The guest can use the semihosting API to open a handle
corresponding to QEMU's own stdin, stdout, or stderr.
When the guest closes this handle, we should not
close the underlying host stdin/stdout/stderr
the way we would do if the handle corresponded to
a host fd we'd opened on behalf of the guest in SYS_OPEN.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20200124172954.28481-1-peter.maydell@linaro.org
According to the specification "Semihosting for AArch32 and Aarch64",
the SYS_OPEN operation should return:
- A nonzero handle if the call is successful
- -1 if the call is not successful
So, it should never return 0.
Prior to commit 35e9a0a8ce ("target/arm/arm-semi: Make semihosting
code hand out its own file descriptors"), the guest fd matched to the
host fd. It returned a nonzero handle on success since the fd 0 is
already used for stdin.
Now that the guest fd is the index of guestfd_array, it starts from 0.
I noticed this issue particularly because Trusted Firmware-A built with
PLAT=qemu is no longer working. Its io_semihosting driver only handles
a positive return value as a valid filehandle.
Basically, there are two ways to fix this:
- Use (guestfd - 1) as the index of guestfs_arrary. We need to insert
increment/decrement to convert the guestfd and the array index back
and forth.
- Keep using guestfd as the index of guestfs_array. The first entry
of guestfs_array is left unused.
I thought the latter is simpler. We end up with wasting a small piece
of memory for the unused first entry of guestfd_array, but this is
probably not a big deal.
Fixes: 35e9a0a8ce ("target/arm/arm-semi: Make semihosting code hand out its own file descriptors")
Cc: qemu-stable@nongnu.org
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200109041228.10131-1-masahiroy@kernel.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Provides a blocking call to read a character from the console using
semihosting.chardev, if specified. This takes some careful command
line options to use stdio successfully as the serial ports, monitor
and semihost all want to use stdio. Here's a sample set of command
line options which share stdio between semihost, monitor and serial
ports:
qemu \
-chardev stdio,mux=on,id=stdio0 \
-serial chardev:stdio0 \
-semihosting-config enable=on,chardev=stdio0 \
-mon chardev=stdio0,mode=readline
This creates a chardev hooked to stdio and then connects all of the
subsystems to it. A shorter mechanism would be good to hear about.
Signed-off-by: Keith Packard <keithp@keithp.com>
Message-Id: <20191104204230.12249-1-keithp@keithp.com>
[AJB: fixed up deadlock, minor commit title reword]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Keith Packard <keithp@keithp.com>
Tested-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
SH_EXT_STDOUT_STDERR is a v2.0 semihosting extension: the guest
can open ":tt" with a file mode requesting append access in
order to open stderr, in addition to the existing "open for
read for stdin or write for stdout". Implement this and
report it via the :semihosting-features data.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20190916141544.17540-16-peter.maydell@linaro.org
SH_EXT_EXIT_EXTENDED is a v2.0 semihosting extension: it
indicates that the implementation supports the SYS_EXIT_EXTENDED
function. This function allows both A64 and A32/T32 guests to
exit with a specified exit status, unlike the older SYS_EXIT
function which only allowed this for A64 guests. Implement
this extension.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20190916141544.17540-15-peter.maydell@linaro.org
Version 2.0 of the semihosting specification added support for
allowing a guest to detect whether the implementation supported
particular features. This works by the guest opening a magic
file ":semihosting-features", which contains a fixed set of
data with some magic numbers followed by a sequence of bytes
with feature flags. The file is expected to behave sensibly
for the various semihosting calls which operate on files
(SYS_FLEN, SYS_SEEK, etc).
