[libvirt] Fixing libvirt's libxl driver breakage -- where to define LIBXL_API_VERSION?
Hi libvirt maintainers, Xen's control library libxenlight (libxl) requires application (libvirt in this case) to explictily define LIBXL_API_VERSION. This is lacking at the moment so libvirt's libxl driver always gets the latest APIs. We changed one of the APIs in libxl so libvirt's libxl driver can't build at the moment. I want to submit a patch for libvirt to define LIBXL_API_VERSION, but I'm not sure where I should add that to. Can you give me some pointers? Or even better -- a specific file that I should edit? src/Makefile.am and src/Makfile.in are good candicate to me as far as I can tell. Thanks Wei.
Wei Liu wrote:
Hi libvirt maintainers,
Sorry for the delay. Slowly catching up on mail after vacation...
Xen's control library libxenlight (libxl) requires application (libvirt in this case) to explictily define LIBXL_API_VERSION.
Where is this requirement written? :-)
This is lacking at the moment so libvirt's libxl driver always gets the latest APIs.
IMO, that is what we want for upstream libvirt. Downstreams can choose a specific version if they want.
We changed one of the APIs in libxl so libvirt's libxl driver can't build at the moment.
A quick glance ahead in my libvirt mail tells me you fixed this with the preferred LIBXL_HAVE_* pattern. Regards, Jim
On Tue, Apr 12, 2016 at 03:31:46PM -0600, Jim Fehlig wrote:
Wei Liu wrote:
Hi libvirt maintainers,
Sorry for the delay. Slowly catching up on mail after vacation...
Xen's control library libxenlight (libxl) requires application (libvirt in this case) to explictily define LIBXL_API_VERSION.
Where is this requirement written? :-)
This is lacking at the moment so libvirt's libxl driver always gets the latest APIs.
IMO, that is what we want for upstream libvirt. Downstreams can choose a specific version if they want.
We changed one of the APIs in libxl so libvirt's libxl driver can't build at the moment.
A quick glance ahead in my libvirt mail tells me you fixed this with the preferred LIBXL_HAVE_* pattern.
It's already done that way. :-) Wei.
Regards, Jim
On Tue, Apr 12, 2016 at 10:31 PM, Jim Fehlig <jfehlig@suse.com> wrote:
Wei Liu wrote:
Hi libvirt maintainers,
Sorry for the delay. Slowly catching up on mail after vacation...
Xen's control library libxenlight (libxl) requires application (libvirt in this case) to explictily define LIBXL_API_VERSION.
Where is this requirement written? :-)
This is lacking at the moment so libvirt's libxl driver always gets the latest APIs.
IMO, that is what we want for upstream libvirt. Downstreams can choose a specific version if they want.
I think one of us isn't understanding the situation properly. Is it not the case that currently, all releases of libvirt *will not compile* against Xen 4.7 once it's released? So people downloading and building libvirt will have to either 1) root around and try to figure out what version of Xen it will build against, 2) manually add in a #define *with the correct API version* to a header somewhere to make it build properly, or 3) update to a version of libvirt that supports the new api (which at the moment hasn't even been released yet)? All of those options are completely unacceptable. Older versions of libvirt should Just Work when compiled against newer versions of Xen. I think it does make sense to have the libvirt development branch not specify an API version; but when it branches for release, it should set LIBXL_API_VERSION to whatever the current version is at the time of the branch. -George
On Wed, Apr 13, 2016 at 10:09:16AM +0100, George Dunlap wrote:
On Tue, Apr 12, 2016 at 10:31 PM, Jim Fehlig <jfehlig@suse.com> wrote:
Wei Liu wrote:
Hi libvirt maintainers,
Sorry for the delay. Slowly catching up on mail after vacation...
Xen's control library libxenlight (libxl) requires application (libvirt in this case) to explictily define LIBXL_API_VERSION.
Where is this requirement written? :-)
This is lacking at the moment so libvirt's libxl driver always gets the latest APIs.
IMO, that is what we want for upstream libvirt. Downstreams can choose a specific version if they want.
I think one of us isn't understanding the situation properly. Is it not the case that currently, all releases of libvirt *will not compile* against Xen 4.7 once it's released? So people downloading and building libvirt will have to either 1) root around and try to figure out what version of Xen it will build against, 2) manually add in a #define *with the correct API version* to a header somewhere to make it build properly, or 3) update to a version of libvirt that supports the new api (which at the moment hasn't even been released yet)?
All of those options are completely unacceptable. Older versions of libvirt should Just Work when compiled against newer versions of Xen.
I think it does make sense to have the libvirt development branch not specify an API version; but when it branches for release, it should set LIBXL_API_VERSION to whatever the current version is at the time of the branch.
