5:10 p.m.
Daniel,
FYI, I'm working on a patch to support hvm guests. Attached is the work
thus far. Calling "virsh dumpxml some_hvm_guest" will (almost)
correctly dump xml config info on hvm guests. Needs to handle
"type=ioemu" component of VIF specification. Currently in the XML there
is a type attribute for the interface element that specifies bridge,
route, etc. How would you like to structure the interface element and
its children to account for hvm guests?
Using "virsh create file" where file contains XML config for hvm guests
may be close to working but I haven't tested it yet. There are several
options that need to be added to the XML to support hvm guests. If we
can agree on the structure I can add the functionality.
Regards,
Jim
4:35 a.m.
New subject: [Libvir] Re: support for hvm guests
On Fri, Apr 07, 2006 at 04:10:36PM -0600, Jim Fehlig wrote:
Daniel,
FYI, I'm working on a patch to support hvm guests.
Okay, cool. Note that I have no such hardware handy (but could get remote
access to those) so that's a kind a scenario I will have some troubles
running regression tests against in the near future.
Attached is the work thus far.
I see, also includes the end of life events patch now in CVS.
Calling "virsh dumpxml some_hvm_guest" will (almost)
correctly dump xml config info on hvm guests. Needs to handle
"type=ioemu" component of VIF specification. Currently in the XML there
is a type attribute for the interface element that specifies bridge,
route, etc. How would you like to structure the interface element and
its children to account for hvm guests?
Well <interface type='iommu'> and then as sub elements the extra
informations needed, sounds the closer to the existing format. But
is that making sense from a logical point of view ?
Using "virsh create file" where file contains XML config
for hvm guests
may be close to working but I haven't tested it yet. There are several
options that need to be added to the XML to support hvm guests. If we
can agree on the structure I can add the functionality.
My two main goals when extending the XML format are:
- try to keep it logical and as generic as possible
- keep it fully documented
second point should be easier if first point is followed :-)
So what else is needed than the IOMMU network interfaces for hvm guests ?
Also since I can't really test it right now, please feel in charge of
driving this :-)
Daniel
--
Daniel Veillard | Red Hat http://redhat.com/
veillard(a)redhat.com | libxml GNOME XML XSLT toolkit http://xmlsoft.org/
http://veillard.com/ | Rpmfind RPM search engine http://rpmfind.net/
7:07 p.m.
New subject: [Libvir] Re: support for hvm guests
Daniel Veillard wrote:
On Fri, Apr 07, 2006 at 04:10:36PM -0600, Jim Fehlig wrote:
>Daniel,
>
>FYI, I'm working on a patch to support hvm guests.
>
>
[snip]
>Calling "virsh dumpxml some_hvm_guest" will (almost)
>correctly dump xml config info on hvm guests. Needs to handle
>"type=ioemu" component of VIF specification. Currently in the XML there
>is a type attribute for the interface element that specifies bridge,
>route, etc. How would you like to structure the interface element and
>its children to account for hvm guests?
>
>
Well <interface type='iommu'> and then as sub elements the extra
informations needed, sounds the closer to the existing format. But
is that making sense from a logical point of view ?
Type 'bridge' can be valid for hvm guests. Perhaps it is better to not
expose ioemu in the XML for now as there will probably be changes in
this area anyway. We know the domain is type hvm, so just add 'ioemu:'
where necessary when talking to xend/xenstore. I'm currently thinking
about the following XML for OS element when type is hvm:
<os>
<type>hvm</type>
<kernel>/usr/lib/xen/boot/hvmloader</kernel>
<device_model>/usr/lib/xen/bin/qemu-dm</device_model>
<boot dev='c'>
<graphics type='vnc'>
<cdrom dev='/dev/hdd'>
</os>
boot, graphics, and cdrom elements are optional.
- boot: The device from which the guest should boot. If not specified
the guest will
be booted from hard disk. 'a' = floppy, 'c' = hard disk,
'd' = cdrom
- graphics: Graphics model to use for the guest. Valid type attribute
values are 'vnc'
and 'sdl'. If not specified the guest will be
launched with sdl.
- cdrom: The cdrom device, e.g. '/dev/hdd', '/path/to/iso/plan9.iso'
The patch I'm currently working on assumes this XML format. What do you
think?
Regards,
Jim
12:43 p.m.
New subject: [Libvir] Re: support for hvm guests
On Fri, Apr 28, 2006 at 06:07:43PM -0600, Jim Fehlig wrote:
boot, graphics, and cdrom elements are optional.
- boot: The device from which the guest should boot. If not specified
the guest will
be booted from hard disk. 'a' = floppy, 'c' = hard disk,
'd' = cdrom
Please, use full names (floppy | hdd | cdrom) instead strange M$
abbreviation.
Karel
--
Karel Zak <kzak(a)redhat.com>
7:35 a.m.
New subject: [Libvir] Re: support for hvm guests
First sorry for being a bit late answering,
On Fri, Apr 28, 2006 at 06:07:43PM -0600, Jim Fehlig wrote:
Type 'bridge' can be valid for hvm guests. Perhaps it is
better to not
expose ioemu in the XML for now as there will probably be changes in
this area anyway. We know the domain is type hvm, so just add 'ioemu:'
where necessary when talking to xend/xenstore. I'm currently thinking
about the following XML for OS element when type is hvm:
<os>
<type>hvm</type>
<kernel>/usr/lib/xen/boot/hvmloader</kernel>
<device_model>/usr/lib/xen/bin/qemu-dm</device_model>
<boot dev='c'>
<graphics type='vnc'>
<cdrom dev='/dev/hdd'>
</os>
Hum, I agree with Karel on the use of <boot dev='c' />, that's not
really
a logical naming, can we avoid that and use more strcutured names like
'/dev/hda' .
Also I don't understand why graphics and cdrom are not defined in the
<devices> section for example
<devices>
<disk type='block'>
<source dev='hdd'/>
<target dev='hdd'/>
<cdrom/>
</disk>
<graphic type='vnc'>
</graphic>
</devices>
boot, graphics, and cdrom elements are optional.
