I accidentally tried --with-sdlabi="1.0", and it failed much later in
a weird way. Instead, throw an error if the value isn't in our
whitelist.
Signed-off-by: NCole Robinson <crobinso@redhat.com>
Message-id: 60e4822e17697d257a914df03bdb9fff4b4c0490.1462557436.git.crobinso@redhat.com
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

Right now if SDL2 is installed but not SDL1, default configure will
entirely disable SDL. Check upfront for SDL2 using pkg-config, but
still prefer SDL1 if both versions are installed.
Signed-off-by: NCole Robinson <crobinso@redhat.com>
Message-id: c9e570b5964d128a3595efe3170129a3da459776.1462557436.git.crobinso@redhat.com
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

sdl 2.0.4 currently has a bug which causes our UI shortcuts to fire
rapidly in succession:

  https://bugzilla.libsdl.org/show_bug.cgi?id=3287

It's a toss up whether ctrl+alt+f or ctrl+alt+2 will fire an
odd or even number of times, thus determining whether the action
succeeds or fails.

Opening monitor/serial windows is doubly broken, since it will often
lock the UI trying to grab the pointer:

  0x00007fffef3720a5 in SDL_Delay_REAL () at /lib64/libSDL2-2.0.so.0
  0x00007fffef3688ba in X11_SetWindowGrab () at /lib64/libSDL2-2.0.so.0
  0x00007fffef2f2da7 in SDL_SendWindowEvent () at /lib64/libSDL2-2.0.so.0
  0x00007fffef2f080b in SDL_SetKeyboardFocus () at /lib64/libSDL2-2.0.so.0
  0x00007fffef35d784 in X11_DispatchFocusIn.isra.8 () at /lib64/libSDL2-2.0.so.0
  0x00007fffef35dbce in X11_DispatchEvent () at /lib64/libSDL2-2.0.so.0
  0x00007fffef35ee4a in X11_PumpEvents () at /lib64/libSDL2-2.0.so.0
  0x00007fffef2eea6a in SDL_PumpEvents_REAL () at /lib64/libSDL2-2.0.so.0
  0x00007fffef2eeab5 in SDL_WaitEventTimeout_REAL () at /lib64/libSDL2-2.0.so.0
  0x000055555597eed0 in sdl2_poll_events (scon=0x55555876f928) at ui/sdl2.c:593

We can work around that hang by ungrabbing the pointer before launching
a new window. This roughly matches what our sdl1 code does
Signed-off-by: NCole Robinson <crobinso@redhat.com>
Message-id: 31c9ab6540b031f7a614c59edcecea9877685612.1462557436.git.crobinso@redhat.com
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

VTE terminal inner-border can be NULL. The vte-0.36 (API 2.90)
code checks for the condition too so I assume it's not just a bug

Fixes a crash on Fedora 24 with gtk 3.20
Signed-off-by: NCole Robinson <crobinso@redhat.com>
Message-id: 2b2e85d403e8760ea53afd735a170500d5c17716.1462557436.git.crobinso@redhat.com
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

vga security fixes (CVE-2016-3710, CVE-2016-3712)

# gpg: Signature made Mon 09 May 2016 13:39:30 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-20160509-1:
  vga: make sure vga register setup for vbe stays intact (CVE-2016-3712).
  vga: update vga register setup on vbe changes
  vga: factor out vga register setup
  vga: add vbe_enabled() helper
  vga: fix banked access bounds checking (CVE-2016-3710)
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

This reverts commit 7070e085.

Commit message claims locking is not needed, but that appears
to not be true, seabios ehci driver runs into timekeeping problems
with this, see
	https://bugzilla.redhat.com/show_bug.cgi?id=1322713Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
Message-id: 1460702609-25971-1-git-send-email-kraxel@redhat.com
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Call vbe_update_vgaregs() when the guest touches GFX, SEQ or CRT
registers, to make sure the vga registers will always have the
values needed by vbe mode.  This makes sure the sanity checks
applied by vbe_fixup_regs() are effective.

Without this guests can muck with shift_control, can turn on planar
vga modes or text mode emulation while VBE is active, making qemu
take code paths meant for CGA compatibility, but with the very
large display widths and heigts settable using VBE registers.

