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
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 | 15 ++
hw/scsi/scsi-disk.c | 14 ++
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, 774 insertions(+), 41 deletions(-)
--
2.13.3