- boot: The device from which the guest should boot. If not specified
the guest will
be booted from hard disk. 'a' = floppy, 'c' = hard disk,
'd' = cdrom
not fond of that
- graphics: Graphics model to use for the guest. Valid type
attribute
values are 'vnc'
and 'sdl'. If not specified the guest will be
launched with sdl.
use a graphic element in the devices section instead, that way it
stay structured. Also be make code which may allow to pass extra informations
in the future as subelements, for example the vnc device may define
authentication mechanism, and default resolution/depth may also be passed
down in the future
- cdrom: The cdrom device, e.g. '/dev/hdd',
'/path/to/iso/plan9.iso'
Well should be a disk device too, with an extra <cdrom/> subelement,
and a source and a target as usual.
The patch I'm currently working on assumes this XML format. What
do you
think?
that I would prefer thing to stay more in line with existing format
details from http://libvirt.org/format.html, it's just semantic sugar but
design error there are usually a burden in the long term,
thanks !
Daniel
--
Daniel Veillard | Red Hat http://redhat.com/
veillard(a)redhat.com | libxml GNOME XML XSLT toolkit http://xmlsoft.org/
http://veillard.com/ | Rpmfind RPM search engine http://rpmfind.net/
10:43 a.m.
New subject: [Libvir] Re: support for hvm guests
Daniel Veillard wrote:
First sorry for being a bit late answering,
On Fri, Apr 28, 2006 at 06:07:43PM -0600, Jim Fehlig wrote:
>Type 'bridge' can be valid for hvm guests. Perhaps it is better to not
>expose ioemu in the XML for now as there will probably be changes in
>this area anyway. We know the domain is type hvm, so just add 'ioemu:'
>where necessary when talking to xend/xenstore. I'm currently thinking
>about the following XML for OS element when type is hvm:
>
><os>
> <type>hvm</type>
> <kernel>/usr/lib/xen/boot/hvmloader</kernel>
> <device_model>/usr/lib/xen/bin/qemu-dm</device_model>
> <boot dev='c'>
> <graphics type='vnc'>
> <cdrom dev='/dev/hdd'>
></os>
>
>
Hum, I agree with Karel on the use of <boot dev='c' />, that's not
really
a logical naming, can we avoid that and use more strcutured names like
'/dev/hda' .
Also I don't understand why graphics and cdrom are not defined in the
<devices> section for example
<devices>
<disk type='block'>
<source dev='hdd'/>
<target dev='hdd'/>
<cdrom/>
</disk>
<graphic type='vnc'>
</graphic>
</devices>
>boot, graphics, and cdrom elements are optional.
>- boot: The device from which the guest should boot. If not specified
>the guest will
> be booted from hard disk. 'a' = floppy, 'c' = hard disk,
>'d' = cdrom
>
>
not fond of that
>- graphics: Graphics model to use for the guest. Valid type attribute
>values are 'vnc'
> and 'sdl'. If not specified the guest will be
>launched with sdl.
>
>
use a graphic element in the devices section instead, that way it
stay structured. Also be make code which may allow to pass extra informations
in the future as subelements, for example the vnc device may define
authentication mechanism, and default resolution/depth may also be passed
down in the future
>- cdrom: The cdrom device, e.g. '/dev/hdd', '/path/to/iso/plan9.iso'
>
>
Well should be a disk device too, with an extra <cdrom/> subelement,
and a source and a target as usual.
>The patch I'm currently working on assumes this XML format. What do you
>think?
>
>
that I would prefer thing to stay more in line with existing format
details from http://libvirt.org/format.html, it's just semantic sugar but
design error there are usually a burden in the long term,
OK, these are great comments that I will incorporate into the patch.
Currently I can get info on hvm domains but unable to create them. The
create request is sent to xend but then blocks reading from xend in
xend_req(). No problem creating the domain using xm. I have looked at
the config coming into xend and it is identical between xm and
virsh/libvirt. Need to poke around xend and see why there is no
response to the virsh/libvirt create request for hvm domains.
Thanks for the comments.
Jim
10:55 a.m.
New subject: [Libvir] Re: support for hvm guests
On Wed, May 03, 2006 at 09:43:36AM -0600, Jim Fehlig wrote:
OK, these are great comments that I will incorporate into the patch.
Okay thanks :-)
Currently I can get info on hvm domains but unable to create them.
The
create request is sent to xend but then blocks reading from xend in
xend_req(). No problem creating the domain using xm. I have looked at
the config coming into xend and it is identical between xm and
virsh/libvirt. Need to poke around xend and see why there is no
response to the virsh/libvirt create request for hvm domains.
Hum, basically to debug this kind of things I spend my time in
/var/log/xend.log especially since it prints what it received at creation
time, you can at least check the informations coming from libvirt and
from xm look alike.
Unfortunately I won't be able to help you, first because I'm about to
take vacations for 3 weeks :-), second because I don't have one of those
new Intel CPUs, but I am sure others will give an hand if needed.
Daniel
--
Daniel Veillard | Red Hat http://redhat.com/
veillard(a)redhat.com | libxml GNOME XML XSLT toolkit http://xmlsoft.org/
http://veillard.com/ | Rpmfind RPM search engine http://rpmfind.net/
7:27 p.m.
New subject: [Libvir] Re: support for hvm guests
Daniel Veillard wrote:
On Wed, May 03, 2006 at 09:43:36AM -0600, Jim Fehlig wrote:
>Currently I can get info on hvm domains but unable to create them. The
>create request is sent to xend but then blocks reading from xend in
>xend_req(). No problem creating the domain using xm. I have looked at
>the config coming into xend and it is identical between xm and
>virsh/libvirt. Need to poke around xend and see why there is no
>response to the virsh/libvirt create request for hvm domains.
