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[RFC PATCH 7/8] plugins: add time control API
From: |
Alex Bennée |
Subject: |
[RFC PATCH 7/8] plugins: add time control API |
Date: |
Fri, 19 May 2023 18:04:53 +0100 |
Expose the ability to control time through the plugin API. Only one
plugin can control time so it has to request control when loaded.
There are probably more corner cases to catch here.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
---
include/qemu/qemu-plugin.h | 19 +++++++++++++++++++
plugins/api.c | 22 ++++++++++++++++++++++
plugins/qemu-plugins.symbols | 2 ++
3 files changed, 43 insertions(+)
diff --git a/include/qemu/qemu-plugin.h b/include/qemu/qemu-plugin.h
index 50a9957279..8385670976 100644
--- a/include/qemu/qemu-plugin.h
+++ b/include/qemu/qemu-plugin.h
@@ -536,7 +536,26 @@ void qemu_plugin_register_vcpu_mem_inline(struct
qemu_plugin_insn *insn,
enum qemu_plugin_op op, void *ptr,
uint64_t imm);
+/**
+ * qemu_plugin_request_time_control() - request the ability to control time
+ *
+ * This grants the plugin the ability to control system time. Only one
+ * plugin can control time so if multiple plugins request the ability
+ * all but the first will fail.
+ *
+ * Returns an opaque handle or NULL if fails
+ */
+const void * qemu_plugin_request_time_control(void);
+/**
+ * qemu_plugin_update_ns() - update system emulation time
+ * @handle: opaque handle returned by qemu_plugin_request_time_control()
+ * @time: time in nanoseconds
+ *
+ * This allows an appropriately authorised plugin (i.e. holding the
+ * time control handle) to move system time forward to @time.
+ */
+void qemu_plugin_update_ns(const void *handle, int64_t new_time);
typedef void
(*qemu_plugin_vcpu_syscall_cb_t)(qemu_plugin_id_t id, unsigned int vcpu_index,
diff --git a/plugins/api.c b/plugins/api.c
index 2078b16edb..8402b3a5f6 100644
--- a/plugins/api.c
+++ b/plugins/api.c
@@ -37,6 +37,7 @@
#include "qemu/osdep.h"
#include "qemu/plugin.h"
#include "qemu/log.h"
+#include "qemu/timer.h"
#include "tcg/tcg.h"
#include "exec/exec-all.h"
#include "exec/ram_addr.h"
@@ -442,3 +443,24 @@ uint64_t qemu_plugin_entry_code(void)
#endif
return entry;
}
+
+/*
+ * Time control
+ */
+static bool has_control;
+
+const void * qemu_plugin_request_time_control(void)
+{
+ if (!has_control) {
+ has_control = true;
+ return &has_control;
+ }
+ return NULL;
+}
+
+void qemu_plugin_update_ns(const void *handle, int64_t new_time)
+{
+ if (handle == &has_control) {
+ qemu_clock_advance_virtual_time(new_time);
+ }
+}
diff --git a/plugins/qemu-plugins.symbols b/plugins/qemu-plugins.symbols
index 71f6c90549..91b882fecc 100644
--- a/plugins/qemu-plugins.symbols
+++ b/plugins/qemu-plugins.symbols
@@ -35,11 +35,13 @@
qemu_plugin_register_vcpu_tb_exec_cb;
qemu_plugin_register_vcpu_tb_exec_inline;
qemu_plugin_register_vcpu_tb_trans_cb;
+ qemu_plugin_request_time_control;
qemu_plugin_reset;
qemu_plugin_start_code;
qemu_plugin_tb_get_insn;
qemu_plugin_tb_n_insns;
qemu_plugin_tb_vaddr;
qemu_plugin_uninstall;
+ qemu_plugin_update_ns;
qemu_plugin_vcpu_for_each;
};
--
2.39.2
- [PATCH 1/8] plugins: force slow path when plugins instrument memory ops, (continued)
- [PATCH 1/8] plugins: force slow path when plugins instrument memory ops, Alex Bennée, 2023/05/19
- [PATCH 2/8] plugins: fix memory leak while parsing options, Alex Bennée, 2023/05/19
- [RFC PATCH 4/8] sysemu: add set_virtual_time to accel ops, Alex Bennée, 2023/05/19
- [RFC PATCH 5/8] qtest: use cpu interface in qtest_clock_warp, Alex Bennée, 2023/05/19
- [RFC PATCH 6/8] sysemu: generalise qtest_warp_clock as qemu_clock_advance_virtual_time, Alex Bennée, 2023/05/19
- [RFC PATCH 8/8] contrib/plugins: add iops plugin example for cost modelling, Alex Bennée, 2023/05/19
- [RFC PATCH 7/8] plugins: add time control API,
Alex Bennée <=
- [PATCH 3/8] plugins: update lockstep to use g_memdup2, Alex Bennée, 2023/05/19