Merge remote-tracking branch 'bonzini/virtio-scsi' into staging

Merge remote-tracking branch 'bonzini/virtio-scsi' into staging

* bonzini/virtio-scsi:
  scsi-block: always use scsi_generic_ops for cache != none
  scsi: fix searching for an empty id
  scsi: fix wrong return for target INQUIRY
  virtio-scsi: add migration support
  virtio-scsi: process control queue requests
  virtio-scsi: add basic SCSI bus operation
  virtio-scsi: Add basic request processing infrastructure
  virtio-scsi: Add virtio-scsi stub device
  scsi-disk: add migration support
  scsi-generic: add migration support
  scsi: add SCSIDevice vmstate definitions
  scsi-disk: enable scatter/gather functionality
  scsi: add scatter/gather functionality
  scsi: pass residual amount to command_complete
  ahci: use new DMA helpers
  dma-helpers: add accounting wrappers
  dma-helpers: add dma_buf_read and dma_buf_write
  dma-helpers: make QEMUSGList target independent