Re: [PATCH] kbase: Add knowledge base for libvirt systemtap

[Daniel P . Berrangé]

On Thu, Aug 06, 2020 at 02:34:02PM +0800, Han Han wrote:
> Signed-off-by: Han Han 
> ---
>  docs/kbase.rst   |   3 ++
>  docs/kbase/meson.build   |   1 +
>  docs/kbase/systemtap.rst | 113 +++
>  3 files changed, 117 insertions(+)
>  create mode 100644 docs/kbase/systemtap.rst
> 
> diff --git a/docs/kbase.rst b/docs/kbase.rst
> index 78daaa5989..d8bff5d41e 100644
> --- a/docs/kbase.rst
> +++ b/docs/kbase.rst
> @@ -36,6 +36,9 @@ Knowledge base
>Examination of the security protections used for QEMU and how they need
>configuring to allow use of QEMU passthrough with host files/devices.
>  
> +   `Systemtap `__
> +  Explanation of how to use systemtap for libvirt tracing.
> +
> `Virtio-FS `__
>Share a filesystem between the guest and the host
>  
> diff --git a/docs/kbase/meson.build b/docs/kbase/meson.build
> index d7f254e163..ca032a4b9b 100644
> --- a/docs/kbase/meson.build
> +++ b/docs/kbase/meson.build
> @@ -13,6 +13,7 @@ docs_kbase_files = [
>'rpm-deployment',
>'s390_protected_virt',
>'secureusage',
> +  'systemtap',
>'virtiofs',
>  ]
>  
> diff --git a/docs/kbase/systemtap.rst b/docs/kbase/systemtap.rst
> new file mode 100644
> index 00..34420efbb2
> --- /dev/null
> +++ b/docs/kbase/systemtap.rst
> @@ -0,0 +1,113 @@
> +===
> +Systemtap of Libvirt
> +===

The "===" are too long here and all the other headings.

> +
> +.. contents::
> +
> +`Systemtap `__ is a scripting
> +language and tool for dynamically probing or tracing in Linux kernel
> +space or user space. This page is about the usage of systemtap
> +in libvirt tracing.
> +
> +Preparation
> +===
> +
> +Libvirt
> +-
> +
> +Libvirt should be configured with the systemtap option to support libvirt
> +probing events in systemtap.
> +
> +For libvirt before **6.7.0**, it can be configured by:
> +
> +::
> +
> +mkdir build
> +cd build
> +   ../configure --with-dtrace
> +
> +For libvirt **6.7.0** or later, configure it by the ``meson`` (seeing
> +`libvirt compiling `__):
> +
> +::
> +
> +   meson build -Ddtrace=enabled
> +
> +For the libvirt binaries installed by the package manager like ``dnf`` or
> +``apt``, if libvirt systemtap tapset 
> ``/usr/share/systemtap/tapset/libvirt_*``
> +exists, it means the libvirt enables the systemtap feature.
> +
> +Systemtap
> +
> +
> +For most of linux distributions, execute ``stap-prep`` by root to prepare the
> +environment for systemtap after installing the systemtap. If your 
> distribution
> +doesn't have ``stap-prep``, install the ``kernel debuginfo`` packages 
> manually.
> +
> +After these above, run this test command to confirm the systemtap works well:
> +
> +::
> +
> +   stap -e 'probe oneshot{ printf("hello world\n")}'
> +
> +
> +Tracing events
> +===
> +
> +The libvirt systemtap tracing events are defined in tapset
> +``/usr/share/systemtap/tapset/libvirt_*``. Libvirt support these type of 
> tracing
> +events: ``dbus``, ``event_glib``, ``object``, ``qemu``, ``rpc``.
> +
> +List all tracing events in libvirt:
> +
> +::
> +
> +   grep 'probe libvirt.[a-z_0-9.]*' /usr/share/systemtap/tapset/libvirt_* 
> -o|cut -f 2 -d :
> +
> +
> +Tracing examples
> +==
> +
> +Here is an example of the systemtap script to trace the QMP messages sent 
> from libvirtd
> +daemon to the qemu process.
> +``qmp.stp``:
> +
> +::
> +
> +   probe begin
> +   {
> + printf("Start tracing\n")
> +   }
> +   probe libvirt.qemu.monitor_send_msg
> +   {
> + printf("QMPs: %s", msg);
> +   }
> +
> +Then run the systemtap script attaching to the libvirtd process:
> +
> +::
> +
> +   stap qmp.stp -x `pidof libvirtd`
> +
> +
> +To trace a libvirtd started from command line, use the option ``-c``
> +
> +::
> +
> +   stap qmp.stp -c "/usr/sbin/libvirtd"
> +
> +
> +Then after seeing the welcome message "Start tracing" from systemtap, then 
> execute a virsh
> +command associated with QMP, for example ``virsh domstats``. Then get the 
> QMP tracing logs
> +from systemtap. For example, the result from ``virsh domstats``
> +
> +::
> +
> +   QMPs: {"execute":"query-balloon","id":"libvirt-393"}
> +   QMPs: 
> {"execute":"qom-get","arguments":{"path":"/machine/peripheral/balloon0","property":"guest-stats"},"id":"libvirt-394"}
> +   QMPs: {"execute":"query-blockstats","id":"libvirt-395"}
> +   QMPs: {"execute":"query-named-block-nodes","id":"libvirt-396"}
> +   QMPs: {"execute":"query-iothreads","id":"libvirt-397"}
> +
> +For more examples of libvirt systemtap scripts, see the scripts in 
> ``/usr/share/doc/libvirt-docs/examples/systemtap``
> +For more details of systemtap language, see `document of systemtap 
> `__
> -- 


