From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52326) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1er6cv-0000MH-Da for qemu-devel@nongnu.org; Wed, 28 Feb 2018 13:38:54 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1er6cs-0006A9-7j for qemu-devel@nongnu.org; Wed, 28 Feb 2018 13:38:53 -0500 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:50856 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1er6ci-00063w-Ez for qemu-devel@nongnu.org; Wed, 28 Feb 2018 13:38:49 -0500 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id E48908182D11 for ; Wed, 28 Feb 2018 18:38:35 +0000 (UTC) Date: Wed, 28 Feb 2018 18:38:21 +0000 From: "Dr. David Alan Gilbert" Message-ID: <20180228183821.GL2981@work-vm> References: <20180216131625.9639-1-dgilbert@redhat.com> <20180227155825-mutt-send-email-mst@kernel.org> <20180227200524.GL2847@work-vm> <20180227222224-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180227222224-mutt-send-email-mst@kernel.org> Subject: Re: [Qemu-devel] [PATCH v3 00/29] postcopy+vhost-user/shared ram List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: qemu-devel@nongnu.org, maxime.coquelin@redhat.com, marcandre.lureau@redhat.com, peterx@redhat.com, imammedo@redhat.com, quintela@redhat.com, aarcange@redhat.com * Michael S. Tsirkin (mst@redhat.com) wrote: > On Tue, Feb 27, 2018 at 08:05:25PM +0000, Dr. David Alan Gilbert wrote: > > * Michael S. Tsirkin (mst@redhat.com) wrote: > > > On Fri, Feb 16, 2018 at 01:15:56PM +0000, Dr. David Alan Gilbert (git) wrote: > > > > From: "Dr. David Alan Gilbert" > > > > > > > > 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. > > > > OK, great - it would be nice to get this merged in the upcoming release > > (Hint: Anyone else please review!) > > > > > I would like to have dependency of specific messages on the > > > protocol features documented, and the order of messages > > > documented a bit more explicitly. > > > > Something like the following? (appropriately merged in with the > > individual commits): > > > > diff --git a/docs/interop/vhost-user.txt b/docs/interop/vhost-user.txt > > index 4bf7d8ef99..7841812766 100644 > > --- a/docs/interop/vhost-user.txt > > +++ b/docs/interop/vhost-user.txt > > @@ -461,7 +461,7 @@ Master message types > > for each memory mapped region. The size and ordering of the fds matches > > the number and ordering of memory regions. > > > > - When postcopy-listening has been received, SET_MEM_TABLE replies with > > + When VHOST_USER_POSTCOPY_LISTEN has been received, SET_MEM_TABLE replies with > > the bases of the memory mapped regions to the master. It must have mmap'd > > the regions but not yet accessed them and should not yet generate a userfault > > event. Note NEED_REPLY_MASK is not set in this case. > > @@ -687,7 +687,8 @@ Master message types > > Master payload: N/A > > Slave payload: userfault fd + u64 > > > > - Master advises slave that a migration with postcopy enabled is underway, > > + When VHOST_USER_PROTOCOL_F_PAGEFAULT is supported, the > > + master advises slave that a migration with postcopy enabled is underway, > > the slave must open a userfaultfd for later use. > > Note that at this stage the migration is still in precopy mode. > > > > @@ -696,6 +697,8 @@ Master message types > > Master payload: N/A > > > > Master advises slave that a transition to postcopy mode has happened. > > + This is always sent sometime after a VHOST_USER_POSTCOPY_ADVISE, and > > + thus only when VHOST_USER_PROTOCOL_F_PAGEFAULT is supported. > > > > * VHOST_USER_POSTCOPY_END > > Id: 28 > > @@ -704,6 +707,8 @@ Master message types > > Master advises that postcopy migration has now completed. The > > slave must disable the userfaultfd. The response is an acknowledgement > > only. > > + This message is sent at the end of the migration, after > > + VHOST_USER_POSTCOPY_LISTEN was previously sent. > > And maybe mention VHOST_USER_PROTOCOL_F_PAGEFAULT here too. Done. Dave > > Slave message types > > ------------------- > > > > Dave > > > > > > > > > > > > > > > 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 > > -- > > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK