Aurelien Jarno [Fri, 21 Sep 2012 16:20:26 +0000 (18:20 +0200)]
tcg/mips: implement rotl/rotr ops on MIPS32R2
rotr operations can be optimized on MIPS32 Release 2 using the ROTR and
ROTRV instructions. Also implemented rotl operations by subtracting the
shift from 32.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Aurelien Jarno [Fri, 21 Sep 2012 16:20:26 +0000 (18:20 +0200)]
tcg/mips: optimize bswap{16,16s,32} on MIPS32R2
bswap operations can be optimized on MIPS32 Release 2 using the ROTR,
WSBH and SEH instructions. We can't use the non-R2 code to implement the
ops due to registers constraints, so don't define the corresponding
TCG_TARGET_HAS_bswap* values.
Also bswap16* operations are supposed to be called with the 16 high bits
zeroed. This is the case everywhere (including for TCG by definition)
except when called from the store helper. Remove the AND instructions from
bswap16* and move it there.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Aurelien Jarno [Fri, 21 Sep 2012 16:20:26 +0000 (18:20 +0200)]
tcg/mips: optimize brcond arg, 0
MIPS has some conditional branch instructions when comparing with zero.
Use them.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Aurelien Jarno [Fri, 21 Sep 2012 16:20:26 +0000 (18:20 +0200)]
tcg/mips: use stack for TCG temps
Use stack instead of temp_buf array in CPUState for TCG
temps.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Aurelien Jarno [Fri, 21 Sep 2012 16:20:26 +0000 (18:20 +0200)]
tcg/mips: don't use global pointer
Don't use the global pointer in TCG, in case helpers try access global
variables.
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Aurelien Jarno [Fri, 21 Sep 2012 16:20:26 +0000 (18:20 +0200)]
tcg/mips: use TCGArg or TCGReg instead of int
Instead of int, use the correct TCGArg and TCGReg type: TCGReg when
representing a TCG target register, TCGArg when representing the latter
or a constant.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Aurelien Jarno [Fri, 21 Sep 2012 16:20:25 +0000 (18:20 +0200)]
tcg/mips: kill warnings in user mode
Recent versions of GCC emit warnings when compiling user mode targets.
Kill them by reordering a bit the #ifdef.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Aurelien Jarno [Fri, 21 Sep 2012 16:20:25 +0000 (18:20 +0200)]
tcg-mips: fix wrong usage of 'Z' constraint
The 'Z' constraint has been introduced to map the zero register. However
when the op also accept a constant, there is no point to accept the zero
register in addition.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Aurelien Jarno [Fri, 21 Sep 2012 17:53:26 +0000 (19:53 +0200)]
Merge branch 'usb.65' of git://git.kraxel.org/qemu
* 'usb.65' of git://git.kraxel.org/qemu:
uhci: Don't queue up packets after one with the SPD flag set
usb-redir: Revert usb-redir part of commit
93bfef4c
usb-redir: Add chardev open / close debug logging
usb-redir: Add support for migration
usb-redir: Store max_packet_size in endp_data
usb-redir: Add an already_in_flight packet-id queue
usb-redir: Change cancelled packet code into a generic packet-id queue
ehci: Walk async schedule before and after migration
ehci: Don't set seen to 0 when removing unseen queue-heads
configure: usbredir fixes
ehci: Don't process too much frames in 1 timer tick (v2)
ehci: Fix interrupts stopping when Interrupt Threshold Control is 8
ehci: switch to new-style memory ops
usb-host: allow emulated (non-async) control requests without USBPacket
Richard Henderson [Wed, 19 Sep 2012 02:59:48 +0000 (19:59 -0700)]
tcg-hppa: Fix broken load/store helpers
The CONFIG_TCG_PASS_AREG0 code for calling ld/st helpers
was not respecting the ABI requirement for 64-bit values
being aligned in registers.
Mirror the ARM port in use of helper functions to marshal
arguments into the correct registers.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Richard Henderson [Wed, 19 Sep 2012 02:59:47 +0000 (19:59 -0700)]
tcg-hppa: Fix brcond2 and setcond2
Neither of these functions were performing double-word
compares properly.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Richard Henderson [Mon, 17 Sep 2012 15:28:52 +0000 (08:28 -0700)]
tcg: Fix !USE_DIRECT_JUMP
Commit
6375e09e changed the type of TranslationBlock.tb_next,
but failed to change the type of TCGContext.tb_next.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Aurelien Jarno [Sun, 16 Sep 2012 11:12:21 +0000 (13:12 +0200)]
gdbstub/sh4: fix build with USE_SOFTFLOAT_STRUCT_TYPES
We have to use different type to access float values when
USE_SOFTFLOAT_STRUCT_TYPES is defined.
Rework SH4 version of cpu_gdb_{read,write}_register() using
a single case, and fixing the coding style. Use ldll_p() and
stfl_p() to access float values.
