From: Simon Glass <sjg(a)chromium.org>
It is often possible to use virtio-blk for block devices, but it is
less flexible than SCSI. SCSI provides a means to probe for multiple
disks through the same interface. It also supports hotplug and other
features.
This series adds a simple virtio-scsi driver for use with QEMU. The new
driver creates a SCSI bus when the virtio buses are scanned. That can be
scanned in turn, using 'scsi scan', to find the available virtio disks.
For this to work, quite a few minor updates are needed in the SCSI
implementation:
- Increase the buffer sizes for commands and sense buffer
- Fix off-by-one error when scanning for devices
- Use REPORT LUN to determine what LUNs are present for a target
- Clean up some open-coded constants
- Make use of a struct to decode the IDENTIFY response
- Clean up of the confusing and error-prone SCSI read/write functions
- Add support for using a scsi disk to the build-qemu/efi scripts
When a SCSI disk is inaccessible (e.g. the LUN is wrong), this is seldom
reported as an error. For example 'part list' does not say 'read error'
but 'unsupported partition type'. Probing the block device results in
each partition-type driver reading blocks, none of which reports the
error. So an attempt is made here to clean this up, so that bad LUNs
show an error.
Another clean-up is to show partition numbers in hex with 'part list',
since the current approach conflicts with the 'part' command.
Some additional x86 debugging is added for the jump from SPL to U-Boot
proper, since this can be confusing when it fails in QEMU.
With all of the above, virtio-scsi can be used on qemu-x86_64 for
loading an OS and associated files, including with standard boot.
Simon Glass (26):
x86: Show jump address in SPL when debugging
x86: Add some info on the memory map
scripts: Move root-disk processing to helper
scripts: Support a root disk connected via virtio-scsi
part: Detect errors when reading partition tables
part: Show partition numbers in hex
scsi: Expand the maximum buffer sizes
scsi: Add a constant for the tempbuff size
scsi: Fix off-by-one error when scanning
scsi: Use hex in block-device names
scsi: Use REPORT LUNS to scan the correct number of LUNs
scsi: Provide some response flags
scsi: Use a struct to decode the inquiry response
scsi: Rename block_dev and dev_desc to desc
scsi: Create a function to add command and LUN to the ccb
scsi: Only add the LUN to the command if needed
scsi: Check SCSI spec version for LUN handling
scsi: Tidy up error returns for read/write
scsi: Use a variable for the number of blocks to process
scsi: Reorder the local variables
scsi: Use mapmem functions
scsi: Move loop counters down next to the loop
scsi: Adjust loop counters once in the loop
virtio: Bring in the virtio_scsi header
virtio: Add support for virtio-scsi
virtio: Add debugging of driver features and device type
arch/x86/lib/spl.c | 8 +-
disk/part.c | 28 ++-
disk/part_amiga.c | 2 +-
disk/part_dos.c | 15 +-
disk/part_efi.c | 20 +-
disk/part_iso.c | 18 +-
disk/part_mac.c | 16 +-
doc/arch/x86/x86.rst | 17 ++
drivers/block/blk-uclass.c | 3 +-
drivers/block/ide.c | 3 +-
drivers/scsi/scsi.c | 348 +++++++++++++++++++++------------
drivers/virtio/Kconfig | 12 ++
drivers/virtio/Makefile | 1 +
drivers/virtio/virtio-uclass.c | 6 +-
drivers/virtio/virtio_scsi.c | 249 +++++++++++++++++++++++
drivers/virtio/virtio_scsi.h | 175 +++++++++++++++++
include/blk.h | 1 +
include/dt-bindings/virtio.h | 1 +
include/part.h | 15 +-
include/scsi.h | 24 ++-
include/virtio.h | 1 +
scripts/build-efi | 9 -
scripts/build-qemu | 11 +-
scripts/build_helper.py | 19 ++
24 files changed, 817 insertions(+), 185 deletions(-)
create mode 100644 drivers/virtio/virtio_scsi.c
create mode 100644 drivers/virtio/virtio_scsi.h
--
2.43.0
base-commit: 08a84c7cc73841f24dcdebe876b1aad7c8058890
branch: qeme
