bwlp/qemu.git/include/semihosting, branch spice_video_codecs

semihosting: Allow optional use of semihosting from userspace

2022-09-13T16:18:21+00:00

Currently our semihosting implementations generally prohibit use of semihosting calls in system emulation from the guest userspace. This is a very long standing behaviour justified originally "to provide some semblance of security" (since code with access to the semihosting ABI can do things like read and write arbitrary files on the host system). However, it is sometimes useful to be able to run trusted guest code which performs semihosting calls from guest userspace, notably for test code. Add a command line suboption to the existing semihosting-config option group so that you can explicitly opt in to semihosting from guest userspace with -semihosting-config userspace=on (There is no equivalent option for the user-mode emulator, because there by definition all code runs in userspace and has access to semihosting already.) This commit adds the infrastructure for the command line option and adds a bool 'is_user' parameter to the function semihosting_userspace_enabled() that target code can use to check whether it should be permitting the semihosting call for userspace. It mechanically makes all the callsites pass 'false', so they continue checking "is semihosting enabled in general". Subsequent commits will make each target that implements semihosting honour the userspace=on option by passing the correct value and removing whatever "don't do this for userspace" checking they were doing by hand. Signed-off-by: Peter Maydell Acked-by: Alex Bennée Reviewed-by: Alistair Francis Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Richard Henderson Message-Id: <20220822141230.3658237-2-peter.maydell@linaro.org> Signed-off-by: Richard Henderson

semihosting: Remove qemu_semihosting_log_out

2022-07-12T20:32:12+00:00

The function is no longer used. Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Richard Henderson Message-Id: <20220628111701.677216-7-richard.henderson@linaro.org> Signed-off-by: Philippe Mathieu-Daudé

semihosting: Create semihost_sys_poll_one

2022-06-27T23:11:37+00:00

This will be used for implementing the xtensa select_one system call. Choose "poll" over "select" so that we can reuse Glib's g_poll constants and to avoid struct timeval. Reviewed-by: Luc Michel Signed-off-by: Richard Henderson

semihosting: Remove qemu_semihosting_console_outs

2022-06-27T23:11:20+00:00

This function has been replaced by *_write. Reviewed-by: Luc Michel Reviewed-by: Alex Bennée Signed-off-by: Richard Henderson

semihosting: Remove qemu_semihosting_console_outc

2022-06-27T23:10:26+00:00

This function has been replaced by *_write. Reviewed-by: Luc Michel Signed-off-by: Richard Henderson

semihosting: Create qemu_semihosting_guestfd_init

2022-06-27T23:06:50+00:00

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 Reviewed-by: Alex Bennée Signed-off-by: Richard Henderson

semihosting: Add GuestFDConsole

2022-06-27T23:06:30+00:00

Add a GuestFDType for connecting to the semihosting console. Hook up to read, write, isatty, and fstat syscalls. Note that the arm-specific syscall flen cannot be applied to the console, because the console is not a descriptor exposed to the guest. Reviewed-by: Luc Michel Reviewed-by: Alex Bennée Signed-off-by: Richard Henderson

semihosting: Create qemu_semihosting_console_write

2022-06-27T23:05:52+00:00

Will replace qemu_semihosting_console_{outs,outc}, but we need more plumbing first. Reviewed-by: Luc Michel Signed-off-by: Richard Henderson

semihosting: Cleanup chardev init

2022-06-27T23:05:52+00:00

Rename qemu_semihosting_connect_chardevs to qemu_semihosting_chardev_init; pass the result directly to qemu_semihosting_console_init. Store the chardev in SemihostingConsole instead of SemihostingConfig, which lets us drop semihosting_get_chardev. Reviewed-by: Luc Michel Signed-off-by: Richard Henderson

semihosting: Expand qemu_semihosting_console_inc to read

2022-06-27T23:05:52+00:00

Allow more than one character to be read at one time. Will be used by m68k and nios2 semihosting for stdio. Reviewed-by: Luc Michel Signed-off-by: Richard Henderson