FYI, libvirt doesn't do branching for releases - we always just cut the release straight from the master branch. We only actually create branches on demand, when we find we want to backport fixes to a previous release. Does libvirt master really need to always use the latest API version ? It feels like libvirt could just set LIBXL_API_VERSION to the lowest version it requires in order to get the functionality we know we are able to currently build against. IOW, we'd only need to update the define for LIBXL_API_VERSION when we merge patches that actually need the newer functionality. Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
On 13/04/16 10:26, Daniel P. Berrange wrote:
On Wed, Apr 13, 2016 at 10:09:16AM +0100, George Dunlap wrote:
On Tue, Apr 12, 2016 at 10:31 PM, Jim Fehlig <jfehlig@suse.com> wrote:
Wei Liu wrote:
Hi libvirt maintainers,
Sorry for the delay. Slowly catching up on mail after vacation...
Xen's control library libxenlight (libxl) requires application (libvirt in this case) to explictily define LIBXL_API_VERSION.
Where is this requirement written? :-)
This is lacking at the moment so libvirt's libxl driver always gets the latest APIs.
IMO, that is what we want for upstream libvirt. Downstreams can choose a specific version if they want.
I think one of us isn't understanding the situation properly. Is it not the case that currently, all releases of libvirt *will not compile* against Xen 4.7 once it's released? So people downloading and building libvirt will have to either 1) root around and try to figure out what version of Xen it will build against, 2) manually add in a #define *with the correct API version* to a header somewhere to make it build properly, or 3) update to a version of libvirt that supports the new api (which at the moment hasn't even been released yet)?
All of those options are completely unacceptable. Older versions of libvirt should Just Work when compiled against newer versions of Xen.
I think it does make sense to have the libvirt development branch not specify an API version; but when it branches for release, it should set LIBXL_API_VERSION to whatever the current version is at the time of the branch.
FYI, libvirt doesn't do branching for releases - we always just cut the release straight from the master branch. We only actually create branches on demand, when we find we want to backport fixes to a previous release.
Does libvirt master really need to always use the latest API version ?
It feels like libvirt could just set LIBXL_API_VERSION to the lowest version it requires in order to get the functionality we know we are able to currently build against. IOW, we'd only need to update the define for LIBXL_API_VERSION when we merge patches that actually need the newer functionality.
Oh, right -- yes, if that's the libvirt development model then it makes more sense to do what works best with that model to make sure each release has an appropriate LIBXL_API_VERSION. On reflection, it's probably a better idea even from a Xen development perspective. I was originally thinking that it would be nice to have the testing automatically flag up an update in libxl that could use a corresponding update in libvirt. But in practice, since we use these tests as a push-gate, having changesets in the xen development branch which break against libvirt master but require changes in libvirt master to fix is actually causes a fair amount of hassle. It might be useful for the XenProject to have a non-pushgate test which tests libvirt without a LIBXL_API_VERSION, just to flag things up, but that's something we can sort out on our side with a sed script. Thanks, -George
On Wed, Apr 13, 2016 at 10:26:54AM +0100, Daniel P. Berrange wrote:
On Wed, Apr 13, 2016 at 10:09:16AM +0100, George Dunlap wrote:
On Tue, Apr 12, 2016 at 10:31 PM, Jim Fehlig <jfehlig@suse.com> wrote:
Wei Liu wrote:
Hi libvirt maintainers,
Sorry for the delay. Slowly catching up on mail after vacation...
Xen's control library libxenlight (libxl) requires application (libvirt in this case) to explictily define LIBXL_API_VERSION.
Where is this requirement written? :-)
This is lacking at the moment so libvirt's libxl driver always gets the latest APIs.
IMO, that is what we want for upstream libvirt. Downstreams can choose a specific version if they want.
I think one of us isn't understanding the situation properly. Is it not the case that currently, all releases of libvirt *will not compile* against Xen 4.7 once it's released? So people downloading and building libvirt will have to either 1) root around and try to figure out what version of Xen it will build against, 2) manually add in a #define *with the correct API version* to a header somewhere to make it build properly, or 3) update to a version of libvirt that supports the new api (which at the moment hasn't even been released yet)?
All of those options are completely unacceptable. Older versions of libvirt should Just Work when compiled against newer versions of Xen.
I think it does make sense to have the libvirt development branch not specify an API version; but when it branches for release, it should set LIBXL_API_VERSION to whatever the current version is at the time of the branch.
FYI, libvirt doesn't do branching for releases - we always just cut the release straight from the master branch. We only actually create branches on demand, when we find we want to backport fixes to a previous release.
Does libvirt master really need to always use the latest API version ?
No, it doesn't.
It feels like libvirt could just set LIBXL_API_VERSION to the lowest version it requires in order to get the functionality we know we are able to currently build against. IOW, we'd only need to update the define for LIBXL_API_VERSION when we merge patches that actually need the newer functionality.
