Special care needs to be taken in ensuring locks are in a consistent
state across fork events. Add helpers so the plugin system can ensure
that.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Fixes: https://gitlab.com/qemu-project/qemu/-/issues/358
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Tested-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20221004115221.2174499-1-alex.bennee@linaro.org>
The hppa target requires a much bigger stack than many other targets,
and the Linux kernel allocates 80 MB by default for it.
This patch increases the guest stack for hppa to 80MB, and prevents
that this default stack size gets reduced by a lower stack limit on the
host.
Since the stack grows upwards on hppa, the stack_limit value marks the
upper boundary of the stack. Fix the output of /proc/self/maps (in the
guest) to show the [stack] marker on the correct memory area.
Signed-off-by: Helge Deller <deller@gmx.de>
Message-Id: <20220924114501.21767-6-deller@gmx.de>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
For arm-compat, initialize console_{in,out}_gf;
otherwise, initialize stdio file descriptors.
This will go some way to cleaning up arm-compat, and
will allow other semihosting to use normal stdio.
Reviewed-by: Luc Michel <lmichel@kalray.eu>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
We had two sets of variables: arg_start/arg_end, and
arg_strings/env_strings. In linuxload.c, we set the
first pair to the bounds of the argv strings, but in
elfload.c, we set the first pair to the bounds of the
argv pointers and the second pair to the bounds of
the argv strings.
Remove arg_start/arg_end, replacing them with the standard
argc/argv/envc/envp values. Retain arg_strings/env_strings
with the meaning we were using in elfload.c.
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/714
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220427025129.160184-1-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
This header only defines the tcg_allowed variable and the tcg_enabled()
function - which are not required in many files that include this
header. Drop the #include statement there.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20220315144107.1012530-1-thuth@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Perform all logfile setup in one step.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220417183019.755276-30-richard.henderson@linaro.org>
We have extra stuff to log at the same time.
Hoist the qemu_log_lock/unlock to the caller and use fprintf.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220417183019.755276-23-richard.henderson@linaro.org>
Do not force exit within qemu_set_log; return bool and pass
an Error value back up the stack as per usual.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220417183019.755276-5-richard.henderson@linaro.org>
This buffering was introduced during the Paleozoic: 9fa3e85353.
There has never been an explanation as to why we may not allow
glibc to allocate the file buffer itself. We certainly have
many other uses of mmap and malloc during user-only startup,
so presumably whatever the issue was, it has been fixed during
the preceeding 18 years.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220417183019.755276-2-richard.henderson@linaro.org>
cpu_get_pic_interrupt() is now unreachable from user-mode,
delete the unnecessary stubs.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210911165434.531552-25-f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Currently the linux-user qemu.h pulls in gdbstub.h. There's no real reason
why it should do this; include it directly from the C files which require
it, and drop the include line in qemu.h.
(Note that several of the C files previously relying on this indirect
include were going out of their way to only include gdbstub.h conditionally
on not CONFIG_USER_ONLY!)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210908154405.15417-9-peter.maydell@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
qemu.h is included in various non-linux-user files (which
mostly want the TaskState struct and the functions for
doing usermode access to guest addresses like lock_user(),
unlock_user(), get_user*(), etc).
Split out the parts that are only used in linux-user itself
into a new user-internals.h. This leaves qemu.h with basically
three things:
* the definition of the TaskState struct
* the user-access functions and macros
* do_brk()
all of which are needed by code outside linux-user that
includes qemu.h.
The addition of all the extra #include lines was done with
sed -i '/include.*qemu\.h/a #include "user-internals.h"' $(git grep -l 'include.*qemu\.h' linux-user)
(and then undoing the change to fpa11.h).
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210908154405.15417-8-peter.maydell@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Split out the mmap prototypes into a new header user-mmap.h
which we only include where required.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210908154405.15417-6-peter.maydell@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Split guest-binary loader prototypes out into a new header
loader.h which we include only where required.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210908154405.15417-5-peter.maydell@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Split the signal related prototypes into the existing header file
signal-common.h, and include it in those places that now require it.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210908154405.15417-4-peter.maydell@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Passing arguments to plugins had to be done through "arg=<argname>".
