Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220323155743.1585078-19-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Closer to other IO functions.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220323155743.1585078-18-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

The macro requires EINTR, which has its header included in osdep.h.

(Not sure what TFR stands for, perhaps "Test For Retry". Rename it ?)

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220323155743.1585078-17-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

According to GLib API:
g_get_current_time has been deprecated since version 2.62 and should not
be used in newly-written code. GTimeVal is not year-2038-safe. Use
g_get_real_time() instead.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220323155743.1585078-14-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Replace the global variables with inlined helper functions. getpagesize() is very
likely annotated with a "const" function attribute (at least with glibc), and thus
optimization should apply even better.

This avoids the need for a constructor initialization too.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220323155743.1585078-12-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Need wrappers for qobject_unref() calls, which is a macro.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220323155743.1585078-10-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220323155743.1585078-9-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Convert the TARGET_WORDS_BIGENDIAN macro, similarly to what was done
with HOST_BIG_ENDIAN. The new TARGET_BIG_ENDIAN macro is either 0 or 1,
and thus should always be defined to prevent misuse.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Suggested-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220323155743.1585078-8-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Replace a config-time define with a compile time condition
define (compatible with clang and gcc) that must be declared prior to
its usage. This avoids having a global configure time define, but also
prevents from bad usage, if the config header wasn't included before.

This can help to make some code independent from qemu too.

gcc supports __BYTE_ORDER__ from about 4.6 and clang from 3.2.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
[ For the s390x parts I'm involved in ]
Acked-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220323155743.1585078-7-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

It is only needed by char-pty.

Fix the code style while at it.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220323155743.1585078-6-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

No longer used after the previous patches.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220307070401.171986-6-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

The spec defines 3 registers, even though only index 0 and 2 are valid
on POWER9. The same model is used on POWER10. Register 1 is defined
there but we currently don't use it in skiboot. So we can keep
reporting an error on write.

Reported by Coverity (CID 1487176).

Fixes: 4f9924c4 ("ppc/pnv: Add models for POWER9 PHB4 PCIe Host bridge")
Suggested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20220401091925.770803-1-fbarrat@linux.ibm.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>

The timebase is allocated during spapr_realize_vcpu() and it's not
freed. This results in memory leaks when doing vcpu unplugs:

==636935==
==636935== 144 (96 direct, 48 indirect) bytes in 1 blocks are definitely lost in loss record 6
,461 of 8,135
==636935==    at 0x4897468: calloc (vg_replace_malloc.c:760)
==636935==    by 0x5077213: g_malloc0 (in /usr/lib64/libglib-2.0.so.0.6400.4)
==636935==    by 0x507757F: g_malloc0_n (in /usr/lib64/libglib-2.0.so.0.6400.4)
==636935==    by 0x93C3FB: cpu_ppc_tb_init (ppc.c:1066)
==636935==    by 0x97BC2B: spapr_realize_vcpu (spapr_cpu_core.c:268)
==636935==    by 0x97C01F: spapr_cpu_core_realize (spapr_cpu_core.c:337)
==636935==    by 0xD4626F: device_set_realized (qdev.c:531)
==636935==    by 0xD55273: property_set_bool (object.c:2273)
==636935==    by 0xD523DF: object_property_set (object.c:1408)
==636935==    by 0xD588B7: object_property_set_qobject (qom-qobject.c:28)
==636935==    by 0xD52897: object_property_set_bool (object.c:1477)
==636935==    by 0xD4579B: qdev_realize (qdev.c:333)
==636935==

This patch adds a cpu_ppc_tb_free() helper in hw/ppc/ppc.c to allow us
to free the timebase. This leak is then solved by calling
cpu_ppc_tb_free() in spapr_unrealize_vcpu().

Fixes: 6f4b5c3e ("spapr: CPU hot unplug support")
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20220329124545.529145-2-danielhb413@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>

These assertions are very useful for developers to find bugs, and so
they have indeed pointed us towards bugs already.  For users, it is not
so useful to find these bugs.  We should probably not enable them in
releases until we are sufficiently certain that they will not fire
during normal operation, unless something is going seriously wrong.