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Richard Henderson [Fri, 21 Sep 2012 17:13:38 +0000 (10:13 -0700)]
tcg: Optimize two-address commutative operations
While swapping constants to the second operand, swap
sources matching destinations to the first operand.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Richard Henderson [Fri, 21 Sep 2012 17:13:37 +0000 (10:13 -0700)]
tcg: Optimize movcond for constant comparisons
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Richard Henderson [Fri, 21 Sep 2012 17:13:36 +0000 (10:13 -0700)]
tcg-i386: Implement movcond
Signed-off-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Richard Henderson [Fri, 21 Sep 2012 17:13:35 +0000 (10:13 -0700)]
target-alpha: Use movcond
For proper cmov insns, as well as the non-goto-tb case
of conditional branch.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Richard Henderson [Fri, 21 Sep 2012 17:13:34 +0000 (10:13 -0700)]
tcg: Introduce movcond
Implemented with setcond if the target does not provide
the optional opcode.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Aurelien Jarno [Sun, 16 Sep 2012 11:12:21 +0000 (13:12 +0200)]
target-sh4: remove useless code
Almost dead code.
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Aurelien Jarno [Sun, 16 Sep 2012 11:12:21 +0000 (13:12 +0200)]
target-sh4: cleanup DisasContext
We should avoid accessing env at translation stage, except of course for
static values like the supported features.
Remove variables copied from env in DisasContext and use the TB flags
instead.
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Aurelien Jarno [Sun, 16 Sep 2012 11:12:21 +0000 (13:12 +0200)]
target-sh4: rework exceptions handling
Since commit
fd4bab102 PC is restored in case of exception through code
retranslation. While it is clearly the thing to do in case it is not
not known if an helper is going to trigger an exception or not
(e.g. for load/store, FPU, etc.), it just make things slower when the
exception is already known at translation time.
Partially revert this commit and save PC in the TCG code. Set bstate to
BS_BRANCH to not generate TCG exit code. Micro-optimize the sleep
helper. Make all the exception helpers to call raise_exception and mark
it as noreturn.
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Aurelien Jarno [Sun, 16 Sep 2012 11:12:20 +0000 (13:12 +0200)]
target-sh4: remove gen_clr_t() and gen_set_t()
gen_clr_t() and gen_set_t() have very few callers and can be remplaced
by a single line. Remove them.
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Aurelien Jarno [Sun, 16 Sep 2012 11:12:20 +0000 (13:12 +0200)]
target-sh4: optimize swap.w
It's possible swap the two 16-bit words of a 32-bit register using a
rotation. If the TCG target doesn't implement rotation, the replacement
code is similar to the previously implemented code.
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Aurelien Jarno [Sun, 16 Sep 2012 11:12:20 +0000 (13:12 +0200)]
target-sh4: optimize xtrct
The register being 32 bit long, after a shift to the right by 16 bits,
the upper 16 bit are already cleared. There is no need to call ext16u
to clear them.
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Aurelien Jarno [Sun, 16 Sep 2012 11:12:20 +0000 (13:12 +0200)]
target-sh4: implement addv and subv using TCG
addv and subv helpers implementation is directly copied from the SH4
manual and looks quite complex. It is however possible to explain it
without branches, and is therefore possible to implement it with TCG.
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Aurelien Jarno [Sun, 16 Sep 2012 11:12:20 +0000 (13:12 +0200)]
target-sh4: implement addc and subc using TCG
Now that setcond is available, the addc and subc can easily be
implemented using TCG.
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Aurelien Jarno [Sun, 16 Sep 2012 11:12:20 +0000 (13:12 +0200)]
target-sh4: use float32_muladd() to implement fmac
There is no need to add a SH4 specific pickNaNMulAdd() to softfloat as
SH4 is always returning a default NaN.
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Aurelien Jarno [Sun, 16 Sep 2012 11:12:20 +0000 (13:12 +0200)]
target-sh4: mark a few helpers const and pure
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Max Filippov [Thu, 20 Sep 2012 22:59:50 +0000 (02:59 +0400)]
target-xtensa: don't emit extra tcg_gen_goto_tb
Unconditional gen_check_loop_end at the end of disas_xtensa_insn
can emit tcg_gen_goto_tb with slot id already used in the TB (e.g. when
TB ends at LEND with a branch).
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Cc: qemu-stable <qemu-stable@nongnu.org>
Signed-off-by: malc <av1474@comtv.ru>
Max Filippov [Thu, 20 Sep 2012 22:59:49 +0000 (02:59 +0400)]
target-xtensa: fix extui shift amount
extui opcode only uses lowermost op1 bit for sa4.
Reported-by: malc <av1474@comtv.ru>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Cc: qemu-stable <qemu-stable@nongnu.org>
Signed-off-by: malc <av1474@comtv.ru>
Aurelien Jarno [Wed, 19 Sep 2012 19:40:30 +0000 (21:40 +0200)]
tcg/optimize: fix end of basic block detection
Commit
e31b0a7c050711884ad570fe73df806520953618 fixed copy propagation on
32-bit host by restricting the copy between different types. This was the
wrong fix.
The real problem is that the all temps states should be reset at the end
of a basic block. This was done by adding such operations in the switch,
but brcond2 was forgotten (that's why the crash was only observed on 32-bit
hosts).
