Il 22/08/2012 13:04, Cong Meng ha scritto: >> >> Cong, what is the limit that the host HBA enforces (and what is the >> HBA)? What commands see a problem? Is it fixed by using scsi-block >> instead of scsi-generic (if you can use scsi-block at all, i.e. it's not >> a tape or similar device)? >> > I don't see real problem caused by the the queue limits actually. It's a > bug which Stefan told me.
I'd rather avoid patching the specification if not to solve real (rather than known-but-theoretical) problems. >> With scsi-generic, QEMU uses a bounce buffer for non-I/O commands to a >> SCSI passthrough device, so the only problem in that case should be the >> maximum segment size. This could change in the future, but max_segments >> and max_sectors should not yet be a problem. > > about bounce buffer, do you meat the buffer allocated in > scsi_send_command() of hw/scsi-generic.c? Yes. Paolo