>
>
Hum, basically to debug this kind of things I spend my time in
/var/log/xend.log especially since it prints what it received at creation
time, you can at least check the informations coming from libvirt and
from xm look alike.
Unfortunately I won't be able to help you, first because I'm about to
take vacations for 3 weeks :-), second because I don't have one of those
new Intel CPUs, but I am sure others will give an hand if needed.
Well, I have found the problem but not a fix :-). When posting the
create op to xend, the libvirt code currently waits for a response from
xend (xend_req() is called after posting in xend_post()). For hvm
guests, xend does not respond and libvirt blocks indefinitely on read.
If I skip over the call to xend_req() for the create operation,
wait_for_devices() and subsequently unpause() are called and the hvm
guest is launched.
This "fix" is just an experimental hack and an appropriate fix would be
to have xend respond to the create op for hvm guests. Being unfamiliar
with the xend code, perhaps someone (Anthony :-)) could direct me to the
appropriate module in xend? Recall that all of this works for
paravirtualized guests so it may not be hard to find even for someone
that has just dabbled in the code.
Regards,
Jim
7:47 p.m.
New subject: [Libvir] Re: support for hvm guests
Jim Fehlig wrote:
Daniel Veillard wrote:
> On Wed, May 03, 2006 at 09:43:36AM -0600, Jim Fehlig wrote:
>
>
>> Currently I can get info on hvm domains but unable to create them.
>> The create request is sent to xend but then blocks reading from xend
>> in xend_req(). No problem creating the domain using xm. I have
>> looked at the config coming into xend and it is identical between xm
>> and virsh/libvirt. Need to poke around xend and see why there is no
>> response to the virsh/libvirt create request for hvm domains.
>>
>
> Hum, basically to debug this kind of things I spend my time in
> /var/log/xend.log especially since it prints what it received at
> creation
> time, you can at least check the informations coming from libvirt and
> from xm look alike.
> Unfortunately I won't be able to help you, first because I'm about to
> take vacations for 3 weeks :-), second because I don't have one of those
> new Intel CPUs, but I am sure others will give an hand if needed.
>
>
Well, I have found the problem but not a fix :-). When posting the
create op to xend, the libvirt code currently waits for a response
from xend (xend_req() is called after posting in xend_post()). For
hvm guests, xend does not respond and libvirt blocks indefinitely on
read. If I skip over the call to xend_req() for the create operation,
wait_for_devices() and subsequently unpause() are called and the hvm
guest is launched.
What do you mean by Xend does not respond?
The path is a normal domain_create(). The path within Xend is
server/XMLRPCServer.py but that's a very thin wrapper around a direct
call to XendDomain.py:domain_create(). domain_create() should always
return. If it's not, there's a bug in Xend I think.
Can you give me a very concrete test case for this? The exact
parameters being passed to domain_create() (it should just be an
S-Expression config).
Regards,
Anthony Liguori
This "fix" is just an experimental hack and an appropriate
fix would
be to have xend respond to the create op for hvm guests. Being
unfamiliar with the xend code, perhaps someone (Anthony :-)) could
direct me to the appropriate module in xend? Recall that all of this
works for paravirtualized guests so it may not be hard to find even
for someone that has just dabbled in the code.
Regards,
Jim
6:03 p.m.
New subject: [Libvir] Re: support for hvm guests
Anthony Liguori wrote:
/usr/lib/python2.4/site-packages/xen/xend/XendDomain.py(227)domain_create()
-> self.domains_lock.acquire()
(Pdb)
and the stack trace using virsh/libvirt:
(Pdb) bt
/usr/lib/python2.4/threading.py(442)__bootstrap()
-> self.run()
/usr/lib/python2.4/threading.py(422)run()
-> self.__target(*self.__args, **self.__kwargs)
/usr/lib/python2.4/site-packages/xen/web/httpserver.py(288)run()
-> self.processRequest(sock, addr)
/usr/lib/python2.4/site-packages/xen/web/httpserver.py(316)processRequest()
-> rp.process()
/usr/lib/python2.4/site-packages/xen/web/httpserver.py(110)process()
-> res = req.process()
/usr/lib/python2.4/site-packages/xen/web/httpserver.py(140)process()
-> return self.render(resource)
/usr/lib/python2.4/site-packages/xen/web/httpserver.py(180)render()
-> val = resource.render(self)
/usr/lib/python2.4/site-packages/xen/web/resource.py(59)render()
-> return meth(req)
/usr/lib/python2.4/site-packages/xen/xend/server/SrvDomainDir.py(135)render_POST()
-> return self.perform(req)
/usr/lib/python2.4/site-packages/xen/web/SrvBase.py(85)perform()
-> return op_method(op, req)
/usr/lib/python2.4/site-packages/xen/xend/server/SrvDomainDir.py(77)op_create()
-> dominfo = self.xd.domain_create(config)
/usr/lib/python2.4/site-packages/xen/xend/XendDomain.py(227)domain_create()
-> self.domains_lock.acquire()
(Pdb)
Continuing in the debugger I find that all routines complete up to
process() in httpserver.py line 110 (note that my line numbers may be
skewed a little due to insertion of debug code). After executing the
statement "res = req.process()", I take the else clause of "if
isinstance(res, ThreadRequest):" - which calls req.finish() which in
turn closes the connection. So no response is sent to libvirt, which is
blocked waiting to read something from xend.
As mentioned before, if I ignore reading a response from xend on the
create op and go directly to wait_for_devices and unpause then the guest
is launched as expected. BTW, I do get responses from xend on
wait_for_devices and unpause ops.
Jim Fehlig wrote:
> Daniel Veillard wrote:
>
>> On Wed, May 03, 2006 at 09:43:36AM -0600, Jim Fehlig wrote:
>>
>>
>>> Currently I can get info on hvm domains but unable to create them.
>>> The create request is sent to xend but then blocks reading from
>>> xend in xend_req(). No problem creating the domain using xm. I
>>> have looked at the config coming into xend and it is identical
>>> between xm and virsh/libvirt. Need to poke around xend and see why
>>> there is no response to the virsh/libvirt create request for hvm
>>> domains.