Which is good for one or another buffer overflow.  Not that
critical as they typically read overflows happening somewhere
in the display code.  So guests can DoS by crashing qemu with a
segfault, but it is probably not possible to break out of the VM.

Fixes: CVE-2016-3712
Reported-by: NZuozhi Fzz <zuozhi.fzz@alibaba-inc.com>
Reported-by: NP J P <ppandit@redhat.com>
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

Call the new vbe_update_vgaregs() function on vbe configuration
changes, to make sure vga registers are up-to-date.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

When enabling vbe mode qemu will setup a bunch of vga registers to make
sure the vga emulation operates in correct mode for a linear
framebuffer.  Move that code to a separate function so we can call it
from other places too.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

Makes code a bit easier to read.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

vga allows banked access to video memory using the window at 0xa00000
and it supports a different access modes with different address
calculations.

The VBE bochs extentions support banked access too, using the
VBE_DISPI_INDEX_BANK register.  The code tries to take the different
address calculations into account and applies different limits to
VBE_DISPI_INDEX_BANK depending on the current access mode.

Which is probably effective in stopping misprogramming by accident.
But from a security point of view completely useless as an attacker
can easily change access modes after setting the bank register.

Drop the bogus check, add range checks to vga_mem_{readb,writeb}
instead.

Fixes: CVE-2016-3710
Reported-by: NQinghao Tang <luodalongde@gmail.com>
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

Fixes build failure with --enable-xfsctl and
new linux headers (>=4.5) and older xfsprogs(<4.5):
In file included from /usr/include/xfs/xfs.h:38:0,
                 from /var/tmp/portage/app-emulation/qemu-2.5.0-r1/work/qemu-2.5.0/block/raw-posix.c:97:
/usr/include/xfs/xfs_fs.h:42:8: error: redefinition of ‘struct fsxattr’
 struct fsxattr {
        ^
In file included from /var/tmp/portage/app-emulation/qemu-2.5.0-r1/work/qemu-2.5.0/block/raw-posix.c:60:0:
/usr/include/linux/fs.h:155:8: note: originally defined here
 struct fsxattr {

This is really a bug in the system headers, but we can work around it
by defining HAVE_FSXATTR in the QEMU headers if linux/fs.h provides
the struct, so that xfs_fs.h doesn't try to define it as well.

CC: qemu-trivial@nongnu.org
CC: Markus Armbruster <armbru@redhat.com>
CC: Peter Maydell <peter.maydell@linaro.org>
CC: Stefan Weil <sw@weilnetz.de>
Tested-by: NStefan Weil <sw@weilnetz.de>
Signed-off-by: NJan Vesely <jano.vesely@gmail.com>
[PMM: adjusted commit message, comments]
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

acpi: last minute fix for 2.6

Minor, obvious fix only affecting BE hosts.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

# gpg: Signature made Sun 01 May 2016 13:43:28 BST using RSA key ID D28D5469
# gpg: Good signature from "Michael S. Tsirkin <mst@kernel.org>"
# gpg:                 aka "Michael S. Tsirkin <mst@redhat.com>"

* remotes/mst/tags/for_upstream:
  acpi: fix bios linker loadder COMMAND_ALLOCATE on bigendian host
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

'make check' fails with:

ERROR:tests/bios-tables-test.c:493:load_expected_aml:
   assertion failed: (g_file_test(aml_file, G_FILE_TEST_EXISTS))

since commit:
caf50c71
tests: pc: acpi: drop not needed 'expected SSDT' blobs

Assert happens because qemu-system-x86_64 generates
SSDT table and test looks for a corresponding expected
table to compare with.

However there is no expected SSDT blob anymore, since
QEMU souldn't generate one. As it happens BIOS is not
able to read ACPI tables from QEMU and fallbacks to
embeded legacy ACPI codepath, which generates SSDT.
That happens due to wrongly sized endiannes conversion
which makes
 uint8_t BiosLinkerLoaderEntry.alloc.zone
end up with 0 due to truncation of 32 bit integer
which on host is 1 or 2.

Fix it by dropping invalid cpu_to_le32() as uint8_t
doesn't require any conversion.

RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1330174Signed-off-by: NIgor Mammedov <imammedo@redhat.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Tested-by: NLaurent Vivier <lvivier@redhat.com>
Reviewed-by: NMarcel Apfelbaum <marcel@redhat.com>

vvfat fixes for 2.6.0-rc4

# gpg: Signature made Fri 29 Apr 2016 10:52:13 BST using RSA key ID C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"

* remotes/kevin/tags/for-upstream:
  vvfat: Fix default volume label
  vvfat: Fix volume name assertion
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

QAPI patches for 2016-04-29

# gpg: Signature made Fri 29 Apr 2016 10:13:08 BST 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-qapi-2016-04-29:
  qapi: Don't pass NULL to printf in string input visitor
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Commit d5941dda documented that it leaves the default volume name as it
was ("QEMU VVFAT"), but it doesn't actually implement this. You get an
empty name (eleven space characters) instead.

This fixes the implementation to apply the advertised default.

Cc: qemu-stable@nongnu.org
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>

Commit d5941dda made the volume name configurable, but it didn't consider
that the rw code compares the volume name string to assert that the
first directory entry is the volume name. This made vvfat crash in rw
mode.

This fixes the assertion to compare with the configured volume name
instead of a literal string.

Cc: qemu-stable@nongnu.org
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>

Make sure the error message for visit_type_uint64() gracefully
handles a NULL 'name' when called from the top level or a list
context, as not all the world behaves like glibc in allowing
NULL through a printf-family %s.
Signed-off-by: NEric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-21-git-send-email-eblake@redhat.com>
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>

On Darwin, connect, sendto and friends want the exact size of the sockaddr,
not more (and in particular, not sizeof(struct sockaddr_storaget))

This commit adds the sockaddr_size helper to be used when passing a sockaddr
size to such function, and makes use of it int sendto and connect calls.
Signed-off-by: NSamuel Thibault <samuel.thibault@ens-lyon.org>
Reviewed-by: NJohn Arbuckle <programmingkidx@gmail.com>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

MIPS patches 2016-04-28

Changes:
* fixed RDHWR exception host PC

# gpg: Signature made Thu 28 Apr 2016 10:11:18 BST using RSA key ID 0B29DA6B
# gpg: Good signature from "Leon Alrae <leon.alrae@imgtec.com>"

* remotes/lalrae/tags/mips-20160428:
  target-mips: Fix RDHWR exception host PC
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Fix dangling pointers and error message regressions

# gpg: Signature made Thu 28 Apr 2016 07:25:51 BST 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-2016-04-28:
  qom: -object error messages lost location, restore it
  replay: Fix dangling location bug in replay_configure()
  QemuOpts: Fix qemu_opts_foreach() dangling location regression
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

ppc patch queue for 2016-04-26 (last minute qemu-2.6 fix)

This just has one, last-minute, fix for a serious regression of memory
hotplug.

Patch author's comment:
    Really sorry for the way last-minute fix, but without this memory
    hotplug is totally broken :( Hoping to get this in for Wednesday's
    RC4, which I think will be the final before release.

# gpg: Signature made Tue 26 Apr 2016 03:52:20 BST using RSA key ID 20D9B392
# gpg: Good signature from "David Gibson <david@gibson.dropbear.id.au>"
# gpg:                 aka "David Gibson (Red Hat) <dgibson@redhat.com>"
# gpg:                 aka "David Gibson (ozlabs.org) <dgibson@ozlabs.org>"
# gpg: WARNING: This key is not certified with sufficiently trusted signatures!
# gpg:          It is not certain that the signature belongs to the owner.
# Primary key fingerprint: 75F4 6586 AE61 A66C C44E  87DC 6C38 CACA 20D9 B392

* remotes/dgibson/tags/ppc-for-2.6-20160426:
  spapr_drc: fix aborts during DRC-count based hotplug
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Commit b00c7218 ("target-mips: add PC, XNP reg numbers to RDHWR")
changed the rdhwr helpers to use check_hwrena() to check the register
being accessed is enabled in CP0_HWREna when used from user mode. If
that check fails an EXCP_RI exception is raised at the host PC
calculated with GETPC().

However check_hwrena() may not be fully inlined as the
do_raise_exception() part of it is common regardless of the arguments.
This causes GETPC() to calculate the address in the call in the helper
instead of the generated code calling the helper. No TB will be found
and the EPC reported with the resulting guest RI exception points to the
beginning of the TB instead of the RDHWR instruction.