That's sensible. Wei.
Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
On 04/13/2016 03:26 AM, Daniel P. Berrange wrote:
On Wed, Apr 13, 2016 at 10:09:16AM +0100, George Dunlap wrote:
Wei Liu wrote:
Hi libvirt maintainers, Sorry for the delay. Slowly catching up on mail after vacation...
Xen's control library libxenlight (libxl) requires application (libvirt in this case) to explictily define LIBXL_API_VERSION. Where is this requirement written? :-)
This is lacking at the moment so libvirt's libxl driver always gets the latest APIs. IMO, that is what we want for upstream libvirt. Downstreams can choose a specific version if they want. I think one of us isn't understanding the situation properly. Is it not the case that currently, all releases of libvirt *will not compile* against Xen 4.7 once it's released? So people downloading and building libvirt will have to either 1) root around and try to
On Tue, Apr 12, 2016 at 10:31 PM, Jim Fehlig <jfehlig@suse.com> wrote: figure out what version of Xen it will build against, 2) manually add in a #define *with the correct API version* to a header somewhere to make it build properly, or 3) update to a version of libvirt that supports the new api (which at the moment hasn't even been released yet)?
All of those options are completely unacceptable. Older versions of libvirt should Just Work when compiled against newer versions of Xen.
I think it does make sense to have the libvirt development branch not specify an API version; but when it branches for release, it should set LIBXL_API_VERSION to whatever the current version is at the time of the branch. FYI, libvirt doesn't do branching for releases - we always just cut the release straight from the master branch. We only actually create branches on demand, when we find we want to backport fixes to a previous release.
Does libvirt master really need to always use the latest API version ?
It feels like libvirt could just set LIBXL_API_VERSION to the lowest version it requires in order to get the functionality we know we are able to currently build against.
I think that is a good idea too. I've sent a patch setting LIBXL_API_VERSION to 0x040200 https://www.redhat.com/archives/libvir-list/2016-April/msg00771.html Changes made to the APIs since 0x040200 (params added to libxl_domain_create_restore and libxl_set_vcpuaffinity) are currently not used by libvirt. Regards, Jim
Jim Fehlig writes ("Re: [libvirt] [Xen-devel] Fixing libvirt's libxl driver breakage -- where to define LIBXL_API_VERSION?"):
I think that is a good idea too. I've sent a patch setting LIBXL_API_VERSION to 0x040200
https://www.redhat.com/archives/libvir-list/2016-April/msg00771.html
It seems that the libvirt LIBXL_API_VERSION is now rather higher, at 0x040400, since libvirt#fccf27253ced libxl: switch to using libxl_domain_create_restore from v4.4 API One unfortunate effect of this is to break the osstest tests of the Xen 4.3 stable branch, which for the moment is still allegedly in security support. I can't really see a way that this kind of problem could be avoided in principle, without - providing a more sophisticated way for libxl callers to set the requested version - providing more compatibility code in libvirt, too, and retaining it for some time I think instead that it would probably be better for osstest to "freeze" the version of libvirt that it is using, every time we branch Xen. So Xen 4.4 would be tested with whatever libvirt we were using when the stable branch for Xen 4.4 was made, and so on. Does that sound sensible ? Ian.
(Adding Jan Beulich) Ian Jackson writes ("Re: [libvirt] [Xen-devel] Fixing libvirt's libxl driver breakage -- where to define LIBXL_API_VERSION?"):
It seems that the libvirt LIBXL_API_VERSION is now rather higher, at 0x040400, since libvirt#fccf27253ced libxl: switch to using libxl_domain_create_restore from v4.4 API
One unfortunate effect of this is to break the osstest tests of the Xen 4.3 stable branch, which for the moment is still allegedly in security support.
I can't really see a way that this kind of problem could be avoided in principle, without - providing a more sophisticated way for libxl callers to set the requested version - providing more compatibility code in libvirt, too, and retaining it for some time
I think instead that it would probably be better for osstest to "freeze" the version of libvirt that it is using, every time we branch Xen.
So Xen 4.4 would be tested with whatever libvirt we were using when the stable branch for Xen 4.4 was made, and so on.
Does that sound sensible ?
In the assumption that it is, I have: Created the following branch refs on xenbits in the toplevel libvirt.git: osstest/frozen/xen-4.3-testing 9a0c7f5f834185db9017c34aabc03ad99cf37bed osstest/frozen/xen-4.4-testing 33fb8ff185846a7b4974105d2c9400690a6f95cf osstest/frozen/xen-4.5-testing cda1cc170f07b45911b3dad03e42c8ebfc210fa1 osstest/frozen/xen-4.6-testing eac167e2610d3e59b32f7ec7ba78cbc8c420a425 osstest/frozen/xen-4.7-testing 1a41ed5af5e1704dd9b0bdca40df5c9cacbdabfc These were those tested by the following `tolerable' osstest push gate flights for the corresponding Xen tree: xen-4.3-testing 9a0c7f5f8341 86673 xen-4.4-testing 33fb8ff18584 85031 xen-4.5-testing cda1cc170f07 83135 xen-4.6-testing eac167e2610d 96031 xen-4.7-testing 1a41ed5af5e1 95728 And I have prepared the patch below, which (together with a prerequisite, in my tree) will implement this in osstest. Ian.
