With automatically generated GUID, on minor version changes, an error
occurred, stating that there is a problem with the installer.
Now, a notification is shown, warning the user that another version of
this product is already installed, and that configuration or removal of
the existing version is possible through Add/Remove Programs on the
Control Panel (expected behavior).

Signed-off-by: Leonid Bloch <leonid@daynix.com>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

Magic constants are a pain to use, especially when we run the
risk that our choice of '1' for QGA_SEEK_CUR might differ from
the host or guest's choice of SEEK_CUR.  Better is to use an
enum value, via a qapi alternate type for back-compatibility.

With this,
 {"command":"guest-file-seek", "arguments":{"handle":1,
  "offset":0, "whence":"cur"}}
becomes a synonym for the older
 {"command":"guest-file-seek", "arguments":{"handle":1,
  "offset":0, "whence":1}}

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

TriCore bugfixes and synchronous trap implementation

# gpg: Signature made Thu 25 Feb 2016 11:57:41 GMT using RSA key ID 6B69CA14
# gpg: Good signature from "Bastian Koppelmann <kbastian@mail.uni-paderborn.de>"

* remotes/bkoppelmann/tags/pull-tricore-20160225:
  target-tricore: add opd trap generation
  target-tricore: add illegal opcode trap generation
  target-tricore: add context managment trap generation
  target-tricore: Add trap handling & SOVF/OVF traps
  target-tricore: Fix wrong precedences on psw_write
  target-tricore: fix save_context_upper using env->PSW

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

vhost, virtio, pci, pc

Fixes all over the place.
virtio dataplane migration support.
Old q35 machine types removed.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

# gpg: Signature made Thu 25 Feb 2016 11:16:46 GMT 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: (21 commits)
  q35: No need to check gigabyte_align
  q35: Remove unused q35-acpi-dsdt.aml file
  ich9: Remove enable_tco arguments from init functions
  machine: Remove no_tco field
  q35: Remove old machine versions
  tests/vhost-user-bridge: fix build on 32 bit systems
  vring: remove
  virtio-scsi: do not use vring in dataplane
  virtio-blk: do not use vring in dataplane
  virtio-blk: fix "disabled data plane" mode
  virtio: export vring_notify as virtio_should_notify
  virtio: add AioContext-specific function for host notifiers
  vring: make vring_enable_notification return void
  block-migration: acquire AioContext as necessary
  pci core: function pci_bus_init() cleanup
  pci core: function pci_host_bus_register() cleanup
  balloon: Use only 'pc-dimm' type dimm for ballooning
  virtio-balloon: rewrite get_current_ram_size()
  move get_current_ram_size to virtio-balloon.c
  vhost-user: don't merge regions with different fds
  ...

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

If an instruction uses a 64 bit register which consists of an even-odd pair
of 32 bit registers and if the register specifier in the instruction is
odd an opd trap is raised.

Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Message-Id: <1455889426-1923-5-git-send-email-kbastian@mail.uni-paderborn.de>

Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Message-Id: <1455889426-1923-4-git-send-email-kbastian@mail.uni-paderborn.de>

Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Message-Id: <1455889426-1923-3-git-send-email-kbastian@mail.uni-paderborn.de>

Add the infrastructure needed to generate and handle traps and
implement the generation of SOVF and OVF traps.

Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Message-Id: <1455889426-1923-2-git-send-email-kbastian@mail.uni-paderborn.de>

Wrong braces on the restore of the cached TCGv SV and V bit could lead to
a wrong PSW. While at this it removes unnecessary braces for the restore
of the cached TCGv AV and SAV bits.

Signed-off-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>

If the cached bits for C, V, SV, AV, or SAV were set, they would
not be saved during the context save since env->PSW was stored instead
of properly reading them using psw_read().

Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>

Second pull req with getrandom fix

# gpg: Signature made Thu 25 Feb 2016 10:57:42 GMT using RSA key ID DE3C9BC0
# gpg: Good signature from "Riku Voipio <riku.voipio@iki.fi>"
# gpg:                 aka "Riku Voipio <riku.voipio@linaro.org>"

* remotes/riku/tags/pull-linux-user-20160225:
  linux-user: add getrandom() syscall
  linux-user: correct timerfd_create syscall numbers
  linux-user: remove unavailable syscalls from aarch64
  linux-user: sync syscall numbers with kernel
  linux-user: Don't assert if guest tries shmdt(0)
  linux-user: set ppc64/ppc64le default CPU to POWER8
  build: [linux-user] Rename "syscall.h" to "target_syscall.h" in target directories
  linux-user: fix realloc size of target_fd_trans.

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

gigabyte_align is always true on q35, so we don't need the
!gigabyte_align compat code anymore.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>

The file was used only by older machine-types, and it is not
needed anymore.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>

The enable_tco arguments are always true, so they are not needed
anymore.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>

The field is always set to zero, so it is not necessary anymore.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>

Migration with q35 was not possible before commit
04329029, because q35
unconditionally creates an ich9-ahci device, that was marked as
unmigratable. So all q35 machine classes before pc-q35-2.4 were
not migratable, so there's no point in keeping compatibility code
for them.

Remove all old pc-q35 machine classes and keep only pc-q35-2.4
and newer.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>

Mainly casts between void * and uint64_t, and wrong
format for size_t.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

In disabled mode, virtio-blk dataplane seems to be enabled, but flow
actually goes through the normal virtio path.  This patch simplifies a bit
the handling of disabled mode.  In disabled mode, virtio_blk_handle_output
might be called even if s->dataplane is not NULL.

This is a bit tricky, because the current check for s->dataplane will
always trigger, causing a continuous stream of calls to
virtio_blk_data_plane_start.  Unfortunately, these calls will not
do anything.  To fix this, set the "started" flag even in disabled
mode, and skip virtio_blk_data_plane_start if the started flag is true.
The resulting changes also prepare the code for the next patch, were
virtio-blk dataplane will reuse the same virtio_blk_handle_output function
as "regular" virtio-blk.

Because struct VirtIOBlockDataPlane is opaque in virtio-blk.c, we have
to move s->dataplane->started inside struct VirtIOBlock.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

Virtio dataplane needs to trigger the irq manually through the
guest notifier.  Export virtio_should_notify so that it can be
used around event_notifier_set.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

This is used to register ioeventfd with a dataplane thread.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

Make the API more similar to the regular virtqueue API.  This will
help when modifying the code to not use vring.c anymore.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

This is needed because dataplane will run during block migration as well.

The block device migration code is quite liberal in taking the iothread
mutex.  For simplicity, keep it the same way, even though one could
actually choose between the BQL (for regular BlockDriverStates) and
the AioContext (for dataplane BlockDriverStates).  When the block layer
is made fully thread safe, aio_context_acquire shall go away altogether.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>

remove unused param

Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>

remove unused param, and rename the other to a meaningful one.

Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>

For now there are only two dimm's: pc-dimm and nvdimm. This patch is
actually needed to disable ballooning on nvdimm. But, to avoid future
bugs, instead of disallowing nvdimm, we allow only pc-dimm. So, if
someone adds new dimm which should be balloon-able, then this ability
should be explicitly specified here.

Why ballooning for nvdimm should be disabled for now:

NVDIMM for now is planned to use as a backing store for DAX filesystem
in the guest and thus this memory is excluded from guest memory
management and LRUs.

In this case libvirt running QEMU along with configured balloon almost
immediately inflates balloon and effectively kill the guest as
qemu counts nvdimm as part of the ram.

