Server class POWER CPUs have a "compat" property, which is used to set the
backwards compatibility mode for the processor.  However, this only makes
sense for machine types which don't give the guest access to hypervisor
privilege - otherwise the compatibility level is under the guest's control.

To reflect this, this removes the CPU 'compat' property and instead
creates a 'max-cpu-compat' property on the pseries machine.  Strictly
speaking this breaks compatibility, but AFAIK the 'compat' option was
never (directly) used with -device or device_add.

The option was used with -cpu.  So, to maintain compatibility, this
patch adds a hack to the cpu option parsing to strip out any compat
options supplied with -cpu and set them on the machine property
instead of the now deprecated cpu property.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Tested-by: NSuraj Jitindar Singh <sjitindarsingh@gmail.com>
Reviewed-by: NGreg Kurz <groug@kaod.org>
Tested-by: NGreg Kurz <groug@kaod.org>
Tested-by: NAndrea Bolognani <abologna@redhat.com>

This may be used for deprecated object properties that are kept for
backwards compatibility.
Signed-off-by: NGreg Kurz <groug@kaod.org>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Tested-by: NAndrea Bolognani <abologna@redhat.com>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

When using the 40p machine, soundhw_init() is currently called twice,
one time from vl.c and one time from ibm_40p_init(). The call in
ibm_40p_init() was likely just a copy-and-paste from a old version
of the prep machine - but there the call to audio_init() (which was
the previous name of this function) has been removed many years ago
already, with commit b3e6d591
("audio: enable PCI audio cards for all PCI-enabled targets"), so
we certainly also do not need the soundhw_init() in the 40p function
anymore nowadays.
Signed-off-by: NThomas Huth <thuth@redhat.com>
Reviewed-by: NSahid Ferdjaoui <sferdjao@redhat.com>
Reviewed-by: NEduardo Habkost <ehabkost@redhat.com>
Reviewed-by: NHervé Poussineau <hpoussin@reactos.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

HMP pull 2017-06-29

# gpg: Signature made Thu 29 Jun 2017 17:27:55 BST
# gpg:                using RSA key 0x0516331EBC5BFDE7
# gpg: Good signature from "Dr. David Alan Gilbert (RH2) <dgilbert@redhat.com>"
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 45F5 C71B 4A0C B7FB 977A  9FA9 0516 331E BC5B FDE7

* remotes/dgilbert/tags/pull-hmp-20170629:
  Add chardev-send-break monitor command
  monitor: Add -a (all) option to info registers
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Sending a break on a serial console can be useful for debugging the
guest. But not all chardev backends support sending breaks (only telnet
and mux do). The chardev-send-break command allows to send a break even
if using other backends.
Signed-off-by: NStefan Fritsch <sf@sfritsch.de>
Acked-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20170611074817.13621-1-sf@sfritsch.de>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
  Use 'send a break' in all 3 pieces of text as suggested by eblake

The info registers command in the qemu monitor is used to dump register
values.

Currently this command uses the monitor cpu (which can be set by the
user) as the cpu for whose registers will be dumped. Sometimes it is
useful to see the registers for all cpus and currently this requires
setting the monitor cpu and the re-running the command for each cpu
in the system. I would be nice if there was an easier way to do this.

Add the "-a" option to the info registers command to dump the register
values for all cpus.
Signed-off-by: NSuraj Jitindar Singh <sjitindarsingh@gmail.com>

Message-Id: <20170608054116.17203-1-sjitindarsingh@gmail.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

- fixes a minor bug that could possibly prevent old guests to remove
  directories
- makes default permissions for new files configurable from the cmdline
  when using mapped security modes
- handle transport errors
- g_malloc()+memcpy() converted to g_memdup()

# gpg: Signature made Thu 29 Jun 2017 14:12:42 BST
# gpg:                using DSA key 0x02FC3AEB0101DBC2
# gpg: Good signature from "Greg Kurz <groug@kaod.org>"
# gpg:                 aka "Greg Kurz <groug@free.fr>"
# gpg:                 aka "Greg Kurz <gkurz@linux.vnet.ibm.com>"
# gpg:                 aka "Gregory Kurz (Groug) <groug@free.fr>"
# gpg:                 aka "[jpeg image of size 3330]"
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 2BD4 3B44 535E C0A7 9894  DBA2 02FC 3AEB 0101 DBC2