We can't reliably force check_hwrena() to be inlined, and converting it
to a macro would be ugly, so instead pass the host PC in as an argument,
with each rdhwr helper passing GETPC(). This should avoid any dependence
on compiler behaviour, and in practice seems to ensure the full inlining
of check_hwrena() on x86_64.

This issue causes failures when running a MIPS KVM (trap & emulate)
guest in a MIPS QEMU TCG guest, as the inner guest kernel will do a
RDHWR of counter, which is disabled in the outer guest's CP0_HWREna by
KVM so it can emulate the inner guest's counter. The emulation fails and
the RI exception is passed to the inner guest.

Fixes: b00c7218 ("target-mips: add PC, XNP reg numbers to RDHWR")
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: Leon Alrae <leon.alrae@imgtec.com>
Cc: Yongbok Kim <yongbok.kim@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: NAurelien Jarno <aurelien@aurel32.net>
Reviewed-by: NLeon Alrae <leon.alrae@imgtec.com>
Signed-off-by: NLeon Alrae <leon.alrae@imgtec.com>

qemu_opts_foreach() runs its callback with the error location set to
the option's location.  Any errors the callback reports use the
option's location automatically.

Commit 90998d58 moved the actual error reporting from "inside"
qemu_opts_foreach() to after it.  Here's a typical hunk:

	 if (qemu_opts_foreach(qemu_find_opts("object"),
    -                          object_create,
    -                          object_create_initial, NULL)) {
    +                          user_creatable_add_opts_foreach,
    +                          object_create_initial, &err)) {
    +        error_report_err(err);
	     exit(1);
	 }

Before, object_create() reports from within qemu_opts_foreach(), using
the option's location.  Afterwards, we do it after
qemu_opts_foreach(), using whatever location happens to be current
there.  Commonly a "none" location.

This is because Error objects don't have location information.
Problematic.

Reproducer:

    $ qemu-system-x86_64 -nodefaults -display none -object secret,id=foo,foo=bar
    qemu-system-x86_64: Property '.foo' not found

Note no location.  This commit restores it:

    qemu-system-x86_64: -object secret,id=foo,foo=bar: Property '.foo' not found

Note that the qemu_opts_foreach() bug just fixed could mask the bug
here: if the location it leaves dangling hasn't been clobbered, yet,
it's the correct one.
Reported-by: NEric Blake <eblake@redhat.com>
Cc: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Message-Id: <1461767349-15329-4-git-send-email-armbru@redhat.com>
Reviewed-by: NDaniel P. Berrange <berrange@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
[Paragraph on Error added to commit message]

replay_configure() pushes and pops a Location with automatic storage
duration.  Except it fails to pop when -icount parameter "rr" isn't
given.  cur_loc then points to unused stack space, and will most
likely get clobbered in short order.

Clobbered cur_loc can make loc_pop() and error_print_loc() crash or
report bogus locations.

Broken in commit 890ad550.

I didn't take the time to find a reproducer.

Cc: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Message-Id: <1461767349-15329-3-git-send-email-armbru@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NEduardo Habkost <ehabkost@redhat.com>

qemu_opts_foreach() pushes and pops a Location with automatic storage
duration.  Except it fails to pop when @func() returns non-zero.
cur_loc then points to unused stack space, and will most likely get
clobbered in short order.

Clobbered cur_loc can make loc_pop() and error_print_loc() crash or
report bogus locations.

Affects several qemu command line options as well as qemu-img,
qemu-io, qemu-nbd -object, and blkdebug's configuration file.

Broken in commit a4c7367f, v2.4.0.

Reproducer:
    $ qemu-system-x86_64 -nodefaults -display none -object secret,id=foo,foo=bar

main() reports "Property '.foo' not found" like this:

    if (qemu_opts_foreach(qemu_find_opts("object"),
                          user_creatable_add_opts_foreach,
                          object_create_delayed, &err)) {
        error_report_err(err);
        exit(1);
    }

cur_loc then points to where qemu_opts_foreach()'s Location used to
be, i.e. unused stack space.  With optimization, this Location doesn't
get clobbered for me, and also happens to be the correct location.
Without optimization, it does get clobbered in a way that makes
error_report_err() report no location.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Message-Id: <1461767349-15329-2-git-send-email-armbru@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

CPU/memory resources can be signalled en-masse via
spapr_hotplug_req_add_by_count(), and when doing so, actually change
the meaning of the 'drc' parameter passed to
spapr_hotplug_req_event() to be a count rather than an index.

f40eb921 added a hook in spapr_hotplug_req_event() to record when a
device had been 'signalled' to the guest, but that code assumes that
drc is always an index. In cases where it's a count, such as memory
hotplug, the DRC lookup will fail, leading to an assert.