Reviewed-by: Daniel P. Berrangé 

and pushed after trimming 

Re: [PATCH] kbase: Add knowledge base for libvirt systemtap

[Han Han]

ping, any more reviews?

On Thu, Aug 6, 2020 at 9:44 PM Daniel Henrique Barboza <
danielhb...@gmail.com> wrote:

>
> On 8/6/20 3:34 AM, Han Han wrote:
> > Signed-off-by: Han Han 
> > ---
> >   docs/kbase.rst   |   3 ++
> >   docs/kbase/meson.build   |   1 +
> >   docs/kbase/systemtap.rst | 113 +++
> >   3 files changed, 117 insertions(+)
> >   create mode 100644 docs/kbase/systemtap.rst
> >
> > diff --git a/docs/kbase.rst b/docs/kbase.rst
> > index 78daaa5989..d8bff5d41e 100644
> > --- a/docs/kbase.rst
> > +++ b/docs/kbase.rst
> > @@ -36,6 +36,9 @@ Knowledge base
> > Examination of the security protections used for QEMU and how
> they need
> > configuring to allow use of QEMU passthrough with host
> files/devices.
> >
> > +   `Systemtap `__
> > +  Explanation of how to use systemtap for libvirt tracing.
> > +
> >  `Virtio-FS `__
> > Share a filesystem between the guest and the host
> >
> > diff --git a/docs/kbase/meson.build b/docs/kbase/meson.build
> > index d7f254e163..ca032a4b9b 100644
> > --- a/docs/kbase/meson.build
> > +++ b/docs/kbase/meson.build
> > @@ -13,6 +13,7 @@ docs_kbase_files = [
> > 'rpm-deployment',
> > 's390_protected_virt',
> > 'secureusage',
> > +  'systemtap',
> > 'virtiofs',
> >   ]
> >
> > diff --git a/docs/kbase/systemtap.rst b/docs/kbase/systemtap.rst
> > new file mode 100644
> > index 00..34420efbb2
> > --- /dev/null
> > +++ b/docs/kbase/systemtap.rst
> > @@ -0,0 +1,113 @@
> > +===
> > +Systemtap of Libvirt
> > +===
> > +
> > +.. contents::
> > +
> > +`Systemtap `__ is a scripting
> > +language and tool for dynamically probing or tracing in Linux kernel
> > +space or user space. This page is about the usage of systemtap
> > +in libvirt tracing.
> > +
> > +Preparation
> > +===
> > +
> > +Libvirt
> > +-
> > +
> > +Libvirt should be configured with the systemtap option to support
> libvirt
> > +probing events in systemtap.
> > +
> > +For libvirt before **6.7.0**, it can be configured by:
> > +
> > +::
> > +
> > +mkdir build
> > +cd build
> > +   ../configure --with-dtrace
> > +
> > +For libvirt **6.7.0** or later, configure it by the ``meson`` (seeing
> > +`libvirt compiling `__):
> > +
> > +::
> > +
> > +   meson build -Ddtrace=enabled
> > +
> > +For the libvirt binaries installed by the package manager like ``dnf``
> or
> > +``apt``, if libvirt systemtap tapset
> ``/usr/share/systemtap/tapset/libvirt_*``
> > +exists, it means the libvirt enables the systemtap feature.
> > +
> > +Systemtap
> > +
> > +
> > +For most of linux distributions, execute ``stap-prep`` by root to
> prepare the
> > +environment for systemtap after installing the systemtap. If your
> distribution
> > +doesn't have ``stap-prep``, install the ``kernel debuginfo`` packages
> manually.
> > +
> > +After these above, run this test command to confirm the systemtap works
> well:
> > +
> > +::
> > +
> > +   stap -e 'probe oneshot{ printf("hello world\n")}'
> > +
> > +
> > +Tracing events
> > +===
> > +
> > +The libvirt systemtap tracing events are defined in tapset
> > +``/usr/share/systemtap/tapset/libvirt_*``. Libvirt support these type
> of tracing
>
> s/type/types
>
> Thanks

>
> With this nit fixed:
>
>
> Reviewed-by: Daniel Henrique Barboza 
>
>
>
> > +events: ``dbus``, ``event_glib``, ``object``, ``qemu``, ``rpc``.
> > +
> > +List all tracing events in libvirt:
> > +
> > +::
> > +
> > +   grep 'probe libvirt.[a-z_0-9.]*'
> /usr/share/systemtap/tapset/libvirt_* -o|cut -f 2 -d :
> > +
> > +
> > +Tracing examples
> > +==
> > +
> > +Here is an example of the systemtap script to trace the QMP messages
> sent from libvirtd
> > +daemon to the qemu process.
> > +``qmp.stp``:
> > +
> > +::
> > +
> > +   probe begin
> > +   {
> > + printf("Start tracing\n")
> > +   }
> > +   probe libvirt.qemu.monitor_send_msg
> > +   {
> > + printf("QMPs: %s", msg);
> > +   }
> > +
> > +Then run the systemtap script attaching to the libvirtd process:
> > +
> > +::
> > +
> > +   stap qmp.stp -x `pidof libvirtd`
> > +
> > +
> > +To trace a libvirtd started from command line, use the option ``-c``
> > +
> > +::
> > +
> > +   stap qmp.stp -c "/usr/sbin/libvirtd"
> > +
> > +
> > +Then after seeing the welcome message "Start tracing" from systemtap,
> then execute a virsh
> > +command associated with QMP, for example ``virsh domstats``. Then get
> the QMP tracing logs
> > +from systemtap. For example, the result from ``virsh domstats``
> > +
> > +::
> > +
> > +   QMPs: {"execute":"query-balloon","id":"libvirt-393"}
> > +   QMPs:
> {"execute":"qom-get","arguments":{"path":"/machine/peripheral/balloon0","property":"guest-stats"},"id":"libvirt-394"}
> > +   QMPs: {"execute":"query-blockstats","id":"libvirt-395"}
> > +   

Re: [PATCH] kbase: Add knowledge base for libvirt systemtap

[Daniel Henrique Barboza]

On 8/6/20 3:34 AM, Han Han wrote:

Signed-off-by: Han Han 
---
  docs/kbase.rst   |   3 ++
  docs/kbase/meson.build   |   1 +
  docs/kbase/systemtap.rst | 113 +++
  3 files changed, 117 insertions(+)
  create mode 100644 docs/kbase/systemtap.rst

diff --git a/docs/kbase.rst b/docs/kbase.rst
index 78daaa5989..d8bff5d41e 100644
--- a/docs/kbase.rst
+++ b/docs/kbase.rst
@@ -36,6 +36,9 @@ Knowledge base
Examination of the security protections used for QEMU and how they need
configuring to allow use of QEMU passthrough with host files/devices.
  
+   `Systemtap `__

+  Explanation of how to use systemtap for libvirt tracing.
+
 `Virtio-FS `__
Share a filesystem between the guest and the host
  
diff --git a/docs/kbase/meson.build b/docs/kbase/meson.build

index d7f254e163..ca032a4b9b 100644
--- a/docs/kbase/meson.build
+++ b/docs/kbase/meson.build
@@ -13,6 +13,7 @@ docs_kbase_files = [
'rpm-deployment',
's390_protected_virt',
'secureusage',
+  'systemtap',
'virtiofs',
  ]
  
