9281fe9eea
this patch changes the driver to uses 16 Byte CDBs for READ/WRITE only if the target requires 64bit lba addressing. On one hand this saves 6 bytes in each PDU on the other hand it seems that 10 Byte CDBs seems to be much better supported and tested as a recent issue I had with a major storage supplier lined out. For WRITESAME the logic is a bit more tricky as WRITESAME10 with UNMAP was added really late. Thus a fallback to WRITESAME16 is possible if it supports UNMAP and WRITESAME10 not. Signed-off-by: Peter Lieven <pl@kamp.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>