For example, we have received a bug report that you cannot add an NBD
server on a BDS in an I/O thread with `-incoming defer`.  I am sure this
is a real bug that needs investigation, but we do not really have that
time right now, so close to release, and so I would rather disable the
assertions to get time to investigate such reports.

(I am just putting the link as "buglink" below, not "closes", because
disabling the assertion will not fix the likely underlying bug.)

Buglink: https://gitlab.com/qemu-project/qemu/-/issues/945


Signed-off-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20220329093545.52114-1-hreitz@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>

Since commit 0439c5a4 ("block/block-backend.c: assertions for
block-backend") QEMU crashes when using Cocoa on Darwin hosts.

Example on macOS:

  $ qemu-system-i386
  Assertion failed: (qemu_in_main_thread()), function blk_all_next, file block-backend.c, line 552.
  Abort trap: 6

Looking with lldb:

  Assertion failed: (qemu_in_main_thread()), function blk_all_next, file block-backend.c, line 552.
  Process 76914 stopped
  * thread #1, queue = 'com.apple.main-thread', stop reason = hit program assert
     frame #4: 0x000000010057c2d4 qemu-system-i386`blk_all_next.cold.1
  at block-backend.c:552:5 [opt]
      549    */
      550   BlockBackend *blk_all_next(BlockBackend *blk)
      551   {
  --> 552       GLOBAL_STATE_CODE();
      553       return blk ? QTAILQ_NEXT(blk, link)
      554                  : QTAILQ_FIRST(&block_backends);
      555   }
  Target 1: (qemu-system-i386) stopped.

  (lldb) bt
  * thread #1, queue = 'com.apple.main-thread', stop reason = hit program assert
     frame #0: 0x00000001908c99b8 libsystem_kernel.dylib`__pthread_kill + 8
     frame #1: 0x00000001908fceb0 libsystem_pthread.dylib`pthread_kill + 288
     frame #2: 0x000000019083a314 libsystem_c.dylib`abort + 164
     frame #3: 0x000000019083972c libsystem_c.dylib`__assert_rtn + 300
   * frame #4: 0x000000010057c2d4 qemu-system-i386`blk_all_next.cold.1 at block-backend.c:552:5 [opt]
     frame #5: 0x00000001003c00b4 qemu-system-i386`blk_all_next(blk=<unavailable>) at block-backend.c:552:5 [opt]
     frame #6: 0x00000001003d8f04 qemu-system-i386`qmp_query_block(errp=0x0000000000000000) at qapi.c:591:16 [opt]
     frame #7: 0x000000010003ab0c qemu-system-i386`main [inlined] addRemovableDevicesMenuItems at cocoa.m:1756:21 [opt]
     frame #8: 0x000000010003ab04 qemu-system-i386`main(argc=<unavailable>, argv=<unavailable>) at cocoa.m:1980:5 [opt]
     frame #9: 0x00000001012690f4 dyld`start + 520

As we are in passed release 7.0 hard freeze, disable the block
backend assertion which, while being valuable during development,
is not helpful to users. We'll restore this assertion immediately
once 7.0 is released and work on a fix.

Suggested-by: Akihiko Odaki <akihiko.odaki@gmail.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Akihiko Odaki <akihiko.odaki@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20220325183707.85733-1-philippe.mathieu.daude@gmail.com>

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>

Move qemu_ether_ntoa() which is only needed in net/.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

This will help to make common code independent.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

Simplify the macro, not depending on headers defines, but compiler
predefined __SIZEOF__POINTER__ only.