Fix this by only explicitly setting the signalled state for cases where
we are doing PCI hotplug.

For other resources types, since we cannot selectively track whether a
resource has been signalled in cases where we signal attach as a count,
set the 'signalled' state to true immediately upon making the
resource available via drck->attach().
Reported-by: NBharata B Rao <bharata@linux.vnet.ibm.com>
Cc: Bharata B Rao <bharata@linux.vnet.ibm.com>
Cc: david@gibson.dropbear.id.au
Cc: qemu-ppc@nongnu.org
Signed-off-by: NMichael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

commit "5f77e06b usb: add pid check at the first of uhci_handle_td()"
moved the pid verification to the start of the uhci_handle_td function,
to simplify the error handling (we don't have to free stuff which we
didn't allocate in the first place ...).

Problem is now the check fires too often, it raises error IRQs even for
TDs which we are not going to process because they are not set active.

So, lets move down the check a bit, so it is done only for active TDs,
but still before we are going to allocate stuff to process the requested
transfer.
Reported-by: NJoe Clifford <joe@thunderbug.co.uk>
Tested-by: NJoe Clifford <joe@thunderbug.co.uk>
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
Message-id: 1461321893-15811-1-git-send-email-kraxel@redhat.com
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

ppc patch queue for 2016-03-23

A single fix for a bug in parameter handling for the spapr PCI host
bridge.

# gpg: Signature made Sat 23 Apr 2016 07:55:29 BST using RSA key ID 20D9B392
# gpg: Good signature from "David Gibson <david@gibson.dropbear.id.au>"
# gpg:                 aka "David Gibson (Red Hat) <dgibson@redhat.com>"
# gpg:                 aka "David Gibson (ozlabs.org) <dgibson@ozlabs.org>"
# gpg: WARNING: This key is not certified with sufficiently trusted signatures!
# gpg:          It is not certain that the signature belongs to the owner.
# Primary key fingerprint: 75F4 6586 AE61 A66C C44E  87DC 6C38 CACA 20D9 B392

* remotes/dgibson/tags/ppc-for-2.6-20160423:
  hw/ppc/spapr: Fix crash when specifying bad parameters to spapr-pci-host-bridge
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

QEMU currently crashes when using bad parameters for the
spapr-pci-host-bridge device:

$ qemu-system-ppc64 -device spapr-pci-host-bridge,buid=0x123,liobn=0x321,mem_win_addr=0x1,io_win_addr=0x10
Segmentation fault

The problem is that spapr_tce_find_by_liobn() might return NULL, but
the code in spapr_populate_pci_dt() does not check for this condition
and then tries to dereference this NULL pointer.
Apart from that, the return value of spapr_populate_pci_dt() also
has to be checked for all PCI buses, not only for the last one, to
make sure we catch all errors.
Signed-off-by: NThomas Huth <thuth@redhat.com>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

Mirror block job fixes for 2.6.0-rc4

# gpg: Signature made Fri 22 Apr 2016 15:46:41 BST using RSA key ID C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"

* remotes/kevin/tags/for-upstream:
  mirror: Workaround for unexpected iohandler events during completion
  aio-posix: Skip external nodes in aio_dispatch
  virtio: Mark host notifiers as external
  event-notifier: Add "is_external" parameter
  iohandler: Introduce iohandler_get_aio_context
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Commit 5a7e7a0b moved mirror_exit to a BH handler but didn't add any
protection against new requests that could sneak in just before the
BH is dispatched. For example (assuming a code base at that commit):

        main_loop_wait # 1
          os_host_main_loop_wait
            g_main_context_dispatch
              aio_ctx_dispatch
                aio_dispatch
                  ...
                    mirror_run
                      bdrv_drain
    (a)               block_job_defer_to_main_loop
          qemu_iohandler_poll
            virtio_queue_host_notifier_read
              ...
                virtio_submit_multiwrite
    (b)           blk_aio_multiwrite

        main_loop_wait # 2
          <snip>
                aio_dispatch
                  aio_bh_poll
    (c)             mirror_exit

At (a) we know the BDS has no pending request. However, the same
main_loop_wait call is going to dispatch iohandlers (EventNotifier
events), which may lead to a new I/O from guest. So the invariant is
already broken at (c). Data loss.