From 5d1c91d3c53b580305e96d62f8ca84f85f8d3011 Mon Sep 17 00:00:00 2001 From: Ian Jackson <ian.jackson@eu.citrix.com> Date: Mon, 27 Jun 2016 16:49:52 +0100 Subject: [OSSTEST PATCH] cr-daily-branch: libvirt: use frozen version on stable branches
libvirt master might increase its LIBXL_API_VERSION. When this feeds through osstest it can cause the push gates of Xen stable branches to break. So for stable Xen branches do not track libvirt upstream. Instead, use a frozen revision. (Only for main push gate tests of stable Xen branches.) The frozen branch is never going to be updated so it is not suitable for other kinds of uses. In particular it won't get security fixes. So we call the refs osstest/frozen/xen-K.L-testing to discourage users from using them. Deployment note: The Xen release checklist needs a new item "add this frozen libvirt branch". Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com> --- cr-daily-branch | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/cr-daily-branch b/cr-daily-branch index 8b7c789..21780b8 100755 --- a/cr-daily-branch +++ b/cr-daily-branch @@ -186,6 +186,12 @@ if [ "x$REVISION_OVMF" = x ]; then fi fi if [ "x$REVISION_LIBVIRT" = x ]; then + case "$xenbranch" in + xen-[0-9]*-testing) + BASE_TAG_LIBVIRT=osstest/frozen/$xenbranch + export BASE_TAG_LIBVIRT + ;; + esac determine_version REVISION_LIBVIRT libvirt LIBVIRT export REVISION_LIBVIRT fi -- 2.1.4
On Mon, Jun 27, 2016 at 04:54:35PM +0100, Ian Jackson wrote:
(Adding Jan Beulich)
Ian Jackson writes ("Re: [libvirt] [Xen-devel] Fixing libvirt's libxl driver breakage -- where to define LIBXL_API_VERSION?"):
It seems that the libvirt LIBXL_API_VERSION is now rather higher, at 0x040400, since libvirt#fccf27253ced libxl: switch to using libxl_domain_create_restore from v4.4 API
One unfortunate effect of this is to break the osstest tests of the Xen 4.3 stable branch, which for the moment is still allegedly in security support.
I can't really see a way that this kind of problem could be avoided in principle, without - providing a more sophisticated way for libxl callers to set the requested version - providing more compatibility code in libvirt, too, and retaining it for some time
I think instead that it would probably be better for osstest to "freeze" the version of libvirt that it is using, every time we branch Xen.
So Xen 4.4 would be tested with whatever libvirt we were using when the stable branch for Xen 4.4 was made, and so on.
Does that sound sensible ?
In the assumption that it is, I have:
Created the following branch refs on xenbits in the toplevel libvirt.git:
osstest/frozen/xen-4.3-testing 9a0c7f5f834185db9017c34aabc03ad99cf37bed osstest/frozen/xen-4.4-testing 33fb8ff185846a7b4974105d2c9400690a6f95cf osstest/frozen/xen-4.5-testing cda1cc170f07b45911b3dad03e42c8ebfc210fa1 osstest/frozen/xen-4.6-testing eac167e2610d3e59b32f7ec7ba78cbc8c420a425 osstest/frozen/xen-4.7-testing 1a41ed5af5e1704dd9b0bdca40df5c9cacbdabfc
How did you pick those hashes ? Would it make more sense to pick the nearest libvirt release tag ? eg v1.3.2 instead of 33fb8ff18584 ?
These were those tested by the following `tolerable' osstest push gate flights for the corresponding Xen tree:
xen-4.3-testing 9a0c7f5f8341 86673 xen-4.4-testing 33fb8ff18584 85031 xen-4.5-testing cda1cc170f07 83135 xen-4.6-testing eac167e2610d 96031 xen-4.7-testing 1a41ed5af5e1 95728
And I have prepared the patch below, which (together with a prerequisite, in my tree) will implement this in osstest.
Ian.
From 5d1c91d3c53b580305e96d62f8ca84f85f8d3011 Mon Sep 17 00:00:00 2001 From: Ian Jackson <ian.jackson@eu.citrix.com> Date: Mon, 27 Jun 2016 16:49:52 +0100 Subject: [OSSTEST PATCH] cr-daily-branch: libvirt: use frozen version on stable branches
libvirt master might increase its LIBXL_API_VERSION. When this feeds through osstest it can cause the push gates of Xen stable branches to break.