Fix that by looking at the TCG_OPF_BB_END instead. We need to keep the case
for op_set_label as temps might be modified through another path.
Cc: Blue Swirl <blauwirbel@gmail.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Richard Henderson [Wed, 19 Sep 2012 04:59:44 +0000 (21:59 -0700)]
target-mips: Implement Loongson Multimedia Instructions
Implements all of the COP2 instructions except for the S<cond>
family of comparisons. The documentation is unclear for those.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Richard Henderson [Wed, 19 Sep 2012 04:55:34 +0000 (21:55 -0700)]
target-mips: Always evaluate debugging macro arguments
this will prevent some of the compilation errors with debugging
enabled from creeping back in.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Richard Henderson [Wed, 19 Sep 2012 04:55:33 +0000 (21:55 -0700)]
target-mips: Fix MIPS_DEBUG.
The macro uses the DisasContext. Pass it around as needed.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Acked-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Richard Henderson [Wed, 19 Sep 2012 04:55:32 +0000 (21:55 -0700)]
target-mips: Set opn in gen_ldst_multiple.
Used by MIPS_DEBUG, when enabled.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Acked-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Peter Maydell [Tue, 18 Sep 2012 13:53:42 +0000 (14:53 +0100)]
hw/pflash_cfi0[12]: Use host-utils.h ctz32()
Drop the private reimplementation of ctz32() from pflash_cfi0[12]
in favour of using the standard version from host-utils.h.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Aurelien Jarno [Mon, 3 Sep 2012 20:47:03 +0000 (22:47 +0200)]
pflash_cfi01: fix vendor specific extended query
pflash_cfi01 announces a version number of 1.1, which implies
"Protection Register Information" and "Burst Read information"
sections, which are not provided.
Decrease the version number to 1.0 so that only the "Protection
Register Information" section is needed.
Set the number of protection fields (0x3f) to 0x01, as 0x00 means 256
protections field, which makes the CFI table bigger than the current
implementation, causing some kernels to fail to read it.
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Aurelien Jarno [Mon, 10 Sep 2012 11:14:12 +0000 (13:14 +0200)]
revert "TCG: fix copy propagation"
Given the copy propagation breakage on 32-bit hosts has been fixed
commit
e31b0a7c050711884ad570fe73df806520953618 can be reverted.
Cc: Blue Swirl <blauwirbel@gmail.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Aurelien Jarno [Mon, 10 Sep 2012 12:23:49 +0000 (14:23 +0200)]
tcg: mark set_label with TCG_OPF_BB_END flag
set_label is effectively the end of a basic block, as no optimization
can be made accross it. It was treated as such in the liveness analysis
code, but as a special case.
Mark it with TCG_OPF_BB_END flag so that this information can be used
by other parts of the TCG code, and remove the special case in the liveness
analysis code.
Cc: Blue Swirl <blauwirbel@gmail.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Aurelien Jarno [Mon, 10 Sep 2012 11:56:24 +0000 (13:56 +0200)]
tcg/i386: allow constants in load/store ops
On x86, it is possible to move a constant value to memory. Add code to
handle a constant argument to load/store ops.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Chris Wulff [Mon, 10 Sep 2012 00:20:07 +0000 (20:20 -0400)]
xilinx_timer: Fix a compile error if debug enabled
There was a missing include of qemu-log and a variable name in a printf was out
of date.
Signed-off-by: Chris Wulff <crwulff@gmail.com>
Signed-off-by: Peter A. G. Crosthwaite <peter.crosthwaite@petalogix.com>
Peter A. G. Crosthwaite [Mon, 17 Sep 2012 04:06:32 +0000 (14:06 +1000)]
xilinx: fix names of ethernet and dma links.
These names were incorrect. Fixed to match to actual link names
Signed-off-by: Peter A. G. Crosthwaite <peter.crosthwaite@petalogix.com>
Peter A. G. Crosthwaite [Mon, 17 Sep 2012 03:41:39 +0000 (13:41 +1000)]
xilinx.h: Error check when setting links
Assert that the ethernet and dma controller are sucessfully linked to their
peers.
Signed-off-by: Peter A. G. Crosthwaite <peter.crosthwaite@petalogix.com>
Peter A. G. Crosthwaite [Fri, 29 Jun 2012 03:20:46 +0000 (13:20 +1000)]
xilinx_timer: Fixed "frequency" prop name
The "frequency" qdev prop matches the "clock-frequency" property in Xilinx EDK.
Renamed "frequency" -> "clock-frequency" accordingly.