Available since gcc 4.3 and clang 2.8.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Acked-by: Richard Henderson <richard.henderson@linaro.org>

One less qemu-specific macro. It also helps to make some headers/units
only depend on glib, and thus moved in standalone projects eventually.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

One less qemu-specific macro. It also helps to make some headers/units
only depend on glib, and thus moved in standalone projects eventually.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

One less qemu-specific macro. It also helps to make some headers/units
only depend on glib, and thus moved in standalone projects eventually.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>

The socket API wrappers were initially introduced in commit
00aa0040 ("Wrap recv to avoid warnings"), but made redundant with
commit a2d96af4 ("osdep: add wrappers for socket functions") which fixes
the win32 declarations and thus removed the earlier warnings.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

g_new(T, n) is neater than g_malloc(sizeof(T) * n).  It's also safer,
for two reasons.  One, it catches multiplication overflowing size_t.
Two, it returns T * rather than void *, which lets the compiler catch
more type errors.

This commit only touches allocations with size arguments of the form
sizeof(T).

Patch created mechanically with:

    $ spatch --in-place --sp-file scripts/coccinelle/use-g_new-etc.cocci \
	     --macro-file scripts/cocci-macro-file.h FILES...

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20220315144156.1595462-4-armbru@redhat.com>
Reviewed-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>

Add the 'memory' bit to the memory attributes to restrict bus
controller accesses to memories.

Introduce flatview_access_allowed() to check bus permission
before running any bus transaction.

Have read/write accessors return MEMTX_ACCESS_ERROR if an access is
restricted.

There is no change for the default case where 'memory' is not set.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20211215182421.418374-4-philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
[thuth: Replaced MEMTX_BUS_ERROR with MEMTX_ACCESS_ERROR, remove "inline"]
Signed-off-by: Thomas Huth <thuth@redhat.com>

On older Solaris releases (before Solaris 11), we didn't get a
prototype for madvise, and so util/osdep.c provides its own prototype.
Some time between the public Solaris 11.4 release and Solaris 11.4.42
CBE, we started getting an madvise prototype that looks like this:

    extern int madvise(void *, size_t, int);

which conflicts with the prototype in util/osdeps.c. Instead of always
declaring this prototype, check if we're missing the madvise()
prototype, and only declare it ourselves if the prototype is missing.
Move the prototype to include/qemu/osdep.h, the normal place to handle
platform-specific header quirks.

The 'missing_madvise_proto' meson check contains an obviously wrong
prototype for madvise. So if that code compiles and links, we must be
missing the actual prototype for madvise.

Signed-off-by: Andrew Deason <adeason@sinenomine.net>
Message-id: 20220316035227.3702-2-adeason@sinenomine.net
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Connect the ZynqMP APU Control device.

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Francisco Iglesias <francisco.iglesias@xilinx.com>
Reviewed-by: Luc Michel <luc@lmichel.fr>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Message-id: 20220316164645.2303510-7-edgar.iglesias@gmail.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Add a model of the Xilinx ZynqMP APU Control.

Reviewed-by: Luc Michel <luc@lmichel.fr>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Message-id: 20220316164645.2303510-6-edgar.iglesias@gmail.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Connect the ZynqMP CRF - Clock Reset FPD device.

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Francisco Iglesias <francisco.iglesias@xilinx.com>
Reviewed-by: Luc Michel <luc@lmichel.fr>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Message-id: 20220316164645.2303510-5-edgar.iglesias@gmail.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Add a model of the Xilinx ZynqMP CRF. At the moment this
is mostly a stub model.

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Message-id: 20220316164645.2303510-4-edgar.iglesias@gmail.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Add an unimplemented SERDES (Serializer/Deserializer) area.

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Francisco Iglesias <francisco.iglesias@xilinx.com>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Message-id: 20220316164645.2303510-2-edgar.iglesias@gmail.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Commit e0220bb5 made cpus.c target-agnostic but didn't notice
the cpu_list() function is only defined in target-specific code
in "cpu.h". Move list_cpus() declaration to "exec/cpu-common.h"
because this function is not softmmu-specific and can also be
used by user-mode, along with moving its implementation to cpu.c,
which is compiled per target.