Commit f3926945 made iohandler to use aio API.  The order of
virtio_queue_host_notifier_read and block_job_defer_to_main_loop within
a main_loop_wait becomes unpredictable, and even worse, if the host
notifier event arrives at the next main_loop_wait call, the
unpredictable order between mirror_exit and
virtio_queue_host_notifier_read is also a trouble. As shown below, this
commit made the bug easier to trigger:

    - Bug case 1:

        main_loop_wait # 1
          os_host_main_loop_wait
            g_main_context_dispatch
              aio_ctx_dispatch (qemu_aio_context)
                ...
                  mirror_run
                    bdrv_drain
    (a)             block_job_defer_to_main_loop
              aio_ctx_dispatch (iohandler_ctx)
                virtio_queue_host_notifier_read
                  ...
                    virtio_submit_multiwrite
    (b)               blk_aio_multiwrite

        main_loop_wait # 2
          ...
                aio_dispatch
                  aio_bh_poll
    (c)             mirror_exit

    - Bug case 2:

        main_loop_wait # 1
          os_host_main_loop_wait
            g_main_context_dispatch
              aio_ctx_dispatch (qemu_aio_context)
                ...
                  mirror_run
                    bdrv_drain
    (a)             block_job_defer_to_main_loop

        main_loop_wait # 2
          ...
            aio_ctx_dispatch (iohandler_ctx)
              virtio_queue_host_notifier_read
                ...
                  virtio_submit_multiwrite
    (b)             blk_aio_multiwrite
              aio_dispatch
                aio_bh_poll
    (c)           mirror_exit

In both cases, (b) breaks the invariant wanted by (a) and (c).

Until then, the request loss has been silent. Later, 3f09bfbc added
asserts at (c) to check the invariant (in
bdrv_replace_in_backing_chain), and Max reported an assertion failure
first visible there, by doing active committing while the guest is
running bonnie++.

2.5 added bdrv_drained_begin at (a) to protect the dataplane case from
similar problems, but we never realize the main loop bug until now.

As a bandage, this patch disables iohandler's external events
temporarily together with bs->ctx.

Launchpad Bug: 1570134

Cc: qemu-stable@nongnu.org
Signed-off-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NJeff Cody <jcody@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

aio_poll doesn't poll the external nodes so this should never be true,
but aio_ctx_dispatch may get notified by the events from GSource. To
make bdrv_drained_begin effective in main loop, we should check the
is_external flag here too.

Also do the check in aio_pending so aio_dispatch is not called
superfluously, when there is no events other than external ones.
Signed-off-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NJeff Cody <jcody@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

The effect of this change is the block layer drained section can work,
for example when mirror job is being completed.
Signed-off-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

All callers pass "false" keeping the old semantics. The windows
implementation doesn't distinguish the flag yet. On posix, it is passed
down to the underlying aio context.
Signed-off-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

For KVM to use Transparent Huge Pages (THP) we have to ensure that the
alignment of the userspace address of the KVM memory slot and the IPA
that the guest sees for a memory region have the same offset from the 2M
huge page size boundary.

One way to achieve this is to always align the IPA region at a 2M
boundary and ensure that the mmap alignment is also at 2M.

Unfortunately, we were only doing this for __arm__, not for __aarch64__,
so add this simple condition.

This fixes a performance regression using KVM/ARM on AArch64 platforms
that showed a performance penalty of more than 50%, introduced by the
following commit:

9fac18f0 (oslib: allocate PROT_NONE pages on top of RAM, 2015-09-10)

We were only lucky before the above commit, because we were allocating
large regions and naturally getting a 2M alignment on those allocations
then.

Cc: qemu-stable@nongnu.org
Reported-by: NShih-Wei Li <shihwei@cs.columbia.edu>
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
[PMM: wrapped long line]
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>