Signed-off-by: Peter A. G. Crosthwaite <peter.crosthwaite@petalogix.com>
Peter A. G. Crosthwaite [Thu, 28 Jun 2012 06:28:03 +0000 (16:28 +1000)]
xilinx_timer: Send dbg msgs to stderr not stdout
Signed-off-by: Peter A. G. Crosthwaite <peter.crosthwaite@petalogix.com>
Peter A. G. Crosthwaite [Thu, 28 Jun 2012 02:52:23 +0000 (12:52 +1000)]
xilinx_timer: Removed comma in device name
Fixes an error in
a61e4b07a30c062260d2d01771773f14820d1eb7
Signed-off-by: Peter A. G. Crosthwaite <peter.crosthwaite@petalogix.com>
Peter Maydell [Wed, 19 Sep 2012 13:51:38 +0000 (14:51 +0100)]
arch_init.c: Improve '-soundhw help' for non-HAS_AUDIO_CHOICE archs
For architectures which don't set HAS_AUDIO_CHOICE, improve the
'-soundhw help' message so that it doesn't simply print an empty
list, implying no sound support at all.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: malc <av1474@comtv.ru>
Anthony Liguori [Mon, 17 Sep 2012 15:23:20 +0000 (10:23 -0500)]
Merge remote-tracking branch 'kiszka/queues/slirp' into staging
* kiszka/queues/slirp:
slirp: Implement TFTP Blocksize option
slirp: Remove unused return value of tftp_send_next_block
slirp: Handle more than 65535 blocks in TFTP transfers
slirp: improve TFTP performance
slirp: Fix error reported by static code analysis
slirp: Remove wrong type casts ins debug statements
Anthony Liguori [Mon, 17 Sep 2012 15:23:15 +0000 (10:23 -0500)]
Merge remote-tracking branch 'kwolf/for-anthony' into staging
* kwolf/for-anthony:
block: Don't forget to delete temporary file
Don't require encryption password for 'qemu-img info' command
qemu-img: Add json output option to the info command.
qapi: Add SnapshotInfo and ImageInfo.
ahci: properly reset PxCMD on HBA reset
block: fix block tray status
vdi: Fix warning from clang
block/curl: Fix wrong free statement
ide: Fix error messages from static code analysis (no real error)
ATAPI: STARTSTOPUNIT only eject/load media if powercondition is 0
sheepdog: fix savevm and loadvm
Anthony Liguori [Mon, 17 Sep 2012 15:21:42 +0000 (10:21 -0500)]
Merge remote-tracking branch 'stefanha/trivial-patches' into staging
* stefanha/trivial-patches:
configure: fix seccomp check
arch_init.c: add missing '%' symbols before PRIu64 in debug printfs
kvm: Fix warning from static code analysis
qapi: Fix enumeration typo error
console: Clean up bytes per pixel calculation
Fix copy&paste typos in documentation comments
linux-user: Remove #if 0'd cpu_get_real_ticks() definition
ui: Fix spelling in comment (ressource -> resource)
Spelling fixes in comments and macro names (ressource -> resource)
Fix spelling (licenced -> licensed) in GPL
Spelling fixes in comments and documentation
srp: Don't use QEMU_PACKED for single elements of a structured type
Anthony Liguori [Mon, 17 Sep 2012 15:21:09 +0000 (10:21 -0500)]
Merge remote-tracking branch 'spice/spice.v60' into staging
* spice/spice.v60:
hw/qxl: support client monitor configuration via device
qxl: add trace-event for QXL_IO_LOG
hw/qxl: tracing fixes
qxl: better cleanup for surface destroy
qxl: Ignore set_client_capabilities pre/post migrate
qxl: dont update invalid area
spice: send updates only for changed screen content
spice: add screen mirror
spice: split qemu_spice_create_update
spice: switch to queue for vga mode updates
Anthony Liguori [Mon, 17 Sep 2012 15:20:48 +0000 (10:20 -0500)]
Merge remote-tracking branch 'stefanha/net' into staging
* stefanha/net:
net: EAGAIN handling for net/socket.c TCP
net: EAGAIN handling for net/socket.c UDP
net: asynchronous send/receive infrastructure for net/socket.c
net: broadcast hub packets if at least one port can receive
net: fix usbnet_receive() packet drops
net: clean up usbnet_receive()
net: add -netdev options to man page
net: do not report queued packets as sent
net: add receive_disabled logic to iov delivery path
eepro100: Fix network hang when rx buffers run out
xen: flush queue when getting an event
e1000: flush queue whenever can_receive can go from false to true
net: notify iothread after flushing queue
Anthony Liguori [Mon, 17 Sep 2012 15:20:27 +0000 (10:20 -0500)]
Merge remote-tracking branch 'qemu-kvm/uq/master' into staging
* qemu-kvm/uq/master:
kvm: Rename irqchip_inject_ioctl to irq_set_ioctl
kvm: Stop flushing coalesced MMIO on vmexit
VGA: Flush coalesced MMIO on related MMIO/PIO accesses
memory: Flush coalesced MMIO on mapping and state changes
memory: Fold memory_region_update_topology into memory_region_transaction_commit
memory: Use transaction_begin/commit also for single-step operations
memory: Flush coalesced MMIO on selected region access
kvm-all.c: Move init of irqchip_inject_ioctl out of kvm_irqchip_create()
update-linux-headers.sh: Don't hard code list of architectures
Anthony Liguori [Fri, 14 Sep 2012 13:17:03 +0000 (08:17 -0500)]
Revert "Add ability to disable build of all targets"
This reverts commit
66d5499b3754b83c09487259c08fe2ce73188a59.