* remotes/gkurz/tags/for-upstream:
  9pfs: handle transport errors in pdu_complete()
  xen-9pfs: disconnect if buffers are misconfigured
  virtio-9p: break device if buffers are misconfigured
  virtio-9p: message header is 7-byte long
  virtio-9p: record element after sanity checks
  9pfs: replace g_malloc()+memcpy() with g_memdup()
  9pfs: local: Add support for custom fmode/dmode in 9ps mapped security modes
  9pfs: local: remove: use correct path component
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

The [NSEvent modifierFlags] method returns an NSEventModifierFlags type value in Mac OS 10.10. It use to be of type NSUInteger. Replacing NSEventModifierFlags with NSUInteger allows for the cooca.m file to be compiled on older versions of Mac OS. This patch was been tested on Mac OS 10.6 and Mac OS 10.12 without problem.
Signed-off-by: NJohn Arbuckle <programmingkidx@gmail.com>
Message-id: F6C36C1A-4661-48F4-BEA6-3994889927D0@gmail.com
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Contrary to what is written in the comment, a buggy guest can misconfigure
the transport buffers and pdu_marshal() may return an error.  If this ever
happens, it is up to the transport layer to handle the situation (9P is
transport agnostic).

This fixes Coverity issue CID1348518.
Signed-off-by: NGreg Kurz <groug@kaod.org>
Reviewed-by: NStefano Stabellini <sstabellini@kernel.org>

Implement xen_9pfs_disconnect by unbinding the event channels. On
xen_9pfs_free, call disconnect if any event channels haven't been
disconnected.

If the frontend misconfigured the buffers set the backend to "Closing"
and disconnect it. Misconfigurations include requesting a read of more
bytes than available on the ring buffer, or claiming to be writing more
data than available on the ring buffer.
Signed-off-by: NStefano Stabellini <stefano@aporeto.com>
Signed-off-by: NGreg Kurz <groug@kaod.org>

The 9P protocol is transport agnostic: if the guest misconfigured the
buffers, the best we can do is to set the broken flag on the device.
Signed-off-by: NGreg Kurz <groug@kaod.org>

The 9p spec at http://man.cat-v.org/plan_9/5/intro reads:

 "Each 9P message begins with a four-byte size field specify-
  ing the length in bytes of the complete message including
  the four bytes of the size field itself.  The next byte is
  the message type, one of the constants in the enumeration in
  the include file <fcall.h>.  The next two bytes are an iden-
  tifying tag, described below."

ie, each message starts with a 7-byte long header.

The core 9P code already assumes this pretty much everywhere. This patch
does the following:
- makes the assumption explicit in the common 9p.h header, since it isn't
  related to the transport
- open codes the header size in handle_9p_output() and hardens the sanity
  check on the space needed for the reply message
Signed-off-by: NGreg Kurz <groug@kaod.org>
Acked-by: NStefano Stabellini <sstabellini@kernel.org>

If the guest sends a malformed request, we end up with a dangling pointer
in V9fsVirtioState. This doesn't seem to cause any bug, but let's remove
this side effect anyway.
Signed-off-by: NGreg Kurz <groug@kaod.org>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>

I found these pattern via grepping the source tree. I don't have a
coccinelle script for it!
Signed-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>

In mapped security modes, files are created with very restrictive
permissions (600 for files and 700 for directories). This makes
file sharing between virtual machines and users on the host rather
complicated. Imagine eg. a group of users that need to access data
produced by processes on a virtual machine. Giving those users access
to the data will be difficult since the group access mode is always 0.

