In order to match host and guest events, a mapping between guest VCPU
and the host task, running this VCPU is needed. Extended existing
struct guest to hold such mapping and added logic in read_qemu_guests()
function to initialize it. Implemented a new internal API,
get_guest_vcpu_pids(), to retrieve VCPU-task mapping for given VM.
Signed-off-by: Tzvetomir Stoyanov <tstoyanov@xxxxxxxxxx>
---
tracecmd/include/trace-local.h | 3 ++
tracecmd/trace-record.c | 57 +++++++++++++++++++++++++++++++++-
2 files changed, 59 insertions(+), 1 deletion(-)
diff --git a/tracecmd/include/trace-local.h b/tracecmd/include/trace-local.h
index d7bdb1f..ef6848f 100644
--- a/tracecmd/include/trace-local.h
+++ b/tracecmd/include/trace-local.h
@@ -236,6 +236,9 @@ void show_instance_file(struct buffer_instance *instance, const char *name);
int count_cpus(void);
+#define VCPUS_MAX 256
+int *get_guest_vcpu_pids(int cid);
+
/* No longer in event-utils.h */
void __noreturn die(const char *fmt, ...); /* Can be overriden */
void *malloc_or_die(unsigned int size); /* Can be overridden */
diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
index c57ed6b..59f0197 100644
--- a/tracecmd/trace-record.c
+++ b/tracecmd/trace-record.c
@@ -2752,6 +2752,7 @@ struct guest {
char *name;
int cid;
int pid;
+ int cpu_pid[VCPUS_MAX];
};
static struct guest *guests;
@@ -2772,9 +2773,10 @@ static char *get_qemu_guest_name(char *arg)
static void read_qemu_guests(void)
{
static bool initialized;
+ struct dirent *entry_t;
struct dirent *entry;
char path[PATH_MAX];
- DIR *dir;
+ DIR *dir, *dir_t;
if (initialized)
return;
@@ -2830,6 +2832,49 @@ static void read_qemu_guests(void)
if (!is_qemu)
goto next;
+ snprintf(path, sizeof(path), "/proc/%s/task", entry->d_name);
+ dir_t = opendir(path);
+ if (dir_t) {
+ unsigned int vcpu;
+ char *buf = NULL;
+ char *cpu_str;
+ FILE *ft;
+ size_t n;
+ int j;
+
+ for (entry_t = readdir(dir_t); entry_t; entry_t = readdir(dir_t)) {
+ if (!(entry_t->d_type == DT_DIR &&
+ is_digits(entry_t->d_name)))
+ continue;
+ snprintf(path, sizeof(path),
+ "/proc/%s/task/%s/comm",
+ entry->d_name, entry_t->d_name);
+ ft = fopen(path, "r");
+ if (!ft)
+ continue;
+ getline(&buf, &n, ft);
+ if (buf && strncmp(buf, "CPU ", 4) == 0) {
+ cpu_str = buf;
+ while (*cpu_str != '\0' &&
+ isdigit(*cpu_str) == 0)
+ cpu_str++;
+ if (*cpu_str != '\0') {
+ j = 0;
+ while (cpu_str[j] != '\0' &&
+ isdigit(cpu_str[j]) != 0)
+ j++;
+ cpu_str[j] = '\0';
+ vcpu = atoi(cpu_str);
+ if (vcpu < VCPUS_MAX)
+ guest.cpu_pid[vcpu] = atoi(entry_t->d_name);
+ }
+ }
+ free(buf);
+ fclose(ft);
+ buf = NULL;
+ }
+ }
+
guests = realloc(guests, (guests_len + 1) * sizeof(*guests));
if (!guests)
die("Can not allocate guest buffer");
@@ -2875,6 +2920,16 @@ static char *parse_guest_name(char *guest, int *cid, int *port)
return guest;
}
+int *get_guest_vcpu_pids(int cid)
+{
+ int i;
+
+ for (i = 0; i < guests_len; i++)
+ if (cid == guests[i].cid)
+ return guests[i].cpu_pid;
+ return NULL;
+}
+
static void set_prio(int prio)
{
struct sched_param sp;
--
2.20.1
|