So for stable Xen branches do not track libvirt upstream. Instead, use a frozen revision. (Only for main push gate tests of stable Xen branches.)
The frozen branch is never going to be updated so it is not suitable for other kinds of uses. In particular it won't get security fixes. So we call the refs osstest/frozen/xen-K.L-testing to discourage users from using them.
Deployment note: The Xen release checklist needs a new item "add this frozen libvirt branch".
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com> --- cr-daily-branch | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/cr-daily-branch b/cr-daily-branch index 8b7c789..21780b8 100755 --- a/cr-daily-branch +++ b/cr-daily-branch @@ -186,6 +186,12 @@ if [ "x$REVISION_OVMF" = x ]; then fi fi if [ "x$REVISION_LIBVIRT" = x ]; then + case "$xenbranch" in + xen-[0-9]*-testing) + BASE_TAG_LIBVIRT=osstest/frozen/$xenbranch + export BASE_TAG_LIBVIRT + ;; + esac determine_version REVISION_LIBVIRT libvirt LIBVIRT export REVISION_LIBVIRT fi
Overall I think your approach makes sense. Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
Daniel P. Berrange writes ("Re: [libvirt] [Xen-devel] Fixing libvirt's libxl driver breakage -- where to define LIBXL_API_VERSION?"):
On Mon, Jun 27, 2016 at 04:54:35PM +0100, Ian Jackson wrote:
Created the following branch refs on xenbits in the toplevel libvirt.git:
osstest/frozen/xen-4.3-testing 9a0c7f5f834185db9017c34aabc03ad99cf37bed osstest/frozen/xen-4.4-testing 33fb8ff185846a7b4974105d2c9400690a6f95cf osstest/frozen/xen-4.5-testing cda1cc170f07b45911b3dad03e42c8ebfc210fa1 osstest/frozen/xen-4.6-testing eac167e2610d3e59b32f7ec7ba78cbc8c420a425 osstest/frozen/xen-4.7-testing 1a41ed5af5e1704dd9b0bdca40df5c9cacbdabfc
How did you pick those hashes ? Would it make more sense to pick the nearest libvirt release tag ? eg v1.3.2 instead of 33fb8ff18584 ?
These were those tested by the following `tolerable' osstest push gate flights for the corresponding Xen tree:
xen-4.3-testing 9a0c7f5f8341 86673 xen-4.4-testing 33fb8ff18584 85031 xen-4.5-testing cda1cc170f07 83135 xen-4.6-testing eac167e2610d 96031 xen-4.7-testing 1a41ed5af5e1 95728
I picked them by searching my mail archives for osstest `tolerable' push gate flights - ie, passes in our CI system. That minimises the risk that the selected versions are themselves troublesome for some reason, needing another round of adjustment. It might indeed be better to convert them to nearby release tags. However: mariner:libvirt> git-describe 9a0c7f5f834185db9017c34aabc03ad99cf37bed v1.3.2-202-g9a0c7f5 mariner:libvirt> git-describe 33fb8ff185846a7b4974105d2c9400690a6f95cf v1.3.2-rc2-1-g33fb8ff mariner:libvirt> git-describe cda1cc170f07b45911b3dad03e42c8ebfc210fa1 v1.3.1-262-gcda1cc1 mariner:libvirt> git-describe eac167e2610d3e59b32f7ec7ba78cbc8c420a425 v1.3.5-318-geac167e mariner:libvirt> git-describe 1a41ed5af5e1704dd9b0bdca40df5c9cacbdabfc v1.3.5-129-g1a41ed5 mariner:libvirt> So in most cases these hashes are well away from a release tag. Does libvirt have stable release branches ? One approach would be to have osstest track a suitable libvirt stable release branche for each Xen stable release branch. That would involve setting up a push gate for each of the chosen libvirt stable branches. That would be worthwhile if we expect those stable branches to acquire commits which break Xen, and which we could like to be told about. But I'm not sure that's the case. Ian.
On Mon, Jun 27, 2016 at 05:12:52PM +0100, Ian Jackson wrote:
Daniel P. Berrange writes ("Re: [libvirt] [Xen-devel] Fixing libvirt's libxl driver breakage -- where to define LIBXL_API_VERSION?"):
On Mon, Jun 27, 2016 at 04:54:35PM +0100, Ian Jackson wrote:
Created the following branch refs on xenbits in the toplevel libvirt.git:
osstest/frozen/xen-4.3-testing 9a0c7f5f834185db9017c34aabc03ad99cf37bed osstest/frozen/xen-4.4-testing 33fb8ff185846a7b4974105d2c9400690a6f95cf osstest/frozen/xen-4.5-testing cda1cc170f07b45911b3dad03e42c8ebfc210fa1 osstest/frozen/xen-4.6-testing eac167e2610d3e59b32f7ec7ba78cbc8c420a425 osstest/frozen/xen-4.7-testing 1a41ed5af5e1704dd9b0bdca40df5c9cacbdabfc
How did you pick those hashes ? Would it make more sense to pick the nearest libvirt release tag ? eg v1.3.2 instead of 33fb8ff18584 ?
