Re: [Xen-devel] [PATCH for-4.13] clang: do not enable live-patching support

[Lars Kurth <lars.kurth.xen@xxxxxxxxx>]

On 6 Dec 2019, at 14:21, Andrew Cooper <andrew.cooper3@xxxxxxxxxx> wrote:

On 03/12/2019 09:17, George Dunlap wrote:

On Dec 2, 2019, at 5:01 PM, Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx> wrote:

On Mon, Dec 02, 2019 at 03:55:04PM +0000, Andrew Cooper wrote:

On 02/12/2019 15:53, Konrad Rzeszutek Wilk wrote:

I plan to release ack the patch in case the missing maintainer's acks
are not coming in too late.

I think Andy's objection was that there has been zero testing of
livepatching on gcc.  Maybe we can find someone to do a smoke-test.

As in integrate livepatch-build tools in osstest smoke-tests?
Because the livepatch test cases are in osstest, unless something went awry?

The sum total of livepatch testing in OSSTest is using the hand-coded
ELF objects from the tests/ directory.

This is perhaps ok for the basic mechanism, but its not representative
of actually building real livepatches using livepatch build tools.

True. But it tests the _hypervisor_ livepatch code.

I am thinking that this discussion about "oh, but livepatch-build tools don't work b/c"
is well <shrug> sucks but should never block an release as the core
livepatch functionality is OK.

I think a parallel is if Xen doesn’t build with a particular version of the compiler, or can’t build on a particular distro for some reason.  We should certainly *try* to make things work with other projects, but if the issue is clearly with the other project, we shouldn’t have to block to wait for that other project to get things sorted out.

This isn't a valid comparison.

livepatch-build-tools is a concrete thing, built and maintained by us
(the Xen community), explicitly for the purpose generating livepatches
between two versions of Xen.  It lives at
https://xenbits.xen.org/gitweb/?p=livepatch-build-tools.git;a=summary on
xenbits, just like xen.git.

First a couple of questions: I noticed that neither Ross to xen-devel is on this thread

I agree with Andy: we got away lucky so far, as there have been few changes to the live patch-build-tools

It *should* be used in OSSTest, have a push gate, and block breaking
changes either to Xen or to the tools themselves, before the breaking
changes get accepted into master of either repo.

Although I agree with you, we should not block 4.13 for it and do some manual testing for this release

But we should have a plan in place for 4.14 to address this and maybe agree to block 4.14 if that has not happened

Lars

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel