[SeaBIOS] Re: [PATCH v6 0/8] Add Qemu to SeaBIOS LCHS interface

[Sam Eiderman]

Gentle ping

On Wed, Sep 11, 2019 at 5:36 PM Sam Eiderman  wrote:
> Gentle ping
>
> On Tue, Aug 27, 2019, 11:24 Sam Eiderman  wrote:
> > v1:
> >
> > Non-standard logical geometries break under QEMU.
> >
> > A virtual disk which contains an operating system which depends on
> > logical geometries (consistent values being reported from BIOS INT13
> > AH=08) will most likely break under QEMU/SeaBIOS if it has non-standard
> > logical geometries - for example 56 SPT (sectors per track).
> > No matter what QEMU will guess - SeaBIOS, for large enough disks - will
> > use LBA translation, which will report 63 SPT instead.
> >
> > In addition we can not enforce SeaBIOS to rely on phyiscal geometries at
> > all. A virtio-blk-pci virtual disk with 255 phyiscal heads can not
> > report more than 16 physical heads when moved to an IDE controller, the
> > ATA spec allows a maximum of 16 heads - this is an artifact of
> > virtualization.
> >
> > By supplying the logical geometies directly we are able to support such
> > "exotic" disks.
> >
> > We will use fw_cfg to do just that.
> >
> > v2:
> >
> > Fix missing parenthesis check in
> >     "hd-geo-test: Add tests for lchs override"
> >
> > v3:
> > Rename fw_cfg key to "bios-geometry".
> > Remove "extendible" interface.
> > Add cpu_to_le32 fix as Laszlo suggested or big endian hosts
> > Fix last qtest commit - automatic docker tester for some reason does not have qemu-img set
> >
> > v4:
> > Change fw_cfg interface from mixed textual/binary to textual only
> >
> > v5:
> > Fix line > 80 chars in tests/hd-geo-test.c
> >
> > v6:
> > Small fixes for issues pointed by Max
> > (&conf->conf)->lcyls to conf->conf.lcyls and so on
> > Remove scsi_unrealize from everything other than scsi-hd
> > Add proper include to sysemu.h
> > scsi_device_unrealize() after scsi_device_purge_requests()
> >
> > Sam Eiderman (8):
> >   block: Refactor macros - fix tabbing
> >   block: Support providing LCHS from user
> >   bootdevice: Add interface to gather LCHS
> >   scsi: Propagate unrealize() callback to scsi-hd
> >   bootdevice: Gather LCHS from all relevant devices
> >   bootdevice: Refactor get_boot_devices_list
> >   bootdevice: FW_CFG interface for LCHS values
> >   hd-geo-test: Add tests for lchs override
> >
> > bootdevice.c             | 148 ++++++++--
> >  hw/block/virtio-blk.c    |   6 +
> >  hw/ide/qdev.c            |   7 +-
> >  hw/nvram/fw_cfg.c        |  14 +-
> >  hw/scsi/scsi-bus.c       |  16 ++
> >  hw/scsi/scsi-disk.c      |  12 +
> >  include/hw/block/block.h |  22 +-
> >  include/hw/scsi/scsi.h   |   1 +
> >  include/sysemu/sysemu.h  |   4 +
> >  tests/Makefile.include   |   2 +-
> >  tests/hd-geo-test.c      | 582 +++++++++++++++++++++++++++++++++++++++
> >  11 files changed, 773 insertions(+), 41 deletions(-)