We recently introduced new plugin API for registration of discontinuity related callbacks. This change introduces a minimal plugin showcasing the new API. It simply counts the occurances of interrupts, exceptions and host calls per CPU and reports the counts when exitting. --- contrib/plugins/meson.build | 3 +- contrib/plugins/traps.c | 96 +++++++++++++++++++++++++++++++++++++ 2 files changed, 98 insertions(+), 1 deletion(-) create mode 100644 contrib/plugins/traps.c
diff --git a/contrib/plugins/meson.build b/contrib/plugins/meson.build index 63a32c2b4f..9a3015e1c1 100644 --- a/contrib/plugins/meson.build +++ b/contrib/plugins/meson.build @@ -1,5 +1,6 @@ contrib_plugins = ['bbv', 'cache', 'cflow', 'drcov', 'execlog', 'hotblocks', - 'hotpages', 'howvec', 'hwprofile', 'ips', 'stoptrigger'] + 'hotpages', 'howvec', 'hwprofile', 'ips', 'stoptrigger', + 'traps'] if host_os != 'windows' # lockstep uses socket.h contrib_plugins += 'lockstep' diff --git a/contrib/plugins/traps.c b/contrib/plugins/traps.c new file mode 100644 index 0000000000..ecd4beac5f --- /dev/null +++ b/contrib/plugins/traps.c @@ -0,0 +1,96 @@ +/* + * Copyright (C) 2024, Julian Ganz <neither@nut.email> + * + * Traps - count traps + * + * License: GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ + +#include <stdio.h> + +#include <qemu-plugin.h> + +QEMU_PLUGIN_EXPORT int qemu_plugin_version = QEMU_PLUGIN_VERSION; + +typedef struct { + uint64_t interrupts; + uint64_t exceptions; + uint64_t hostcalls; + bool active; +} TrapCounters; + +static struct qemu_plugin_scoreboard *traps; +static size_t max_vcpus; + +static void vcpu_init(qemu_plugin_id_t id, unsigned int vcpu_index) +{ + TrapCounters* rec = qemu_plugin_scoreboard_find(traps, vcpu_index); + rec->active = true; +} + +static void vcpu_discon(qemu_plugin_id_t id, unsigned int vcpu_index, + enum qemu_plugin_discon_type type, uint64_t from_pc, + uint64_t to_pc) +{ + TrapCounters* rec = qemu_plugin_scoreboard_find(traps, vcpu_index); + switch (type) { + case QEMU_PLUGIN_DISCON_INTERRUPT: + rec->interrupts++; + break; + case QEMU_PLUGIN_DISCON_EXCEPTION: + rec->exceptions++; + break; + case QEMU_PLUGIN_DISCON_HOSTCALL: + rec->hostcalls++; + break; + default: + /* unreachable */ + break; + } +} + +static void plugin_exit(qemu_plugin_id_t id, void *p) +{ + g_autoptr(GString) report; + report = g_string_new("VCPU, interrupts, exceptions, hostcalls\n"); + int vcpu; + + for (vcpu = 0; vcpu < max_vcpus; vcpu++) { + TrapCounters *rec = qemu_plugin_scoreboard_find(traps, vcpu); + if (rec->active) { + g_string_append_printf(report, + "% 4d, % 10"PRId64", % 10"PRId64", % 10" + PRId64"\n", + vcpu, + rec->interrupts, rec->exceptions, + rec->hostcalls); + } + } + + qemu_plugin_outs(report->str); + qemu_plugin_scoreboard_free(traps); +} + +QEMU_PLUGIN_EXPORT +int qemu_plugin_install(qemu_plugin_id_t id, const qemu_info_t *info, + int argc, char **argv) +{ + if (!info->system_emulation) { + fputs("trap plugin can only be used in system emulation mode.\n", + stderr); + return -1; + } + + max_vcpus = info->system.max_vcpus; + traps = qemu_plugin_scoreboard_new(sizeof(TrapCounters)); + qemu_plugin_register_vcpu_init_cb(id, vcpu_init); + qemu_plugin_vcpu_for_each(id, vcpu_init); + + qemu_plugin_register_vcpu_discon_cb(id, QEMU_PLUGIN_DISCON_TRAPS, + vcpu_discon); + + qemu_plugin_register_atexit_cb(id, plugin_exit, NULL); + + return 0; +} -- 2.45.2