This is not a normal header and should only be included in the main
softfloat.c file to bring in the various target specific
specialisations. Indeed as it contains non-inlined C functions it is
not even a legal header. Rename it to match our included C convention.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

The macros use the "flags" type and to be consistent if anyone just
needs the macros we should bring in the header we need. There is an
outstanding TODO to audit the use of "flags" and replace with bool at
which point this include could be dropped.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Acked-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

There are a bunch of users of the inline helpers who do not need
access to the entire softfloat API. Move those inline helpers into a
new header file which can be included without bringing in the rest of
the world.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

Now the rest of the code has been cleaned up we can remove this.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

In our quest to eliminate the home rolled LIT64 macro we fixup usage
inside for m68k's many constants.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

In our quest to eliminate the home rolled LIT64 macro we fixup usage
inside the softfloat code. While we are at it we remove some of the
extraneous spaces to closer fit the house style.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

Remove some more use of LIT64 while making the meaning more clear. We
also avoid the need of casts as the results by definition fit into the
return type.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

This also allows us to remove the extractFloat16exp/frac helpers. We
avoid using the floatXX_pack_raw functions as they are slight overkill
for masking out all but the top bit of the number. The generated code
is almost exactly the same as makes no difference to the
pre-conversion code.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

We have a wrapper that does the right thing from stdint.h so lets use
it for our constants in softfloat-specialize.h

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

target-arm queue:
 * target/arm: generate a custom MIDR for -cpu max
 * hw/misc/zynq_slcr: refactor to use standard register definition
 * Set ENET_BD_BDU in I.MX FEC controller
 * target/arm: Fix routing of singlestep exceptions
 * refactor a32/t32 decoder handling of PC
 * minor optimisations/cleanups of some a32/t32 codegen
 * target/arm/cpu64: Ensure kvm really supports aarch64=off
 * target/arm/cpu: Ensure we can use the pmu with kvm
 * target/arm: Minor cleanups preparatory to KVM SVE support

# gpg: Signature made Fri 16 Aug 2019 14:15:55 BST
# gpg:                using RSA key E1A5C593CD419DE28E8315CF3C2525ED14360CDE
# gpg:                issuer "peter.maydell@linaro.org"
# gpg: Good signature from "Peter Maydell <peter.maydell@linaro.org>" [ultimate]
# gpg:                 aka "Peter Maydell <pmaydell@gmail.com>" [ultimate]
# gpg:                 aka "Peter Maydell <pmaydell@chiark.greenend.org.uk>" [ultimate]
# Primary key fingerprint: E1A5 C593 CD41 9DE2 8E83  15CF 3C25 25ED 1436 0CDE

* remotes/pmaydell/tags/pull-target-arm-20190816: (29 commits)
  target/arm: Use tcg_gen_extrh_i64_i32 to extract the high word
  target/arm: Simplify SMMLA, SMMLAR, SMMLS, SMMLSR
  target/arm: Use tcg_gen_rotri_i32 for gen_swap_half
  target/arm: Use ror32 instead of open-coding the operation
  target/arm: Remove redundant shift tests
  target/arm: Use tcg_gen_deposit_i32 for PKHBT, PKHTB
  target/arm: Use tcg_gen_extract_i32 for shifter_out_im
  target/arm/kvm64: Move the get/put of fpsimd registers out
  target/arm/kvm64: Fix error returns
  target/arm/cpu: Use div-round-up to determine predicate register array size
  target/arm/helper: zcr: Add build bug next to value range assumption
  target/arm/cpu: Ensure we can use the pmu with kvm
  target/arm/cpu64: Ensure kvm really supports aarch64=off
  target/arm: Remove helper_double_saturate
  target/arm: Use unallocated_encoding for aarch32
  target/arm: Remove offset argument to gen_exception_bkpt_insn
  target/arm: Replace offset with pc in gen_exception_internal_insn
  target/arm: Replace offset with pc in gen_exception_insn
  target/arm: Replace s->pc with s->base.pc_next
  target/arm: Remove redundant s->pc & ~1
  ...

