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 <rka...@virtuozzo.com> > >> > >>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 <rka...@virtuozzo.com> > >>Signed-off-by: Denis V. Lunev <d...@openvz.org> > >>CC: Michael S. Tsirkin <m...@redhat.com> > >>CC: Igor Mammedov <imamm...@redhat.com> > >>CC: Paolo Bonzini <pbonz...@redhat.com> > >>CC: Richard Henderson <r...@twiddle.net> > >>CC: Eduardo Habkost <ehabk...@redhat.com> > >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