[virt-tools-list] [vhostmd v2 3/5] Activate virtio support in vhostmd
Michael Trapp
Michael.Trapp at sap.com
Fri Oct 5 14:34:05 UTC 2018
Activate the virtio code and extend DTD/XML to support a virtio section
for virtio related configuration and a new transport type virtio.
---
README | 56 ++++++++++++++++++++++++++++++++++++-----
vhostmd.changes | 5 ++++
vhostmd.dtd | 6 ++++-
vhostmd.xml | 6 +++++
vhostmd/Makefile.am | 4 +--
vhostmd/vhostmd.c | 61 +++++++++++++++++++++++++++++++++++++++++++--
6 files changed, 127 insertions(+), 11 deletions(-)
diff --git a/README b/README
index cb23226..44dbbd1 100644
--- a/README
+++ b/README
@@ -50,8 +50,15 @@ includes a few examples of user-defined metrics, which provide a
<path>/dev/shm/vhostmd0</path>
<size unit="k">256</size>
</disk>
+ <virtio>
+ <max_channels>1024</max_channels>
+ <expiration_time>15</expiration_time>
+ <path>/var/lib/libvirt/qemu/channels</path>
+ </virtio>
<update_period>5</update_period>
<path>/usr/bin:/usr/sbin:/usr/share/vhostmd/scripts</path>
+ <transport>vbd</transport>
+ <transport>virtio</transport>
</globals>
<metrics>
<metric type="string" context="host">
@@ -116,10 +123,13 @@ includes a few examples of user-defined metrics, which provide a
A valid configuration file must contain the root element <vhostmd>.
The <globals> element contains configuration global to vhostmd, such as
-the metrics disk path and the metrics refresh interval. The <metrics>
-element is a container for all of the <metric> elements. A metric element
-is used to define a metric, giving it a name and an action that produces
-the metric value.
+the metrics disk path and the metrics refresh interval. In addition
+metrics can also be read over QEMU virtio channels. Active transports
+can be specified by <transport> element.
+
+The <metrics> element is a container for all of the <metric> elements.
+A metric element is used to define a metric, giving it a name and an action
+that produces the metric value.
The supplied vhostmd configuration file provides a useful set of default
metrics to be collected. This can be extended or modified by editing
@@ -277,14 +287,48 @@ section:
(Note: Change target dev and bus as appropriate for the domain)
+Virtio access to Metrics
+------------------------
+
+Basically for a virtio serial device, QEMU creates
+- a unix domain socket on the Host
+- a serial port on the VM
+- 'connects' both to a 'communication channel'
+
+
+Sample VM config with virtio serial:
+
+ <channel type='unix'>
+ <source mode='bind' path='/var/lib/libvirt/qemu/channels/\
+org.github.vhostmd.1.a70605c8-7d69-8c44-7e1a-5ecd092cb1e1'/>
+ <target type='virtio' name='vhostmd'/>
+ <address type='virtio-serial' controller='0' bus='0' port='1'/>
+ </channel>
+
+
+Vhostmd accepts metric requests 'GET /metrics/XML\n\n' and responds with
+
+ <metrics>
+ <metric type='real64' context='host'>
+ <name>TotalCPUTime</name>
+ <value>179645.910000</value>
+ </metric>
+ ...
+ <metric type='uint64' context='vm' id='9' uuid='a70605c8-7d69-8c44-7e1a-5ecd092cb1e1'>
+ <name>UsedMemory</name>
+ <value>524288</value>
+ </metric>
+ </metrics>
+
+
Guest Tool/Library for Accessing Metrics Data
---------------------------------------------
Tool: vm_dump_metrics
Stand alone static utility will read all the metrics and write them
to stdout or optionally an argumented file.