These were those tested by the following `tolerable' osstest push gate flights for the corresponding Xen tree:
xen-4.3-testing 9a0c7f5f8341 86673 xen-4.4-testing 33fb8ff18584 85031 xen-4.5-testing cda1cc170f07 83135 xen-4.6-testing eac167e2610d 96031 xen-4.7-testing 1a41ed5af5e1 95728
I picked them by searching my mail archives for osstest `tolerable' push gate flights - ie, passes in our CI system.
That minimises the risk that the selected versions are themselves troublesome for some reason, needing another round of adjustment.
It might indeed be better to convert them to nearby release tags. However:
mariner:libvirt> git-describe 9a0c7f5f834185db9017c34aabc03ad99cf37bed v1.3.2-202-g9a0c7f5 mariner:libvirt> git-describe 33fb8ff185846a7b4974105d2c9400690a6f95cf v1.3.2-rc2-1-g33fb8ff mariner:libvirt> git-describe cda1cc170f07b45911b3dad03e42c8ebfc210fa1 v1.3.1-262-gcda1cc1 mariner:libvirt> git-describe eac167e2610d3e59b32f7ec7ba78cbc8c420a425 v1.3.5-318-geac167e mariner:libvirt> git-describe 1a41ed5af5e1704dd9b0bdca40df5c9cacbdabfc v1.3.5-129-g1a41ed5 mariner:libvirt>
So in most cases these hashes are well away from a release tag.
Does libvirt have stable release branches ? One approach would be to have osstest track a suitable libvirt stable release branche for each Xen stable release branch.
Yep, there is a vN.N.N-maint branch for every release NB, with our new numbering that'll be changing nto vN.N-maint instead.
That would involve setting up a push gate for each of the chosen libvirt stable branches. That would be worthwhile if we expect those stable branches to acquire commits which break Xen, and which we could like to be told about. But I'm not sure that's the case.
Stuff goes onto the stable branches on an as-needed basis - mostly coming from the distro maintainers response to bug fixes from their users. There's probably not a whole lot that's touching xen on a regular basis and we're quite strict in what we accept for stable. Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
On 06/27/2016 10:12 AM, Ian Jackson wrote:
On Mon, Jun 27, 2016 at 04:54:35PM +0100, Ian Jackson wrote:
Created the following branch refs on xenbits in the toplevel libvirt.git:
osstest/frozen/xen-4.3-testing 9a0c7f5f834185db9017c34aabc03ad99cf37bed osstest/frozen/xen-4.4-testing 33fb8ff185846a7b4974105d2c9400690a6f95cf osstest/frozen/xen-4.5-testing cda1cc170f07b45911b3dad03e42c8ebfc210fa1 osstest/frozen/xen-4.6-testing eac167e2610d3e59b32f7ec7ba78cbc8c420a425 osstest/frozen/xen-4.7-testing 1a41ed5af5e1704dd9b0bdca40df5c9cacbdabfc How did you pick those hashes ? Would it make more sense to pick the nearest libvirt release tag ? eg v1.3.2 instead of 33fb8ff18584 ?
These were those tested by the following `tolerable' osstest push gate flights for the corresponding Xen tree:
xen-4.3-testing 9a0c7f5f8341 86673 xen-4.4-testing 33fb8ff18584 85031 xen-4.5-testing cda1cc170f07 83135 xen-4.6-testing eac167e2610d 96031 xen-4.7-testing 1a41ed5af5e1 95728 I picked them by searching my mail archives for osstest `tolerable'
Daniel P. Berrange writes ("Re: [libvirt] [Xen-devel] Fixing libvirt's libxl driver breakage -- where to define LIBXL_API_VERSION?"): push gate flights - ie, passes in our CI system.
That minimises the risk that the selected versions are themselves troublesome for some reason, needing another round of adjustment.
It might indeed be better to convert them to nearby release tags. However:
mariner:libvirt> git-describe 9a0c7f5f834185db9017c34aabc03ad99cf37bed v1.3.2-202-g9a0c7f5 mariner:libvirt> git-describe 33fb8ff185846a7b4974105d2c9400690a6f95cf v1.3.2-rc2-1-g33fb8ff mariner:libvirt> git-describe cda1cc170f07b45911b3dad03e42c8ebfc210fa1 v1.3.1-262-gcda1cc1
It seems odd that Xen 4.5 would use an older libvirt release than Xen 4.3.
mariner:libvirt> git-describe eac167e2610d3e59b32f7ec7ba78cbc8c420a425 v1.3.5-318-geac167e mariner:libvirt> git-describe 1a41ed5af5e1704dd9b0bdca40df5c9cacbdabfc v1.3.5-129-g1a41ed5 mariner:libvirt>
So in most cases these hashes are well away from a release tag.
