[virt-tools-list] [vhostmd virtio PATCH v3 6/6] Add virtio support to vm-dump-metrics

Michael Trapp Michael.Trapp at sap.com
Mon Nov 12 15:13:19 UTC 2018


virtio functions are available in libmetrics
and in libserialclient (with minimal dependencies).

---
We would like to have the serialclient code available in a library without
additional dependencies, because linking against libmetrics requires libxml2.

virtio adds the 3rd transport method to vhostmd and the available
'#ifdef WITH_XENSTORE' sections in vm-dump-metrics/main.c should be reviewed.

 libmetrics/Makefile.am       |  17 +++-
 libmetrics/libmetrics.h      |   6 ++
 libmetrics/libserialclient.c | 172 +++++++++++++++++++++++++++++++++++
 libmetrics/libserialclient.h |  30 ++++++
 vm-dump-metrics/main.c       |  29 ++++--
 5 files changed, 246 insertions(+), 8 deletions(-)
 create mode 100644 libmetrics/libserialclient.c
 create mode 100644 libmetrics/libserialclient.h

diff --git a/libmetrics/Makefile.am b/libmetrics/Makefile.am
index 28490ee..468f08f 100644
--- a/libmetrics/Makefile.am
+++ b/libmetrics/Makefile.am
@@ -6,7 +6,7 @@ if WITH_XENSTORE
 AM_CFLAGS += -DWITH_XENSTORE
 endif
 
-lib_LTLIBRARIES=libmetrics.la
+lib_LTLIBRARIES=libmetrics.la libserialclient.la
 
 libmetricsincdir=$(includedir)/vhostmd
 libmetricsinc_HEADERS = libmetrics.h
@@ -15,8 +15,21 @@ libmetrics_la_SOURCES =  \
      libmetrics.c \
      vm_metrics.c \
      host_metrics.c \
+     libserialclient.c \
      libmetrics.h
 
 libmetrics_la_DEPENDENCIES = \
-     libmetrics.h
+     libmetrics.h \
+     libserialclient.h
+
+
+libserialclientincdir=
+libserialclientinc_HEADERS = libserialclient.h
+
+libserialclient_la_SOURCES =  \
+     libserialclient.c \
+     libserialclient.h
+
+libserialclient_la_DEPENDENCIES = \
+     libserialclient.h
 
diff --git a/libmetrics/libmetrics.h b/libmetrics/libmetrics.h
index 717bc73..1908de8 100644
--- a/libmetrics/libmetrics.h
+++ b/libmetrics/libmetrics.h
@@ -100,4 +100,10 @@ int dump_metrics(const char *dest_file);
 /* dump metrics from xenstore to xml formatted file */
 int dump_xenstore_metrics(const char *dest_file);
 
