From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37160) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a9FEc-000554-40 for qemu-devel@nongnu.org; Wed, 16 Dec 2015 11:47:27 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1a9FEb-0003s9-66 for qemu-devel@nongnu.org; Wed, 16 Dec 2015 11:47:26 -0500 Received: from mx1.redhat.com ([209.132.183.28]:37335) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a9FEb-0003rz-0g for qemu-devel@nongnu.org; Wed, 16 Dec 2015 11:47:25 -0500 References: <1450266458-3178-1-git-send-email-dgilbert@redhat.com> <1450266458-3178-5-git-send-email-dgilbert@redhat.com> From: Eric Blake Message-ID: <5671959B.60509@redhat.com> Date: Wed, 16 Dec 2015 09:47:23 -0700 MIME-Version: 1.0 In-Reply-To: <1450266458-3178-5-git-send-email-dgilbert@redhat.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="pVsSIoMFB6oRJ8wJFVDd9CKqwOteh9eXV" Subject: Re: [Qemu-devel] [PATCH v2 4/6] Migration: Emit event at start of pass List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Dr. David Alan Gilbert (git)" , qemu-devel@nongnu.org, quintela@redhat.com, amit.shah@redhat.com Cc: jdenemar@redhat.com, liang.z.li@intel.com, zhang.zhanghailiang@huawei.com This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --pVsSIoMFB6oRJ8wJFVDd9CKqwOteh9eXV Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 12/16/2015 04:47 AM, Dr. David Alan Gilbert (git) wrote: > From: "Dr. David Alan Gilbert" >=20 > Emit an event each time we sync the dirty bitmap on the source; > this helps libvirt use postcopy by giving it a kick when it > might be a good idea to start the postcopy. >=20 > Signed-off-by: Dr. David Alan Gilbert > --- > docs/qmp-events.txt | 14 ++++++++++++++ > migration/ram.c | 4 ++++ > qapi/event.json | 13 +++++++++++++ > 3 files changed, 31 insertions(+) >=20 > =20 > +MIGRATION_PASS > +-------------- > + > +Emitted from the source side of a migration at the start of each pass > +(when it syncs the dirty bitmap) > + > +Data: None. > + > + - "pass": An incrementing count (starting at 1 on the first pass) > + > +Example: > +{"timestamp": {"seconds": 1449669631, "microseconds": 239225}, > + "event": "MIGRATION_PASS", "data": {"pass": 2}} How frequently can this event be emitted? It is not under guest control, so it's harder to argue that it could be abused as a way for the guest to DoS the host. And hopefully it is slow enough (considering that each pass also requires lots more effort for actually transmitting state from source to dest), so I don't think we have to worry about adding rate-limiting to avoid overwhelming the monitor client. Reviewed-by: Eric Blake --=20 Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org --pVsSIoMFB6oRJ8wJFVDd9CKqwOteh9eXV Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 Comment: Public key at http://people.redhat.com/eblake/eblake.gpg Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBCAAGBQJWcZWbAAoJEKeha0olJ0NqgpUH/13uBp+ChHLhW/aMU/uCJUit F/NiuueJqIbaWqEm0DJWfFu6kkIsNE8MKMUZlwLtiDYTb4fzTUbJpNq7oBXnn2BO Mf5w4V17R71eE4ll3CxwIIXxRjGYuQssnj+vQ/PKIntaAMSZyCqCbpXPMfTD0UfD CaRjI5GpDlz6CnLKMfwdR8xKFWRBzN61CwXhjFstS8gx5KeJnhgk7No4wrAZJEWj y6t/muM4sWCZ6hpTOOLuGWC7H8fT426bfezCSUZAv+U5DUIiTeWXXzj7csjCKzku MT8uRYAwo32v7yjY8m5JwopxXA/vKd1XBpjo/r76kwWh0hiMgjcNtuekyxB2XIQ= =YeVD -----END PGP SIGNATURE----- --pVsSIoMFB6oRJ8wJFVDd9CKqwOteh9eXV--