@@ -368,4 +368,13 @@ config DOM0_MEM
Leave empty if you are not sure what to specify.
+config TRACEBUFFER
+ bool "Enable tracing infrastructure" if EXPERT = "y"
+ default y
+ ---help---
+ Enable tracing infrastructure and pre-defined tracepoints within Xen.
+ This will allow live information about Xen’s execution and performance
+ to be collected at run time for debugging or performance analysis.
+ Memory and execution overhead when not active is minimal.
+
endmenu
@@ -56,7 +56,7 @@ obj-y += sysctl.o
obj-y += tasklet.o
obj-y += time.o
obj-y += timer.o
-obj-y += trace.o
+obj-$(CONFIG_TRACEBUFFER) += trace.o
obj-y += version.o
obj-y += virtual_region.o
obj-y += vm_event.o
@@ -21,12 +21,18 @@
#ifndef __XEN_TRACE_H__
#define __XEN_TRACE_H__
+/* Put 'tb_init_done' here because 'asm/trace.h' may use it */
+#ifdef CONFIG_TRACEBUFFER
extern int tb_init_done;
+#else
+#define tb_init_done false
+#endif
#include <public/sysctl.h>
#include <public/trace.h>
#include <asm/trace.h>
+#ifdef CONFIG_TRACEBUFFER
/* Used to initialise trace buffer functionality */
void init_trace_bufs(void);
@@ -47,6 +53,26 @@ static inline void trace_var(u32 event, int cycles, int extra,
void __trace_hypercall(uint32_t event, unsigned long op,
const xen_ulong_t *args);
+#else
+static inline void init_trace_bufs(void) {}
+static inline int tb_control(struct xen_sysctl_tbuf_op *tbc)
+{
+ return -ENOSYS;
+}
+
+static inline int trace_will_trace_event(uint32_t event)
+{
+ return 0;
+}
+
+static inline void trace_var(uint32_t event, int cycles, int extra,
+ const void *extra_data) {}
+static inline void __trace_var(uint32_t event, bool cycles, unsigned int extra,
+ const void *extra_data) {}
+static inline void __trace_hypercall(uint32_t event, unsigned long op,
+ const xen_ulong_t *args) {}
+#endif
+
/* Convenience macros for calling the trace function. */
#define TRACE_0D(_e) \
do { \
Xen internal running status(trace event at pre-defined trace point) will be saved to trace memory when enabled. Trace event data and config params can be read/changed by system control hypercall at run time. Can be disabled for smaller code footprint. Signed-off-by: Baodong Chen <chenbaodong@mxnavi.com> --- xen/common/Kconfig | 9 +++++++++ xen/common/Makefile | 2 +- xen/include/xen/trace.h | 26 ++++++++++++++++++++++++++ 3 files changed, 36 insertions(+), 1 deletion(-)