Counting dimm devices as part of the ram for ballooning was started from
commit 463756d0:
 virtio-balloon: Fix balloon not working correctly when hotplug memory

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Use pc_dimm_built_list() instead of qmp_pc_dimm_device_list()

Actually, Qapi is not related to this internal helper.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

ppc patch queue for 2016-02-25

Hopefully final queue before qemu-2.6 soft freeze.  Currently
accumulated patches for target-ppc, pseries machine type and related
devices:
    * SLOF firmware update
        - Many new features, including virtio 1.0 non-legacy support
    * H_PAGE_INIT hypercall implementation
    * Small cleanups and bugfixes.

# gpg: Signature made Thu 25 Feb 2016 03:00:56 GMT 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-2.6-20160225:
  ppc/kvm: Tell the user what might be wrong when using bad CPU types with kvm-hv
  ppc/kvm: Use error_report() instead of cpu_abort() for user-triggerable errors
  spapr: initialize local Error pointer
  hw/ppc/spapr: Implement the h_page_init hypercall
  pseries: Update SLOF firmware image to 20160223

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

Using a CPU type that does not match the host is not possible when using
the kvm-hv kernel module - the PVR is checked in the kernel function
kvm_arch_vcpu_ioctl_set_sregs_hv() and rejected with -EINVAL if it
does not match the host.
However, when the user tries to specify a non-matching CPU type, QEMU
currently only reports "kvm_init_vcpu failed: Invalid argument", and
this is of course not very helpful for the user to solve the problem.
So this patch adds a more descriptive error message that tells the
user to specify "-cpu host" instead.

Signed-off-by: Thomas Huth <thuth@redhat.com>
[Removed melodramatic '!' :)]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

Setting the KVM_CAP_PPC_PAPR capability can fail if either the KVM
kernel module does not support it, or if the specified vCPU type
is not a 64-bit Book3-S CPU type. For example, the user can trigger
it easily with "-M pseries -cpu G2leLS" when using the kvm-pr kernel
module. So the error should not be reported with cpu_abort() since
this function is rather meant for reporting programming errors than
reporting user-triggerable errors (it prints out all CPU registers
and then calls abort() to kills the program - two things that the
normal user does not expect here) . So let's use error_report() with
exit(1) here instead.
A similar problem exists in the code that sets the KVM_CAP_PPC_EPR
capability, so while we're at it, fix that, too.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

This fixes a crash in the target QEMU during migration.

Broken in commit c5f54f3e.

Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[reworded commit message]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

This hypercall either initializes a page with zeros, or copies
another page.
According to LoPAPR, the i-cache of the page should also be
flushed if using H_ICACHE_INVALIDATE or H_ICACHE_SYNCHRONIZE,
and the d-cache should be synchronized to the RAM if the
H_ICACHE_SYNCHRONIZE flag is used. For this, two new functions
are introduced, kvmppc_dcbst_range() and kvmppc_icbi()_range, which
use the corresponding assembler instructions to flush the caches
if running with KVM on Power. If the code runs with TCG instead,
the code only uses tb_flush(), assuming that this will be
enough for synchronization.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

The main change is virtio 1.0 support.

The complete changelog is:
  > dhcp: fix warning messages when calling strtoip()
  > virtio-scsi: enable virtio 1.0
  > virtio-scsi: use virtio_fill desc api
  > virtio-scsi: use idx during initialization
  > virtio-net: enable virtio 1.0
  > virtio-blk: enable virtio 1.0
  > virtio: 1.0 helper to read 16/32/64 bit value
  > virtio: add and enable 1.0 device setup
  > virtio: 1.0 guest features negotiation
  > virtio: update features set/get register accessor
  > virtio: make all virtio apis 1.0 aware
  > virtio: add 64-bit virtio helpers for 1.0
  > virtio: add virtio 1.0 related struct and defines
  > virtio: get rid of type variable in virtio_device
  > virtio-net: move setup-mac to the open routine
  > virtio-net: make net_hdr_size a variable
  > virtio-net: replace vq array with vq_{tx,rx}
  > virtio-net: use virtio_fill_desc
  > virtio-{net,blk,scsi,9p}: use status variable
  > virtio-blk: add helpers for filling descriptors
  > virtio-{blk,9p}: enable resetting the device
  > virtio: introduce helper for initializing virt queue
  > virtio: fix code style/design issues.
  > fix code style in byteorder.h
  > pci: add byte read/write helper routines
  > virtio-net: fix gcc warnings (-Wextra)
  > virtio-blk: fix gcc warnings (-Wextra)
  > readme: Add a note about coding style
  > dhcp: Remove duplicated strtoip()
  > ethernet: Fix gcc warnings
  > net-snk: Fix gcc warnings
  > net-snk: Fix coding style
  > net-snk: Fix memory leak in dhcp6_process_options()
  > net-snk: Fix memory leak in ip6_to_multicast_mac() / send_ipv6()
  > net-snk: Remove bad NEIGHBOUR_SOLICITATION code in send_ipv6()
  > Fix dma-alloc and dma-map-in functions on board-js2x
  > net-snk: Allow stateless autoconfig IPv6 addresses with IP_INIT_IPV6_MANUAL
  > net-snk: Simplify the ip6_is_multicast() function
  > net-snk: Move global variable definition out of the header file
  > net-snk: Prefer non-link-local unicast IPv6 addresses if possible
  > net-snk: Fix the check for link-local addresses when receiving RAs
  > net-snk: Remove junk at the end of IPv6 TFTP ACK and error packets
  > Fix format strings in usb-ohci.c
  > net-snk: Get rid of junk at the end of sent DHCPv6 packets
  > net-snk: Use transaction IDs in DHCPv4, too
  > net-snk: Make use of DHCPv6 transaction IDs
  > net-snk: Seed the pseudo-random number generator
  > libc: Add srand() call
  > libc: Fix the rand() function to return non-zero values
  > net-snk: Improve printed text when booting via network
  > Increase temporary buffer size of ibm,client-architecture-support call
  > Move archsupport.fs into board-qemu directory
  > boot: stop booting when we encounter HALT
  > fat-files: Fix bug with root-entries = 0 on certain FAT32 file systems
  > usb: print unhandled descriptor in debug mode
  > Improve stack usage with libnvram get_partition function
  > Improve stack usage in libnvram environment variable code
  > libc: Port vsnprintf back from skiboot
  > Move the code for rfill into a separate function
  > Rework wrapper for new_nvram_partition() and fix possible bug in there
  > Stack optimization in libusb: split up setup_new_device()
  > Check for stack overflow in paflof engine
  > Clean up pending packet variable in ipv4 code
  > Fix tracking of pending outgoing packets when handling ARP replies

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

getrandom() has been introduced in kernel 3.17 and is now used during
the boot sequence of Debian unstable (stretch/sid).

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>

x86, m68k, ppc, sh4 and sparc failed to enable timerfd, because they
didn't have timerfd_create system call defined. Instead QEMU
defined timerfd syscall. Checking with kernel sources, it appears
kernel developers reused timerfd syscall number with timerfd_create,
presumably since no userspace called the old syscall number.

Reported-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>

QEMU lists deprecated system call numbers in for Aarch64. These
are never enabled for Linux kernel, so don't define them in Qemu
either. Remove the ifdef around host_to_target_stat64 since
all architectures need it now.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>

Sync syscall numbers to match the linux v4.5-rc1 kernel.

Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>

Our implementation of shmat() and shmdt() for linux-user was
using "zero guest address" as its marker for "entry in the
shm_regions[] array is not in use". This meant that if the
guest did a shmdt(0) we would match on an unused array entry
and call page_set_flags() with both start and end addresses zero,
which causes an assertion failure.

Use an explicit in_use flag to manage the shm_regions[] array,
so that we avoid this problem.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reported-by: Pavel Shamis <pasharesearch@gmail.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>