[Virtio-SCSI] Drives not detected, access errors

[dasebek]

If I connect a single Virtio-SCSI virtual drive to a KVM virtual machine and make sure that its address is specified as controller 0, bus 0, target 0, unit 0, it seems to work well. But if I connect the drive to another port or if I connect multiple Virtio-SCSI drives, Haiku has problems recognizing those drives. And even if those drives appear in the DriveSetup app, only at most one of the drives works, while others give errors when attempting a read or write access.

This bug affects both R1/beta2 and current nightlies (hrev55184). I am using x86_64 Haiku versions. If I set up the virtual machine to use a chipset other than i440FX or if I enable UEFI, Virtio-SCSI drives are not detected at all.