--- /dev/null
+/* libxenstat: statistics-collection library for Xen
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ */
+
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/poll.h>
+#include <sys/un.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <xenctrl.h>
+
+#include "xenstat_priv.h"
+
+#ifdef HAVE_YAJL_YAJL_VERSION_H
+# include <yajl/yajl_version.h>
+#endif
+
+/* YAJL version check */
+#if defined(YAJL_MAJOR) && (YAJL_MAJOR > 1)
+# define HAVE_YAJL_V2 1
+#endif
+
+#ifdef HAVE_YAJL_V2
+
+#include <yajl/yajl_tree.h>
+
+static unsigned char *qmp_query(int, char *);
+
+enum query_blockstats {
+ QMP_STATS_RETURN = 0,
+ QMP_STATS_DEVICE = 1,
+ QMP_STATS = 2,
+ QMP_RD_BYTES = 3,
+ QMP_WR_BYTES = 4,
+ QMP_RD_OPERATIONS = 5,
+ QMP_WR_OPERATIONS = 6,
+};
+
+enum query_block {
+ QMP_BLOCK_RETURN = 0,
+ QMP_BLOCK_DEVICE = 1,
+ QMP_INSERTED = 2,
+ QMP_FILE = 3,
+};
+
+
+/* Given the qmp device name, get the image filename associated with it
+ QMP Syntax for querying block infomation:
+ In: { "execute": "query-block" }
+ Out: {"return": [{
+ "device": 'str, "locked": 'bool', "removable": bool,
+ "inserted": {
+ "iops_rd": 'int',
+ "image": {
+ "virtual-size": 'int', "filename": 'str', "cluster-size": 'int',
+ "format": 'str', "actual-size": 'int', "dirty-flag": 'bool'
+ },
+ "iops_wr": 'int', "ro": 'bool', "backing_file_depth": 'int',
+ "drv": 'str', "iops": 'int', "bps_wr": 'int', "encrypted": 'bool',
+ "bps": 'int', "bps_rd": 'int',
+ "file": 'str', "encryption_key_missing": 'bool'
+ },
+ "type": 'str'
+ }]}
+*/
+static char *qmp_get_block_image(xenstat_node *node, char *qmp_devname, int qfd)
+{
+ char *tmp, *file = NULL;
+ char *query_block_cmd = "{ \"execute\": \"query-block\" }";
+ static const char *const qblock[] = {
+ [ QMP_BLOCK_RETURN ] = "return",
+ [ QMP_BLOCK_DEVICE ] = "device",
+ [ QMP_INSERTED ] = "inserted",
+ [ QMP_FILE ] = "file",
+ };
+ const char *ptr[] = {0, 0};
+ unsigned char *qmp_stats;
+ yajl_val info, ret_obj, dev_obj, n;
+ int i;
+
+ if ((qmp_stats = qmp_query(qfd, query_block_cmd)) == NULL)
+ return NULL;
+
+ /* Use libyajl version 2.0.3 or newer for the tree parser feature with bug fixes */
+ if ((info = yajl_tree_parse((char *)qmp_stats, NULL, 0)) == NULL) {
+ free(qmp_stats);
+ return NULL;
+ }
+
+ ptr[0] = qblock[QMP_BLOCK_RETURN]; /* "return" */
+ if ((ret_obj = yajl_tree_get(info, ptr, yajl_t_array)) == NULL)
+ goto done;
+
+ for (i=0; i<YAJL_GET_ARRAY(ret_obj)->len; i++) {
+ n = YAJL_GET_ARRAY(ret_obj)->values[i];
+
+ ptr[0] = qblock[QMP_BLOCK_DEVICE]; /* "device" */
+ if ((dev_obj = yajl_tree_get(n, ptr, yajl_t_any)) != NULL) {
+ tmp = YAJL_GET_STRING(dev_obj);
+ if (strcmp(qmp_devname, tmp))
+ continue;
+ }
+ else
+ continue;
+
+ ptr[0] = qblock[QMP_INSERTED]; /* "inserted" */
+ n = yajl_tree_get(n, ptr, yajl_t_any);
+ if (n) {
+ ptr[0] = qblock[QMP_FILE]; /* "file" */
+ n = yajl_tree_get(n, ptr, yajl_t_any);
+ if (n && YAJL_IS_STRING(n)) {
+ tmp = YAJL_GET_STRING(n);
