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- // SPDX-License-Identifier: GPL-2.0-only
- /*
- * Guest agent for virtio-trace
- *
- * Copyright (C) 2012 Hitachi, Ltd.
- * Created by Yoshihiro Yunomae <[email protected]>
- * Masami Hiramatsu <[email protected]>
- */
- #define _GNU_SOURCE
- #include <limits.h>
- #include <stdio.h>
- #include <stdlib.h>
- #include <unistd.h>
- #include "trace-agent.h"
- #define PAGE_SIZE (sysconf(_SC_PAGE_SIZE))
- #define PIPE_DEF_BUFS 16
- #define PIPE_MIN_SIZE (PAGE_SIZE*PIPE_DEF_BUFS)
- #define PIPE_MAX_SIZE (1024*1024)
- #define READ_PATH_FMT \
- "/sys/kernel/debug/tracing/per_cpu/cpu%d/trace_pipe_raw"
- #define WRITE_PATH_FMT "/dev/virtio-ports/trace-path-cpu%d"
- #define CTL_PATH "/dev/virtio-ports/agent-ctl-path"
- pthread_mutex_t mutex_notify = PTHREAD_MUTEX_INITIALIZER;
- pthread_cond_t cond_wakeup = PTHREAD_COND_INITIALIZER;
- static int get_total_cpus(void)
- {
- int nr_cpus = (int)sysconf(_SC_NPROCESSORS_CONF);
- if (nr_cpus <= 0) {
- pr_err("Could not read cpus\n");
- goto error;
- } else if (nr_cpus > MAX_CPUS) {
- pr_err("Exceed max cpus(%d)\n", (int)MAX_CPUS);
- goto error;
- }
- return nr_cpus;
- error:
- exit(EXIT_FAILURE);
- }
- static void *agent_info_new(void)
- {
- struct agent_info *s;
- int i;
- s = zalloc(sizeof(struct agent_info));
- if (s == NULL) {
- pr_err("agent_info zalloc error\n");
- exit(EXIT_FAILURE);
- }
- s->pipe_size = PIPE_INIT;
- s->use_stdout = false;
- s->cpus = get_total_cpus();
- s->ctl_fd = -1;
- /* read/write threads init */
- for (i = 0; i < s->cpus; i++)
- s->rw_ti[i] = rw_thread_info_new();
- return s;
- }
- static unsigned long parse_size(const char *arg)
- {
- unsigned long value, round;
- char *ptr;
- value = strtoul(arg, &ptr, 10);
- switch (*ptr) {
- case 'K': case 'k':
- value <<= 10;
- break;
- case 'M': case 'm':
- value <<= 20;
- break;
- default:
- break;
- }
- if (value > PIPE_MAX_SIZE) {
- pr_err("Pipe size must be less than 1MB\n");
- goto error;
- } else if (value < PIPE_MIN_SIZE) {
- pr_err("Pipe size must be over 64KB\n");
- goto error;
- }
- /* Align buffer size with page unit */
- round = value & (PAGE_SIZE - 1);
- value = value - round;
- return value;
- error:
- return 0;
- }
- static void usage(char const *prg)
- {
- pr_err("usage: %s [-h] [-o] [-s <size of pipe>]\n", prg);
- }
- static const char *make_path(int cpu_num, bool this_is_write_path)
- {
- int ret;
- char *buf;
- buf = zalloc(PATH_MAX);
- if (buf == NULL) {
- pr_err("Could not allocate buffer\n");
- goto error;
- }
- if (this_is_write_path)
- /* write(output) path */
- ret = snprintf(buf, PATH_MAX, WRITE_PATH_FMT, cpu_num);
- else
- /* read(input) path */
- ret = snprintf(buf, PATH_MAX, READ_PATH_FMT, cpu_num);
- if (ret <= 0) {
- pr_err("Failed to generate %s path(CPU#%d):%d\n",
- this_is_write_path ? "read" : "write", cpu_num, ret);
- goto error;
- }
- return buf;
- error:
- free(buf);
- return NULL;
- }
- static const char *make_input_path(int cpu_num)
- {
- return make_path(cpu_num, false);
- }
- static const char *make_output_path(int cpu_num)
- {
- return make_path(cpu_num, true);
- }
- static void *agent_info_init(struct agent_info *s)
- {
- int cpu;
- const char *in_path = NULL;
- const char *out_path = NULL;
- /* init read/write threads */
- for (cpu = 0; cpu < s->cpus; cpu++) {
- /* set read(input) path per read/write thread */
- in_path = make_input_path(cpu);
- if (in_path == NULL)
- goto error;
- /* set write(output) path per read/write thread*/
- if (!s->use_stdout) {
- out_path = make_output_path(cpu);
- if (out_path == NULL)
- goto error;
- } else
- /* stdout mode */
- pr_debug("stdout mode\n");
- rw_thread_init(cpu, in_path, out_path, s->use_stdout,
- s->pipe_size, s->rw_ti[cpu]);
- }
- /* init controller of read/write threads */
- s->ctl_fd = rw_ctl_init((const char *)CTL_PATH);
- return NULL;
- error:
- exit(EXIT_FAILURE);
- }
- static void *parse_args(int argc, char *argv[], struct agent_info *s)
- {
- int cmd;
- unsigned long size;
- while ((cmd = getopt(argc, argv, "hos:")) != -1) {
- switch (cmd) {
- /* stdout mode */
- case 'o':
- s->use_stdout = true;
- break;
- /* size of pipe */
- case 's':
- size = parse_size(optarg);
- if (size == 0)
- goto error;
- s->pipe_size = size;
- break;
- case 'h':
- default:
- usage(argv[0]);
- goto error;
- }
- }
- agent_info_init(s);
- return NULL;
- error:
- exit(EXIT_FAILURE);
- }
- static void agent_main_loop(struct agent_info *s)
- {
- int cpu;
- pthread_t rw_thread_per_cpu[MAX_CPUS];
- /* Start all read/write threads */
- for (cpu = 0; cpu < s->cpus; cpu++)
- rw_thread_per_cpu[cpu] = rw_thread_run(s->rw_ti[cpu]);
- rw_ctl_loop(s->ctl_fd);
- /* Finish all read/write threads */
- for (cpu = 0; cpu < s->cpus; cpu++) {
- int ret;
- ret = pthread_join(rw_thread_per_cpu[cpu], NULL);
- if (ret != 0) {
- pr_err("pthread_join() error:%d (cpu %d)\n", ret, cpu);
- exit(EXIT_FAILURE);
- }
- }
- }
- static void agent_info_free(struct agent_info *s)
- {
- int i;
- close(s->ctl_fd);
- for (i = 0; i < s->cpus; i++) {
- close(s->rw_ti[i]->in_fd);
- close(s->rw_ti[i]->out_fd);
- close(s->rw_ti[i]->read_pipe);
- close(s->rw_ti[i]->write_pipe);
- free(s->rw_ti[i]);
- }
- free(s);
- }
- int main(int argc, char *argv[])
- {
- struct agent_info *s = NULL;
- s = agent_info_new();
- parse_args(argc, argv, s);
- agent_main_loop(s);
- agent_info_free(s);
- return 0;
- }
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