diff --git a/docs/kbase/systemtap.rst b/docs/kbase/systemtap.rst

new file mode 100644
index 00..34420efbb2
--- /dev/null
+++ b/docs/kbase/systemtap.rst
@@ -0,0 +1,113 @@
+===
+Systemtap of Libvirt
+===
+
+.. contents::
+
+`Systemtap `__ is a scripting
+language and tool for dynamically probing or tracing in Linux kernel
+space or user space. This page is about the usage of systemtap
+in libvirt tracing.
+
+Preparation
+===
+
+Libvirt
+-
+
+Libvirt should be configured with the systemtap option to support libvirt
+probing events in systemtap.
+
+For libvirt before **6.7.0**, it can be configured by:
+
+::
+
+mkdir build
+cd build
+   ../configure --with-dtrace
+
+For libvirt **6.7.0** or later, configure it by the ``meson`` (seeing
+`libvirt compiling `__):
+
+::
+
+   meson build -Ddtrace=enabled
+
+For the libvirt binaries installed by the package manager like ``dnf`` or
+``apt``, if libvirt systemtap tapset ``/usr/share/systemtap/tapset/libvirt_*``
+exists, it means the libvirt enables the systemtap feature.
+
+Systemtap
+
+
+For most of linux distributions, execute ``stap-prep`` by root to prepare the
+environment for systemtap after installing the systemtap. If your distribution
+doesn't have ``stap-prep``, install the ``kernel debuginfo`` packages manually.
+
+After these above, run this test command to confirm the systemtap works well:
+
+::
+
+   stap -e 'probe oneshot{ printf("hello world\n")}'
+
+
+Tracing events
+===
+
+The libvirt systemtap tracing events are defined in tapset
+``/usr/share/systemtap/tapset/libvirt_*``. Libvirt support these type of 
tracing


s/type/types


With this nit fixed:


Reviewed-by: Daniel Henrique Barboza 




+events: ``dbus``, ``event_glib``, ``object``, ``qemu``, ``rpc``.
+
+List all tracing events in libvirt:
+
+::
+
+   grep 'probe libvirt.[a-z_0-9.]*' /usr/share/systemtap/tapset/libvirt_* 
-o|cut -f 2 -d :
+
+
+Tracing examples
+==
+
+Here is an example of the systemtap script to trace the QMP messages sent from 
libvirtd
+daemon to the qemu process.
+``qmp.stp``:
+
+::
+
+   probe begin
+   {
+ printf("Start tracing\n")
+   }
+   probe libvirt.qemu.monitor_send_msg
+   {
+ printf("QMPs: %s", msg);
+   }
+
+Then run the systemtap script attaching to the libvirtd process:
+
+::
+
+   stap qmp.stp -x `pidof libvirtd`
+
+
+To trace a libvirtd started from command line, use the option ``-c``
+
+::
+
+   stap qmp.stp -c "/usr/sbin/libvirtd"
+
+
+Then after seeing the welcome message "Start tracing" from systemtap, then 
execute a virsh
+command associated with QMP, for example ``virsh domstats``. Then get the QMP 
tracing logs
+from systemtap. For example, the result from ``virsh domstats``
+
+::
+
+   QMPs: {"execute":"query-balloon","id":"libvirt-393"}
+   QMPs: 
{"execute":"qom-get","arguments":{"path":"/machine/peripheral/balloon0","property":"guest-stats"},"id":"libvirt-394"}
+   QMPs: {"execute":"query-blockstats","id":"libvirt-395"}
+   QMPs: {"execute":"query-named-block-nodes","id":"libvirt-396"}
+   QMPs: {"execute":"query-iothreads","id":"libvirt-397"}
+
+For more examples of libvirt systemtap scripts, see the scripts in 
``/usr/share/doc/libvirt-docs/examples/systemtap``
+For more details of systemtap language, see `document of systemtap 
`__

[PATCH] kbase: Add knowledge base for libvirt systemtap

[Han Han]

Signed-off-by: Han Han 
---
 docs/kbase.rst   |   3 ++
 docs/kbase/meson.build   |   1 +
 docs/kbase/systemtap.rst | 113 +++
 3 files changed, 117 insertions(+)
 create mode 100644 docs/kbase/systemtap.rst

diff --git a/docs/kbase.rst b/docs/kbase.rst
index 78daaa5989..d8bff5d41e 100644
--- a/docs/kbase.rst
+++ b/docs/kbase.rst
@@ -36,6 +36,9 @@ Knowledge base
   Examination of the security protections used for QEMU and how they need
   configuring to allow use of QEMU passthrough with host files/devices.
 
+   `Systemtap `__
+  Explanation of how to use systemtap for libvirt tracing.
+
`Virtio-FS `__
   Share a filesystem between the guest and the host
 
diff --git a/docs/kbase/meson.build b/docs/kbase/meson.build
index d7f254e163..ca032a4b9b 100644
--- a/docs/kbase/meson.build
+++ b/docs/kbase/meson.build
@@ -13,6 +13,7 @@ docs_kbase_files = [
   'rpm-deployment',
   's390_protected_virt',
   'secureusage',
+  'systemtap',
   'virtiofs',
 ]
 
diff --git a/docs/kbase/systemtap.rst b/docs/kbase/systemtap.rst
new file mode 100644
index 00..34420efbb2
--- /dev/null
+++ b/docs/kbase/systemtap.rst
@@ -0,0 +1,113 @@
+===
+Systemtap of Libvirt
+===
+
+.. contents::
+
+`Systemtap `__ is a scripting
+language and tool for dynamically probing or tracing in Linux kernel
+space or user space. This page is about the usage of systemtap
+in libvirt tracing.
+
+Preparation
+===
+
+Libvirt
+-
+
+Libvirt should be configured with the systemtap option to support libvirt
+probing events in systemtap.
+
+For libvirt before **6.7.0**, it can be configured by:
+
+::
+
+mkdir build
+cd build
+   ../configure --with-dtrace
+
+For libvirt **6.7.0** or later, configure it by the ``meson`` (seeing
+`libvirt compiling `__):
+
+::
+
+   meson build -Ddtrace=enabled
+
+For the libvirt binaries installed by the package manager like ``dnf`` or
+``apt``, if libvirt systemtap tapset ``/usr/share/systemtap/tapset/libvirt_*``
+exists, it means the libvirt enables the systemtap feature.
+
+Systemtap
+
+
+For most of linux distributions, execute ``stap-prep`` by root to prepare the
+environment for systemtap after installing the systemtap. If your distribution
+doesn't have ``stap-prep``, install the ``kernel debuginfo`` packages manually.
+
+After these above, run this test command to confirm the systemtap works well:
+
+::
+
+   stap -e 'probe oneshot{ printf("hello world\n")}'
+
+
+Tracing events
+===
+
+The libvirt systemtap tracing events are defined in tapset
+``/usr/share/systemtap/tapset/libvirt_*``. Libvirt support these type of 
tracing
+events: ``dbus``, ``event_glib``, ``object``, ``qemu``, ``rpc``.
+
+List all tracing events in libvirt:
+
+::
+
+   grep 'probe libvirt.[a-z_0-9.]*' /usr/share/systemtap/tapset/libvirt_* 
-o|cut -f 2 -d :
+
+
+Tracing examples
+==
+
+Here is an example of the systemtap script to trace the QMP messages sent from 
libvirtd
+daemon to the qemu process.
+``qmp.stp``:
+
+::
+
+   probe begin
+   {
+ printf("Start tracing\n")
+   }
+   probe libvirt.qemu.monitor_send_msg
+   {
+ printf("QMPs: %s", msg);
+   }
+
+Then run the systemtap script attaching to the libvirtd process:
+
+::
+
+   stap qmp.stp -x `pidof libvirtd`
+
+
+To trace a libvirtd started from command line, use the option ``-c``
+
+::
+
+   stap qmp.stp -c "/usr/sbin/libvirtd"
+
+
+Then after seeing the welcome message "Start tracing" from systemtap, then 
execute a virsh
+command associated with QMP, for example ``virsh domstats``. Then get the QMP 
tracing logs
+from systemtap. For example, the result from ``virsh domstats``
+
+::
+
+   QMPs: {"execute":"query-balloon","id":"libvirt-393"}
+   QMPs: 
{"execute":"qom-get","arguments":{"path":"/machine/peripheral/balloon0","property":"guest-stats"},"id":"libvirt-394"}
+   QMPs: {"execute":"query-blockstats","id":"libvirt-395"}
+   QMPs: {"execute":"query-named-block-nodes","id":"libvirt-396"}
+   QMPs: {"execute":"query-iothreads","id":"libvirt-397"}
+
+For more examples of libvirt systemtap scripts, see the scripts in 
``/usr/share/doc/libvirt-docs/examples/systemtap``
+For more details of systemtap language, see `document of systemtap 
`__
-- 
2.27.0