This is redundant and introduces confusion especially when the argument
has a name and value (e.g. `-plugin plugin_name,arg="argname=argvalue"`).
This allows passing plugin arguments directly e.g:
`-plugin plugin_name,argname=argvalue`
For now, passing arguments through "arg=" is still supports but outputs
a deprecation warning.
Also, this commit makes boolean arguments passed to plugins in the
`argname=on|off` form instead of the deprecated short-boolean form.
Signed-off-by: Mahmoud Mandour <ma.mandourr@gmail.com>
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20210730135817.17816-2-ma.mandourr@gmail.com>
The mapping from file-descriptors to translator functions is not guarded
on realloc which may cause invalid function pointers to be read from a
previously deallocated mapping.
Signed-off-by: Owen Anderson <oanderso@google.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210701221255.107976-1-oanderso@google.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Instead of delaying tcg_region_init until after tcg_prologue_init
is complete, do tcg_region_init first and let tcg_prologue_init
shrink the first region by the size of the generated prologue.
Reviewed-by: Luis Pires <luis.pires@eldorado.org.br>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
We can not use watchpoints in user-mode emulation because we
need the softmmu slow path to detect accesses to watchpointed
memory. This code is expanded as empty stub in "hw/core/cpu.h"
anyway, so we can drop it.
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210303214708.1727801-18-f4bug@amsat.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
move the call for sysemu specifically in machine_run_board_init,
mirror the calling sequence for user mode too.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Claudio Fontana <cfontana@suse.de>
Message-Id: <20210322132800.7470-23-cfontana@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Stop including cpu.h in files that don't need it.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20210416171314.2074665-4-thuth@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Add --preserve-argv0 in qemu-binfmt-conf.sh to configure the preserve-argv0
flag.
This patch allows to use new flag in AT_FLAGS to detect if
preserve-argv0 is configured for this interpreter:
argv[0] (the full pathname provided by binfmt-misc) is removed and
replaced by argv[1] (the original argv[0] provided by binfmt-misc when
'P'/preserve-arg[0] is set)
For instance with this patch and kernel support for AT_FLAGS:
$ sudo chroot m68k-chroot sh -c 'echo $0'
sh
without this patch:
$ sudo chroot m68k-chroot sh -c 'echo $0'
/usr/bin/sh
The new flag is available in kernel (v5.12) since:
2347961b11d4 ("binfmt_misc: pass binfmt_misc flags to the interpreter")
This can be tested with something like:
# cp ..../qemu-ppc /chroot/powerpc/jessie
# qemu-binfmt-conf.sh --qemu-path / --systemd ppc --credential yes \
--persistent no --preserve-argv0 yes
# systemctl restart systemd-binfmt.service
# cat /proc/sys/fs/binfmt_misc/qemu-ppc
enabled
interpreter //qemu-ppc
flags: POC
offset 0
magic 7f454c4601020100000000000000000000020014
mask ffffffffffffff00fffffffffffffffffffeffff
# chroot /chroot/powerpc/jessie sh -c 'echo $0'
sh
# qemu-binfmt-conf.sh --qemu-path / --systemd ppc --credential yes \
--persistent no --preserve-argv0 no
# systemctl restart systemd-binfmt.service
# cat /proc/sys/fs/binfmt_misc/qemu-ppc
enabled
interpreter //qemu-ppc
flags: OC
offset 0
magic 7f454c4601020100000000000000000000020014
mask ffffffffffffff00fffffffffffffffffffeffff
# chroot /chroot/powerpc/jessie sh -c 'echo $0'
/bin/sh
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210222105004.1642234-1-laurent@vivier.eu>
The primary motivation is to remove a dozen insns along
the fast-path in tb_lookup. As a byproduct, this allows
us to completely remove parallel_cpus.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This is more descriptive than 'unsigned long'.