- Usaga:
- vhostmd [-f dest_file]
+ Usage:
+ vhostmd -d|-i|-x [-f dest_file]
Library: libmetrics.so.0
Dynamic library that supports individual metrics gathering
diff --git a/vhostmd.changes b/vhostmd.changes
index c7b453d..d32ba5a 100644
--- a/vhostmd.changes
+++ b/vhostmd.changes
@@ -1,3 +1,8 @@
+-------------------------------------------------------------------
+Wed Jul 25 10:00:20 CEST 2018 - michael.trapp at sap.com
+
+- add virtio support
+
-------------------------------------------------------------------
Mon Jun 29 16:42:39 MDT 2009 - jfehlig at novell.com
diff --git a/vhostmd.dtd b/vhostmd.dtd
index 471c72f..6480532 100644
--- a/vhostmd.dtd
+++ b/vhostmd.dtd
@@ -9,7 +9,7 @@ Virtual Host Metrics Daemon (vhostmd). Configuration file DTD
-->
<!ELEMENT vhostmd (globals,metrics)>
-<!ELEMENT globals (disk,update_period,path,transport+)>
+<!ELEMENT globals (disk,virtio,update_period,path,transport+)>
<!ELEMENT disk (name,path,size)>
<!ELEMENT name (#PCDATA)>
@@ -20,6 +20,10 @@ Virtual Host Metrics Daemon (vhostmd). Configuration file DTD
<!ELEMENT update_period (#PCDATA)>
<!ELEMENT transport (#PCDATA)>
+<!ELEMENT virtio (max_channels,expiration_time,path)>
+<!ELEMENT max_channels (#PCDATA)>
+<!ELEMENT expiration_time (#PCDATA)>
+
<!ELEMENT metrics (metric*)>
<!ELEMENT metric (name,action,variable*)>
<!ELEMENT action (#PCDATA)>
diff --git a/vhostmd.xml b/vhostmd.xml
index 9b048df..5400981 100644
--- a/vhostmd.xml
+++ b/vhostmd.xml
@@ -33,9 +33,15 @@ the logical && operator must be replaced with "&&".
<path>/dev/shm/vhostmd0</path>
<size unit="k">256</size>
</disk>
+ <virtio>
+ <max_channels>1024</max_channels>
+ <expiration_time>15</expiration_time>
+ <path>/var/lib/libvirt/qemu/channels</path>
+ </virtio>
<update_period>5</update_period>
<path>/usr/sbin:/sbin:/usr/bin:/bin:/usr/share/vhostmd/scripts</path>
<transport>vbd</transport>
+ <transport>virtio</transport>
<!-- <transport>xenstore</transport> -->
</globals>
<metrics>
diff --git a/vhostmd/Makefile.am b/vhostmd/Makefile.am
index 3585970..34a15e0 100644
--- a/vhostmd/Makefile.am
+++ b/vhostmd/Makefile.am
@@ -3,9 +3,9 @@ INCLUDES = \
-I../include
sbin_PROGRAMS = vhostmd
-vhostmd_SOURCES = vhostmd.c util.c metric.c virt-util.c
+vhostmd_SOURCES = vhostmd.c util.c metric.c virt-util.c virtio.c
vhostmd_CFLAGS = $(LIBXML_CFLAGS) $(LIBVIRT_CFLAGS)
-vhostmd_LDADD = -lm $(LIBXML_LIBS) $(LIBVIRT_LIBS)
+vhostmd_LDADD = -lm $(LIBXML_LIBS) $(LIBVIRT_LIBS) -lpthread
if WITH_XENSTORE
vhostmd_SOURCES += xenstore-update.c
diff --git a/vhostmd/vhostmd.c b/vhostmd/vhostmd.c
index dc80345..1718df2 100644
--- a/vhostmd/vhostmd.c
+++ b/vhostmd/vhostmd.c
@@ -41,10 +41,11 @@
#include <sys/stat.h>
#include <libxml/parser.h>
#include <libxml/xpath.h>
+#include <pthread.h>
#include "util.h"
#include "metric.h"
-
+#include "virtio.h"
/*
* vhostmd will periodically write metrics to a disk. The metrics
@@ -84,6 +85,7 @@ typedef struct _mdisk_header
*/
#define VBD (1 << 0)
#define XENSTORE (1 << 1)
+#define VIRTIO (1 << 2)
/* Global variables */
static int down = 0;
@@ -102,6 +104,9 @@ static mdisk_header md_header =
};
static char *search_path = NULL;
static int transports = 0;
+static char *virtio_path = "/var/lib/libvirt/qemu/channels";
+static unsigned virtio_max_channels = 1024;
+static unsigned virtio_expiration_time = 15;
/**********************************************************************
@@ -469,6 +474,8 @@ static int parse_transports(xmlDocPtr xml,
return -1;
#endif
}
+ if (strncasecmp((char *)str, "virtio", strlen("virtio")) == 0)
+ transports |= VIRTIO;
free(str);
}
}
@@ -604,6 +611,19 @@ static int parse_config_file(const char *filename)
goto out;
}
+ if (transports & VIRTIO) {
+ char *p = NULL;
+
+ if (vu_xpath_long("string(./globals/virtio/max_channels[1])", ctxt, &l) == 0)
+ virtio_max_channels = (unsigned)l;
+
+ if (vu_xpath_long("string(./globals/virtio/expiration_time[1])", ctxt, &l) == 0)
+ virtio_expiration_time = (unsigned)l;
+
+ if ((p = vu_xpath_string("string(./globals/virtio/path[1])", ctxt)) != NULL)
+ virtio_path = p;
+ }
+
/* Parse requested metrics definitions */
if (parse_metrics(xml, ctxt)) {
vu_log(VHOSTMD_ERR, "Unable to parse metrics definition "
@@ -837,7 +857,8 @@ static int metrics_disk_create(void)
static int metrics_host_get(vu_buffer *buf)
{
metric *m = metrics;
-
+ unsigned start = buf->use;
+
while (m) {
if (m->ctx != METRIC_CONTEXT_HOST) {
m = m->next;
@@ -849,12 +870,18 @@ static int metrics_host_get(vu_buffer *buf)
m = m->next;
}
+
+ if (transports & VIRTIO)
+ virtio_metrics_update(&buf->content[start], buf->use - start, NULL,
+ METRIC_CONTEXT_HOST);
+
return 0;
}
static int metrics_vm_get(vu_vm *vm, vu_buffer *buf)
{
metric *m = metrics;
+ unsigned start = buf->use;
while (m) {
if (m->ctx != METRIC_CONTEXT_VM) {
@@ -867,6 +894,11 @@ static int metrics_vm_get(vu_vm *vm, vu_buffer *buf)
m = m->next;
}
+
+ if (transports & VIRTIO)
+ virtio_metrics_update(&buf->content[start], buf->use - start, vm->uuid,
+ METRIC_CONTEXT_VM);
+
return 0;
}
@@ -911,11 +943,30 @@ static int vhostmd_run(int diskfd)
int *ids = NULL;
int num_vms = 0;
vu_buffer *buf = NULL;
+ pthread_t virtio_tid;
if (vu_buffer_create(&buf, MDISK_SIZE_MIN - MDISK_HEADER_SIZE)) {
vu_log(VHOSTMD_ERR, "Unable to allocate memory");
return -1;
}
+
+ if (transports & VIRTIO) {
+ int rc;
+
+ if (virtio_expiration_time < (update_period * 3))
+ virtio_expiration_time = (update_period * 3);
+
+ if (virtio_init(virtio_path, virtio_max_channels, virtio_expiration_time))
+ return -1;
+
+ rc = pthread_create(&virtio_tid, NULL, virtio_run, NULL);
+
+ if (rc != 0) {
+ vu_log(VHOSTMD_ERR, "Failed to start virtio thread '%s'\n",
+ strerror(rc));
+ return -1;
+ }
+ }
while (!down) {
vu_buffer_add(buf, "<metrics>\n", -1);
@@ -940,6 +991,12 @@ static int vhostmd_run(int diskfd)
vu_buffer_erase(buf);
}
vu_buffer_delete(buf);
+
+ if (transports & VIRTIO) {
+ virtio_stop();
+ pthread_join(virtio_tid, NULL);
+ }
+
return 0;
}
--
2.17.1 (Apple Git-112)
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