This commit broke --target-list="x86_64-softmmu" and the fix isn't immediatley
obvious.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
David Gibson [Mon, 10 Sep 2012 02:30:57 +0000 (12:30 +1000)]
cpu_physical_memory_write_rom() needs to do TB invalidates
cpu_physical_memory_write_rom(), despite the name, can also be used to
write images into RAM - and will often be used that way if the machine
uses load_image_targphys() into RAM addresses.
However, cpu_physical_memory_write_rom(), unlike cpu_physical_memory_rw()
doesn't invalidate any cached TBs which might be affected by the region
written.
This was breaking reset (under full emu) on the pseries machine - we loaded
our firmware image into RAM, and while executing it rewrite the code at
the entry point (correctly causing a TB invalidate/refresh). When we
reset the firmware image was reloaded, but the TB from the rewrite was
still active and caused us to get an illegal instruction trap.
This patch fixes the bug by duplicating the tb invalidate code from
cpu_physical_memory_rw() in cpu_physical_memory_write_rom().
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
David Gibson [Mon, 10 Sep 2012 02:30:56 +0000 (12:30 +1000)]
qemu-char: BUGFIX, don't call FD_ISSET with negative fd
tcp_chr_connect(), unlike for example udp_chr_update_read_handler() does
not check if the fd it is using is valid (>= 0) before passing it to
qemu_set_fd_handler2(). If using e.g. a TCP serial port, which is not
initially connected, this can result in -1 being passed to FD_ISSET, which
has undefined behaviour. On x86 it seems to harmlessly return 0, but on
PowerPC, it causes a fortify buffer overflow error to be thrown.
This patch fixes this by putting an extra test in tcp_chr_connect(), and
also adds an assert qemu_set_fd_handler2() to catch other such errors on
all platforms, rather than just some.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Anthony Liguori [Wed, 12 Sep 2012 19:34:07 +0000 (14:34 -0500)]
Revert
455aa1e08 and
c3767ed0eb
commit
c3767ed0eb5d0bb25fe409ae5dec06e3411ff1b6
qemu-char: (Re-)connect for tcp_chr_write() unconnected writing
Has no hope of working because tcp_chr_connect() does not actually connect.
455aa1e08 just fixes the SEGV with server() but the attempt to connect a client
socket is still completely broken.
This patch reverts both.
Reported-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Jan Kiszka [Tue, 11 Sep 2012 14:38:25 +0000 (16:38 +0200)]
pc: Drop practically unused BOCHS BIOS debug ports
We have debugcon these days to listen on those ports that receive debug
messages. Also drop the others that have no effect anymore.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Luiz Capitulino [Wed, 5 Sep 2012 19:50:16 +0000 (16:50 -0300)]
add -machine mem-merge=on|off option
It allows to disable memory merge support (KSM on Linux), which is
enabled by default otherwise.
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Blue Swirl [Sun, 2 Sep 2012 15:28:56 +0000 (15:28 +0000)]
Remove unused CONFIG_TCG_PASS_AREG0 and dead code
Now that CONFIG_TCG_PASS_AREG0 is enabled for all targets,
remove dead code and support for !CONFIG_TCG_PASS_AREG0 case.
Remove dyngen-exec.h and all references to it. Although included by
hw/spapr_hcall.c, it does not seem to use it.
Remove unused HELPER_CFLAGS.
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Blue Swirl [Sun, 2 Sep 2012 14:52:59 +0000 (14:52 +0000)]
target-mips: switch to AREG0 free mode
Add an explicit CPUState parameter instead of relying on AREG0
and switch to AREG0 free mode.
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Acked-by: Aurelien Jarno <aurelien@aurel32.net>
Blue Swirl [Sun, 2 Sep 2012 10:37:06 +0000 (10:37 +0000)]
target-sh4: switch to AREG0 free mode
Add an explicit CPUState parameter instead of relying on AREG0
and switch to AREG0 free mode.
Acked-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Aurelien Jarno [Fri, 7 Sep 2012 14:13:27 +0000 (16:13 +0200)]
target-cris: Switch to AREG0 free mode
Add an explicit CPUCRISState parameter instead of relying on AREG0, and
use cpu_ld* in translation and interrupt handling. Remove AREG0 swapping
in tlb_fill(). Switch to AREG0 free mode
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Aurelien Jarno [Thu, 30 Aug 2012 14:56:39 +0000 (16:56 +0200)]
target-cris: Avoid AREG0 for helpers
Add an explicit CPUCRISState parameter instead of relying on AREG0.
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Blue Swirl [Sun, 2 Sep 2012 08:39:22 +0000 (08:39 +0000)]
target-microblaze: switch to AREG0 free mode
Add an explicit CPUState parameter instead of relying on AREG0
and switch to AREG0 free mode.
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Blue Swirl [Tue, 4 Sep 2012 20:25:59 +0000 (20:25 +0000)]
target-arm: final conversion to AREG0 free mode
Convert code load functions and switch to AREG0 free mode.
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Blue Swirl [Tue, 4 Sep 2012 20:19:15 +0000 (20:19 +0000)]
target-arm: convert remaining helpers
Convert remaining helpers to AREG0 free mode: add an explicit
CPUState parameter instead of relying on AREG0.
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Blue Swirl [Tue, 4 Sep 2012 20:08:34 +0000 (20:08 +0000)]
target-arm: convert void helpers
Add an explicit CPUState parameter instead of relying on AREG0.
For easier review, convert only op helpers which don't return any value.
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Blue Swirl [Sun, 2 Sep 2012 07:42:33 +0000 (07:42 +0000)]
target-unicore32: switch to AREG0 free mode
Add an explicit CPUState parameter instead of relying on AREG0
and switch to AREG0 free mode.
Tested-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Blue Swirl [Sat, 8 Sep 2012 10:48:20 +0000 (10:48 +0000)]
target-m68k: avoid using cpu_single_env
Pass around CPUState instead of using global cpu_single_env.
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Blue Swirl [Sun, 2 Sep 2012 07:27:38 +0000 (07:27 +0000)]
target-m68k: switch to AREG0 free mode
Add an explicit CPUState parameter instead of relying on AREG0
and switch to AREG0 free mode.
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Blue Swirl [Sun, 2 Sep 2012 06:57:17 +0000 (06:57 +0000)]
target-lm32: switch to AREG0 free mode
Add an explicit CPUState parameter instead of relying on AREG0
and switch to AREG0 free mode.
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Blue Swirl [Sat, 8 Sep 2012 11:15:37 +0000 (11:15 +0000)]
target-s390x: avoid cpu_single_env
Pass around CPUState instead of using global cpu_single_env.
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Natanael Copa [Wed, 12 Sep 2012 09:06:51 +0000 (09:06 +0000)]
configure: properly check if -lrt and -lm is needed
Fixes build against uClibc.
uClibc provides 2 versions of clock_gettime(), one with realtime
support and one without (this is so you can avoid linking in -lrt
unless actually needed). This means that the clock_gettime() don't
need -lrt. We still need it for timer_create() so we check for this
function in addition.
We also need check if -lm is needed for isnan().
Both -lm and -lrt are needed for libs_qga.
Signed-off-by: Natanael Copa <ncopa@alpinelinux.org>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Stefan Weil [Wed, 12 Sep 2012 17:18:55 +0000 (19:18 +0200)]
tcg: Fix MAX_OPC_PARAM_IARGS
DEF_HELPER_FLAGS_5 was added some time ago without adjusting
MAX_OPC_PARAM_IARGS.
Fixing the definition becomes more important as QEMU is using
an increasing number of helper functions called with 5 arguments.
Add also a comment to avoid future problems when DEF_HELPER_FLAGS_6
will be added.
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Yann E. MORIN [Thu, 6 Sep 2012 20:40:30 +0000 (22:40 +0200)]
configure: fix seccomp check
Currently, if libseccomp is missing but the user explicitly requested
seccomp support using --enable-seccomp, configure silently ignores the
situation and disables seccomp support.
This is unlike all other tests that explicitly fail in such situation.
Fix that.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Stefan Hajnoczi <stefanha@gmail.com>
Stefan Hajnoczi [Mon, 20 Aug 2012 09:14:35 +0000 (10:14 +0100)]
net: EAGAIN handling for net/socket.c TCP
Replace spinning send_all() with a proper non-blocking send. When the
socket write buffer limit is reached, we should stop trying to send and
wait for the socket to become writable again.
Non-blocking TCP sockets can return in two different ways when the write
buffer limit is reached:
1. ret = -1 and errno = EAGAIN/EWOULDBLOCK. No data has been written.
2. ret < total_size. Short write, only part of the message was
transmitted.
Handle both cases and keep track of how many bytes have been written in
s->send_index. (This includes the 'length' header before the actual
payload buffer.)
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Stefan Hajnoczi [Mon, 20 Aug 2012 09:28:53 +0000 (10:28 +0100)]
net: EAGAIN handling for net/socket.c UDP
Implement asynchronous send for UDP (or other SOCK_DGRAM) sockets. If
send fails with EAGAIN we wait for the socket to become writable again.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Stefan Hajnoczi [Mon, 20 Aug 2012 09:21:54 +0000 (10:21 +0100)]
net: asynchronous send/receive infrastructure for net/socket.c
The net/socket.c net client is not truly asynchronous. This patch
borrows the qemu_set_fd_handler2() code from net/tap.c as the basis for
proper asynchronous send/receive.
Only read packets from the socket when the peer is able to receive.
This avoids needless queuing.
Later patches implement asynchronous send.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Stefan Hajnoczi [Fri, 24 Aug 2012 12:50:30 +0000 (13:50 +0100)]
net: broadcast hub packets if at least one port can receive
In commit
60c07d933c66c4b30a83b7ccbc8a0cb3df1b2d0e ("net: fix
qemu_can_send_packet logic") the "VLAN" broadcast behavior was changed
to queue packets if any net client cannot receive. It turns out that
this was not actually the right fix and just hides the real bug that
hw/usb/dev-network.c:usbnet_receive() clobbers its receive buffer when
called multiple times in a row. The commit also introduced a new bug
that "VLAN" packets would not be sent if one of multiple net clients was
down.
