From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36227) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a8U0e-0001AG-3I for qemu-devel@nongnu.org; Mon, 14 Dec 2015 09:22:05 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1a8U0J-0002ee-VB for qemu-devel@nongnu.org; Mon, 14 Dec 2015 09:21:51 -0500 Received: from mx1.redhat.com ([209.132.183.28]:50879) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a8U0J-0002eR-LO for qemu-devel@nongnu.org; Mon, 14 Dec 2015 09:21:31 -0500 Date: Mon, 14 Dec 2015 16:21:27 +0200 From: "Michael S. Tsirkin" Message-ID: <20151214161950-mutt-send-email-mst@redhat.com> References: <1450081359-7753-1-git-send-email-den@openvz.org> <20151214112012-mutt-send-email-mst@redhat.com> <566E8B39.5070202@openvz.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <566E8B39.5070202@openvz.org> Subject: Re: [Qemu-devel] [PATCH for 2.5? 1/1] DSDT: add floppy-related objects List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Denis V. Lunev" Cc: Eduardo Habkost , qemu-devel@nongnu.org, Roman Kagan , Paolo Bonzini , Igor Mammedov , Richard Henderson On Mon, Dec 14, 2015 at 12:26:17PM +0300, Denis V. Lunev wrote: > On 12/14/2015 12:21 PM, Michael S. Tsirkin wrote: > >On Mon, Dec 14, 2015 at 11:22:39AM +0300, Denis V. Lunev wrote: > >>From: Roman Kagan > >> > >>On x86-based systems Linux determines the presence and the type of > >>floppy drives via a query of a CMOS field. So does SeaBIOS when > >>populating the return data for int 0x13 function 0x08. > >> > >>Windows doesn't; instead, it requests this information from BIOS via int > >>0x13/0x08 or through ACPI objects _FDE (Floppy Drive Enumerate) and _FDI > >>(Floppy Drive Information). On UEFI systems only ACPI-based detection > >>is supported. > >> > >>QEMU used not to provide those objects in its DSDT; as a result floppy > >>drives were invisible to Windows on UEFI/OVMF. > >> > >>This patch implements those objects in ASL, making the ACPI interpreter > >>query the CMOS field and populate the objects. The data values used for > >>_FDI (which, per ACPI spec, is supposed to be equivalent to BIOS int > >>0x13/0x08) are taken from SeaBIOS. > >> > >>Signed-off-by: Roman Kagan > >>Signed-off-by: Denis V. Lunev > >>CC: Michael S. Tsirkin > >>CC: Igor Mammedov > >>CC: Paolo Bonzini > >>CC: Richard Henderson > >>CC: Eduardo Habkost > >This is not a regression, so I'm inclined not to merge this for 2.5. > >Pls correct me if I'm wrong. > > > > this was a question actually. > > Yes, this is not a regression but user observable bug. The floppy > is not available in Windows UEFI guests and it is not that easy > to get VirtIO drivers in this case installed especially for root > disk. > > Den So it's an important patch but I don't think it's a showstopper for 2.5, and this is too risky to merge without doing another rc. This can go into 2.5.1 perhaps. -- MST