> -----Original Message----- > From: Andrew Cooper <andrew.coop...@citrix.com> > Sent: 19 December 2019 11:30 > To: Durrant, Paul <pdurr...@amazon.com>; xen-devel@lists.xenproject.org > Cc: Wei Liu <w...@xen.org>; Jan Beulich <jbeul...@suse.com>; Roger Pau Monné > <roger....@citrix.com> > Subject: Re: [Xen-devel] [PATCH] x86/save: reserve HVM save record numbers > that have been consumed... > > On 19/12/2019 11:06, Durrant, Paul wrote: > >> It is not fair or reasonable to include extra headroom in a "oh dear we > >> screwed up - will the community be kind enough to help us work around > >> our ABI problems" scenario. > >> > > I would have thought all the pain you went through to keep XenServer > going with its non-upstreamed hypercall numbers would have made you a > little more sympathetic to dealing with past mistakes. > > I could object to the principle of the patch, if you'd prefer :) > > If you recall for the legacy window PV driver ABI breakages, I didn't > actually reserve any numbers upstream in the end. All compatibility was > handled locally.
And I remember how nasty the hacks were ;-) Given we don't yet have a clash that requires such nastiness, I just want to avoid it happening before we manage to dispense with the downstream-only legacy code. > > >> For now, I'd just leave it as a comment, and strictly only covering the > >> ones you have used. There is no need to actually bump the structure > >> sizes in xen for now - simply that the ones you have currently used > >> don't get allocated for something different in the future. > >> > > Ok, we can defer actually bumping HVM_SAVE_CODE_MAX, but it's almost > certain to happen eventually. > > That's fine. > Ok. I'll send a v2 with just the comment (and assume Wei's R-b still stands). Paul _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