The hw/usb/dev-network.c bug has since been fixed, so this patch reverts
broadcast behavior to send packets as long as one net client can
receive. Packets simply get queued for the net clients that are
temporarily unable to receive.
Reported-by: Roy.Li <rongqing.li@windriver.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Stefan Hajnoczi [Fri, 24 Aug 2012 12:37:29 +0000 (13:37 +0100)]
net: fix usbnet_receive() packet drops
The USB network interface has a single buffer which the guest reads
from. This patch prevents multiple calls to usbnet_receive() from
clobbering the input buffer. Instead we queue packets until buffer
space becomes available again.
This is inspired by virtio-net and e1000 rxbuf handling.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Stefan Hajnoczi [Fri, 24 Aug 2012 12:32:16 +0000 (13:32 +0100)]
net: clean up usbnet_receive()
The USB network interface has two code paths depending on whether or not
RNDIS mode is enabled. Refactor usbnet_receive() so that there is a
common path throughout the function instead of duplicating everything
across if (is_rndis(s)) ... else ... code paths.
Clean up coding style and 80 character line wrap along the way.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Stefan Hajnoczi [Tue, 14 Aug 2012 13:14:27 +0000 (14:14 +0100)]
net: add -netdev options to man page
Document the -netdev syntax which supercedes the older -net syntax.
This patch is a first step to making -netdev prominent in the QEMU
manual.
Reported-by: Anatoly Techtonik <techtonik@gmail.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Stefan Hajnoczi [Mon, 20 Aug 2012 12:35:23 +0000 (13:35 +0100)]
net: do not report queued packets as sent
Net send functions have a return value where 0 means the packet has not
been sent and will be queued. A non-zero value means the packet was
sent or an error caused the packet to be dropped.
This patch fixes two instances where packets are queued but we return
their size. This causes callers to believe the packets were sent. When
the caller uses the async send interface this creates a real problem
because the callback will be invoked for a packet that the caller
believed to be already sent. This bug can cause double-frees in the
caller.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Stefan Hajnoczi [Fri, 17 Aug 2012 20:16:42 +0000 (21:16 +0100)]
net: add receive_disabled logic to iov delivery path
This patch adds the missing NetClient->receive_disabled logic in the
sendv delivery code path. It seems that commit
893379efd0e1b84ceb0c42a713293f3dbd27b1bd ("net: disable receiving if
client returns zero") only added the logic to qemu_deliver_packet() and
not qemu_deliver_packet_iov().
The receive_disabled flag should be automatically set when .receive(),
.receive_raw(), or .receive_iov() return 0. No further packets will be
delivered to the NetClient until the receive_disabled flag is cleared
again by calling qemu_flush_queued_packets().
Typically the NetClient will wait until its file descriptor becomes
writable and then invoke qemu_flush_queued_packets() to resume
transmission.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Bo Yang [Wed, 29 Aug 2012 11:26:11 +0000 (19:26 +0800)]
eepro100: Fix network hang when rx buffers run out
This is reported by QA. When installing os with pxe, after the initial
kernel and initrd are loaded, the procedure tries to copy files from install
server to local harddisk, the network becomes stall because of running out of
receive descriptor.
[Whitespace fixes and removed qemu_notify_event() because Paolo's
earlier net patches have moved it into qemu_flush_queued_packets().
Additional info:
I can reproduce the network hang with a tap device doing a iPXE HTTP
boot as follows:
$ qemu -enable-kvm -m 1024 \
-netdev tap,id=netdev0,script=no,downscript=no \
-device i82559er,netdev=netdev0,romfile=
80861209.rom \
-drive if=virtio,cache=none,file=test.img
iPXE> ifopen net0
iPXE> config # set static network configuration
iPXE> kernel http://mirror.bytemark.co.uk/fedora/linux/releases/17/Fedora/x86_64/os/images/pxeboot/vmlinuz
I needed a vanilla iPXE ROM to get to the iPXE prompt. I think the boot
prompt has been disabled in the ROMs that ship with QEMU to reduce boot
time.
During the vmlinuz HTTP download there is a network hang. hw/eepro100.c
has reached the end of the rx descriptor list. When the iPXE driver
replenishes the rx descriptor list we don't kick the QEMU net subsystem
and event loop, thereby leaving the tap netdev without its file
descriptor in select(2).
Stefan Hajnoczi <stefanha@gmail.com>]
Signed-off-by: Bo Yang <boyang@suse.com>
Signed-off-by: Stefan Hajnoczi <stefanha@gmail.com>
Paolo Bonzini [Thu, 9 Aug 2012 14:45:57 +0000 (16:45 +0200)]
xen: flush queue when getting an event
xen does not have a register that, when written, will cause can_receive
to go from false to true. However, flushing the queue can be attempted
whenever the front-end raises its side of the Xen event channel. There
is a single event channel for tx and rx.