Does libvirt have stable release branches ? One approach would be to have osstest track a suitable libvirt stable release branche for each Xen stable release branch.
I see Daniel already answered this question.
That would involve setting up a push gate for each of the chosen libvirt stable branches. That would be worthwhile if we expect those stable branches to acquire commits which break Xen, and which we could like to be told about. But I'm not sure that's the case.
I occasionally backport Xen bug fixes to -maint branches. Cole has also grabbed some Xen bug fixes when making a stable release of a -maint branch. But such backports should be trivial and obvious bug fixes that shouldn't cause build or runtime breakage with Xen. Regards, Jim
Jim Fehlig writes ("Re: [libvirt] [Xen-devel] Fixing libvirt's libxl driver breakage -- where to define LIBXL_API_VERSION?"):
On 06/27/2016 10:12 AM, Ian Jackson wrote:
Does libvirt have stable release branches ? One approach would be to have osstest track a suitable libvirt stable release branche for each Xen stable release branch.
I see Daniel already answered this question.
That would involve setting up a push gate for each of the chosen libvirt stable branches. That would be worthwhile if we expect those stable branches to acquire commits which break Xen, and which we could like to be told about. But I'm not sure that's the case.
I occasionally backport Xen bug fixes to -maint branches. Cole has also grabbed some Xen bug fixes when making a stable release of a -maint branch. But such backports should be trivial and obvious bug fixes that shouldn't cause build or runtime breakage with Xen.
OK. Thanks for the feedback. I'll go ahead with my plan with the git commit ids named in my earlier email. Thanks, Ian.
On 27.06.16 at 18:54, <ian.jackson@eu.citrix.com> wrote: Jim Fehlig writes ("Re: [libvirt] [Xen-devel] Fixing libvirt's libxl driver breakage -- where to define LIBXL_API_VERSION?"): On 06/27/2016 10:12 AM, Ian Jackson wrote: Does libvirt have stable release branches ? One approach would be to have osstest track a suitable libvirt stable release branche for each Xen stable release branch.
I see Daniel already answered this question.
That would involve setting up a push gate for each of the chosen libvirt stable branches. That would be worthwhile if we expect those stable branches to acquire commits which break Xen, and which we could like to be told about. But I'm not sure that's the case.
I occasionally backport Xen bug fixes to -maint branches. Cole has also grabbed some Xen bug fixes when making a stable release of a -maint branch. But such backports should be trivial and obvious bug fixes that shouldn't cause build or runtime breakage with Xen.
OK. Thanks for the feedback. I'll go ahead with my plan with the git commit ids named in my earlier email.
The only (hopefully highly theoretical) problem I see with this is that we may end up picking a libvirt commit which subsequently (e.g. via a libxl backport) turns out to have an issue. Such a problem could be dealt with in the suggested the stable branch tracking model (or any other model not dealing with something completely frozen). Jan
Jan Beulich writes ("Re: [libvirt] [Xen-devel] Fixing libvirt's libxl driver breakage -- where to define LIBXL_API_VERSION?"):
On 27.06.16 at 18:54, <ian.jackson@eu.citrix.com> wrote:
OK. Thanks for the feedback. I'll go ahead with my plan with the git commit ids named in my earlier email.
The only (hopefully highly theoretical) problem I see with this is that we may end up picking a libvirt commit which subsequently (e.g. via a libxl backport) turns out to have an issue. Such a problem could be dealt with in the suggested the stable branch tracking model (or any other model not dealing with something completely frozen).
I don't think there is anything stopping us manually updating one of these frozen "branches", should such a situation occur. Ian.
On 04/13/2016 03:09 AM, George Dunlap wrote:
Wei Liu wrote:
Hi libvirt maintainers, Sorry for the delay. Slowly catching up on mail after vacation...
Xen's control library libxenlight (libxl) requires application (libvirt in this case) to explictily define LIBXL_API_VERSION. Where is this requirement written? :-)
This is lacking at the moment so libvirt's libxl driver always gets the latest APIs. IMO, that is what we want for upstream libvirt. Downstreams can choose a specific version if they want. I think one of us isn't understanding the situation properly. Is it not the case that currently, all releases of libvirt *will not compile* against Xen 4.7 once it's released? So people downloading and building libvirt will have to either 1) root around and try to
On Tue, Apr 12, 2016 at 10:31 PM, Jim Fehlig <jfehlig@suse.com> wrote: figure out what version of Xen it will build against, 2) manually add in a #define *with the correct API version* to a header somewhere to make it build properly, or 3) update to a version of libvirt that supports the new api (which at the moment hasn't even been released yet)?
