108fc82596
This patch adds a user tool, "trace agent" for sending trace data of a guest to a Host in low overhead. This agent has the following functions: - splice a page of ring-buffer to read_pipe without memory copying - splice the page from write_pipe to virtio-console without memory copying - write trace data to stdout by using -o option - controlled by start/stop orders from a Host Changes in v2: - Cleanup (change fprintf() to pr_err() and an include guard) Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com> Acked-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
75 lines
2.1 KiB
C
75 lines
2.1 KiB
C
#ifndef __TRACE_AGENT_H__
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#define __TRACE_AGENT_H__
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#include <pthread.h>
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#include <stdbool.h>
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#define MAX_CPUS 256
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#define PIPE_INIT (1024*1024)
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/*
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* agent_info - structure managing total information of guest agent
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* @pipe_size: size of pipe (default 1MB)
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* @use_stdout: set to true when o option is added (default false)
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* @cpus: total number of CPUs
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* @ctl_fd: fd of control path, /dev/virtio-ports/agent-ctl-path
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* @rw_ti: structure managing information of read/write threads
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*/
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struct agent_info {
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unsigned long pipe_size;
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bool use_stdout;
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int cpus;
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int ctl_fd;
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struct rw_thread_info *rw_ti[MAX_CPUS];
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};
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/*
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* rw_thread_info - structure managing a read/write thread a cpu
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* @cpu_num: cpu number operating this read/write thread
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* @in_fd: fd of reading trace data path in cpu_num
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* @out_fd: fd of writing trace data path in cpu_num
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* @read_pipe: fd of read pipe
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* @write_pipe: fd of write pipe
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* @pipe_size: size of pipe (default 1MB)
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*/
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struct rw_thread_info {
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int cpu_num;
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int in_fd;
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int out_fd;
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int read_pipe;
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int write_pipe;
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unsigned long pipe_size;
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};
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/* use for stopping rw threads */
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extern bool global_sig_receive;
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/* use for notification */
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extern bool global_run_operation;
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extern pthread_mutex_t mutex_notify;
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extern pthread_cond_t cond_wakeup;
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/* for controller of read/write threads */
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extern int rw_ctl_init(const char *ctl_path);
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extern void *rw_ctl_loop(int ctl_fd);
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/* for trace read/write thread */
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extern void *rw_thread_info_new(void);
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extern void *rw_thread_init(int cpu, const char *in_path, const char *out_path,
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bool stdout_flag, unsigned long pipe_size,
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struct rw_thread_info *rw_ti);
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extern pthread_t rw_thread_run(struct rw_thread_info *rw_ti);
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static inline void *zalloc(size_t size)
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{
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return calloc(1, size);
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}
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#define pr_err(format, ...) fprintf(stderr, format, ## __VA_ARGS__)
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#define pr_info(format, ...) fprintf(stdout, format, ## __VA_ARGS__)
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#ifdef DEBUG
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#define pr_debug(format, ...) fprintf(stderr, format, ## __VA_ARGS__)
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#else
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#define pr_debug(format, ...) do {} while (0)
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#endif
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#endif /*__TRACE_AGENT_H__*/
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