This allows the a plugin which has control of time to supply a callback
so it can control the reported virtual time instead of using the
default cpu_get_clock().
Time control plugins still need to call qemu_plugin_update_ns() to
ensure timers are moved forward.
Signed-off-by: Alex Bennée <alex.ben...@linaro.org>
---
include/qemu/plugin-event.h | 1 +
include/qemu/plugin.h | 9 +++++++++
include/qemu/qemu-plugin.h | 18 ++++++++++++++++++
accel/tcg/tcg-accel-ops.c | 5 +++++
plugins/api-system.c | 8 ++++++++
plugins/core.c | 22 ++++++++++++++++++++++
6 files changed, 63 insertions(+)
diff --git a/include/qemu/plugin-event.h b/include/qemu/plugin-event.h
index 7056d8427b..ae9ec5ce85 100644
--- a/include/qemu/plugin-event.h
+++ b/include/qemu/plugin-event.h
@@ -20,6 +20,7 @@ enum qemu_plugin_event {
QEMU_PLUGIN_EV_VCPU_SYSCALL_RET,
QEMU_PLUGIN_EV_FLUSH,
QEMU_PLUGIN_EV_ATEXIT,
+ QEMU_PLUGIN_EV_GET_TIME,
QEMU_PLUGIN_EV_MAX, /* total number of plugin events we support */
};
diff --git a/include/qemu/plugin.h b/include/qemu/plugin.h
index 9726a9ebf3..a9371a9a42 100644
--- a/include/qemu/plugin.h
+++ b/include/qemu/plugin.h
@@ -63,6 +63,7 @@ union qemu_plugin_cb_sig {
qemu_plugin_vcpu_mem_cb_t vcpu_mem;
qemu_plugin_vcpu_syscall_cb_t vcpu_syscall;
qemu_plugin_vcpu_syscall_ret_cb_t vcpu_syscall_ret;
+ qemu_plugin_time_cb_t time;
void *generic;
};
@@ -175,6 +176,14 @@ void qemu_plugin_flush_cb(void);
void qemu_plugin_atexit_cb(void);
+/**
+ * qemu_plugin_maybe_fetch_time() - fetch virtual time from plugin
+ * @tptr: pointer to int64_t for result
+ *
+ * Returns true if the plugin has set time, otherwise false
+ */
+bool qemu_plugin_maybe_fetch_time(int64_t *tptr);
+
void qemu_plugin_add_dyn_cb_arr(GArray *arr);
static inline void qemu_plugin_disable_mem_helpers(CPUState *cpu)
diff --git a/include/qemu/qemu-plugin.h b/include/qemu/qemu-plugin.h
index 3a850aa216..c5f1cad8fb 100644
--- a/include/qemu/qemu-plugin.h
+++ b/include/qemu/qemu-plugin.h
@@ -713,6 +713,22 @@ void qemu_plugin_register_vcpu_mem_inline_per_vcpu(
QEMU_PLUGIN_API
const void *qemu_plugin_request_time_control(void);
+/**
+ * typedef qemu_plugin_vcpu_mem_cb_t - time callback function
+ * Returns time in ns (starting from 0)
+ */
+typedef int64_t (*qemu_plugin_time_cb_t) (void);
+
+/**
+ * qemu_plugin_register_time_cb() - register a time callback
+ *
+ * This can only be called once a plugin has successfully called
+ * qemu_plugin_request_time_control(). The callback will get called
+ * whenever qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) is called.
+ */
+QEMU_PLUGIN_API
+void qemu_plugin_register_time_cb(qemu_plugin_id_t id, const void *handle,
qemu_plugin_time_cb_t cb);
+
/**
* qemu_plugin_update_ns() - update system emulation time
* @handle: opaque handle returned by qemu_plugin_request_time_control()
@@ -723,6 +739,8 @@ const void *qemu_plugin_request_time_control(void);
* user-mode emulation the time is not changed by this as all reported
* time comes from the host kernel.
*
+ * This allows QEMU to execute any pending timers.
+ *
* Start time is 0.
*/
QEMU_PLUGIN_API
diff --git a/accel/tcg/tcg-accel-ops.c b/accel/tcg/tcg-accel-ops.c
index 1432d1c5b1..5ed748f5cc 100644
--- a/accel/tcg/tcg-accel-ops.c
+++ b/accel/tcg/tcg-accel-ops.c
@@ -33,6 +33,7 @@
#include "qemu/main-loop.h"
#include "qemu/guest-random.h"
#include "qemu/timer.h"
+#include "qemu/plugin.h"
#include "exec/cputlb.h"
#include "exec/hwaddr.h"
#include "exec/tb-flush.h"
@@ -199,6 +200,10 @@ static inline void tcg_remove_all_breakpoints(CPUState
*cpu)
static int64_t tcg_get_virtual_clock(void)
{
+ int64_t from_plugin;
+ if (qemu_plugin_maybe_fetch_time(&from_plugin)) {
+ return from_plugin;
+ }
return cpu_get_clock();
}
diff --git a/plugins/api-system.c b/plugins/api-system.c
index cc190b167e..0f2a3eb5a6 100644
--- a/plugins/api-system.c
+++ b/plugins/api-system.c
@@ -17,6 +17,7 @@
#include "hw/boards.h"
#include "qemu/plugin-memory.h"
#include "qemu/plugin.h"
+#include "plugin.h"
/*
* In system mode we cannot trace the binary being executed so the
@@ -129,3 +130,10 @@ void qemu_plugin_update_ns(const void *handle, int64_t
new_time)
RUN_ON_CPU_HOST_ULONG(new_time));
}
}
+
+void qemu_plugin_register_time_cb(qemu_plugin_id_t id, const void *handle,
qemu_plugin_time_cb_t cb)
+{
+ if (handle == &has_control) {
+ plugin_register_cb(id, QEMU_PLUGIN_EV_GET_TIME, cb);
+ }
+}
diff --git a/plugins/core.c b/plugins/core.c
index eb9281fe54..d56b4c9d48 100644
--- a/plugins/core.c
+++ b/plugins/core.c
@@ -571,6 +571,28 @@ void qemu_plugin_flush_cb(void)
plugin_cb__simple(QEMU_PLUGIN_EV_FLUSH);
}
+/*
+ * Disable CFI checks.
+ * The callback function has been loaded from an external library so we do not
+ * have type information
+ */
+QEMU_DISABLE_CFI
+bool qemu_plugin_maybe_fetch_time(int64_t *tptr)
+{
+ enum qemu_plugin_event ev = QEMU_PLUGIN_EV_GET_TIME;
+
+ /* there should only be one callback */
+ if (!QLIST_EMPTY(&plugin.cb_lists[ev])) {
+ struct qemu_plugin_cb *cb = QLIST_FIRST(&plugin.cb_lists[ev]);
+ qemu_plugin_time_cb_t func = cb->f.generic;
+ *tptr = func();
+ return true;
+ }
+
+ return false;
+}
+
+
void exec_inline_op(enum plugin_dyn_cb_type type,
struct qemu_plugin_inline_cb *cb,
int cpu_index)
