This commit tests the readonly feature for registers exposed via the plugin API introduced earlier in the patch series.
Signed-off-by: Florian Hofhammer <[email protected]> --- tests/tcg/plugins/meson.build | 1 + tests/tcg/plugins/registers.c | 68 +++++++++++++++++++++++++++++++++++ 2 files changed, 69 insertions(+) create mode 100644 tests/tcg/plugins/registers.c diff --git a/tests/tcg/plugins/meson.build b/tests/tcg/plugins/meson.build index c5e49753fd..5005aa8dc9 100644 --- a/tests/tcg/plugins/meson.build +++ b/tests/tcg/plugins/meson.build @@ -6,6 +6,7 @@ test_plugins = [ 'insn.c', 'mem.c', 'patch.c', +'registers.c', 'reset.c', 'syscall.c', ] diff --git a/tests/tcg/plugins/registers.c b/tests/tcg/plugins/registers.c new file mode 100644 index 0000000000..a7bd692225 --- /dev/null +++ b/tests/tcg/plugins/registers.c @@ -0,0 +1,68 @@ +/* + * Copyright (C) 2026, Florian Hofhammer <[email protected]> + * + * License: GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ +#include "glib.h" +#include <inttypes.h> +#include <assert.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <stdio.h> + +#include <qemu-plugin.h> + +QEMU_PLUGIN_EXPORT int qemu_plugin_version = QEMU_PLUGIN_VERSION; + +/* + * This callback is called when a vCPU is initialized. It tests whether we + * successfully read from a register and write value back to it. It also tests + * that read-only registers cannot be written to, i.e., we can read a read-only + * register but writing to it fails. + */ +static void vcpu_init_cb(qemu_plugin_id_t id, unsigned int vcpu_index) +{ + g_autoptr(GArray) regs = qemu_plugin_get_registers(); + g_autoptr(GByteArray) buf = g_byte_array_sized_new(0); + bool success = false; + + /* Make sure we can read and write an arbitrary register */ + qemu_plugin_reg_descriptor *reg_desc = &g_array_index(regs, + qemu_plugin_reg_descriptor, 0); + g_assert(reg_desc->is_readonly == false); + success = qemu_plugin_read_register(reg_desc->handle, buf); + g_assert(success); + success = qemu_plugin_write_register(reg_desc->handle, buf); + g_assert(success); + + /* + * Reset the buffer and find a read-only register. On each architecture, at + * least the PC should be read-only because it's only supposed to be + * modified via the qemu_plugin_set_pc() function. + */ + g_byte_array_set_size(buf, 0); + for (size_t i = 0; i < regs->len; i++) { + reg_desc = &g_array_index(regs, qemu_plugin_reg_descriptor, i); + if (reg_desc->is_readonly) { + success = qemu_plugin_read_register(reg_desc->handle, buf); + g_assert(success); + break; + } else { + reg_desc = NULL; + } + } + /* Make sure there is a read-only register and we cannot write to it */ + g_assert(reg_desc != NULL); + success = qemu_plugin_write_register(reg_desc->handle, buf); + g_assert(!success); +} + +QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id, + const qemu_info_t *info, + int argc, char **argv) +{ + qemu_plugin_register_vcpu_init_cb(id, vcpu_init_cb); + return 0; +} -- 2.53.0
