On Wed, 04/26 16:46, Eric Farman wrote: > The short version of what happens is the host device driver rejects our > requests because the transfer lengths are too long for it to satisfy. > A virtio-scsi disk connected via scsi-generic is fine as a non-boot device > because the guest kernel is able to break up the requests for us. So we just > need to handle this situation for the boot process. > > Patches 2-N in this series do that, but rely on us to specify the max_sectors > parameter for the virtio-scsi-ccw device: > > /usr/bin/qemu-system-s390x ... > -device virtio-scsi-ccw,id=scsi0,devno=fe.0.0001,max_sectors=2048
Can you instead do an INQUIRY from the bios code to check the Block Limits page? The response is intercepted by hw/scsi/scsi-generic.c to merge in the host LUN's limits. That's how Linux kernel finds the granularity for request splitting. That way, patch 1 is not necessary too. I don't like it because it doesn't always work considering LUN hotplug. Fam
