On Wed, Feb 7, 2024 at 12:38 AM Liu, Yuan1 <yuan1....@intel.com> wrote: > > Thank you very much for your reminder and the rapid updates to the > multifd function. I will incorporate your suggestions into the next > version (IAA Accelerated Live Migration solution). > > Regarding the QAT and DSA optimization, my colleagues and I have > already started reviewing and testing them, and it seems like a > promising optimization direction. I am more than willing to contribute > further efforts to the long-term maintenance of Intel accelerators in > live migration. > > > -----Original Message----- > > From: Peter Xu <pet...@redhat.com> > > Sent: Wednesday, February 7, 2024 4:10 PM > > To: Bryan Zhang <bryan.zh...@bytedance.com>; Hao Xiang > > <hao.xi...@bytedance.com>; Liu, Yuan1 <yuan1....@intel.com> > > Cc: Fabiano Rosas <faro...@suse.de>; QEMU Devel Mailing List <qemu- > > de...@nongnu.org> > > Subject: Regarding to the recent Intel IAA/DSA/QAT support on migration > > > > Copy qemu-devel. > > > > On Wed, Feb 07, 2024 at 04:07:40PM +0800, Peter Xu wrote: > > > Hi, > > > > > > I'm sending this email just to leave a generic comment to the recent > > > migration efforts to enable these new Intel technologies. > > > > > > The relevant patchsets (latest version so far) we're discussing are: > > > > > > [PATCH v3 0/4] Live Migration Acceleration with IAA Compression > > > > > > https://lore.kernel.org/r/20240103112851.908082-1-yuan1....@intel.com > > > > > > [PATCH v3 00/20] Use Intel DSA accelerator to offload zero page > > checking in multifd live migration. > > > > > > https://lore.kernel.org/r/20240104004452.324068-1-hao.xiang@bytedance. > > > com > > > > > > [PATCH 0/5] *** Implement using Intel QAT to offload ZLIB > > > > > > https://lore.kernel.org/r/20231231205804.2366509-1-bryan.zhang@bytedan > > > ce.com > > > > > > I want to comment in a generic way since this should apply to all > > > these > > > series: > > > > > > - A heads-up that multifd code is rapidly changing recently, I > > apologize > > > that you'll need a rebase. It's just that it's probably much better > > to > > > do this before anything lands there. > > > > > > IIUC the good thing is we found that send_prepare() doesn't need to > > be > > > changed that much, however there's still some change; please refer > > to > > > the new code (I'll prepare a pull tomorrow to include most of the > > > changes, and we should have a major thread race fixed too with > > Fabiano > > > & Avihai's help). I hope this will also provide some kind of > > isolation > > > to e.g. other works that may touch other areas. E.g., I hope fixed- > > ram > > > won't need to conflict much with any of the above series now.
Thanks for the update. The rebase shouldn't be that bad so no worries. > > > > > > - When posting the new patchset (if there is a plan..), please make > > sure > > > we have: > > > > > > - Proper unit tests for the new code (probably mostly software > > > fallbacks to be tested on the new libraries being introduced; just > > to > > > make sure the new library code paths can get some torture please). > > > > > > - Proper documentation for the new code. Please feel free to start > > > creating your own .rst file under docs/devel/migration/, we can > > try > > > to merge them later. It should help avoid conflictions. Please > > also > > > link the new file into index.rst there. > > > > > > IMHO the document can contain many things, the important ones > > could > > > start from: who should enable such feature; what one can get from > > > having it enabled; what is the HW requirement to enable it; how > > > should one tune the new parameters, and so on... some links to the > > > technology behinds it would be nice too to be referenced. > > > > > > - Try to add new code (especially HW/library based) into new file. > > > I see that QPL & QAT already proposed its own files (multifd- > > pql.c, > > > multifd-qatzip.c) which is great. > > > > > > Xiang, please also consider doing so for the DSA based zero page > > > detection. It can be called multifd-zero-page.c, for example, and > > > you can create it when working on the > > > offload-zero-page-detect-to-multifd patchset already. Sounds good. > > > > > > - Please provide someone who can potentially maintain this code if > > ever > > > possible. Pushing these code upstream is great, but maintaining > > will > > > also take effort. It might be impractical this keeps growing for > > > migration maintainers (currently Fabiano and myself), so we may > > like > > > to have people covering these areas, especially when the new codes > > > are not directly relevant to migration framework. > > > > > > I'd suggest for each of the project we can add an entry in > > > MAINTAINERS below "Migration" section, adding relevant files (and > > > these files should exist in both the new section and "Migration"). > > I > > > am not sure whether Bytedance would be able to cover this, or we > > > should try to find someone from Intel? If you're willing to add > > > yourself to maintain such codes, please attach the maintainers > > file > > > change together with the series. It will be very much > > appreciated. I will add myself to maintain this. In addition, I will talk to Intel about adding someone from Intel (hopefully Yuan or someone from his team?) as well to maintain the DSA work. > > > > > > Thanks, > > > > > > -- > > > Peter Xu > > > > -- > > Peter Xu >