This patch makes the default mode for both files and directories
configurable. Existing setups that don't know about the new parameters
keep using the current secure behavior.
Signed-off-by: NTobias Schramm <tobleminer@gmail.com>
Signed-off-by: NGreg Kurz <groug@kaod.org>

Commit a0e640a8 introduced a path processing error.
Pass fstatat the dirpath based path component instead
of the entire path.
Signed-off-by: NBruce Rogers <brogers@suse.com>
Signed-off-by: NGreg Kurz <groug@kaod.org>

migration/next for 20170628

# gpg: Signature made Wed 28 Jun 2017 12:16:44 BST
# gpg:                using RSA key 0xF487EF185872D723
# gpg: Good signature from "Juan Quintela <quintela@redhat.com>"
# gpg:                 aka "Juan Quintela <quintela@trasno.org>"
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 1899 FF8E DEBF 58CC EE03  4B82 F487 EF18 5872 D723

* remotes/juanquintela/tags/migration/20170628:
  exec: fix access to ram_list.dirty_memory when sync dirty bitmap
  migration: add "return-path" capability
  vmstate: error hint for failed equal checks
  migration: add comment for TYPE_MIGRATE
  migration: hmp: dump globals
  migration: merge enforce_config_section somewhat
  migration: move skip_section_footers
  migration: move skip_configuration out
  migration: move only_migratable to MigrationState
  migration: move global_state.optional out
  migration: let MigrationState be a qdev
  vl: clean up global property registration
  accel: introduce AccelClass.global_props
  machine: export register_compat_prop()
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Xen 2017/06/27

# gpg: Signature made Tue 27 Jun 2017 23:02:43 BST
# gpg:                using RSA key 0x894F8F4870E1AE90
# gpg: Good signature from "Stefano Stabellini <stefano.stabellini@eu.citrix.com>"
# gpg:                 aka "Stefano Stabellini <sstabellini@kernel.org>"
# Primary key fingerprint: D04E 33AB A51F 67BA 07D3  0AEA 894F 8F48 70E1 AE90

* remotes/sstabellini/tags/xen-20170627-tag:
  xen-disk: add support for multi-page shared rings
  xen-disk: only advertize feature-persistent if grant copy is not available
  xen/disk: don't leak stack data via response ring
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

The 32-bit PPC auxv is a bit complicated because in the
mists of time it used to be 16-aligned rather than directly
after the environment. Older glibc versions had code to
try to probe for whether it needed alignment or not:
https://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/unix/sysv/linux/powerpc/dl-sysdep.c;hb=e84eabb3871c9b39e59323bf3f6b98c2ca9d1cd0
and the kernel has code which puts some magic entries at
the bottom to ensure that the alignment probe fails:
http://elixir.free-electrons.com/linux/latest/source/arch/powerpc/include/asm/elf.h#L158

QEMU has similar code too, but it was broken by commit
7c4ee5bc, which changed elfload.c from filling in
the auxv starting at the highest address and working down
to starting at the lowest address and working up. This
means that the ARCH_DLINFO hook must now be invoked first
rather than last, and the entries in it for PPC must
be reversed so that the magic AT_IGNOREPPC entries come
at the lowest address in the auxv as they should.

The effect of this was that if running a guest binary that
used an old glibc with the alignment probing the guest ld.so
code would segfault if the size of the guest environment and
argv happened to put the auxv at an address that triggered
the alignment code in the guest glibc.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Tested-by: NRichard Henderson <rth@twiddle.net>
Message-id: 1498582198-6649-1-git-send-email-peter.maydell@linaro.org

In cpu_physical_memory_sync_dirty_bitmap(rb, start, ...), the 2nd
argument 'start' is relative to the start of the ramblock 'rb'. When
it's used to access the dirty memory bitmap of ram_list (i.e.
ram_list.dirty_memory[DIRTY_MEMORY_MIGRATION]->blocks[]), an offset to
the start of all RAM (i.e. rb->offset) should be added to it, which has
however been missed since c/s 6b6712ef. For a ramblock of host memory
backend whose offset is not zero, cpu_physical_memory_sync_dirty_bitmap()
synchronizes the incorrect part of the dirty memory bitmap of ram_list
to the per ramblock dirty bitmap. As a result, a guest with host
memory backend may crash after migration.

Fix it by adding the offset of ramblock when accessing the dirty memory
bitmap of ram_list in cpu_physical_memory_sync_dirty_bitmap().
Reported-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NHaozhong Zhang <haozhong.zhang@intel.com>
Message-Id: <20170628083704.24997-1-haozhong.zhang@intel.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Tested-by: NJuan Quintela <quintela@redhat.com>
Tested-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

When this capability is enabled, QEMU will use the return path even for
precopy migration. This is helpful at least in one case when destination
failed to load the image while source quited without confirmation. With
return path, source will wait for the last response from destination,
and if destination fails, it'll fail the migration on source, then the
guest can be run again on the source (rather than assuming to be good,
then the guest will be lost after source quits).

It needs to be enabled explicitly on source, otherwise disabled.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <1498472935-14461-1-git-send-email-peterx@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

In some cases a failing VMSTATE_*_EQUAL does not mean we detected a bug,
but it's actually the best we can do. Especially in these cases a verbose
error message is required.

Let's introduce infrastructure for specifying a error hint to be used if
equal check fails. Let's do this by adding a parameter to the _EQUAL
macros called _err_hint. Also change all current users to pass NULL as
last parameter so nothing changes for them.
Signed-off-by: NHalil Pasic <pasic@linux.vnet.ibm.com>

Message-Id: <20170623144823.42936-1-pasic@linux.vnet.ibm.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

It'll be strange that the migration object inherits TYPE_DEVICE. Add
some explanations to it.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <1498634144-26508-1-git-send-email-peterx@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

Now we have some globals that can be configured for migration. Dump them
in HMP info migration for better debugging.

(we can also use this to monitor whether COMPAT fields are applied
correctly on compatible machines)
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <1498536619-14548-11-git-send-email-peterx@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

These two parameters:

- MachineState::enforce_config_section
- MigrationState::send_configuration

are playing similar role here. This patch merges the first one into
second, then we'll have a single place to reference whether we need to
send the configuration section.

I didn't remove the MachineState.enforce_config_section field since when
applying that machine property (in machine_set_property()) we haven't
yet initialized global properties and migration object. Then, it's
still not easy to pass that boolean to MigrationState at such an early
time.

A natural benefit for current patch is that now we kept the meaning of
"enforce-config-section" since it'll still have the highest
priority (that's what "enforce" mean I guess).
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <1498536619-14548-10-git-send-email-peterx@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

Move it into MigrationState, revert its meaning and renaming it to
send_section_footer, with a property bound to it. Same trick is played
like previous patches.

Removing savevm_skip_section_footers().
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <1498536619-14548-9-git-send-email-peterx@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

It was in SaveState but now moved to MigrationState altogether, reverted
its meaning, then renamed to "send_configuration". Again, using
HW_COMPAT_2_3 for old PC/SPAPR machines, and accel_register_prop() for
xen_init().

Removing savevm_skip_configuration().
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <1498536619-14548-8-git-send-email-peterx@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

One less global variable, and it does only matter with migration.

We keep the old "--only-migratable" option, but also now we support:

  -global migration.only-migratable=true

Currently still keep the old interface.

Hmm, now vl.c has no way to access migrate_get_current(). Export a
function for it to setup only_migratable.
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <1498536619-14548-7-git-send-email-peterx@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

Put it into MigrationState then we can use the properties to specify
whether to enable storing global state.

Removing global_state_set_optional() since now we can use HW_COMPAT_2_3
for x86/power, and AccelClass.global_props for Xen.
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <1498536619-14548-6-git-send-email-peterx@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

Let the old man "MigrationState" join the object family. Direct benefit
is that we can start to use all the property features derived from
current QDev, like: HW_COMPAT_* bits, command line setup for migration
parameters (so will never need to set them up each time using HMP/QMP,
this is really, really attractive for test writters), etc.

I see no reason to disallow this happen yet. So let's start from this
one, to see whether it would be anything good.

Now we init the MigrationState struct statically in main() to make sure
it's initialized after global properties are applied, since we'll use
them during creation of the object.

No functional change at all.
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <1498536619-14548-5-git-send-email-peterx@redhat.com>
Reviewed-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

It's not that clear on how the global properties are registered to
global_props (and also its priority relationship). Let's provide a
single function to be called in main() for that, with comment to explain
it a bit.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <1498536619-14548-4-git-send-email-peterx@redhat.com>
Reviewed-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

Introduce this new field for the accelerator classes so that each
specific accelerator in the future can register its own global
properties to be used further by the system. It works just like how the
old machine compatible properties do, but only tailored for
accelerators.