No functional change, since these match on all linux+bsd hosts.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20210212184902.1251044-4-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This will allow us to centralize the registration of
the cpus.c module accelerator operations (in accel/accel-softmmu.c),
and trigger it automatically using object hierarchy lookup from the
new accel_init_interfaces() initialization step, depending just on
which accelerators are available in the code.
Rename all tcg-cpus.c, kvm-cpus.c, etc to tcg-accel-ops.c,
kvm-accel-ops.c, etc, matching the object type names.
Signed-off-by: Claudio Fontana <cfontana@suse.de>
Message-Id: <20210204163931.7358-18-cfontana@suse.de>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Plumb the value through to alloc_code_gen_buffer. This is not
supported by any os or tcg backend, so for now enabling it will
result in an error.
Reviewed-by: Joelle van Dyne <j@getutm.app>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
qemu_finish_machine_init currently can only exit QEMU if it fails.
Prepare for giving it proper error propagation, and possibly for
adding a plugin_add monitor command that calls an accelerator
method.
While at it, make all errors from plugin_load look the same.
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
It is not needed, all the callers are just saving what was
retrieved from -trace and trace_init_file can retrieve it
on its own.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20201102115841.4017692-1-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
When the chroot does not have /proc mounted, we can read neither
/proc/sys/vm/mmap_min_addr nor /proc/sys/maps.
The enforcement of mmap_min_addr in the host kernel is done by
the security module, and so does not apply to processes owned
by root. Which leads pgd_find_hole_fallback to succeed in probing
a reservation at address 0. Which confuses pgb_reserved_va to
believe that guest_base has not actually been initialized.
We don't actually want NULL addresses to become accessible, so
make sure that mmap_min_addr is initialized with a non-zero value.
Buglink: https://bugs.launchpad.net/qemu/+bug/1888728
Reported-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Acked-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20200724212314.545877-1-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
First we ensure all guest space initialisation logic comes through
probe_guest_base once we understand the nature of the binary we are
loading. The convoluted init_guest_space routine is removed and
replaced with a number of pgb_* helpers which are called depending on
what requirements we have when loading the binary.
We first try to do what is requested by the host. Failing that we try
and satisfy the guest requested base address. If all those options
fail we fall back to finding a space in the memory map using our
recently written read_self_maps() helper.
There are some additional complications we try and take into account
when looking for holes in the address space. We try not to go directly
after the system brk() space so there is space for a little growth. We
also don't want to have to use negative offsets which would result in
slightly less efficient code on x86 when it's unable to use the
segment offset register.
Less mind-binding gotos and hopefully clearer logic throughout.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Acked-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20200513175134.19619-5-alex.bennee@linaro.org>
While debugging over TCP is fairly straightforward now we have test
cases that want to orchestrate via make and currently a parallel build
fails as two processes can't use the same listening port. While system
emulation offers a wide cornucopia of connection methods thanks to the
chardev abstraction we are a little more limited for linux user.
Thankfully the programming API for a TCP socket and a local UNIX
socket is pretty much the same once it's set up.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20200430190122.4592-7-alex.bennee@linaro.org>
Now that all uses have been migrated to `qemu_log' it is no longer
needed.
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Josh Kunz <jkz@google.com>
Message-Id: <20200204025416.111409-4-jkz@google.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
This change switches linux-user strace logging to use the newer `qemu_log`
logging subsystem rather than the older `gemu_log` (notice the "g")
logger. `qemu_log` has several advantages, namely that it allows logging
to a file, and provides a more unified interface for configuration
of logging (via the QEMU_LOG environment variable or options).
This change introduces a new log mask: `LOG_STRACE` which is used for
logging of user-mode strace messages.
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Josh Kunz <jkz@google.com>
Message-Id: <20200204025416.111409-3-jkz@google.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
We currently search both the root and the tcg/ directories for tcg
files:
$ git grep '#include "tcg/' | wc -l
28
$ git grep '#include "tcg[^/]' | wc -l
94
To simplify the preprocessor search path, unify by expliciting the
tcg/ directory.
