For accessing single blocks during boot, it's the logical block size that
matters. (Physical block sizes are rather interesting e.g. for creating
file systems with the correct alignment for speed reasons etc.).
So the s390-ccw bios has to use the logical block size for calculating
sector numbers during the boot phase, the "physical_block_exp" shift
value must not be taken into account. This change fixes the boot process
when the guest hast been installed on a disk where the logical block size
differs from the physical one, e.g. if the guest has been installed
like this:
qemu-system-s390x -nographic -accel kvm -m 2G \
-drive if=none,id=d1,file=fedora.iso,format=raw,media=cdrom \
-device virtio-scsi -device scsi-cd,drive=d1 \
-drive if=none,id=d2,file=test.qcow2,format=qcow2
-device virtio-blk,drive=d2,physical_block_size=4096,logical_block_size=512
Linux correctly uses the logical block size of 512 for the installation,
but the s390-ccw bios tries to boot from a disk with 4096 block size so
far, as long as this patch has not been applied yet (well, it used to work
by accident in the past due to the virtio_assume_scsi() hack that used to
enforce 512 byte sectors on all virtio-block disks, but that hack has been
well removed in commit 5447de2619 to fix other scenarios).
Fixes: 5447de2619 ("pc-bios/s390-ccw/virtio-blkdev: Remove virtio_assume_scsi()")
Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=2112303
Message-Id: <20220805094214.285223-1-thuth@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
The virtio-blk code uses the block size and geometry fields in the
config area. According to the virtio-spec, these have to be negotiated
with the right feature bits during initialization, otherwise they
might not be available. QEMU is so far very forgiving and always
provides them, but we should not rely on this behavior, so let's
better request them properly via the VIRTIO_BLK_F_GEOMETRY and
VIRTIO_BLK_F_BLK_SIZE feature bits.
Message-Id: <20220704111903.62400-11-thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
The next patch is going to add more virtio-block specific code to
virtio_blk_setup_device(), and if the virtio-scsi code is also in
there, this is more cumbersome. And the calling function virtio_setup()
in main.c looks at the device type already anyway, so it's more
logical to separate the virtio-scsi stuff into a new function in
virtio-scsi.c instead.
Message-Id: <20220704111903.62400-10-thuth@redhat.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
The virtio_assume_scsi() function is very questionable: First, it
is only called for virtio-blk, and not for virtio-scsi, so the naming
is already quite confusing. Second, it is called if we detected a
"invalid" IPL disk, trying to fix it by blindly setting a sector
size of 512. This of course won't work in most cases since disks
might have a different sector size for a reason.
Thus let's remove this strange function now. The calling code can
also be removed completely, since there is another spot in main.c
that does "IPL_assert(virtio_ipl_disk_is_valid(), ...)" to make
sure that we do not try to IPL from an invalid device.
Message-Id: <20220704111903.62400-6-thuth@redhat.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
The s390-ccw bios fails to boot if the boot disk is a virtio-blk
disk with a sector size of 4096. For example:
dasdfmt -b 4096 -d cdl -y -p -M quick /dev/dasdX
fdasd -a /dev/dasdX
install a guest onto /dev/dasdX1 using virtio-blk
qemu-system-s390x -nographic -hda /dev/dasdX1
The bios then bails out with:
! Cannot read block 0 !
Looking at virtio_ipl_disk_is_valid() and especially the function
virtio_disk_is_scsi(), it does not really make sense that we expect
only such a limited disk geometry (like a block size of 512) for
our boot disks. Let's relax the check and allow everything that
remotely looks like a sane disk.
Message-Id: <20220704111903.62400-5-thuth@redhat.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Use VIRTIO_DASD_DEFAULT_BLOCK_SIZE instead of the magic value 4096.
Message-Id: <20220704111903.62400-3-thuth@redhat.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
In case the user did not specify a boot device, we want to continue
looking for other devices if there are no valid SCSI disks on a virtio-
scsi controller. As a first step, do not panic in this case and let
the control flow carry the error to the upper functions instead.
Message-Id: <20200806105349.632-6-thuth@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
The netboot code is going to link against the code from virtio.c, too, so
we've got to move the virtio-block and -scsi related code out of the way.
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <1499863793-18627-4-git-send-email-thuth@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
