diff options
Diffstat (limited to 'tools/virtio/virtio-trace/trace-agent.c')
| -rw-r--r-- | tools/virtio/virtio-trace/trace-agent.c | 270 |
1 files changed, 270 insertions, 0 deletions
diff --git a/tools/virtio/virtio-trace/trace-agent.c b/tools/virtio/virtio-trace/trace-agent.c new file mode 100644 index 000000000..0a0a7dd4e --- /dev/null +++ b/tools/virtio/virtio-trace/trace-agent.c @@ -0,0 +1,270 @@ +/* + * Guest agent for virtio-trace + * + * Copyright (C) 2012 Hitachi, Ltd. + * Created by Yoshihiro Yunomae <yoshihiro.yunomae.ez@hitachi.com> + * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> + * + * Licensed under GPL version 2 only. + * + */ + +#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; +} |