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

Block layer patches:

- file-posix: Fix O_DIRECT alignment detection
- Fixes for concurrent block jobs
- block-backend: Queue requests while drained (fix IDE vs. job crashes)
- qemu-img convert: Deprecate using -n and -o together
- iotests: Migration tests with filter nodes
- iotests: More media change tests

# gpg: Signature made Fri 16 Aug 2019 10:29:18 BST
# gpg:                using RSA key 7F09B272C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" [full]
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream:
  file-posix: Handle undetectable alignment
  qemu-img convert: Deprecate using -n and -o together
  block-backend: Queue requests while drained
  mirror: Keep mirror_top_bs drained after dropping permissions
  block: Remove blk_pread_unthrottled()
  iotests: Add test for concurrent stream/commit
  tests: Test mid-drain bdrv_replace_child_noperm()
  tests: Test polling in bdrv_drop_intermediate()
  block: Reduce (un)drains when replacing a child
  block: Keep subtree drained in drop_intermediate
  block: Simplify bdrv_filter_default_perms()
  iotests: Test migration with all kinds of filter nodes
  iotests: Move migration helpers to iotests.py
  iotests/118: Add -blockdev based tests
  iotests/118: Create test classes dynamically
  iotests/118: Test media change for scsi-cd

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

nbd patches for 2019-08-15

- Addition of InetSocketAddress keep-alive
- Addition of BDRV_REQ_PREFETCH for more efficient copy-on-read
- Initial refactoring in preparation of NBD reconnect

# gpg: Signature made Thu 15 Aug 2019 19:28:41 BST
# gpg:                using RSA key A7A16B4A2527436A
# gpg: Good signature from "Eric Blake <eblake@redhat.com>" [full]
# gpg:                 aka "Eric Blake (Free Software Programmer) <ebb9@byu.net>" [full]
# gpg:                 aka "[jpeg image of size 6874]" [full]
# Primary key fingerprint: 71C2 CC22 B1C4 6029 27D2  F3AA A7A1 6B4A 2527 436A

* remotes/ericb/tags/pull-nbd-2019-08-15:
  block/nbd: refactor nbd connection parameters
  block/nbd: add cmdline and qapi parameter reconnect-delay
  block/nbd: move from quit to state
  block/nbd: use non-blocking io channel for nbd negotiation
  block/nbd: split connection_co start out of nbd_client_connect
  nbd: improve CMD_CACHE: use BDRV_REQ_PREFETCH
  block/stream: use BDRV_REQ_PREFETCH
  block: implement BDRV_REQ_PREFETCH
  qapi: Add InetSocketAddress member keep-alive

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

Header cleanup patches for 2019-08-13

# gpg: Signature made Fri 16 Aug 2019 12:39:12 BST
# gpg:                using RSA key 354BC8B3D7EB2A6B68674E5F3870B400EB918653
# gpg:                issuer "armbru@redhat.com"
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>" [full]
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>" [full]
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867  4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-include-2019-08-13-v2: (29 commits)
  sysemu: Split sysemu/runstate.h off sysemu/sysemu.h
  sysemu: Move the VMChangeStateEntry typedef to qemu/typedefs.h
  Include sysemu/sysemu.h a lot less
  Clean up inclusion of sysemu/sysemu.h
  numa: Move remaining NUMA declarations from sysemu.h to numa.h
  Include sysemu/hostmem.h less
  numa: Don't include hw/boards.h into sysemu/numa.h
  Include hw/boards.h a bit less
  Include hw/qdev-properties.h less
  Include qemu/main-loop.h less
  Include qemu/queue.h slightly less
  Include hw/hw.h exactly where needed
  Include qom/object.h slightly less
  Include exec/memory.h slightly less
  Include migration/vmstate.h less
  migration: Move the VMStateDescription typedef to typedefs.h
  Clean up inclusion of exec/cpu-common.h
  Include hw/irq.h a lot less
  typedefs: Separate incomplete types and function types
  ide: Include hw/ide/internal a bit less outside hw/ide/
  ...