All of those options are completely unacceptable. Older versions of libvirt should Just Work when compiled against newer versions of Xen.
Yes, agreed. In practice though folks want a new libvirt with the new Xen, which is probably why no one has complained thus far. I'll knock up a patch to set the LIBXL_API_VERSION to 0x040200. The only APIs that have changed since 0x040200 are libxl_set_vcpuaffinity and libxl_domain_create_restore, but libvirt does not use the changes (added params). libvirt does use new libxl APIs added since Xen 4.2, but those aren't tied to a specific LIBXL_API_VERSION. Regards, Jim
On Wed, 2016-04-13 at 17:31 -0600, Jim Fehlig wrote:
I'll knock up a patch to set the LIBXL_API_VERSION to 0x040200. The only APIs
On Tue, Apr 12, 2016 at 10:31 PM, Jim Fehlig <jfehlig@suse.com> wrote: that have changed since 0x040200 are libxl_set_vcpuaffinity and libxl_domain_create_restore, but libvirt does not use the changes (added params).
I think this is a good choice.
libvirt does use new libxl APIs added since Xen 4.2, but those aren't tied to a specific LIBXL_API_VERSION.
And, in those cases, usage should be gated by the appropriate LIBXL_HAVE_FOOBAR symbol, which I see in the sources (e.g., for LIBXL_HAVE_NO_SUSPEND_RESUME or LIBXL_HAVE_DOMAIN_NODEAFFINITY) to be the case, so good again. :-) Regards, Dario -- <<This happens because I choose it to happen!>> (Raistlin Majere) ----------------------------------------------------------------- Dario Faggioli, Ph.D, http://about.me/dario.faggioli Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK)
Dario Faggioli writes ("Re: [Xen-devel] Fixing libvirt's libxl driver breakage -- where to define LIBXL_API_VERSION?"):
And, in those cases, usage should be gated by the appropriate LIBXL_HAVE_FOOBAR symbol, which I see in the sources (e.g., for LIBXL_HAVE_NO_SUSPEND_RESUME or LIBXL_HAVE_DOMAIN_NODEAFFINITY) to be the case, so good again. :-)
If libvirt specifies LIBXL_API_VERSION then it does not need to check any LIBXL_HAVE_*, since it will actually get an API corresponding to the specified API_VERSION. Ian.
On Thu, 2016-04-14 at 18:59 +0100, Ian Jackson wrote:
Dario Faggioli writes ("Re: [Xen-devel] Fixing libvirt's libxl driver breakage -- where to define LIBXL_API_VERSION?"):
And, in those cases, usage should be gated by the appropriate LIBXL_HAVE_FOOBAR symbol, which I see in the sources (e.g., for LIBXL_HAVE_NO_SUSPEND_RESUME or LIBXL_HAVE_DOMAIN_NODEAFFINITY) to be the case, so good again. :-)
If libvirt specifies LIBXL_API_VERSION then it does not need to check any LIBXL_HAVE_*, since it will actually get an API corresponding to the specified API_VERSION.
I concur. And in fact, this patch introduces an LIBXL_API_VERSION and drops the use of LIBXL_HAVE_*. And I think the patch is right. :-) Regards, Dario -- <<This happens because I choose it to happen!>> (Raistlin Majere) ----------------------------------------------------------------- Dario Faggioli, Ph.D, http://about.me/dario.faggioli Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK)
On Thu, Apr 14, Ian Jackson wrote:
Dario Faggioli writes ("Re: [Xen-devel] Fixing libvirt's libxl driver breakage -- where to define LIBXL_API_VERSION?"):
And, in those cases, usage should be gated by the appropriate LIBXL_HAVE_FOOBAR symbol, which I see in the sources (e.g., for LIBXL_HAVE_NO_SUSPEND_RESUME or LIBXL_HAVE_DOMAIN_NODEAFFINITY) to be the case, so good again. :-)
If libvirt specifies LIBXL_API_VERSION then it does not need to check any LIBXL_HAVE_*, since it will actually get an API corresponding to the specified API_VERSION.
This cant be true, because otherwise it will be unable to use vscsi and perhaps usb (and whatever else showed up after 4.2). Does that also mean that for example things related to LIBXL_HAVE_VSCSI need to be wrapped in "#if LIBXL_API_VERSION > $whatever"? Maybe I'm just misunderstand what you are trying to say. Olaf
participants (9)
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Daniel P. Berrange -
Dario Faggioli -
George Dunlap -
Ian Jackson -
Ian Jackson
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Jan Beulich -
Jim Fehlig -
Olaf Hering -
Wei Liu