Implement this as another kind of guest FD using our function
table dispatch mechanism. Initially we report no extended
features, so we have just one feature flag byte which is zero.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20190916141544.17540-14-peter.maydell@linaro.org
Factor out the implementation of SYS_FLEN via the new
function tables.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190916141544.17540-13-peter.maydell@linaro.org
Factor out the implementation of SYS_SEEK via the new function
tables.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190916141544.17540-12-peter.maydell@linaro.org
Factor out the implementation of SYS_ISTTY via the new function
tables.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190916141544.17540-11-peter.maydell@linaro.org
Factor out the implementation of SYS_READ via the
new function tables.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190916141544.17540-10-peter.maydell@linaro.org
Factor out the implementation of SYS_WRITE via the
new function tables.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190916141544.17540-9-peter.maydell@linaro.org
Currently for the semihosting calls which take a file descriptor
(SYS_CLOSE, SYS_WRITE, SYS_READ, SYS_ISTTY, SYS_SEEK, SYS_FLEN)
we have effectively two implementations, one for real host files
and one for when we indirect via the gdbstub. We want to add a
third one to deal with the magic :semihosting-features file.
Instead of having a three-way if statement in each of these
cases, factor out the implementation of the calls to separate
functions which we dispatch to via function pointers selected
via the GuestFDType for the guest fd.
In this commit, we set up the framework for the dispatch,
and convert the SYS_CLOSE call to use it.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190916141544.17540-8-peter.maydell@linaro.org
When we are routing semihosting operations through the gdbstub, the
work of sorting out the return value and setting errno if necessary
is done by callback functions which are invoked by the gdbstub code.
Clean up some ifdeffery in those functions by having them call
set_swi_errno() to set the semihosting errno.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190916141544.17540-7-peter.maydell@linaro.org
The semihosting code needs accuss to the linux-user only
TaskState pointer so it can set the semihosting errno per-thread
for linux-user mode. At the moment we do this by having some
ifdefs so that we define a 'ts' local in do_arm_semihosting()
which is either a real TaskState * or just a CPUARMState *,
depending on which mode we're compiling for.
This is awkward if we want to refactor do_arm_semihosting()
into other functions which might need to be passed the TaskState.
Restrict usage of the TaskState local by:
* making set_swi_errno() always take the CPUARMState pointer
and (for the linux-user version) get TaskState from that
* creating a new get_swi_errno() which reads the errno
* having the two semihosting calls which need the TaskState
for other purposes (SYS_GET_CMDLINE and SYS_HEAPINFO)
define a variable with scope restricted to just that code
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190916141544.17540-6-peter.maydell@linaro.org
Currently the Arm semihosting code returns the guest file descriptors
(handles) which are simply the fd values from the host OS or the
remote gdbstub. Part of the semihosting 2.0 specification requires
that we implement special handling of opening a ":semihosting-features"
filename. Guest fds which result from opening the special file
won't correspond to host fds, so to ensure that we don't end up
with duplicate fds we need to have QEMU code control the allocation
of the fd values we give the guest.
Add in an abstraction layer which lets us allocate new guest FD
values, and translate from a guest FD value back to the host one.
This also fixes an odd hole where a semihosting guest could
use the semihosting API to read, write or close file descriptors
that it had never allocated but which were being used by QEMU itself.
(This isn't a security hole, because enabling semihosting permits
the guest to do arbitrary file access to the whole host filesystem,
and so should only be done if the guest is completely trusted.)
Currently the only kind of guest fd is one which maps to a
host fd, but in a following commit we will add one which maps
to the :semihosting-features magic data.
If the guest is migrated with an open semihosting file descriptor
then subsequent attempts to use the fd will all fail; this is
not a change from the previous situation (where the host fd
being used on the source end would not be re-opened on the
destination end).
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190916141544.17540-5-peter.maydell@linaro.org
In arm_gdb_syscall() we have a comment suggesting a race
because the syscall completion callback might not happen
before the gdb_do_syscallv() call returns. The comment is
correct that the callback may not happen but incorrect about
the effects. Correct it and note the important caveat that
callers must never do any work of any kind after return from
arm_gdb_syscall() that depends on its return value.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190916141544.17540-4-peter.maydell@linaro.org
If we fail a semihosting call we should always set the
semihosting errno to something; we were failing to do
this for some of the "check inputs for sanity" cases.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190916141544.17540-3-peter.maydell@linaro.org
The set_swi_errno() function is called to capture the errno
from a host system call, so that we can return -1 from the
semihosting function and later allow the guest to get a more
specific error code with the SYS_ERRNO function. It comes in
two versions, one for user-only and one for softmmu. We forgot
to capture the errno in the softmmu version; fix the error.