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

Separate shift + extract low will result in one extra insn
for hosts like RISC-V, MIPS, and Sparc.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190808202616.13782-8-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

All of the inputs to these instructions are 32-bits.  Rather than
extend each input to 64-bits and then extract the high 32-bits of
the output, use tcg_gen_muls2_i32 and other 32-bit generator functions.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190808202616.13782-7-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Rotate is the more compact and obvious way to swap 16-bit
elements of a 32-bit word.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190808202616.13782-6-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

The helper function is more documentary, and also already
handles the case of rotate by zero.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190808202616.13782-5-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

The immediate shift generator functions already test for,
and eliminate, the case of a shift by zero.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190808202616.13782-4-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Use deposit as the composit operation to merge the
bits from the two inputs.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190808202616.13782-3-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Extract is a compact combination of shift + and.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190808202616.13782-2-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Move the getting/putting of the fpsimd registers out of
kvm_arch_get/put_registers() into their own helper functions
to prepare for alternatively getting/putting SVE registers.

No functional change.

Signed-off-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

A couple return -EINVAL's forgot their '-'s.

Signed-off-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Unless we're guaranteed to always increase ARM_MAX_VQ by a multiple of
four, then we should use DIV_ROUND_UP to ensure we get an appropriate
array size.

Signed-off-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

The current implementation of ZCR_ELx matches the architecture, only
implementing the lower four bits, with the rest RAZ/WI. This puts
a strict limit on ARM_MAX_VQ of 16. Make sure we don't let ARM_MAX_VQ
grow without a corresponding update here.

Suggested-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

We first convert the pmu property from a static property to one with
its own accessors. Then we use the set accessor to check if the PMU is
supported when using KVM. Indeed a 32-bit KVM host does not support
the PMU, so this check will catch an attempt to use it at property-set
time.

Signed-off-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

If -cpu <cpu>,aarch64=off is used then KVM must also be used, and it
and the host must support running the vcpu in 32-bit mode. Also, if
-cpu <cpu>,aarch64=on is used, then it doesn't matter if kvm is
enabled or not.

Signed-off-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Replace x = double_saturate(y) with x = add_saturate(y, y).
There is no need for a separate more specialized helper.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190807045335.1361-12-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Promote this function from aarch64 to fully general use.
Use it to unify the code sequences for generating illegal
opcode exceptions.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190807045335.1361-11-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Unlike the other more generic gen_exception{,_internal}_insn
interfaces, breakpoints always refer to the current instruction.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190807045335.1361-10-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

The offset is variable depending on the instruction set.
Passing in the actual value is clearer in intent.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190807045335.1361-9-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

The offset is variable depending on the instruction set, whereas
we have stored values for the current pc and the next pc.  Passing
in the actual value is clearer in intent.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190807045335.1361-8-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

We must update s->base.pc_next when we return from the translate_insn
hook to the main translator loop.  By incrementing s->base.pc_next
immediately after reading the insn word, "pc_next" contains the address
of the next instruction throughout translation.

All remaining uses of s->pc are referencing the address of the next insn,
so this is now a simple global replacement.  Remove the "s->pc" field.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190807045335.1361-7-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

The thumb bit has already been removed from s->pc, and is always even.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190807045335.1361-6-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Provide a common routine for the places that require ALIGN(PC, 4)
as the base address as opposed to plain PC.  The two are always
the same for A32, but the difference is meaningful for thumb mode.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190807045335.1361-5-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

We currently have 3 different ways of computing the architectural
value of "PC" as seen in the ARM ARM.

The value of s->pc has been incremented past the current insn,
but that is all.  Thus for a32, PC = s->pc + 4; for t32, PC = s->pc;
for t16, PC = s->pc + 2.  These differing computations make it
impossible at present to unify the various code paths.

With the newly introduced s->pc_curr, we can compute the correct
value for all cases, using the formula given in the ARM ARM.

