Re: [Qemu-devel] [PATCH v3 00/29] postcopy+vhost-user/shared ram

["Michael S. Tsirkin" <mst@redhat.com>]

On Fri, Feb 16, 2018 at 01:15:56PM +0000, Dr. David Alan Gilbert (git) wrote:
> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> 
> Hi,
>   This is the first non-RFC version of this patch set that
> enables postcopy migration with shared memory to a vhost user process.
> It's based off current head.
> 
> I've tested with vhost-user-bridge and a modified dpdk; both very
> lightly.
> 
> Compared to v2 we're now using the just-merged reworks to the vhost
> code (suggested by Igor), so that the huge page region merging is now a lot simpler
> in this series. The handshake between the client and the qemu for the
> set-mem-table is now a bit more complex to resolve a previous race where
> the client would start sending requests to the qemu prior to the qemu
> being ready to accept them.
> 
> Dave

>From vhost-user POV this seems mostly fine to me.

I would like to have dependency of specific messages on the
protocol features documented, and the order of messages
documented a bit more explicitly.




> Dr. David Alan Gilbert (29):
>   migrate: Update ram_block_discard_range for shared
>   qemu_ram_block_host_offset
>   postcopy: use UFFDIO_ZEROPAGE only when available
>   postcopy: Add notifier chain
>   postcopy: Add vhost-user flag for postcopy and check it
>   vhost-user: Add 'VHOST_USER_POSTCOPY_ADVISE' message
>   libvhost-user: Support sending fds back to qemu
>   libvhost-user: Open userfaultfd
>   postcopy: Allow registering of fd handler
>   vhost+postcopy: Register shared ufd with postcopy
>   vhost+postcopy: Transmit 'listen' to client
>   postcopy+vhost-user: Split set_mem_table for postcopy
>   migration/ram: ramblock_recv_bitmap_test_byte_offset
>   libvhost-user+postcopy: Register new regions with the ufd
>   vhost+postcopy: Send address back to qemu
>   vhost+postcopy: Stash RAMBlock and offset
>   vhost+postcopy: Send requests to source for shared pages
>   vhost+postcopy: Resolve client address
>   postcopy: wake shared
>   postcopy: postcopy_notify_shared_wake
>   vhost+postcopy: Add vhost waker
>   vhost+postcopy: Call wakeups
>   libvhost-user: mprotect & madvises for postcopy
>   vhost-user: Add VHOST_USER_POSTCOPY_END message
>   vhost+postcopy: Wire up POSTCOPY_END notify
>   vhost: Huge page align and merge
>   postcopy: Allow shared memory
>   libvhost-user: Claim support for postcopy
>   postcopy shared docs
> 
>  contrib/libvhost-user/libvhost-user.c | 303 ++++++++++++++++++++++++-
>  contrib/libvhost-user/libvhost-user.h |   8 +
>  docs/devel/migration.rst              |  41 ++++
>  docs/interop/vhost-user.txt           |  42 ++++
>  exec.c                                |  85 +++++--
>  hw/virtio/trace-events                |  16 +-
>  hw/virtio/vhost-user.c                | 411 +++++++++++++++++++++++++++++++++-
>  hw/virtio/vhost.c                     |  66 +++++-
>  include/exec/cpu-common.h             |   4 +
>  migration/migration.c                 |   6 +
>  migration/migration.h                 |   4 +
>  migration/postcopy-ram.c              | 350 +++++++++++++++++++++++------
>  migration/postcopy-ram.h              |  69 ++++++
>  migration/ram.c                       |   5 +
>  migration/ram.h                       |   1 +
>  migration/savevm.c                    |  13 ++
>  migration/trace-events                |   6 +
>  trace-events                          |   3 +-
>  vl.c                                  |   2 +
>  19 files changed, 1337 insertions(+), 98 deletions(-)
> 
> -- 
> 2.14.3