Fixes: e0220bb5 ("softmmu: Build target-agnostic objects once")
Reported-by: Max Filippov <jcmvbkbc@gmail.com>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220314140108.26222-1-philippe.mathieu.daude@gmail.com>
Tested-by: Max Filippov <jcmvbkbc@gmail.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

Remove the Clang specific __builtin_available() to allow building
with GCC, otherwise we get:

  include/qemu/osdep.h: In function 'qemu_thread_jit_write':
  include/qemu/osdep.h:787:9: warning: implicit declaration of function '__builtin_available'; did you mean '__builtin_scalbl'? [-Wimplicit-function-declaration]
    787 |     if (__builtin_available(macOS 11.0, *)) {
        |         ^~~~~~~~~~~~~~~~~~~
        |         __builtin_scalbl
  include/qemu/osdep.h:787:9: warning: nested extern declaration of '__builtin_available' [-Wnested-externs]
  include/qemu/osdep.h:787:29: error: 'macOS' undeclared (first use in this function)
    787 |     if (__builtin_available(macOS 11.0, *)) {
        |                             ^~~~~
  include/qemu/osdep.h:787:29: note: each undeclared identifier is reported only once for each function it appears in
  include/qemu/osdep.h:787:34: error: expected ')' before numeric constant
    787 |     if (__builtin_available(macOS 11.0, *)) {
        |                            ~     ^~~~~
        |                                  )

Beside, on macOS Catalina we get 2254 times:

  include/qemu/osdep.h:780:5: warning: 'pthread_jit_write_protect_np' is only available on macOS 11.0 or newer [-Wunguarded-availability-new]
      pthread_jit_write_protect_np(true);
      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~

Fix by using a stricker toolchain version low range, replacing
MAC_OS_X_VERSION_MAX_ALLOWED by MAC_OS_X_VERSION_MIN_REQUIRED.

Reviewed-by: Akihiko Odaki <akihiko.odaki@gmail.com>
Tested-by: Akihiko Odaki <akihiko.odaki@gmail.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

We invoke the kvm_irqchip_commit_routes() for each addition to MSI route
table, which is not efficient if we are adding lots of routes in some cases.

This patch lets callers invoke the kvm_irqchip_commit_routes(), so the
callers can decide how to optimize.

[1] https://lists.gnu.org/archive/html/qemu-devel/2021-11/msg00967.html



Signed-off-by: Longpeng <longpeng2@huawei.com>
Message-Id: <20220222141116.2091-3-longpeng2@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Paolo suggested adding the new API to support route changes [1]. We should invoke
kvm_irqchip_begin_route_changes() before changing the routes, increasing the
KVMRouteChange.changes if the routes are changed, and commit the changes at last.

[1] https://lists.gnu.org/archive/html/qemu-devel/2021-11/msg02898.html



Signed-off-by: Longpeng <longpeng2@huawei.com>
Message-Id: <20220222141116.2091-2-longpeng2@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

The DBus listener naively create, update and destroy textures without
taking into account other listeners. The texture were shared, but
texture update was unnecessarily duplicated.

Teach DisplayGLCtx to do optionally shared texture handling. This is
only implemented for DBus display at this point, however the same
infrastructure could potentially be used for other future combinations.

Reported-by: Akihiko Odaki <akihiko.odaki@gmail.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>

SVQ is able to log the dirty bits by itself, so let's use it to not
block migration.

Also, ignore set and clear of VHOST_F_LOG_ALL on set_features if SVQ is
enabled. Even if the device supports it, the reports would be nonsense
because SVQ memory is in the qemu region.

The log region is still allocated. Future changes might skip that, but
this series is already long enough.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>

Use translations added in VhostIOVATree in SVQ.

Only introduce usage here, not allocation and deallocation. As with
previous patches, we use the dead code paths of shadow_vqs_enabled to
avoid commiting too many changes at once. These are impossible to take
at the moment.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>

This function does the reverse operation of iova_tree_find: To look for
a mapping that match a translated address so we can do the reverse.

This have linear complexity instead of logarithmic, but it supports
overlapping HVA. Future developments could reduce it.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>

This iova tree function allows it to look for a hole in allocated
regions and return a totally new translation for a given translated
address.

It's usage is mainly to allow devices to access qemu address space,
remapping guest's one into a new iova space where qemu can add chunks of
addresses.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>