+/* dump metrics from virtio serial port to xml formatted file */
+int dump_virtio_metrics(const char *dest_file);
+
+/* dump metrics from virtio serial port to buffer */
+const char *get_virtio_metrics(const char *dev_name);
+
 #endif
diff --git a/libmetrics/libserialclient.c b/libmetrics/libserialclient.c
new file mode 100644
index 0000000..61adc2b
--- /dev/null
+++ b/libmetrics/libserialclient.c
@@ -0,0 +1,172 @@
+/*
+ * Copyright (C) 2018 SAP SE
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA
+ *
+ * Author: Michael Trapp <michael.trapp at sap.com>
+ */
+
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <string.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include "libserialclient.h"
+
+
+/*
+ * dump metrics from virtio serial port to xml formatted file
+ */
+int dump_virtio_metrics(const char *dest_file)
+{
+    FILE *fp = stdout;
+    char *response;
+    size_t len;
+
+    response = get_virtio_metrics(NULL);
+    if (response == NULL)
+        goto error;
+
+    len = strlen(response);
+
+    if (dest_file) {
+        fp = fopen(dest_file, "w");
+        if (fp == NULL) {
+            fprintf(stderr,
+                    "LIB_SERIALCLIENT: Error, unable to dump metrics: fopen(%s) %s\n",
+                    dest_file, strerror(errno));
+            goto error;
+        }
+    }
+
+    if (fwrite(response, 1UL, len, fp) != len) {
+        fprintf(stderr,
+                "LIB_SERIALCLIENT: Error, unable to export metrics to file:%s - error:%s\n",
+                dest_file ? dest_file : "STDOUT", strerror(errno));
+        goto error;
+    }
+
+    if (response)
+        free(response);
+
+    return 0;
+
+  error:
+    if (dest_file && fp)
+        fclose(fp);
+
+    if (response)
+        free(response);
+
+    return -1;
+}
+
+/*
+ * dump metrics from virtio serial port to buffer
+ */
+char *get_virtio_metrics(const char *dev_name)
+{
+    const char request[] = "GET /metrics/XML\n\n", end_token[] = "\n\n";
+    const char *dev;
+    char *response = NULL;
+    int fd = -1;
+    size_t pos;
+    size_t buf_size = (1 << 16);
+    const size_t req_len = (size_t) strlen(request);
+    const time_t start_time = time(NULL);
+
+    if (dev_name)
+        dev = dev_name;
+    else
+        dev = "/dev/virtio-ports/vhostmd";
+
+    response = calloc(1UL, buf_size);
+    if (response == NULL)
+        goto error;
+
+    fd = open(dev, O_RDWR | O_NONBLOCK);
+
+    if (fd < 0) {
+        fprintf(stderr,
+                "LIB_SERIALCLIENT: Error, unable to dump metrics: open(%s) %s\n",
+                dev, strerror(errno));
+        goto error;
+    }
+
+    pos = 0;
+    while (pos < req_len) {
+        ssize_t len = write(fd, &request[pos], req_len - pos);
+        if (len > 0)
+            pos += (size_t) len;
+        else {
+            if (errno == EAGAIN)
+                usleep(10000);
+            else
+                goto error;
+        }
+    }
+
+    pos = 0;
+    do {
+        ssize_t len = read(fd, &response[pos], buf_size - pos - 1);
+        if (len > 0) {
+            pos += (size_t) len;
+            response[pos] = 0;
+
+            if ((pos + 1) >= buf_size) {
+                buf_size = buf_size << 1;       // increase response buffer
+                if (buf_size > (1 << 24))       // max 16MB
+                    goto error;
+
+                response = realloc(response, buf_size);
+                if (response == NULL)
+                    goto error;
+
+                memset(&response[pos], 0, buf_size - pos);
+            }
+        } else {
+            if (errno == EAGAIN) {
+                usleep(10000);
+                if (time(NULL) > (start_time + 30)) {
+                    fprintf(stderr,
+                            "LIB_SERIALCLIENT: Error, unable to read metrics"
+                            " - timeout after 30s\n");
+                    goto error;
+                }
+            } else
+                goto error;
+        }
+    } while ((pos < (size_t) strlen(end_token) ||
+              strcmp(end_token, &response[pos - (size_t) strlen(end_token)]) != 0) &&
+             pos < buf_size);
+
+    if (fd >= 0)
+        close(fd);
+
+    return response;
+
+  error:
+    if (fd >= 0)
+        close(fd);
+    if (response)
+        free(response);
+
+    return NULL;
+}
diff --git a/libmetrics/libserialclient.h b/libmetrics/libserialclient.h
new file mode 100644
index 0000000..887c6a5
--- /dev/null
+++ b/libmetrics/libserialclient.h
@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) 2018 SAP SE
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA
+ *
+ * Author: Michael Trapp <michael.trapp at sap.com>
+ */
+
+#ifndef __LIBSERIALCLIENT_H__
+#define __LIBSERIALCLIENT_H__
+
+/* dump metrics from virtio serial port to xml formatted file */
+int dump_virtio_metrics(const char *dest_file);
+
+/* dump metrics from virtio serial port to buffer */
+char *get_virtio_metrics(const char *dev_name);
+
+#endif
diff --git a/vm-dump-metrics/main.c b/vm-dump-metrics/main.c
index 53874e8..aff92ad 100644
--- a/vm-dump-metrics/main.c
+++ b/vm-dump-metrics/main.c
@@ -34,6 +34,7 @@ static void usage(const char *argv0)
 #ifdef WITH_XENSTORE
          "\t-x | --xenstore        Get metrics from xenstore.\n"
 #endif
+         "\t-i | --virtio          Get metrics from virtio channel.\n"
          "\t-b | --vbd             Get metrics from vbd.\n";
 
    fprintf (stderr, "\nUsage: %s [options]\n\n%s\n", argv0, options_str);
@@ -46,6 +47,7 @@ int main(int argc, char *argv[])
 #ifdef WITH_XENSTORE
    int xenstore = 0;
 #endif
+   int virtio = 0;
    const char *dfile = NULL;
 
    struct option opts[] = {
@@ -54,6 +56,7 @@ int main(int argc, char *argv[])
 #ifdef WITH_XENSTORE
       { "xenstore", no_argument, &xenstore, 1},
 #endif
+      { "virtio", no_argument, &virtio, 1},
       { "help", no_argument, NULL, '?' },
       { "dest", optional_argument, NULL, 'd'},
       {0, 0, 0, 0}
@@ -64,9 +67,9 @@ int main(int argc, char *argv[])
       int c;
 
 #ifdef WITH_XENSTORE
-      c = getopt_long(argc, argv, "d:vbx", opts, &optidx);
+      c = getopt_long(argc, argv, "d:vbix", opts, &optidx);
 #else
-      c = getopt_long(argc, argv, "d:vb", opts, &optidx);
+      c = getopt_long(argc, argv, "d:vbi", opts, &optidx);
 #endif
 
       if (c == -1)
@@ -82,6 +85,9 @@ int main(int argc, char *argv[])
          case 'b':
             vbd = 1;
             break;
+         case 'i':
+            virtio = 1;
+            break;
 #ifdef WITH_XENSTORE
          case 'x':
             xenstore = 1;
@@ -107,20 +113,31 @@ int main(int argc, char *argv[])
    }
 #endif
 
+   if (virtio) {
+       if (dump_virtio_metrics(dfile) == -1)
+           exit(1);
+       exit(0);
+   }
+
    if (vbd) {
        if (dump_metrics(dfile) == -1)
            exit(1);
        exit(0);
    }
 
-   /* If no metrics source is specfied, try disk first and then xenstore */
+   /*
+    * If no metrics source is specfied, try default order
+    * disk, virtio, xenstore
+    */
    if (dump_metrics(dfile) == -1) {
+       if (dump_virtio_metrics(dfile) == -1) {
 #ifdef WITH_XENSTORE
-       if (dump_xenstore_metrics(dfile) == -1)
-	       exit(1);
+           if (dump_xenstore_metrics(dfile) == -1)
+               exit(1);
 #else
-       exit(1);
+           exit(1);
 #endif
+       }
    }
 
    exit(0);
-- 
2.17.1 (Apple Git-112)




More information about the virt-tools-list mailing list