Patch created mechanically by running:
$ for x in \
tcg.h tcg-mo.h tcg-op.h tcg-opc.h \
tcg-op-gvec.h tcg-gvec-desc.h; do \
sed -i "s,#include \"$x\",#include \"tcg/$x\"," \
$(git grep -l "#include \"$x\""); \
done
Acked-by: David Gibson <david@gibson.dropbear.id.au> (ppc parts)
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200101112303.20724-2-philmd@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The CPU_LOG_PAGE flag is woefully underused and could stand to do
extra duty tracking page changes. If the user doesn't want to see the
details as things change they still have the tracepoints available.
We push the locking into log_page_dump and pass a reason for the
banner text.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20191205122518.10010-5-alex.bennee@linaro.org>
QEMU_STRACE and QEMU_RAND_SEED are handled by the parse_args, no need to
do it again in main.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20190906165736.5612-1-jcmvbkbc@gmail.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Xtensa binaries built for call0 ABI don't rotate register window on
function calls and returns. Invocation of signal handlers from the
kernel is therefore different in windowed and call0 ABIs.
There's currently no way to determine xtensa ELF binary ABI from the
binary itself. Add handler for the -xtensa-abi-call0 command line
parameter/QEMU_XTENSA_ABI_CALL0 envitonment variable to the qemu-user
and record ABI choice. Use it to initialize PS.WOE in xtensa_cpu_reset.
Check PS.WOE in setup_rt_frame to determine how a signal should be
delivered.
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Message-Id: <20190906165713.5558-1-jcmvbkbc@gmail.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Turn the scalar macro into a functional macro. Move the creation
of the cpu up a bit within main() so that we can pass it to the
invocation of MAX_RESERVED_VA. Delay the validation of the -R
parameter until MAX_RESERVED_VA is computed.
So far no changes to any of the MAX_RESERVED_VA macros to actually
use the cpu in any way, but ARM will need it.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20190822185929.16891-2-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Just passing NULL means we end up ignoring the bad dfilter spec
instead of reporting it and exiting as we should.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20190830143648.2967-1-alex.bennee@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
filename is only used to open the file if AT_EXECFD is not provided.
But exec_path already contains the path of the file to open.
Remove filename as it is only used in main.c whereas exec_path is
also used in syscall.c.
Fixes: d088d664f2 ("linux-user: identify running binary in /proc/self/exe")
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Message-Id: <20190714134028.315-1-laurent@vivier.eu>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190812052359.30071-20-armbru@redhat.com>
The alternate signal stack set up by the sigaltstack syscall is
supposed to be per-thread. We were incorrectly implementing it as
process-wide. This causes problems for guest binaries that rely on
this. Notably the Go runtime does, and so we were seeing crashes
caused by races where two guest threads might incorrectly both
execute on the same stack simultaneously.
Replace the global target_sigaltstack_used with a field
sigaltstack_used in the TaskState, and make all the references to the
old global instead get a pointer to the TaskState and use the field.
Fixes: https://bugs.launchpad.net/qemu/+bug/1696773
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20190725131645.19501-1-peter.maydell@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
No header includes qemu-common.h after this commit, as prescribed by
qemu-common.h's file comment.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190523143508.25387-5-armbru@redhat.com>
[Rebased with conflicts resolved automatically, except for
include/hw/arm/xlnx-zynqmp.h hw/arm/nrf51_soc.c hw/arm/msf2-soc.c
block/qcow2-refcount.c block/qcow2-cluster.c block/qcow2-cache.c
target/arm/cpu.h target/lm32/cpu.h target/m68k/cpu.h target/mips/cpu.h
target/moxie/cpu.h target/nios2/cpu.h target/openrisc/cpu.h
target/riscv/cpu.h target/tilegx/cpu.h target/tricore/cpu.h
target/unicore32/cpu.h target/xtensa/cpu.h; bsd-user/main.c and
net/tap-bsd.c fixed up]