(Semihosting calls directed to gdb are unaffected because
they go through a different code path that captures the
error return from the gdbstub call in arm_semi_cb() or
arm_semi_flen_cb().)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190916141544.17540-2-peter.maydell@linaro.org
This is ostensibly to avoid the weirdness of len looking like it might
come from a guest and sometimes being used. While we are at it fix up
the error checking for the arm-linux-user implementation of the API
which got flagged up by Coverity (CID 1401700).
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
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]
Cleanup in the boilerplate that each target must define.
Replace arm_env_get_cpu with env_archcpu. The combination
CPU(arm_env_get_cpu) should have used ENV_GET_CPU to begin;
use env_cpu now.
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The documentation says the write should return the number of bytes not
written on an error (0 means everything was written). Read provides a
buffer length and the return value should be the buffer length - bytes
actually read. Remove the incorrect FIXME's and return the correct
values.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Clean-up our unimplemented bits with a proper message.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Now we have a common semihosting console interface use that for our
string output. However ARM is currently unique in also supporting
semihosting for linux-user so we need to replicate the API in
linux-user. If other architectures gain this support we can move the
file later.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
This cleans up a number of the block comments to fit the proper style.
While we are at it we also reference the official specification and
document what the return register value can be.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
In preparation for having some more common semihosting code let's
excise the current config magic from vl.c into its own file. We shall
later add more conditionals to the build configurations so we can
avoid building this if we don't need it.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
The hw/arm/arm.h header now only includes declarations relating
to boot.c code, so it is only needed by Arm board or SoC code.
Remove some unnecessary inclusions of it from target/arm files
and from hw/intc/armv7m_nvic.c.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190516163857.6430-3-peter.maydell@linaro.org
CPUClass method dump_statistics() takes an fprintf()-like callback and
a FILE * to pass to it. Most callers pass fprintf() and stderr.
log_cpu_state() passes fprintf() and qemu_log_file.
hmp_info_registers() passes monitor_fprintf() and the current monitor
cast to FILE *. monitor_fprintf() casts it right back, and is
otherwise identical to monitor_printf().
The callback gets passed around a lot, which is tiresome. The
type-punning around monitor_fprintf() is ugly.
Drop the callback, and call qemu_fprintf() instead. Also gets rid of
the type-punning, since qemu_fprintf() takes NULL instead of the
current monitor cast to FILE *.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20190417191805.28198-15-armbru@redhat.com>
Following the bulk conversion of the iwMMXt code, there are
just a handful of hard coded tabs in target/arm; fix them.
This is a whitespace-only patch.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20180821165215.29069-4-peter.maydell@linaro.org
We've currently got 18 architectures in QEMU, and thus 18 target-xxx
folders in the root folder of the QEMU source tree. More architectures
(e.g. RISC-V, AVR) are likely to be included soon, too, so the main
folder of the QEMU sources slowly gets quite overcrowded with the
target-xxx folders.
To disburden the main folder a little bit, let's move the target-xxx
folders into a dedicated target/ folder, so that target-xxx/ simply
becomes target/xxx/ instead.
Acked-by: Laurent Vivier <laurent@vivier.eu> [m68k part]
Acked-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de> [tricore part]
Acked-by: Michael Walle <michael@walle.cc> [lm32 part]
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> [s390x part]
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> [s390x part]
Acked-by: Eduardo Habkost <ehabkost@redhat.com> [i386 part]
Acked-by: Artyom Tarasenko <atar4qemu@gmail.com> [sparc part]
Acked-by: Richard Henderson <rth@twiddle.net> [alpha part]
Acked-by: Max Filippov <jcmvbkbc@gmail.com> [xtensa part]
Reviewed-by: David Gibson <david@gibson.dropbear.id.au> [ppc part]
Acked-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com> [crisµblaze part]
Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn> [unicore32 part]
Signed-off-by: Thomas Huth <thuth@redhat.com>