Introduce register_compat_props_array() for it. Export it so that it may
be used in other codes as well in the future.
Suggested-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <1498536619-14548-3-git-send-email-peterx@redhat.com>
Reviewed-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

We have HW_COMPAT_*, however that's only bound to machines, not other
things (like accelerators).  Behind it, it was register_compat_prop()
that played the trick.  Let's export the function for further use
outside HW_COMPAT_* magic.

Meanwhile, move it to qdev-properties.c where seems more proper (since
it'll be used not only in machine codes).
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <1498536619-14548-2-git-send-email-peterx@redhat.com>
Reviewed-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

The blkif protocol has had provision for negotiation of multi-page shared
rings for some time now and many guest OS have support in their frontend
drivers.

This patch makes the necessary modifications to xen-disk support a shared
ring up to order 4 (i.e. 16 pages).
Signed-off-by: NPaul Durrant <paul.durrant@citrix.com>
Signed-off-by: NStefano Stabellini <sstabellini@kernel.org>
Reviewed-by: NStefano Stabellini <sstabellini@kernel.org>

If grant copy is available then it will always be used in preference to
persistent maps. In this case feature-persistent should not be advertized
to the frontend, otherwise it may needlessly copy data into persistently
granted buffers.
Signed-off-by: NPaul Durrant <paul.durrant@citrix.com>
Signed-off-by: NStefano Stabellini <sstabellini@kernel.org>
Reviewed-by: NStefano Stabellini <sstabellini@kernel.org>

Rather than constructing a local structure instance on the stack, fill
the fields directly on the shared ring, just like other (Linux)
backends do. Build on the fact that all response structure flavors are
actually identical (aside from alignment and padding at the end).

This is XSA-216.

Reported by: Anthony Perard <anthony.perard@citrix.com>
Signed-off-by: NJan Beulich <jbeulich@suse.com>
Signed-off-by: NStefano Stabellini <sstabellini@kernel.org>
Acked-by: NAnthony PERARD <anthony.perard@citrix.com>

edgar/mmio-exec-v2.for-upstream

# gpg: Signature made Tue 27 Jun 2017 16:22:30 BST
# gpg:                using RSA key 0x29C596780F6BCA83
# gpg: Good signature from "Edgar E. Iglesias (Xilinx key) <edgar.iglesias@xilinx.com>"
# gpg:                 aka "Edgar E. Iglesias <edgar.iglesias@gmail.com>"
# Primary key fingerprint: AC44 FEDC 14F7 F1EB EDBF  4151 29C5 9678 0F6B CA83

* remotes/edgar/tags/edgar/mmio-exec-v2.for-upstream:
  xilinx_spips: allow mmio execution
  exec: allow to get a pointer for some mmio memory region
  introduce mmio_interface
  qdev: add MemoryRegion property
  cputlb: fix the way get_page_addr_code fills the tlb
  cputlb: move get_page_addr_code
  cputlb: cleanup get_page_addr_code to use VICTIM_TLB_HIT
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

This allows to execute from the lqspi area.

When the request_ptr is called the device loads 1024bytes from the SPI device.
Then this code can be executed by the guest.
Tested-by: NEdgar E. Iglesias <edgar.iglesias@xilinx.com>
Reviewed-by: NEdgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: NKONRAD Frederic <fred.konrad@greensocs.com>
Signed-off-by: NEdgar E. Iglesias <edgar.iglesias@xilinx.com>

This introduces a special callback which allows to run code from some MMIO
devices.

SysBusDevice with a MemoryRegion which implements the request_ptr callback will
be notified when the guest try to execute code from their offset. Then it will
be able to eg: pre-load some code from an SPI device or ask a pointer from an
external simulator, etc..

When the pointer or the data in it are no longer valid the device has to
invalidate it.
Reviewed-by: NEdgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: NKONRAD Frederic <fred.konrad@greensocs.com>
Signed-off-by: NEdgar E. Iglesias <edgar.iglesias@xilinx.com>

This introduces mmio_interface object which contains a MemoryRegion
and can be hotplugged/hotunplugged.
Reviewed-by: NEdgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: NKONRAD Frederic <fred.konrad@greensocs.com>
Signed-off-by: NEdgar E. Iglesias <edgar.iglesias@xilinx.com>