From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from list by lists.gnu.org with archive (Exim 4.71) id 1Uoq8e-0002ly-8M for mharc-qemu-trivial@gnu.org; Tue, 18 Jun 2013 03:15:36 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57278) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Uoobt-0003zC-Br for qemu-trivial@nongnu.org; Tue, 18 Jun 2013 01:37:42 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Uoobs-0002uj-HB for qemu-trivial@nongnu.org; Tue, 18 Jun 2013 01:37:41 -0400 Received: from mx1.redhat.com ([209.132.183.28]:46801) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Uoobq-0002uD-Fa; Tue, 18 Jun 2013 01:37:38 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r5I5bYBL030424 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Tue, 18 Jun 2013 01:37:35 -0400 Received: from rincewind.home.kraxel.org (ovpn-116-37.ams2.redhat.com [10.36.116.37]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id r5I5bVtM013206; Tue, 18 Jun 2013 01:37:33 -0400 Message-ID: <51BFF21A.7050008@redhat.com> Date: Tue, 18 Jun 2013 07:37:30 +0200 From: Gerd Hoffmann User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130513 Thunderbird/17.0.6 MIME-Version: 1.0 To: Michael Tokarev References: <1371487106-17194-1-git-send-email-anthony.perard@citrix.com> <51BFCDA1.8040507@msgid.tls.msk.ru> In-Reply-To: <51BFCDA1.8040507@msgid.tls.msk.ru> X-Enigmail-Version: 1.5.1 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 X-Mailman-Approved-At: Tue, 18 Jun 2013 03:15:35 -0400 Cc: Anthony PERARD , qemu-trivial@nongnu.org, Alon Levy , QEMU-devel , qemu-stable Subject: Re: [Qemu-trivial] [PATCH] qxl: Fix QXLRam initialisation. X-BeenThere: qemu-trivial@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 18 Jun 2013 05:37:42 -0000 Hi, >> If memory is set to 0xc2c2.., it leads to a spice-critical error when >> trying to start qxl. > But maybe instead of doing it this way, we should just memset the > whole thing to 0, to avoid similar bugs in the future? Are there > any arches out there which have cpu_to_le32(0) != 0 ? On qemu + kvm guest memory (including pci device memory where this lives in) _is_ zero initialized. IIRC xen has a debug mode where it fills memory with non-zero values instead, for debugging / testing purposes, and this is where things blow up. So while the fix is clearly correct, the patch isn't as critical as it initially looks like. Reviewed-by: Gerd Hoffmann cheers, Gerd From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57260) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Uoobr-0003z7-KN for qemu-devel@nongnu.org; Tue, 18 Jun 2013 01:37:40 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Uoobq-0002uP-Me for qemu-devel@nongnu.org; Tue, 18 Jun 2013 01:37:39 -0400 Message-ID: <51BFF21A.7050008@redhat.com> Date: Tue, 18 Jun 2013 07:37:30 +0200 From: Gerd Hoffmann MIME-Version: 1.0 References: <1371487106-17194-1-git-send-email-anthony.perard@citrix.com> <51BFCDA1.8040507@msgid.tls.msk.ru> In-Reply-To: <51BFCDA1.8040507@msgid.tls.msk.ru> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [Qemu-trivial] [PATCH] qxl: Fix QXLRam initialisation. List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Michael Tokarev Cc: Anthony PERARD , qemu-trivial@nongnu.org, Alon Levy , QEMU-devel , qemu-stable Hi, >> If memory is set to 0xc2c2.., it leads to a spice-critical error when >> trying to start qxl. > But maybe instead of doing it this way, we should just memset the > whole thing to 0, to avoid similar bugs in the future? Are there > any arches out there which have cpu_to_le32(0) != 0 ? On qemu + kvm guest memory (including pci device memory where this lives in) _is_ zero initialized. IIRC xen has a debug mode where it fills memory with non-zero values instead, for debugging / testing purposes, and this is where things blow up. So while the fix is clearly correct, the patch isn't as critical as it initially looks like. Reviewed-by: Gerd Hoffmann cheers, Gerd