From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:42779) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UXZbC-0006VW-5F for qemu-devel@nongnu.org; Wed, 01 May 2013 12:09:45 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UXZbA-0000cD-CQ for qemu-devel@nongnu.org; Wed, 01 May 2013 12:09:42 -0400 Received: from mail-yh0-x233.google.com ([2607:f8b0:4002:c01::233]:36378) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UXZbA-0000c7-6a for qemu-devel@nongnu.org; Wed, 01 May 2013 12:09:40 -0400 Received: by mail-yh0-f51.google.com with SMTP id l109so315279yhq.24 for ; Wed, 01 May 2013 09:09:39 -0700 (PDT) Sender: Paolo Bonzini Message-ID: <51813E31.5070500@redhat.com> Date: Wed, 01 May 2013 18:09:21 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <1367378320-9246-1-git-send-email-david@gibson.dropbear.id.au> <1367378320-9246-16-git-send-email-david@gibson.dropbear.id.au> <20130501051631.GB14106@truffula.fritz.box> In-Reply-To: <20130501051631.GB14106@truffula.fritz.box> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 16/17] spapr_vio: take care of creating our own AddressSpace/DMAContext List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: David Gibson Cc: Alexey Kardashevskiy , qemu-devel@nongnu.org -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Il 01/05/2013 07:16, David Gibson ha scritto: > Lack of atomicity makes me a little nervous there, although I > guess its ok since qemu is single-threaded. Yes. The original plan was to add a boolean return value to address_space_rw, but I left this for later since I wasn't sure of the semantics for multipage writes. What happens if the second half of the destination buffer has an invalid translation? Right now it's atomic, but it sounds weird for real hardware. Paolo > It does mean we do the translations twice, effectively, which isn't > ideal, although emulated devices are already so slow it probably > doesn't matter. > -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQIcBAEBAgAGBQJRgT4xAAoJEBvWZb6bTYbyePoP/3BC7W/3LC/YfEJ16CbSsnhN tJ2kLdjuI9+OAzAfb++TKoxkAAGtPSCFpBiS7s1T2r9gTSYMQX15enppU+lBFxwq qfK7UF11carjnsDB3rXhUnZTGYPWYwA17mR4U2PBFy4EeZZ1p57m1QmJsrgI9UI7 u7QyC+NrNPM3fA0R/CCSn5ld3hh14GK3gEv+SK9IIsnwmoyQ6NKsDi3AAzdnSbMZ pnMpFCb2Vu2MT/8M80r7J3aRUMGsVwlQgVyqxDpWJ4YJSDO6SaoIj7U+0gv867sa gJwg94N6umurU49esGGjOzvTxlwdgQQDkG/sDUeMPsGS/cqb4RYeJKRK6ieFqdTY SPUOz0ssUQhqzRX9zoUQE8aA0rt/CLL+E9+8MYmqAkKMLPpMmLsqrZxl11d19MTN WdZnYmJvVLAVn+YUae4N0ehhgXSMv2MTabb39V7VG2QziEdcIn8wQIWGTTTw6o/p GBFu0P05mXL8jvSQ5CQp3k36OqwKGlgjaHB4MOsbCKTahLBQ9VoarKB6Xh/4xWxj 3+kYjYdydnJMogOe4FE5mld6LJnlo66e/GJNdZyHzsdyB9cK9qMg+i3yXQElNSp9 H34sMKfpFgJ/6z/cwbrNrSWesgKDTqhhXKzocgvZkQUbvJCF5I2xigi8aKB3vC+N wjEs5RUYBzb3ARKWCwy/ =Jr5p -----END PGP SIGNATURE-----