>>>
>>
>>
>> Hum, basically to debug this kind of things I spend my time in
>> /var/log/xend.log especially since it prints what it received at
>> creation
>> time, you can at least check the informations coming from libvirt and
>> from xm look alike.
>> Unfortunately I won't be able to help you, first because I'm about to
>> take vacations for 3 weeks :-), second because I don't have one of
>> those
>> new Intel CPUs, but I am sure others will give an hand if needed.
>>
>>
>
> Well, I have found the problem but not a fix :-). When posting the
> create op to xend, the libvirt code currently waits for a response
> from xend (xend_req() is called after posting in xend_post()). For
> hvm guests, xend does not respond and libvirt blocks indefinitely on
> read. If I skip over the call to xend_req() for the create
> operation, wait_for_devices() and subsequently unpause() are called
> and the hvm guest is launched.
What do you mean by Xend does not respond?
OK, let me try this again after some experimentation today. First, I'm
using CVS libvirt and it does not use xmlrpc but the "old" S-expression
over http - so I take a different code path to domain_create(). I set a
breakpoint (pdb.set_trace()) in domain_create() and attempted to launch
the hvm guest with xm and virsh/libvirt. The stack trace from xm is
(Pdb) bt
/usr/lib/python2.4/threading.py(442)__bootstrap()
-> self.run()
/usr/lib/python2.4/threading.py(422)run()
-> self.__target(*self.__args, **self.__kwargs)
/usr/lib/python2.4/SocketServer.py(463)process_request_thread()
-> self.finish_request(request, client_address)
/usr/lib/python2.4/SocketServer.py(254)finish_request()
-> self.RequestHandlerClass(request, client_address, self)
/usr/lib/python2.4/SocketServer.py(521)__init__()
-> self.handle()
/usr/lib/python2.4/BaseHTTPServer.py(316)handle()
-> self.handle_one_request()
/usr/lib/python2.4/BaseHTTPServer.py(310)handle_one_request()
-> method()
/usr/lib/python2.4/SimpleXMLRPCServer.py(432)do_POST()
-> response = self.server._marshaled_dispatch(
/usr/lib/python2.4/site-packages/xen/util/xmlrpclib2.py(103)_marshaled_dispatch()
-> response = self._dispatch(method, params)
/usr/lib/python2.4/SimpleXMLRPCServer.py(406)_dispatch()
-> return func(*params)
/usr/lib/python2.4/site-packages/xen/xend/server/XMLRPCServer.py(65)domain_create()
-> info = XendDomain.instance().domain_create(config)
The path is a normal domain_create(). The path within Xend is
server/XMLRPCServer.py but that's a very thin wrapper around a direct
call to XendDomain.py:domain_create(). domain_create() should always
return. If it's not, there's a bug in Xend I think.
Not in the case of libvirt - see above.
Can you give me a very concrete test case for this? The exact
parameters being passed to domain_create() (it should just be an
S-Expression config).
Sent in a previous post.
I will look into this more tomorrow - have other fires that need
attention now.
Thanks for the help :-).
Jim
6:57 p.m.
New subject: [Libvir] Re: support for hvm guests
Jim Fehlig wrote:
Anthony Liguori wrote:
[snip]
Continuing in the debugger I find that all routines complete up to
process() in httpserver.py line 110 (note that my line numbers may be
skewed a little due to insertion of debug code). After executing the
statement "res = req.process()", I take the else clause of "if
isinstance(res, ThreadRequest):" - which calls req.finish() which in
turn closes the connection. So no response is sent to libvirt, which
is blocked waiting to read something from xend.
As mentioned before, if I ignore reading a response from xend on the
create op and go directly to wait_for_devices and unpause then the
guest is launched as expected. BTW, I do get responses from xend on
wait_for_devices and unpause ops.
> The path is a normal domain_create(). The path within Xend is
> server/XMLRPCServer.py but that's a very thin wrapper around a direct
> call to XendDomain.py:domain_create(). domain_create() should always
> return. If it's not, there's a bug in Xend I think.
Not in the case of libvirt - see above.
> Can you give me a very concrete test case for this? The exact
> parameters being passed to domain_create() (it should just be an
> S-Expression config).
Sent in a previous post.
I will look into this more tomorrow - have other fires that need
attention now.
Tomorrow ended up being several days later :-). I looked at this again
today and must say that this is a frustrating bug - feeling like some
CS101 student.
So I was wrong in stating that xend does not respond to the create op
issued by libvirt. I get the expected response from xend but the
connection is not closed upon completing the request, thus I set in some
read loop in libvirt waiting for eof. I stepped through the request
processing code in xend for create op for both paravirtualized and hvm
guests and all seems fine, i.e. request is processed, finished, socket
closed, etc. in httpserver.py. Looking at a packet trace shows
connection is terminated for paravirt case (which breaks out of the read
loop in libvirt) but not so for hvm case.
Don't think I want to waste anymore time with this bug since the http /
sexp interface is going away - which brings me to a question. Why is
libvirt still using this interface and not xmlrpc? Perhaps my time
would be better spent moving libvirt to this interface. I would like to
submit the hvm patch for libvirt but can't reliably test it at this point.
Regards,
Jim
10:05 p.m.
New subject: [Libvir] Re: support for hvm guests
On Tue, May 09, 2006 at 05:57:52PM -0600, Jim Fehlig wrote:
closed, etc. in httpserver.py. Looking at a packet trace shows
connection is terminated for paravirt case (which breaks out of the read
loop in libvirt) but not so for hvm case.
very strange indeed ...
Don't think I want to waste anymore time with this bug since the
http /
sexp interface is going away - which brings me to a question. Why is
libvirt still using this interface and not xmlrpc? Perhaps my time
Basically it took longuer than expect to get 3.0.2 in the fedora environment
and I didn't started to work on it before leaving. Sorry :-\
would be better spent moving libvirt to this interface. I would like
to
submit the hvm patch for libvirt but can't reliably test it at this point.