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Amos Kong <akong@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Paolo Bonzini [Thu, 9 Aug 2012 14:45:56 +0000 (16:45 +0200)]
e1000: flush queue whenever can_receive can go from false to true
When the guests replenish the receive ring buffer, the network device
should flush its queue of pending packets. This is done with
qemu_flush_queued_packets.
e1000's can_receive can go from false to true when RCTL or RDT are
modified.
Reported-by: Luigi Rizzo <rizzo@iet.unipi.it>
Cc: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Cc: Jan Kiszka <jan.kiszka@siemens.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Amos Kong <akong@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Paolo Bonzini [Thu, 9 Aug 2012 14:45:55 +0000 (16:45 +0200)]
net: notify iothread after flushing queue
virtio-net has code to flush the queue and notify the iothread
whenever new receive buffers are added by the guest. That is
fine, and indeed we need to do the same in all other drivers.
However, notifying the iothread should be work for the network
subsystem. And since we are at it we can add a little smartness:
if some of the queued packets already could not be delivered,
there is no need to notify the iothread.
Reported-by: Luigi Rizzo <rizzo@iet.unipi.it>
Cc: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Cc: Jan Kiszka <jan.kiszka@siemens.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Amos Kong <akong@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Igor Mitsyanko [Wed, 5 Sep 2012 09:04:56 +0000 (13:04 +0400)]
arch_init.c: add missing '%' symbols before PRIu64 in debug printfs
'%' symbols were missing in front of PRIu64 macros in DPRINTF() messages in
arch_init.c, this caused compilation warnings when compiled with DEBUG_ARCH_INIT defined.
Signed-off-by: Igor Mitsyanko <i.mitsyanko@samsung.com>
Signed-off-by: Stefan Hajnoczi <stefanha@gmail.com>
Stefan Weil [Mon, 3 Sep 2012 20:40:40 +0000 (22:40 +0200)]
kvm: Fix warning from static code analysis
Report from smatch:
kvm-all.c:1373 kvm_init(135) warn:
variable dereferenced before check 's' (see line 1360)
's' cannot by NULL (it was alloced using g_malloc0), so there is no need
to check it here.
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Stefan Hajnoczi <stefanha@gmail.com>
Lei Li [Thu, 23 Aug 2012 05:14:25 +0000 (13:14 +0800)]
qapi: Fix enumeration typo error
Signed-off-by: Lei Li <lilei@linux.vnet.ibm.com>
Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@gmail.com>
BALATON Zoltan [Wed, 22 Aug 2012 15:19:42 +0000 (17:19 +0200)]
console: Clean up bytes per pixel calculation
Division with round up is the correct way to compute this even if the
only case where division with round down gives incorrect result is
probably 15 bpp. This case was explicitely patched up in one of these
functions but was unhandled in the other. (I'm not sure about setting
16 bpp for the 15bpp case either but I left that there for now.)
Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
BALATON Zoltan [Wed, 22 Aug 2012 15:18:38 +0000 (17:18 +0200)]
Fix copy&paste typos in documentation comments
Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Peter Maydell [Mon, 20 Aug 2012 13:03:36 +0000 (14:03 +0100)]
linux-user: Remove #if 0'd cpu_get_real_ticks() definition
Remove the cpu_get_real_ticks() definition from linux-user/main.c.
This has been disabled via #if 0 and unused since commit
1dce7c3c22
in 2006; the definitions we actually use are in qemu-timer.h.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Stefan Weil [Fri, 17 Aug 2012 13:20:00 +0000 (15:20 +0200)]
ui: Fix spelling in comment (ressource -> resource)
The function is called interface_release_resource.
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Stefan Weil [Thu, 16 Aug 2012 13:12:21 +0000 (15:12 +0200)]
Spelling fixes in comments and macro names (ressource -> resource)
Macro XEN_HOST_PCI_RESOURCE_BUFFER_SIZE is only used locally,
so the change should be safe.
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Stefan Weil [Fri, 10 Aug 2012 20:03:26 +0000 (22:03 +0200)]
Fix spelling (licenced -> licensed) in GPL
The patch also fixes the case of "written".
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Stefan Weil [Fri, 10 Aug 2012 20:03:25 +0000 (22:03 +0200)]
Spelling fixes in comments and documentation
These wrong spellings were detected by codespell:
* successully -> successfully
* alot -> a lot
* wanna -> want to
* infomation -> information
* occured -> occurred
["also is" -> "is also" and "ressources" -> "resources" suggested by
Peter Maydell <peter.maydell@linaro.org>]
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Stefan Weil [Fri, 10 Aug 2012 20:03:27 +0000 (22:03 +0200)]
srp: Don't use QEMU_PACKED for single elements of a structured type
QEMU_PACKED results in a MinGW compiler warning when it is
used for single structure elements:
warning: 'gcc_struct' attribute ignored
Using QEMU_PACKED for the whole structure avoids the compiler warning
without changing the memory layout.
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>