Hi Julian,
On 5/11/25 6:13 AM, Julian Ganz wrote:
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.
Signed-off-by: Julian Ganz <neither@nut.email>
---
include/qemu/plugin.h | 1 +
include/qemu/qemu-plugin.h | 44 ++++++++++++++++++++++++++++++++++++++
2 files changed, 45 insertions(+)
[...]
+/**
+ * typedef qemu_plugin_vcpu_discon_cb_t - vcpu discontinuity callback
+ * @id: plugin ID
+ * @vcpu_index: the current vcpu context
+ * @type: the type of discontinuity
+ * @from_pc: the source of the discontinuity, e.g. the PC before the
+ * transition
+ * @to_pc: the PC pointing to the next instruction to be executed
+ *
+ * The excact semantics of @from_pc depends on @the type of discontinuity. For
s/excact/exact
+ * interrupts, @from_pc will point to the next instruction which would have
+ * been executed. For exceptions and host calls, @from_pc will point to the
+ * instruction that caused the exception or issued the host call. Note that
+ * in the case of exceptions, the instruction may not be retired and thus not
+ * observable via general instruction exec callbacks. The same may be the case
+ * for some host calls such as hypervisor call "exceptions".
+ */
thanks for respinning this series.
Reviewed-by: Pierrick Bouvier <pierrick.bouv...@linaro.org>
