From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from list by lists.gnu.org with archive (Exim 4.71) id 1SANFS-0007B1-0F for mharc-qemu-trivial@gnu.org; Wed, 21 Mar 2012 11:14:50 -0400 Received: from eggs.gnu.org ([208.118.235.92]:38556) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SANFK-00079b-36 for qemu-trivial@nongnu.org; Wed, 21 Mar 2012 11:14:48 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SANFI-0003F4-51 for qemu-trivial@nongnu.org; Wed, 21 Mar 2012 11:14:41 -0400 Received: from mail-ob0-f173.google.com ([209.85.214.173]:42537) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SANFI-0003Ei-0e for qemu-trivial@nongnu.org; Wed, 21 Mar 2012 11:14:40 -0400 Received: by obbwd20 with SMTP id wd20so860323obb.4 for ; Wed, 21 Mar 2012 08:14:38 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding :x-gm-message-state; bh=vm3dQVmQferR36la3ynTsZo4F8+0CN76obxFq9pPWT8=; b=lRJ+rEXNb6o+A1P6fBMPKjUj+6anSNBU8tsg223F5bmtfaFVUEGp0vGsb7bZ7qm418 Ah6jDNkWkCJ43yj7sTV2meikO39brSgr0zQEhjHRFDMkeNGiL1AhlQj2IeWLNPf31Fn+ 0RfnIJEuspaxc2xvBXjENz/xlDJKcdqosnX+UYtHck5OAXbHiHflJIryLMkgIlZjy35t 2tHY0dvyx4NawiyUkKOOk7H+hJOiYZRKPf6aOgjfP+QMuNjkOfAHuAi+ckKGEeQnfqCp VTNrmEgcMaXqlidB50LlCOc88DErSoLhbVyBYayRZ6/kCwzJPpddTrVv8fARP2ZnOhUe uRmw== Received: by 10.182.114.3 with SMTP id jc3mr5224750obb.18.1332342878431; Wed, 21 Mar 2012 08:14:38 -0700 (PDT) Received: from [192.168.0.108] (cpe-70-123-132-139.austin.res.rr.com. [70.123.132.139]) by mx.google.com with ESMTPS id d9sm1836011obq.0.2012.03.21.08.14.36 (version=TLSv1/SSLv3 cipher=OTHER); Wed, 21 Mar 2012 08:14:37 -0700 (PDT) Message-ID: <4F69F05B.5010500@codemonkey.ws> Date: Wed, 21 Mar 2012 10:14:35 -0500 From: Anthony Liguori User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.2) Gecko/20120216 Thunderbird/10.0.2 MIME-Version: 1.0 To: "Michael S. Tsirkin" References: <1332133163-7890-1-git-send-email-david@gibson.dropbear.id.au> <20120319113310.GD30033@stefanha-thinkpad.localdomain> <20120320004206.GB22089@truffala.fritz.box> <20120320101947.GA19542@truffala.fritz.box> <20120321112615.GA15090@stefanha-thinkpad.localdomain> <20120321130852.GC21467@redhat.com> <4F69E8E1.8050004@codemonkey.ws> <20120321151043.GA22707@redhat.com> In-Reply-To: <20120321151043.GA22707@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Gm-Message-State: ALoCoQnyH2Hs29EmBrc9FeCWKbJsZ6e1PJT1SbQcJptqlPceBNEvQdHl7XrEfHNmqNDRc6xW05Oo X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 209.85.214.173 Cc: qemu-trivial@nongnu.org, Rusty Russell , qemu-devel@nongnu.org Subject: Re: [Qemu-trivial] [Qemu-devel] [PATCH] Remove PCI class code from virtio balloon device 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: Wed, 21 Mar 2012 15:14:48 -0000 On 03/21/2012 10:10 AM, Michael S. Tsirkin wrote: > On Wed, Mar 21, 2012 at 09:42:41AM -0500, Anthony Liguori wrote: >> On 03/21/2012 08:08 AM, Michael S. Tsirkin wrote: >>> On Wed, Mar 21, 2012 at 11:26:15AM +0000, Stefan Hajnoczi wrote: >>>> On Tue, Mar 20, 2012 at 09:19:47PM +1100, David Gibson wrote: >>>> Looking at hw/pc_piix.c there are QEMUMachine types for each QEMU >>>> release. Legacy machine types (e.g. pc_machine_v0_14) have a >>>> .compat_props array that can override qdev properties. >>>> >>>> Perhaps Michael Tsirkin or someone else can comment on how to wire up >>>> hw/virtio-pci.c so that the class code can be overridden. >>>> >>>> Stefan >>> >>> afaik we already let users over-write it for some other pci devices, >>> look there for examples. >> >> From hw/pc_piix.c: >> >> .name = "pc-0.10", >> .desc = "Standard PC, qemu 0.10", >> .init = pc_init_pci_no_kvmclock, >> .max_cpus = 255, >> .compat_props = (GlobalProperty[]) { >> { >> .driver = "virtio-blk-pci", >> .property = "class", >> .value = stringify(PCI_CLASS_STORAGE_OTHER), >> },{ >> >> And from the earlier part of the thread, yes, it's imperative that >> we do not change anything in the PCI configuration space for older >> pc versions regardless of whether it may or may not work. >> >> Certain guests (like Windows) use a complex fingerprinting algorithm >> to determine when hardware changes. It can be hard to detect in >> simple testing because it's based on a threshold. >> >> Regards, >> >> Anthony Liguori > > Which reminds me - qemu sticks the release version in > guest visible places like CPU version. > This is wrong and causes windows guests to print messages > about driver updates when you switch. > We should find all these places and stop doing this. We could probably get away with doing a query/replace of QEMU_VERSION with qemu_get_version(), make version a static variable that defaults to QEMU_VERSION, and then provide a way for machines to override it. Then pc-0.10 could report a version of 0.10. Regards, Anthony Liguori >>> >>>