Hum, there are other areas we didn't completely test in the code, that
should not prevent it from posting it. Maybe it's not worth commiting to
CVS right now, but having the code on the archived list meansthis can be
looked at by more people :-)
Daniel
--
Daniel Veillard | Red Hat http://redhat.com/
veillard(a)redhat.com | libxml GNOME XML XSLT toolkit http://xmlsoft.org/
http://veillard.com/ | Rpmfind RPM search engine http://rpmfind.net/
11:53 a.m.
New subject: [Libvir] Re: support for hvm guests
Jim Fehlig wrote:
Tomorrow ended up being several days later :-). I looked at this
again today and must say that this is a frustrating bug - feeling like
some CS101 student.
So I was wrong in stating that xend does not respond to the create op
issued by libvirt. I get the expected response from xend but the
connection is not closed upon completing the request, thus I set in
some read loop in libvirt waiting for eof. I stepped through the
request processing code in xend for create op for both paravirtualized
and hvm guests and all seems fine, i.e. request is processed,
finished, socket closed, etc. in httpserver.py. Looking at a packet
trace shows connection is terminated for paravirt case (which breaks
out of the read loop in libvirt) but not so for hvm case.
The proper way to do the S-Expression RPC (or XML-RPC for that matter)
is to look at the Content-Length header in the response and read back
that much data (close()'ing the connection once you've gotten that
amount). We shouldn't wait for EOF to occur to stop reading.
There was a patch recently that changed the read() behavior to read in
larger amounts. It appears that when this was added, the behavior was
changed to expect EOF. Sorry, I should have looked at that patch more
carefully. If you revert xend_post to the older code, things should go
back to working.
Don't think I want to waste anymore time with this bug since the
http
/ sexp interface is going away - which brings me to a question. Why
is libvirt still using this interface and not xmlrpc? Perhaps my time
would be better spent moving libvirt to this interface. I would like
to submit the hvm patch for libvirt but can't reliably test it at this
point.
wrt XML-RPC, I think I'm to blame for that. I've not gotten around to
modifying the internals of libvirt to switch between
XML-RPC/S-Expression. I'd suggest just reverting the xend_post to the
older code so you can keep making progress.
Regards,
Anthony Liguori
Regards,
Jim
2:52 p.m.
New subject: [Libvir] Re: support for hvm guests
On Wed, May 10, 2006 at 11:53:02AM -0500, Anthony Liguori wrote:
>Don't think I want to waste anymore time with this bug since
the http
>/ sexp interface is going away - which brings me to a question. Why
>is libvirt still using this interface and not xmlrpc? Perhaps my time
>would be better spent moving libvirt to this interface. I would like
>to submit the hvm patch for libvirt but can't reliably test it at this
>point.
wrt XML-RPC, I think I'm to blame for that. I've not gotten around to
modifying the internals of libvirt to switch between
XML-RPC/S-Expression. I'd suggest just reverting the xend_post to the
older code so you can keep making progress.
Note, I've commited some XMP-RPC tests and minor xml/xmlrpc code
changes to libvirt. It seems that Anthony's xmlrpc code works fine
against Python SimpleXMLRPCServer. For more details see CVS.
Karel
--
Karel Zak <kzak(a)redhat.com>
3:20 p.m.
New subject: [Libvir] Re: support for hvm guests
Karel Zak wrote:
On Wed, May 10, 2006 at 11:53:02AM -0500, Anthony Liguori wrote:
>> Don't think I want to waste anymore time with this bug since the http
>> / sexp interface is going away - which brings me to a question. Why
>> is libvirt still using this interface and not xmlrpc? Perhaps my time
>> would be better spent moving libvirt to this interface. I would like
>> to submit the hvm patch for libvirt but can't reliably test it at this
>> point.
>>
> wrt XML-RPC, I think I'm to blame for that. I've not gotten around to
> modifying the internals of libvirt to switch between
> XML-RPC/S-Expression. I'd suggest just reverting the xend_post to the
> older code so you can keep making progress.
>
Note, I've commited some XMP-RPC tests and minor xml/xmlrpc code
changes to libvirt. It seems that Anthony's xmlrpc code works fine
against Python SimpleXMLRPCServer. For more details see CVS.
As if there ever was any doubt ;-)
I ran most of that code through valgrind and tested it against the Xend
XML-RPC support. The remaining work should be just plumbing the libvir
functions to use the XML-RPC functions. The hardest part is probably
dealing with the S-Expressions since in XML-RPC they're going to be
returned as an Array instead of a string which means someone needs to
implement an XmlRpcArray -> struct sexpr conversion function.
The other outstanding issue is that I used libxml2's nanoHttp interface
which won't work for a domain socket. I think we may need to implement
our own HTTP code (or just borrow the code in the S-Expression interface
code).
Regards,
Anthony Liguori
Karel
5:11 p.m.
New subject: [Libvir] Re: support for hvm guests
On Wed, May 10, 2006 at 03:20:15PM -0500, Anthony Liguori wrote:
Karel Zak wrote:
>On Wed, May 10, 2006 at 11:53:02AM -0500, Anthony Liguori wrote:
>
>>>Don't think I want to waste anymore time with this bug since the http
>>>/ sexp interface is going away - which brings me to a question. Why
>>>is libvirt still using this interface and not xmlrpc? Perhaps my time
>>>would be better spent moving libvirt to this interface. I would like
>>>to submit the hvm patch for libvirt but can't reliably test it at this
>>>point.
>>>
>>wrt XML-RPC, I think I'm to blame for that. I've not gotten around to
>>modifying the internals of libvirt to switch between
>>XML-RPC/S-Expression. I'd suggest just reverting the xend_post to the
>>older code so you can keep making progress.
