

When the ROP function is called from cirrus_bitblt_cputovideo_next(),
we pass 0 for the pitch but only operate on one line at a time. The
added test was tripping because after the initial substraction, the
pitch becomes negative. Make the test only trip when the height is
larger than one (ie. the pitch is actually used).

This fixes HW cursor support in Windows NT4.0 (which otherwise was
a white rectangle) and general display of icons in that OS when using
8bpp mode.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

Use PRIu64 to print uint64_t
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

when configure a invalid vram size for cirrus card, such as less
2 MB, which will crash qemu. Follow the real hardware, the cirrus
card has 4 MB video memory. Also for backward compatibility, accept
8 MB and 16 MB vram size.
Signed-off-by: NGonglei <arei.gonglei@huawei.com>
Reviewed-by: NAndreas Färber <afaerber@suse.de>
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

Set auth to sasl when sasl is enabled, this makes "info spice" correctly
display sasl auth.  Also throw an error in case someone tries to set
a spice password via monitor without auth mode being "spice".
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

* remotes/kvm/uq/master:
  qtest: fix vhost-user-test compilation with old GLib
  mc146818rtc: register the clock reset notifier on the right clock
  oslib-posix: Fix new compiler error with -Wclobbered
  target-i386: Add "kvmclock-stable-bit" feature bit name
  Enforce stack protector usage
  watchdog: fix deadlock with -watchdog-action pause
  mips_malta: Catch kernels linked at wrong address
  mips_malta: Remove incorrect KVM T&E references
  mips/kvm: Disable FPU on reset with KVM
  mips/kvm: Init EBase to correct KSEG0
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Mising G_TIME_SPAN_SECOND definition breaks the RHEL6 compilation as GLib
version before 2.26 does not have it. In such case just define it.
Reported-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NNikolay Nikolaev <n.nikolaev@virtualopensystems.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Commit 884f17c2 (aio / timers: Convert rtc_clock to be a QEMUClockType,
2013-08-21) erroneously changed an occurrence of rtc_clock to
QEMU_CLOCK_REALTIME, which broke the RTC reset notifier in
mc146818rtc.  Fix this.

I redid the patch myself since the original reporter did not sign
off on his.

Cc: qemu-stable@nongnu.org
Reported-by: NLb peace <peaceustc@gmail.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Newer versions of gcc report a warning (or an error with -Werror) when
compiler option -Wclobbered (or -Wextra) is active:

util/oslib-posix.c:372:12: error:
 variable ‘hpagesize’ might be clobbered by ‘longjmp’ or ‘vfork’ [-Werror=clobbered]

The rewritten code fixes this warning: variable 'hpagesize' is now set and
used in a block without any call of sigsetjmp or similar functions.
Signed-off-by: NStefan Weil <sw@weilnetz.de>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

KVM_FEATURE_CLOCKSOURCE_STABLE_BIT is enabled by default and supported
by KVM. But not having a name defined makes QEMU treat it as an unknown
and unmigratable feature flag (as any unknown feature may possibly
require state to be migrated), and disable it by default on "-cpu host".

As a side-effect, the new name also makes the flag configurable,
allowing the user to disable it (which may be useful for testing or for
compatibility with old kernels).
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>