From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47443) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WuLfE-0000xB-U8 for qemu-devel@nongnu.org; Tue, 10 Jun 2014 09:00:38 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WuLf9-0007zG-3B for qemu-devel@nongnu.org; Tue, 10 Jun 2014 09:00:32 -0400 Received: from mx1.redhat.com ([209.132.183.28]:29313) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WuLf8-0007z7-Oe for qemu-devel@nongnu.org; Tue, 10 Jun 2014 09:00:27 -0400 Message-ID: <53970165.2050503@redhat.com> Date: Tue, 10 Jun 2014 07:00:21 -0600 From: Eric Blake MIME-Version: 1.0 References: <1402392556-21844-1-git-send-email-pl@kamp.de> <53970052.4040402@redhat.com> In-Reply-To: <53970052.4040402@redhat.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="UlmDMEBr97amC9WL8pLlTpNrE8cdGaXV6" Subject: Re: [Qemu-devel] [PATCHv4] migration: catch unknown flags in ram_load List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Lieven , qemu-devel@nongnu.org Cc: amit.shah@redhat.com, pbonzini@redhat.com, dgilbert@redhat.com, quintela@redhat.com This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --UlmDMEBr97amC9WL8pLlTpNrE8cdGaXV6 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 06/10/2014 06:55 AM, Eric Blake wrote: > On 06/10/2014 03:29 AM, Peter Lieven wrote: >> if a saved vm has unknown flags in the memory data qemu >> currently simply ignores this flag and continues which >> yields in an unpredictable result. >> >> This patch catches all unknown flags and aborts the >> loading of the vm. Additionally error reports are thrown >> if the migration aborts abnormally. >> >> } else if (flags & RAM_SAVE_FLAG_HOOK) { >> ram_control_load_hook(f, flags); >> + } else if (flags & RAM_SAVE_FLAG_EOS) { >=20 > Umm, is the migration format specifically documented as having at most > one flag per operation, or is it valid to send two flags at once? That= > is, can I send RAM_SAVE_FLAG_XBZRLE | RAM_SAVE_FLAG_HOOK on a single > packet? Should we be flagging streams that send unexpected flag > combinations as invalid, even when each flag is in isolation okay, > rather than the current behavior of silently prioritizing one flag and > ignoring the other? For that matter, would it be better to change the if-tree into a switch, so that the default case catches unsupported combinations? switch (flags) { ... case RAM_SAVE_FLAG_HOOK: ... case RAM_SAVE_FLAG_EOS: ... default: report unsupported flags value } --=20 Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org --UlmDMEBr97amC9WL8pLlTpNrE8cdGaXV6 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 Comment: Public key at http://people.redhat.com/eblake/eblake.gpg Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBCAAGBQJTlwFlAAoJEKeha0olJ0NqmUsH/1SPW9ErsHdAHkh+P5x1fsU4 ERJAbu2EMS1PrL0gSSRvSJ5T8dwdMKlwEN1rB/HhJmfueKxpOpchOI8aPpv0rhvh GVEv5buRDFvk7bap62OK9vYaeER2Foh1PGIzU4Ze86WAezM8qxJtRzXHsnHViuRF fBSxySfyD//ACRk5EqfiY6DB1jIKBBZktnsV7YZx4qYxZAZH1QhySFoaXS6v3Bvl G1DLu6v9g4KPMpF6GfWo0HBLjZGabWZnm6yxRXK+tI2QjjwVxuKKHsn1ZuBLYRCK L5BoCMT9UFCUmg12Ak9eW3pKl1+jT6ZlXZH2M+Ft2YGoq1LLiI2ZtNw9v+Yvl5w= =8tHn -----END PGP SIGNATURE----- --UlmDMEBr97amC9WL8pLlTpNrE8cdGaXV6--