>>
>
> Note, I've commited some XMP-RPC tests and minor xml/xmlrpc code
> changes to libvirt. It seems that Anthony's xmlrpc code works fine
> against Python SimpleXMLRPCServer. For more details see CVS.
>
As if there ever was any doubt ;-)
No doubt about your code, but about my dirty hands that touch the
code :-)
I'd like to add maximum unit tests. It's good way how we can
detect possible regressions in future changes.
I ran most of that code through valgrind and tested it against the
Xend
XML-RPC support. The remaining work should be just plumbing the libvir
functions to use the XML-RPC functions. The hardest part is probably
dealing with the S-Expressions since in XML-RPC they're going to be
returned as an Array instead of a string which means someone needs to
implement an XmlRpcArray -> struct sexpr conversion function.
The other outstanding issue is that I used libxml2's nanoHttp interface
which won't work for a domain socket. I think we may need to implement
our own HTTP code (or just borrow the code in the S-Expression interface
code).
I think only one HTTP code in the library will be the best solution
(= reuse the code in the S-Expression interface).
Karel
--
Karel Zak <kzak(a)redhat.com>
7:25 p.m.
New subject: [Libvir] Re: support for hvm guests
Anthony Liguori wrote:
Jim Fehlig wrote:
>
> Tomorrow ended up being several days later :-). I looked at this
> again today and must say that this is a frustrating bug - feeling
> like some CS101 student.
>
> So I was wrong in stating that xend does not respond to the create op
> issued by libvirt. I get the expected response from xend but the
> connection is not closed upon completing the request, thus I set in
> some read loop in libvirt waiting for eof. I stepped through the
> request processing code in xend for create op for both
> paravirtualized and hvm guests and all seems fine, i.e. request is
> processed, finished, socket closed, etc. in httpserver.py. Looking
> at a packet trace shows connection is terminated for paravirt case
> (which breaks out of the read loop in libvirt) but not so for hvm case.
The proper way to do the S-Expression RPC (or XML-RPC for that matter)
is to look at the Content-Length header in the response and read back
that much data (close()'ing the connection once you've gotten that
amount). We shouldn't wait for EOF to occur to stop reading.
There was a patch recently that changed the read() behavior to read in
larger amounts. It appears that when this was added, the behavior was
changed to expect EOF. Sorry, I should have looked at that patch more
carefully. If you revert xend_post to the older code, things should
go back to working.
grr... Yes, this worked. So I'm able to launch hvm guests now but in
the process of incorporating comments about the XML format for such
guests I have come across another issue that could be handled in libvirt
but perhaps a better place would be xend. The issue is structure of
s-exp sent to xend. Currently xend appears to only accept things such
as (vnc 1), (cdrom /dev/hdd) within the (image (hvm ...)) node. Well
xend does accept something like "... (image (hvm ...(boot d))) (cdrom
/dev/hdd) (vnc 1)...", but the resulting domain is not configured
properly. With this config I get the following in xend.log:
[2006-05-10 17:11:48 xend] DEBUG (image:267) args: cdrom, val: None
This list has agreed that cdrom and graphics should be in the devices
section of libvirt's XML format, e.g.
<os>
<type>hvm</type>
...
<boot dev='hdd'>
<os>
<devices>
<disk type='block'>
<source dev='hdd'/>
<target dev='hdd'/>
<cdrom/>
</disk>
<graphics type='vnc'>
</graphics>
...
</devices>
I can certainly add code in libvirt to handle converting this XML to the
s-exp currently expected by xend but it makes for a larger patch. It
almost seems better to have xend accept definition of cdrom and graphics
outside of image node, e.g.
(image
(hvm
...
(boot d)
)
)
(cdrom /dev/hdd)
(vnc 1)
(other graphics-related options)
Any thoughts before I go off and rework the XML -> s-exp code in libvirt?
Regards,
Jim
8:28 p.m.
New subject: [Libvir] Re: support for hvm guests
Jim Fehlig wrote:
Anthony Liguori wrote:
> Jim Fehlig wrote:
>
>>
>> Tomorrow ended up being several days later :-). I looked at this
>> again today and must say that this is a frustrating bug - feeling
>> like some CS101 student.
>>
>> So I was wrong in stating that xend does not respond to the create
>> op issued by libvirt. I get the expected response from xend but the
>> connection is not closed upon completing the request, thus I set in
>> some read loop in libvirt waiting for eof. I stepped through the
>> request processing code in xend for create op for both
>> paravirtualized and hvm guests and all seems fine, i.e. request is
>> processed, finished, socket closed, etc. in httpserver.py. Looking
>> at a packet trace shows connection is terminated for paravirt case
>> (which breaks out of the read loop in libvirt) but not so for hvm case.
>
>
> The proper way to do the S-Expression RPC (or XML-RPC for that
> matter) is to look at the Content-Length header in the response and
> read back that much data (close()'ing the connection once you've
> gotten that amount). We shouldn't wait for EOF to occur to stop
> reading.
>
> There was a patch recently that changed the read() behavior to read
> in larger amounts. It appears that when this was added, the behavior
> was changed to expect EOF. Sorry, I should have looked at that patch
> more carefully. If you revert xend_post to the older code, things
> should go back to working.
grr... Yes, this worked. So I'm able to launch hvm guests now but in
the process of incorporating comments about the XML format for such
guests I have come across another issue that could be handled in
libvirt but perhaps a better place would be xend. The issue is
structure of s-exp sent to xend. Currently xend appears to only
accept things such as (vnc 1), (cdrom /dev/hdd) within the (image (hvm
...)) node. Well xend does accept something like "... (image (hvm
...(boot d))) (cdrom /dev/hdd) (vnc 1)...", but the resulting domain
is not configured properly. With this config I get the following in
xend.log:
wrt the S-Expression format, that stuff is all changing in the very near
future. I've been sitting on patches to remove the S-Expression stuff
completely for a few weeks now. The thing that's kept me from
submitting it is that I haven't gotten around to enabling the XML-RPC
support in libvirt.
As soon as we get XML-RPC support working in libvirt, we can start
making some aggressive changes to the Xend side of the API.
Regards,
Anthony Liguori
[2006-05-10 17:11:48 xend] DEBUG (image:267) args: cdrom, val: None
This list has agreed that cdrom and graphics should be in the devices
section of libvirt's XML format, e.g.
<os>
<type>hvm</type>
...
<boot dev='hdd'>
<os>
<devices>
<disk type='block'>
<source dev='hdd'/>
<target dev='hdd'/>
<cdrom/>
</disk>
<graphics type='vnc'>
</graphics>
...
</devices>
I can certainly add code in libvirt to handle converting this XML to
the s-exp currently expected by xend but it makes for a larger patch.
It almost seems better to have xend accept definition of cdrom and
graphics outside of image node, e.g.
(image
(hvm
...
(boot d)
)
)
(cdrom /dev/hdd)
(vnc 1)
(other graphics-related options)
Any thoughts before I go off and rework the XML -> s-exp code in libvirt?
Regards,
Jim
9:57 a.m.
New subject: [Libvir] Re: support for hvm guests
Hi Jim,
On Wed, May 10, 2006 at 06:25:07PM -0600, Jim Fehlig wrote:
This list has agreed that cdrom and graphics should be in the devices
section of libvirt's XML format, e.g.
<os>
<type>hvm</type>
...
<boot dev='hdd'>
<os>
<devices>
<disk type='block'>
<source dev='hdd'/>
<target dev='hdd'/>
<cdrom/>
</disk>
<graphics type='vnc'>
</graphics>
...
</devices>
I can certainly add code in libvirt to handle converting this XML to the
s-exp currently expected by xend but it makes for a larger patch. It
almost seems better to have xend accept definition of cdrom and graphics
outside of image node, e.g.
(image
(hvm
...
(boot d)
)
)
(cdrom /dev/hdd)
(vnc 1)
(other graphics-related options)
Any thoughts before I go off and rework the XML -> s-exp code in libvirt?
Did you get any further dealing with this issue ? It'd be nice to get the
support for HVM guests into libvirt in the near future, since I'm working
on some higher level UI tools which could be improved with more detail
about HVM guests. I could probably find time to do some coding on the patches
if there are areas you've not currently got time to address yourself
Regards,
Dan.
--
|=- Red Hat, Engineering, Emerging Technologies, Boston. +1 978 392 2496 -=|
|=- Perl modules: http://search.cpan.org/~danberr/ -=|
|=- Projects: http://freshmeat.net/~danielpb/ -=|
|=- GnuPG: 7D3B9505 F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 -=|
11:59 a.m.
New subject: [Libvir] Re: support for hvm guests
Daniel P. Berrange wrote:
Hi Jim,
[snip]
Did you get any further dealing with this issue ? It'd be nice to
get the
support for HVM guests into libvirt in the near future, since I'm working
on some higher level UI tools which could be improved with more detail
about HVM guests. I could probably find time to do some coding on the patches
if there are areas you've not currently got time to address yourself
I put this patch on the back burner given Anthony's response in
https://www.redhat.com/archives/libvir-list/2006-May/msg00017.html
I recently considered continuing this work until we started the
discussions on Xen Management API :-). To be honest, now I'm not sure
what to do. I will be on vacation next week but probably have time to
finish this patch before leaving. However this code will certainly be
thrown out at some point. Guess the question is how far out is "some
point"? Is it worth doing the xml -> sexp conversion and working around
some of the inconveniences in xend discussed earlier in this thread? If
we think the current state of affairs will exist for several more months
then perhaps so.
Thoughts?
Jim
12:05 p.m.
New subject: [Libvir] Re: support for hvm guests
On Wed, Jun 28, 2006 at 10:59:20AM -0600, Jim Fehlig wrote:
Daniel P. Berrange wrote:
>Hi Jim,
>
[snip]
>Did you get any further dealing with this issue ? It'd be nice to get the
>support for HVM guests into libvirt in the near future, since I'm working
>on some higher level UI tools which could be improved with more detail
>about HVM guests. I could probably find time to do some coding on the
>patches
>if there are areas you've not currently got time to address yourself
>
I put this patch on the back burner given Anthony's response in
https://www.redhat.com/archives/libvir-list/2006-May/msg00017.html
I recently considered continuing this work until we started the
discussions on Xen Management API :-). To be honest, now I'm not sure
what to do. I will be on vacation next week but probably have time to
finish this patch before leaving. However this code will certainly be
thrown out at some point. Guess the question is how far out is "some
point"? Is it worth doing the xml -> sexp conversion and working around
some of the inconveniences in xend discussed earlier in this thread? If
we think the current state of affairs will exist for several more months
then perhaps so.
Unfortunately I think we'll need to get an implementation done that works
with SEXPR. Even if everything progresses smoothly with the new XML-RPC
protocol for XenD, realistically it is going to be 2-3 months into the
future before its anywhere near ready for use by libvirt, and even then
there'll be a non-trivial existing userbase still on the SEXPR based XenD
for quite a while after that.
Regards,
Dan.
--
|=- Red Hat, Engineering, Emerging Technologies, Boston. +1 978 392 2496 -=|
|=- Perl modules: http://search.cpan.org/~danberr/ -=|
|=- Projects: http://freshmeat.net/~danielpb/ -=|
|=- GnuPG: 7D3B9505 F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 -=|
7:02 p.m.
New subject: [Libvir] Re: support for hvm guests
Daniel P. Berrange wrote:
Unfortunately I think we'll need to get an implementation done
that works
with SEXPR. Even if everything progresses smoothly with the new XML-RPC
protocol for XenD, realistically it is going to be 2-3 months into the
future before its anywhere near ready for use by libvirt, and even then
there'll be a non-trivial existing userbase still on the SEXPR based XenD
for quite a while after that.
Here is a first cut of the patch for review. I have minimally tested
the "get" side of the patch, e.g. virsh dumpxml <some_hvm_domain>. Have
not tried the "put" side, e.g. virsh create. I hope to test/fix the
create side tomorrow as well as test the get side with more interesting
configurations.
I haven't quite decided on how to handle the cdrom yet. I'm hardly and
expert on libxml so perhaps someone can suggest how to elegantly extract
the cdrom info from the incoming xml :-). See the TODO related to cdrom
in xml.c.
Regards,
Jim
4:06 a.m.
New subject: [Libvir] xencreate : What is the error with my program ?
Hello,
I am getting this error on trying to create a xen
domain
Unable to create domain .
This is the code snippet. I am unable to figure out
the root cause .
Any help will be appreciated ..
Thanks,
Dakshina
/* XML descriptor to create a new Domain */
const char *xmlDesc="<domain type='xen' id='18'
<name>newxen</name>
<os><type>linux</type> <kernel>
/boot/vmlinuz-2.6.12-xenU
</kernel>
<root>/dev/hda5</root><cmdline>3</cmdline></os><memory>65536</memory><vcpu>1</vcpu><devices><disk
type='file'><source file='/copyfed.img'/>
</disk></devices></domain>";
static void createNewDomain(){
virConnectPtr conn = NULL; /* the hypervisor
connection */
virDomainPtr dom = NULL; /* the domain being
checked */
virDomainInfo info; /* the informations
being fetched */
virErrorPtr err; /* Ptr to the error
structure*/
int errorCode;
char xmlDesc[250];
unsigned int flags=0;
/* NULL means connect to local Xen hypervisor */
conn = virConnectOpenReadOnly(NULL);
if (conn == NULL) {
fprintf(stderr, "Failed to connect to
hypervisor\n");
goto error;
}
printf("Connected to the hypervisor
successfully");
dom=virDomainCreateLinux(conn,xmlDesc,0);
if (dom == NULL) {
fprintf(stderr,"Unable to create a domain\n");
goto error;
}
dom = virDomainLookupByID(conn, 0);
printf(" %s\n" ,virDomainGetXMLDesc(dom,0));
error:
#if 0
err=virGetLastError();
printf("Error is %s\n" ,err->message);
#endif
errorCode=virConnCopyLastError(conn,err);
printf("Error is %d\n" ,errorCode);
if (dom != NULL)
virDomainFree(dom);
if (conn != NULL)
virConnectClose(conn);
}
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4:16 a.m.
New subject: [Libvir] xencreate : What is the error with my program ?
On Mon, Jul 03, 2006 at 02:06:30AM -0700, dasari dakshina wrote:
Hello,
I am getting this error on trying to create a xen
domain
Unable to create domain .
This is the code snippet. I am unable to figure out
the root cause .
Any help will be appreciated ..
[...]
conn = virConnectOpenReadOnly(NULL);
First you should not open a Read Only connection to do a domain creation
this is obviously an operation with side effect.
Second the best way to debug what's happening is check /var/log/xend.log .
Xend gives back nearly no debug information when an operation fails, and
libvirt really can't guess whatb went wrong, check what xend reported.
Daniel
--
Daniel Veillard | Red Hat http://redhat.com/
veillard(a)redhat.com | libxml GNOME XML XSLT toolkit http://xmlsoft.org/
http://veillard.com/ | Rpmfind RPM search engine http://rpmfind.net/
5:55 a.m.
New subject: [Libvir] xencreate : What is the error with my program ?
Hello Daniel,
Thanks.
I used the virConnectOpen() function.
I did check for the log file entries .I deleted the
log file ,stopped xend and created a new log file and
ran xend .I dont find any help there.
Is there any other mistake that I am making while
using tht API / writing the XML description?
Thanks,
Dakshina
--- Daniel Veillard <veillard(a)redhat.com> wrote:
On Mon, Jul 03, 2006 at 02:06:30AM -0700, dasari
dakshina wrote:
> Hello,
> I am getting this error on trying to create a xen
> domain
> Unable to create domain .
> This is the code snippet. I am unable to figure
out
> the root cause .
> Any help will be appreciated ..
[...]
> conn = virConnectOpenReadOnly(NULL);
First you should not open a Read Only connection
to do a domain creation
this is obviously an operation with side effect.
Second the best way to debug what's happening is
check /var/log/xend.log .
Xend gives back nearly no debug information when an
operation fails, and
libvirt really can't guess whatb went wrong, check
what xend reported.
Daniel
--
Daniel Veillard | Red Hat http://redhat.com/
veillard(a)redhat.com | libxml GNOME XML XSLT toolkit
http://xmlsoft.org/
http://veillard.com/ | Rpmfind RPM search engine
http://rpmfind.net/
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6:39 a.m.
New subject: [Libvir] xencreate : What is the error with my program ?
On Mon, Jul 03, 2006 at 03:55:15AM -0700, dasari dakshina wrote:
Hello Daniel,
Thanks.
I used the virConnectOpen() function.
I did check for the log file entries .I deleted the
log file ,stopped xend and created a new log file and
ran xend .
I dont find any help there.
What does this mean ? No log or you don't understand the logs or
there is no error in the logs ?
Is there any other mistake that I am making while
using tht API / writing the XML description?
I don't know. You should use virsh and see how it work. I would be
very surprized if you only got that "domain create failed" error without
any additional informations either from libvirt or from xend logs.
This may happen. But there is way too much information I don't have,
I can't reproduce your problem as is, so you must find more on your side.
Daniel
--
Daniel Veillard | Red Hat http://redhat.com/
veillard(a)redhat.com | libxml GNOME XML XSLT toolkit http://xmlsoft.org/
http://veillard.com/ | Rpmfind RPM search engine http://rpmfind.net/
6530
days inactive
6617
days old
25 comments
6 participants
participants (6)
-
Anthony Liguori -
Daniel P. Berrange -
Daniel Veillard -
dasari dakshina -
Jim Fehlig -
Karel Zak