+ file = malloc(strlen(tmp)+1);
+ if (file != NULL)
+ strcpy(file, tmp);
+ goto done;
+ }
+ }
+ }
+done:
+ yajl_tree_free(info);
+ return file;
+}
+
+
+/* Given a QMP device name, lookup the associated xenstore qdisk device id */
+static void lookup_xenstore_devid(xenstat_node * node, unsigned int domid, char *qmp_devname,
+ int qfd, unsigned int *dev, unsigned int *sector_size)
+{
+ char **dev_ids, *tmp, *ptr, *image, path[80];
+ unsigned int num_dev_ids;
+ int i, devid;
+
+ /* Get all the qdisk dev IDs associated with the this VM */
+ snprintf(path, sizeof(path),"/local/domain/0/backend/qdisk/%i", domid);
+ dev_ids = xs_directory(node->handle->xshandle, XBT_NULL, path, &num_dev_ids);
+ if (dev_ids == NULL) {
+ return;
+ }
+
+ /* Get the filename of the image associated with this QMP device */
+ image = qmp_get_block_image(node, qmp_devname, qfd);
+ if (image == NULL) {
+ free(dev_ids);
+ return;
+ }
+
+ /* Look for a matching image in xenstore */
+ for (i=0; i<num_dev_ids; i++) {
+ devid = atoi(dev_ids[i]);
+ /* Get the xenstore name of the image */
+ snprintf(path, sizeof(path),"/local/domain/0/backend/qdisk/%i/%i/params", domid, devid);
+ if ((ptr = xs_read(node->handle->xshandle, XBT_NULL, path, NULL)) == NULL)
+ continue;
+
+ /* Get to actual path in string */
+ if ((tmp = strchr(ptr, '/')) == NULL)
+ tmp = ptr;
+ if (!strcmp(tmp,image)) {
+ *dev = devid;
+ free(ptr);
+
+ /* Get the xenstore sector size of the image while we're here */
+ snprintf(path, sizeof(path),"/local/domain/0/backend/qdisk/%i/%i/sector-size", domid, devid);
+ if ((ptr = xs_read(node->handle->xshandle, XBT_NULL, path, NULL)) != NULL) {
+ *sector_size = atoi((char *)ptr);
+ free(ptr);
+ }
+ break;
+ }
+ free(ptr);
+ }
+
+ free(image);
+ free(dev_ids);
+}
+
+/* Parse the stats buffer which contains I/O data for all the disks belonging to domid */
+static void qmp_parse_stats(xenstat_node *node, unsigned int domid, unsigned char *stats_buf, int qfd)
+{
+ char *qmp_devname;
+ static const char *const qstats[] = {
+ [ QMP_STATS_RETURN ] = "return",
+ [ QMP_STATS_DEVICE ] = "device",
+ [ QMP_STATS ] = "stats",
+ [ QMP_RD_BYTES ] = "rd_bytes",
+ [ QMP_WR_BYTES ] = "wr_bytes",
+ [ QMP_RD_OPERATIONS ] = "rd_operations",
+ [ QMP_WR_OPERATIONS ] = "wr_operations",
+ };
+ const char *ptr[] = {0, 0};
+ yajl_val info, ret_obj, stats_obj, n;
+ xenstat_vbd vbd;
+ xenstat_domain *domain;
+ unsigned int sector_size = 512;
+ int i, j;
+
+ /* Use libyajl version 2.0.3 or newer for the tree parser feature */
+ if ((info = yajl_tree_parse((char *)stats_buf, NULL, 0)) == NULL)
+ return;
+
+ ptr[0] = qstats[QMP_STATS_RETURN]; /* "return" */
+ if ((ret_obj = yajl_tree_get(info, ptr, yajl_t_array)) == NULL)
+ goto done;
+
+ /* Array of devices */
+ for (i=0; i<YAJL_GET_ARRAY(ret_obj)->len; i++) {
+ memset(&vbd, 0, sizeof(xenstat_vbd));
+ qmp_devname = NULL;
+ stats_obj = YAJL_GET_ARRAY(ret_obj)->values[i];
+
+ ptr[0] = qstats[QMP_STATS_DEVICE]; /* "device" */
