> -----Original Message----- > From: Jinpu Wang [mailto:jinpu.wang@xxxxxxxxx] > Sent: Friday, June 7, 2024 1:54 PM > To: Gonglei (Arei) <arei.gonglei@xxxxxxxxxx> > Cc: qemu-devel@xxxxxxxxxx; peterx@xxxxxxxxxx; yu.zhang@xxxxxxxxx; > mgalaxy@xxxxxxxxxx; elmar.gerdes@xxxxxxxxx; zhengchuan > <zhengchuan@xxxxxxxxxx>; berrange@xxxxxxxxxx; armbru@xxxxxxxxxx; > lizhijian@xxxxxxxxxxx; pbonzini@xxxxxxxxxx; mst@xxxxxxxxxx; Xiexiangyou > <xiexiangyou@xxxxxxxxxx>; linux-rdma@xxxxxxxxxxxxxxx; lixiao (H) > <lixiao91@xxxxxxxxxx>; Wangjialin <wangjialin23@xxxxxxxxxx> > Subject: Re: [PATCH 0/6] refactor RDMA live migration based on rsocket API > > Hi Gonglei, hi folks on the list, > > On Tue, Jun 4, 2024 at 2:14 PM Gonglei <arei.gonglei@xxxxxxxxxx> wrote: > > > > From: Jialin Wang <wangjialin23@xxxxxxxxxx> > > > > Hi, > > > > This patch series attempts to refactor RDMA live migration by > > introducing a new QIOChannelRDMA class based on the rsocket API. > > > > The /usr/include/rdma/rsocket.h provides a higher level rsocket API > > that is a 1-1 match of the normal kernel 'sockets' API, which hides > > the detail of rdma protocol into rsocket and allows us to add support > > for some modern features like multifd more easily. > > > > Here is the previous discussion on refactoring RDMA live migration > > using the rsocket API: > > > > https://lore.kernel.org/qemu-devel/20240328130255.52257-1-philmd@linar > > o.org/ > > > > We have encountered some bugs when using rsocket and plan to submit > > them to the rdma-core community. > > > > In addition, the use of rsocket makes our programming more convenient, > > but it must be noted that this method introduces multiple memory > > copies, which can be imagined that there will be a certain performance > > degradation, hoping that friends with RDMA network cards can help verify, > thank you! > First thx for the effort, we are running migration tests on our IB fabric, different > generation of HCA from mellanox, the migration works ok, there are a few > failures, Yu will share the result later separately. > Thank you so much. > The one blocker for the change is the old implementation and the new rsocket > implementation; they don't talk to each other due to the effect of different wire > protocol during connection establishment. > eg the old RDMA migration has special control message during the migration > flow, which rsocket use a different control message, so there lead to no way to > migrate VM using rdma transport pre to the rsocket patchset to a new version > with rsocket implementation. > > Probably we should keep both implementation for a while, mark the old > implementation as deprecated, and promote the new implementation, and > high light in doc, they are not compatible. > IMO It makes sense. What's your opinion? @Peter. Regards, -Gonglei > Regards! > Jinpu > > > > > > > Jialin Wang (6): > > migration: remove RDMA live migration temporarily > > io: add QIOChannelRDMA class > > io/channel-rdma: support working in coroutine > > tests/unit: add test-io-channel-rdma.c > > migration: introduce new RDMA live migration > > migration/rdma: support multifd for RDMA migration > > > > docs/rdma.txt | 420 --- > > include/io/channel-rdma.h | 165 ++ > > io/channel-rdma.c | 798 ++++++ > > io/meson.build | 1 + > > io/trace-events | 14 + > > meson.build | 6 - > > migration/meson.build | 3 +- > > migration/migration-stats.c | 5 +- > > migration/migration-stats.h | 4 - > > migration/migration.c | 13 +- > > migration/migration.h | 9 - > > migration/multifd.c | 10 + > > migration/options.c | 16 - > > migration/options.h | 2 - > > migration/qemu-file.c | 1 - > > migration/ram.c | 90 +- > > migration/rdma.c | 4205 +---------------------------- > > migration/rdma.h | 67 +- > > migration/savevm.c | 2 +- > > migration/trace-events | 68 +- > > qapi/migration.json | 13 +- > > scripts/analyze-migration.py | 3 - > > tests/unit/meson.build | 1 + > > tests/unit/test-io-channel-rdma.c | 276 ++ > > 24 files changed, 1360 insertions(+), 4832 deletions(-) delete mode > > 100644 docs/rdma.txt create mode 100644 include/io/channel-rdma.h > > create mode 100644 io/channel-rdma.c create mode 100644 > > tests/unit/test-io-channel-rdma.c > > > > -- > > 2.43.0 > >