This changes the behaviour for load_reg() and load_reg_var()
when called with reg==15 from a 32-bit Thumb instruction:
previously they would have returned the incorrect value
of pc_curr + 6, and now they will return the architecturally
correct value of PC, which is pc_curr + 4. This will not
affect well-behaved guest software, because all of the places
we call these functions from T32 code are instructions where
using r15 is UNPREDICTABLE. Using the architectural PC value
here is more consistent with the T16 and A32 behaviour.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190807045335.1361-4-richard.henderson@linaro.org
[PMM: added commit message note about UNPREDICTABLE T32 cases]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Add a new field to retain the address of the instruction currently
being translated.  The 32-bit uses are all within subroutines used
by a32 and t32.  This will become less obvious when t16 support is
merged with a32+t32, and having a clear definition will help.

Convert aarch64 as well for consistency.  Note that there is one
instance of a pre-assert fprintf that used the wrong value for the
address of the current instruction.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190807045335.1361-3-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

This function is used in two different contexts, and it will be
clearer if the function is given the address to which it applies.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190807045335.1361-2-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

When generating an architectural single-step exception we were
routing it to the "default exception level", which is to say
the same exception level we execute at except that EL0 exceptions
go to EL1. This is incorrect because the debug exception level
can be configured by the guest for situations such as single
stepping of EL0 and EL1 code by EL2.

We have to track the target debug exception level in the TB
flags, because it is dependent on CPU state like HCR_EL2.TGE
and MDCR_EL2.TDE. (That we were previously calling the
arm_debug_target_el() function to determine dc->ss_same_el
is itself a bug, though one that would only have manifested
as incorrect syndrome information.) Since we are out of TB
flag bits unless we want to expand into the cs_base field,
we share some bits with the M-profile only HANDLER and
STACKCHECK bits, since only A-profile has this singlestep.

Fixes: https://bugs.launchpad.net/qemu/+bug/1838913


Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20190805130952.4415-3-peter.maydell@linaro.org

Factor out code to 'generate a singlestep exception', which is
currently repeated in four places.

To do this we need to also pull the identical copies of the
gen-exception() function out of translate-a64.c and translate.c
into translate.h.

(There is a bug in the code: we're taking the exception to the wrong
target EL.  This will be simpler to fix if there's only one place to
do it.)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20190805130952.4415-2-peter.maydell@linaro.org

This commit properly sets the ENET_BD_BDU flag once the emulated FEC controller
has finished processing the last descriptor. This is done for both transmit
and receive descriptors.

This allows the QNX 7.0.0 BSP for the Sabrelite board (which can be
found at http://blackberry.qnx.com/en/developers/bsp) to properly
control the FEC. Without this patch, the BSP ethernet driver will never
re-use FEC descriptors, as the unset ENET_BD_BDU flag will cause
it to believe that the descriptors are still in use by the NIC.

Note that Linux does not appear to use this field at all, and is
unaffected by this patch.

Without this patch, QNX will think that the NIC is still processing its
transaction descriptors, and won't send any more data over the network.

For reference:

On page 1192 of the I.MX 6DQ reference manual revision (Rev. 5, 06/2018),
which can be found at https://www.nxp.com/products/processors-and-microcontrollers/arm-based-processors-and-mcus/i.mx-applications-processors/i.mx-6-processors/i.mx-6quad-processors-high-performance-3d-graphics-hd-video-arm-cortex-a9-core:i.MX6Q?&tab=Documentation_Tab&linkline=Application-Note



the 'BDU' field is described as follows for the 'Enhanced transmit
buffer descriptor':

'Last buffer descriptor update done. Indicates that the last BD data has been updated by
uDMA. This field is written by the user (=0) and uDMA (=1).'

The same description is used for the receive buffer descriptor.

Signed-off-by: Aaron Hill <aa1ronham@gmail.com>
Message-id: 20190805142417.10433-1-aaron.hill@alertinnovation.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>