We recently introduced new plugin API for registration of trap related
callbacks. This change introduces a minimal plugin showcasing the new
API. It simply counts the occurances of interrupts, exceptions and
semihosting events per CPU and reports the counts when exitting.
Signed-off-by: Julian Ganz <neither@nut.email>
---
contrib/plugins/Makefile | 1 +
contrib/plugins/traps.c | 89 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 90 insertions(+)
create mode 100644 contrib/plugins/traps.c
diff --git a/contrib/plugins/Makefile b/contrib/plugins/Makefile
index bbddd4800f..6085fd701f 100644
--- a/contrib/plugins/Makefile
+++ b/contrib/plugins/Makefile
@@ -31,6 +31,7 @@ NAMES += drcov
NAMES += ips
NAMES += stoptrigger
NAMES += cflow
+NAMES += traps
ifeq ($(CONFIG_WIN32),y)
SO_SUFFIX := .dll
diff --git a/contrib/plugins/traps.c b/contrib/plugins/traps.c
new file mode 100644
index 0000000000..2a38dbb8b3
--- /dev/null
+++ b/contrib/plugins/traps.c
@@ -0,0 +1,89 @@
+/*
+ * 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 semihosting;
+ bool active;
+} TrapCounters;
+
+static TrapCounters *traps;
+size_t max_vcpus;
+
+static void vcpu_init(qemu_plugin_id_t id, unsigned int vcpu_index)
+{
+ traps[vcpu_index].active = true;
+}
+
+static void vcpu_interrupt(qemu_plugin_id_t id, unsigned int vcpu_index)
+{
+ traps[vcpu_index].interrupts++;
+}
+
+static void vcpu_exception(qemu_plugin_id_t id, unsigned int vcpu_index)
+{
+ traps[vcpu_index].exceptions++;
+}
+
+static void vcpu_semihosting(qemu_plugin_id_t id, unsigned int vcpu_index)
+{
+ traps[vcpu_index].semihosting++;
+}
+
+static void plugin_exit(qemu_plugin_id_t id, void *p)
+{
+ g_autoptr(GString) report;
+ report = g_string_new("VCPU, interrupts, exceptions, semihosting\n");
+ int vcpu;
+
+ for (vcpu = 0; vcpu < max_vcpus; vcpu++) {
+ TrapCounters *rec = &traps[vcpu];
+ if (rec->active) {
+ g_string_append_printf(report,
+ "% 4d, % 10"PRId64", % 10"PRId64", % 10"
+ PRId64"\n",
+ vcpu,
+ rec->interrupts, rec->exceptions,
+ rec->semihosting);
+ }
+ }
+
+ qemu_plugin_outs(report->str);
+}
+
+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 = calloc(max_vcpus, sizeof(TrapCounters));
+ qemu_plugin_register_vcpu_init_cb(id, vcpu_init);
+ qemu_plugin_vcpu_for_each(id, vcpu_init);
+
+ qemu_plugin_register_vcpu_interrupt_cb(id, vcpu_interrupt);
+ qemu_plugin_register_vcpu_exception_cb(id, vcpu_exception);
+ qemu_plugin_register_vcpu_semihosting_cb(id, vcpu_semihosting);
+
+ qemu_plugin_register_atexit_cb(id, plugin_exit, NULL);
+
+ return 0;
+}
--
2.45.2
On 10/19/24 09:39, Julian Ganz wrote: > We recently introduced new plugin API for registration of trap related > callbacks. This change introduces a minimal plugin showcasing the new > API. It simply counts the occurances of interrupts, exceptions and > semihosting events per CPU and reports the counts when exitting. > > Signed-off-by: Julian Ganz <neither@nut.email> > --- > contrib/plugins/Makefile | 1 + > contrib/plugins/traps.c | 89 ++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 90 insertions(+) > create mode 100644 contrib/plugins/traps.c > > diff --git a/contrib/plugins/Makefile b/contrib/plugins/Makefile > index bbddd4800f..6085fd701f 100644 > --- a/contrib/plugins/Makefile > +++ b/contrib/plugins/Makefile > @@ -31,6 +31,7 @@ NAMES += drcov > NAMES += ips > NAMES += stoptrigger > NAMES += cflow > +NAMES += traps > > ifeq ($(CONFIG_WIN32),y) > SO_SUFFIX := .dll > diff --git a/contrib/plugins/traps.c b/contrib/plugins/traps.c > new file mode 100644 > index 0000000000..2a38dbb8b3 > --- /dev/null > +++ b/contrib/plugins/traps.c > @@ -0,0 +1,89 @@ > +/* > + * 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 semihosting; > + bool active; > +} TrapCounters; > + > +static TrapCounters *traps; > +size_t max_vcpus; > + > +static void vcpu_init(qemu_plugin_id_t id, unsigned int vcpu_index) > +{ > + traps[vcpu_index].active = true; > +} > + > +static void vcpu_interrupt(qemu_plugin_id_t id, unsigned int vcpu_index) > +{ > + traps[vcpu_index].interrupts++; > +} > + > +static void vcpu_exception(qemu_plugin_id_t id, unsigned int vcpu_index) > +{ > + traps[vcpu_index].exceptions++; > +} > + > +static void vcpu_semihosting(qemu_plugin_id_t id, unsigned int vcpu_index) > +{ > + traps[vcpu_index].semihosting++; > +} > + > +static void plugin_exit(qemu_plugin_id_t id, void *p) > +{ > + g_autoptr(GString) report; > + report = g_string_new("VCPU, interrupts, exceptions, semihosting\n"); > + int vcpu; > + > + for (vcpu = 0; vcpu < max_vcpus; vcpu++) { > + TrapCounters *rec = &traps[vcpu]; > + if (rec->active) { > + g_string_append_printf(report, > + "% 4d, % 10"PRId64", % 10"PRId64", % 10" > + PRId64"\n", > + vcpu, > + rec->interrupts, rec->exceptions, > + rec->semihosting); > + } > + } > + > + qemu_plugin_outs(report->str); > +} > + > +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 = calloc(max_vcpus, sizeof(TrapCounters)); Instead of allocating data for max number of vcpu, you can use a qemu_plugin_scoreboard, which was introduced recently, and covers exactly this need, by providing an array that gets automatically redimensioned when a vcpu is added. A simple example using it can be found with bb plugin: https://gitlab.com/qemu-project/qemu/-/blob/master/tests/tcg/plugins/bb.c > + qemu_plugin_register_vcpu_init_cb(id, vcpu_init); > + qemu_plugin_vcpu_for_each(id, vcpu_init); > + > + qemu_plugin_register_vcpu_interrupt_cb(id, vcpu_interrupt); > + qemu_plugin_register_vcpu_exception_cb(id, vcpu_exception); > + qemu_plugin_register_vcpu_semihosting_cb(id, vcpu_semihosting); > + > + qemu_plugin_register_atexit_cb(id, plugin_exit, NULL); > + > + return 0; > +}
October 21, 2024 at 8:07 PM, "Pierrick Bouvier" wrote: > On 10/19/24 09:39, Julian Ganz wrote: > > + max_vcpus = info->system.max_vcpus; > > + traps = calloc(max_vcpus, sizeof(TrapCounters)); > > > Instead of allocating data for max number of vcpu, you can use a qemu_plugin_scoreboard, which was introduced recently, and covers exactly this need, by providing an array that gets automatically redimensioned when a vcpu is added. > > A simple example using it can be found with bb plugin: > https://gitlab.com/qemu-project/qemu/-/blob/master/tests/tcg/plugins/b(id, vb.c Thanks for pointing this out! I scrolled past the scoreboard API at least once without realizing what it was. Regards, Julian
On 10/19/24 09:39, Julian Ganz wrote: > We recently introduced new plugin API for registration of trap related > callbacks. This change introduces a minimal plugin showcasing the new > API. It simply counts the occurances of interrupts, exceptions and > semihosting events per CPU and reports the counts when exitting. > > Signed-off-by: Julian Ganz <neither@nut.email> > --- > contrib/plugins/Makefile | 1 + > contrib/plugins/traps.c | 89 ++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 90 insertions(+) > create mode 100644 contrib/plugins/traps.c > > diff --git a/contrib/plugins/Makefile b/contrib/plugins/Makefile > index bbddd4800f..6085fd701f 100644 > --- a/contrib/plugins/Makefile > +++ b/contrib/plugins/Makefile > @@ -31,6 +31,7 @@ NAMES += drcov > NAMES += ips > NAMES += stoptrigger > NAMES += cflow > +NAMES += traps > > ifeq ($(CONFIG_WIN32),y) > SO_SUFFIX := .dll > diff --git a/contrib/plugins/traps.c b/contrib/plugins/traps.c > new file mode 100644 > index 0000000000..2a38dbb8b3 > --- /dev/null > +++ b/contrib/plugins/traps.c > @@ -0,0 +1,89 @@ > +/* > + * 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 semihosting; > + bool active; > +} TrapCounters; > + > +static TrapCounters *traps; > +size_t max_vcpus; > + > +static void vcpu_init(qemu_plugin_id_t id, unsigned int vcpu_index) > +{ > + traps[vcpu_index].active = true; > +} > + > +static void vcpu_interrupt(qemu_plugin_id_t id, unsigned int vcpu_index) > +{ > + traps[vcpu_index].interrupts++; > +} > + > +static void vcpu_exception(qemu_plugin_id_t id, unsigned int vcpu_index) > +{ > + traps[vcpu_index].exceptions++; > +} > + > +static void vcpu_semihosting(qemu_plugin_id_t id, unsigned int vcpu_index) > +{ > + traps[vcpu_index].semihosting++; > +} > + > +static void plugin_exit(qemu_plugin_id_t id, void *p) > +{ > + g_autoptr(GString) report; > + report = g_string_new("VCPU, interrupts, exceptions, semihosting\n"); > + int vcpu; > + > + for (vcpu = 0; vcpu < max_vcpus; vcpu++) { > + TrapCounters *rec = &traps[vcpu]; > + if (rec->active) { > + g_string_append_printf(report, > + "% 4d, % 10"PRId64", % 10"PRId64", % 10" > + PRId64"\n", > + vcpu, > + rec->interrupts, rec->exceptions, > + rec->semihosting); > + } > + } > + > + qemu_plugin_outs(report->str); > +} > + > +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 = calloc(max_vcpus, sizeof(TrapCounters)); > + qemu_plugin_register_vcpu_init_cb(id, vcpu_init); > + qemu_plugin_vcpu_for_each(id, vcpu_init); > + > + qemu_plugin_register_vcpu_interrupt_cb(id, vcpu_interrupt); > + qemu_plugin_register_vcpu_exception_cb(id, vcpu_exception); > + qemu_plugin_register_vcpu_semihosting_cb(id, vcpu_semihosting); > + > + qemu_plugin_register_atexit_cb(id, plugin_exit, NULL); > + > + return 0; > +
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