+ if ((n = yajl_tree_get(stats_obj, ptr, yajl_t_any)) != NULL)
+ qmp_devname = YAJL_GET_STRING(n);
+
+ ptr[0] = qstats[QMP_STATS]; /* "stats" */
+ stats_obj = yajl_tree_get(stats_obj, ptr, yajl_t_object);
+ if (stats_obj && YAJL_IS_OBJECT(stats_obj)) {
+ for (j=3; j<7; j++) {
+ ptr[0] = qstats[j];
+ n = yajl_tree_get(stats_obj, ptr, yajl_t_number);
+ if (n && YAJL_IS_NUMBER(n)) {
+ switch(j) {
+ case QMP_RD_BYTES: /* "rd_bytes" */
+ vbd.rd_sects = YAJL_GET_INTEGER(n) / sector_size;
+ break;
+ case QMP_WR_BYTES: /* "wr_bytes" */
+ vbd.wr_sects = YAJL_GET_INTEGER(n) / sector_size;
+ break;
+ case QMP_RD_OPERATIONS: /* "rd_operations" */
+ vbd.rd_reqs = YAJL_GET_INTEGER(n);
+ break;
+ case QMP_WR_OPERATIONS: /* "wr_operations" */
+ vbd.wr_reqs = YAJL_GET_INTEGER(n);
+ break;
+ }
+ }
+ }
+ /* With the QMP device name, lookup the xenstore qdisk device ID and set vdb.dev */
+ if (qmp_devname)
+ lookup_xenstore_devid(node, domid, qmp_devname, qfd, &vbd.dev, §or_size);
+ if ((domain = xenstat_node_domain(node, domid)) == NULL)
+ continue;
+ if ((xenstat_save_vbd(domain, &vbd)) == NULL)
+ goto done;
+ }
+ }
+done:
+ yajl_tree_free(info);
+}
+
+/* Write a command via the QMP. Returns number of bytes written */
+static size_t qmp_write(int qfd, char *cmd, size_t cmd_len)
+{
+ size_t pos = 0;
+ ssize_t res;
+
+ while (cmd_len > pos) {
+ res = write(qfd, cmd + pos, cmd_len - pos);
+ switch (res) {
+ case -1:
+ if (errno == EINTR || errno == EAGAIN)
+ continue;
+ return 0;
+ case 0:
+ errno = EPIPE;
+ return pos;
+ default:
+ pos += (size_t)res;
+ }
+ }
+ return pos;
+}
+
+/* Read the data sent in response to a QMP execute query. Returns 1 for success */
+static int qmp_read(int qfd, unsigned char **qstats)
+{
+ unsigned char buf[1024], *ptr;
+ struct pollfd pfd[2];
+ int n, qsize = 0;
+
+ *qstats = NULL;
+ pfd[0].fd = qfd;
+ pfd[0].events = POLLIN;
+ while ((n = poll(pfd, POLLIN, 10)) > 0) {
+ if (pfd[0].revents & POLLIN) {
+ if ((n = read(qfd, buf, sizeof(buf))) < 0) {
+ return 0;
+ }
+ ptr = realloc(*qstats, qsize+n+1);
+ if (ptr == NULL) {
+ free(*qstats);
+ return 0;
+ }
+ memcpy(&ptr[qsize], buf, n);
+ qsize += n;
+ ptr[qsize] = 0;
+ *qstats = ptr;
+ }
+ }
+ return 1;
+}
+
+/* With the given cmd, query QMP for requested data. Returns allocated buffer containing data or NULL */
+static unsigned char *qmp_query(int qfd, char *cmd)
+{
+ unsigned char *qstats = NULL;
+ int n;
+
+ n = strlen(cmd);
+ if (qmp_write(qfd, cmd, n) != n)
+ return NULL;
+ if (!qmp_read(qfd, &qstats))
+ return NULL;
+ return qstats;
+}
+
+/* Returns a socket connected to the QMP socket. Returns -1 on failure. */
+static int qmp_connect(char *path)
+{
+ struct sockaddr_un sun;
+ int s;
+
+ if ((s = socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
+ return -1;
+ (void)fcntl(s, F_SETFD, 1);
+
+ memset(&sun, 0, sizeof(struct sockaddr_un));
+ sun.sun_family = AF_UNIX;
+
+ if (strlen(path) >= sizeof(sun.sun_path)) {
+ close(s);
+ return -1;
+ }
+
+ strcpy(sun.sun_path, path);
+ if (connect(s, (struct sockaddr *)&sun, SUN_LEN(&sun)) < 0) {
+ close(s);
+ return -1;
+ }
+
+ return s;
+}
+
+/* Get up to 1024 active domains */
+static xc_domaininfo_t *get_domain_ids(int *num_doms)
+{
+ xc_domaininfo_t *dominfo;
+ xc_interface *xc_handle;
+
+ dominfo = calloc(1024, sizeof(xc_domaininfo_t));
+ if (dominfo == NULL)
+ return NULL;
+ xc_handle = xc_interface_open(0,0,0);
+ *num_doms = xc_domain_getinfolist(xc_handle, 0, 1024, dominfo);
+ xc_interface_close(xc_handle);
+ return dominfo;
+}
+
+/* Gather the qdisk statistics by querying QMP
+ Resources: http://wiki.qemu.org/QMP and qmp-commands.hx from the qemu code
+ QMP Syntax for entering command mode. This command must be issued before
+ issuing any other command:
+ In: {"execute": "qmp_capabilities"}
+ Out: {"return": {}}
+ QMP Syntax for querying block statistics:
+ In: { "execute": "query-blockstats" }
+ Out: {"return": [{
+ "device": 'str',
+ "parent": {
+ "stats": {
+ "flush_total_time_ns": 'int', "wr_highest_offset": 'int',
+ "wr_total_time_ns": 'int', "wr_bytes": 'int',
+ "rd_total_time_ns": 'int', "flush_operations": 'int',
+ "wr_operations": 'int', "rd_bytes": 'int', "rd_operations": 'int'
+ }
+ },
+ "stats": {
+ "flush_total_time_ns": 'int', "wr_highest_offset": 'int',
+ "wr_total_time_ns": 'int', "wr_bytes": 'int',
+ "rd_total_time_ns": 'int', "flush_operations": 'int',
+ "wr_operations": 'int', "rd_bytes": 'int', "rd_operations": 'int'
+ }
+ }]}
+*/
+void read_attributes_qdisk(xenstat_node * node)
+{
+ char *cmd_mode = "{ \"execute\": \"qmp_capabilities\" }";
+ char *query_blockstats_cmd = "{ \"execute\": \"query-blockstats\" }";
+ xc_domaininfo_t *dominfo = NULL;
+ unsigned char *qmp_stats, *val;
+ char path[80];
+ int i, qfd, num_doms;
+
+ dominfo = get_domain_ids(&num_doms);
+ if (dominfo == NULL)
+ return;
+
+ for (i=0; i<num_doms; i++) {
+ if (dominfo[i].domain <= 0)
+ continue;
+
+ /* Verify that qdisk disks are used with this VM */
+ snprintf(path, sizeof(path),"/local/domain/0/backend/qdisk/%i", dominfo[i].domain);
+ if ((val = xs_read(node->handle->xshandle, XBT_NULL, path, NULL)) == NULL)
+ continue;
+ free(val);
+
+ /* Connect to this VMs QMP socket */
+ snprintf(path, sizeof(path), "/var/run/xen/qmp-libxenstat-%i", dominfo[i].domain);
+ if ((qfd = qmp_connect(path)) < 0) {
+ continue;
+ }
+
+ /* First enable QMP capabilities so that we can query for data */
+ if ((qmp_stats = qmp_query(qfd, cmd_mode)) != NULL) {
+ free(qmp_stats);
+ /* Query QMP for this VMs blockstats */
+ if ((qmp_stats = qmp_query(qfd, query_blockstats_cmd)) != NULL) {
+ qmp_parse_stats(node, dominfo[i].domain, qmp_stats, qfd);
+ free(qmp_stats);
+ }
+ }
+ close(qfd);
+ }
+
+ free(dominfo);
+}
+
+#else /* !HAVE_YAJL_V2 */
+
+/* Statistics gathering for qdisks requires at least yajl v2 */
+void read_attributes_qdisk(xenstat_node * node)
+{
+}
+
+#endif /* !HAVE_YAJL_V2 */
projects / people / pauldu / xen.git / commitdiff