The plugin API allows registration of callbacks for a variety of VCPU
related events, such as VCPU reset, idle and resume. However, traps of
any kind, i.e. interrupts or exceptions, were previously not covered.
These kinds of events are arguably quite significant and usually go hand
in hand with a PC discontinuity. On most platforms, the discontinuity
also includes a transition from some "mode" to another. Thus, plugins
for the analysis of (virtualized) embedded systems may benefit from or
even require the possiblity to perform work on the occurance of an
interrupt or exception.
This change introduces the concept of such a discontinuity event in
the
form of an enumeration. Currently only traps are covered. Specifically
we (loosely) define interrupts, exceptions and host calls across all
platforms. In addition, this change introduces a type to use for
callback functions related to such events. Since possible modes and the
enumeration of interupts and exceptions vary greatly between different
architectures, the callback type only receives the VCPU id, the type of
event as well as the old and new PC.
---
include/qemu/plugin.h | 1 +
include/qemu/qemu-plugin.h | 43 ++++++++++++++++++++++++++++++++++++++
2 files changed, 44 insertions(+)
diff --git a/include/qemu/plugin.h b/include/qemu/plugin.h
index 9726a9ebf3..27a176b631 100644
--- a/include/qemu/plugin.h
+++ b/include/qemu/plugin.h
@@ -59,6 +59,7 @@ union qemu_plugin_cb_sig {
qemu_plugin_udata_cb_t udata;
qemu_plugin_vcpu_simple_cb_t vcpu_simple;
qemu_plugin_vcpu_udata_cb_t vcpu_udata;
+ qemu_plugin_vcpu_discon_cb_t vcpu_discon;
qemu_plugin_vcpu_tb_trans_cb_t vcpu_tb_trans;
qemu_plugin_vcpu_mem_cb_t vcpu_mem;
qemu_plugin_vcpu_syscall_cb_t vcpu_syscall;
diff --git a/include/qemu/qemu-plugin.h b/include/qemu/qemu-plugin.h
index 0fba36ae02..9c67374b7e 100644
--- a/include/qemu/qemu-plugin.h
+++ b/include/qemu/qemu-plugin.h
@@ -154,6 +154,49 @@ typedef void
(*qemu_plugin_vcpu_simple_cb_t)(qemu_plugin_id_t id,
typedef void (*qemu_plugin_vcpu_udata_cb_t)(unsigned int vcpu_index,
void *userdata);
+
+/**
+ * enum qemu_plugin_discon_type - type of a (potential) PC discontinuity
+ *
+ * @QEMU_PLUGIN_DISCON_INTERRUPT: an interrupt, defined across all
architectures
+ * as an asynchronous event, usually originating
+ * from outside the CPU
+ * @QEMU_PLUGIN_DISCON_EXCEPTION: an exception, defined across all
architectures
+ * as a synchronous event in response to a
+ * specific instruction being executed
+ * @QEMU_PLUGIN_DISCON_HOSTCALL: a host call, functionally a special kind of
+ * exception that is not handled by code run by
+ * the vCPU but machinery outside the vCPU
+ * @QEMU_PLUGIN_DISCON_ALL: all types of disconinuity events currently covered
+ */
+enum qemu_plugin_discon_type {
+ QEMU_PLUGIN_DISCON_INTERRUPT = 1,
+ QEMU_PLUGIN_DISCON_EXCEPTION = 2,
+ QEMU_PLUGIN_DISCON_HOSTCALL = 4,
+ QEMU_PLUGIN_DISCON_ALL = 7
+};