Hi Martin, I'll let Nic comment on your patch. However, I should point out that we're now shipping a Beta version of LIO with VAAI support (COMPARE_AND_WRITE and BLOCK_ZERO, EXTENDED_COPY is being added). This comes with our RTS OS Enterprise Edition. Perhaps you might be interested in that, too. Thanks much. Best regards, Marc Fleischmann risingtidesystems.com | 650.384.6366 -----Original Message----- From: target-devel-owner@xxxxxxxxxxxxxxx [mailto:target-devel-owner@xxxxxxxxxxxxxxx] On Behalf Of Martin Svec Sent: Monday, February 06, 2012 4:25 AM To: Nicholas A. Bellinger Cc: Sven Lüder; target-devel@xxxxxxxxxxxxxxx; 'Christoph Hellwig' Subject: Re: VMware ESXi 5 and LIO target: "WRITE_SAME w/o UNMAP bit not supported for Block Discard Emulation" Hello Nicholas, is there any follow-up regarding the WRITE SAME support required by ESXi 5? Although it is possible to globally disable hardware I/O acceleration on ESXi hosts, this is not a solution if we want to use LIO and enterprise arrays in the same environment. Yesterday, I played with ESXi 5 for a while and tried a workaround that seems to fix it. If transport_generic_cmd_sequencer() returns sense reason TCM_UNSUPPORTED_SCSI_OPCODE instead of TCM_INVALID_CDB_FIELD, ESXi sends WRITE SAME only once and then (probably) falls back to non-accelerated block zeroing. The patch is below. Unfortunately I've found no relevant VMware docs about hardware acceleration requirements in ESXi 5, except for the general announcements that ESXi 5 uses standardized T10 versions of WRITE SAME, XCOPY and COMPARE AND WRITE. So I still don't know if this is the right way to tell ESXi initiator that we don't support block zeroing offload. Best regards Martin --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -2665,7 +2665,7 @@ static int transport_generic_cmd_sequencer( cmd->se_cmd_flags |= SCF_SCSI_CONTROL_SG_IO_CDB; if (target_check_write_same_discard(&cdb[10], dev) < 0) - goto out_invalid_cdb_field; + goto out_unsupported_cdb; if (!passthrough) cmd->execute_task = target_emulate_write_same; break; @@ -2948,7 +2948,7 @@ static int transport_generic_cmd_sequencer( cmd->se_cmd_flags |= SCF_SCSI_CONTROL_SG_IO_CDB; if (target_check_write_same_discard(&cdb[1], dev) < 0) - goto out_invalid_cdb_field; + goto out_unsupported_cdb; if (!passthrough) cmd->execute_task = target_emulate_write_same; break; @@ -2971,7 +2971,7 @@ static int transport_generic_cmd_sequencer( * of byte 1 bit 3 UNMAP instead of original reserved field */ if (target_check_write_same_discard(&cdb[1], dev) < 0) - goto out_invalid_cdb_field; + goto out_unsupported_cdb; if (!passthrough) cmd->execute_task = target_emulate_write_same; break; -- To unsubscribe from this list: send the line "unsubscribe target-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe target-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
