Re: [Qemu-devel] Re: [PATCH 1/2] [scsi-bus]: Add PR-OUT and PR-IN case for SCSIRequest xfer and xfer_mode setup

["Nicholas A. Bellinger" <nab@linux-iscsi.org>]

On Wed, 2010-06-16 at 06:03 -0700, Nicholas A. Bellinger wrote:
> On Wed, 2010-06-16 at 14:13 +0200, Kevin Wolf wrote:
> > Am 04.06.2010 16:06, schrieb Kevin Wolf:
> > > Am 31.05.2010 03:43, schrieb Nicholas A. Bellinger:
> > >> From: Nicholas Bellinger <nab@linux-iscsi.org>
> > >>
> > >> This patch updates hw/scsi-bus.c to add PERSISTENT_RESERVE_OUT and PERSISTENT_RESERVE_IN
> > >> case in scsi_req_length() to extra the incoming buffer length into SCSIRequest->cmd.xfer,
> > >> and adds a second PERSISTENT_RESERVE_OUT case in scsi_req_xfer_mode() in order to properly
> > >> set SCSI_XFER_TO_DEV for WRITE data.
> > >>
> > >> Tested with Linux KVM guests and Megasas 8708EM2 HBA emulation and TCM_Loop target ports.
> > >>
> > >> Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
> > >> ---
> > >>  hw/scsi-bus.c |    5 +++++
> > >>  1 files changed, 5 insertions(+), 0 deletions(-)
> > >>
> > >> diff --git a/hw/scsi-bus.c b/hw/scsi-bus.c
> > >> index b8e4b71..75ec74e 100644
> > >> --- a/hw/scsi-bus.c
> > >> +++ b/hw/scsi-bus.c
> > >> @@ -325,6 +325,10 @@ static int scsi_req_length(SCSIRequest *req, uint8_t *cmd)
> > >>      case INQUIRY:
> > >>          req->cmd.xfer = cmd[4] | (cmd[3] << 8);
> > >>          break;
> > >> +    case PERSISTENT_RESERVE_OUT:
> > >> +    case PERSISTENT_RESERVE_IN:
> > >> +        req->cmd.xfer = cmd[8] | (cmd[7] << 8);
> > > 
> > > Maybe I'm missing something, but isn't exactly the same value set in the
> > > switch block above? (for cmd[0] >> 5 == 2)
> > 
> > Nicholas? This isn't applied yet because I'm waiting for your answer.
> > 
> > Is there a reason why it makes sense to do it explicitly here instead
> > using the generic code a few lines above? I think the same applied to
> > patch 2/2.
> 
> Hi Kevin,
> 
> I just tested this again and you are correct, the reassignment of
> req->cmd.xfer for PR and Maintence CDBs is unnecessary in
> scsi_req_length().  I will go ahead and drop part this from my tree.
> 
> Please let me know if you would like me to resend the patch series.
> 

Actually, I should mention that I have only tested this with TYPE_DISK
so far.  I think we do still need the Maintenance CDBs length
reassignment for MMC and TYPE_ROM from the second patch:

diff --git a/hw/scsi-bus.c b/hw/scsi-bus.c
index 75ec74e..7d80405 100644
--- a/hw/scsi-bus.c
+++ b/hw/scsi-bus.c
@@ -329,6 +329,17 @@ static int scsi_req_length(SCSIRequest *req, uint8_t *cmd)
     case PERSISTENT_RESERVE_IN:
         req->cmd.xfer = cmd[8] | (cmd[7] << 8);
         break;
+    case MAINTENANCE_OUT:
+    case MAINTENANCE_IN:
+        if (req->dev->type != TYPE_ROM) {
+            /* Used for MI_REPORT_TARGET_PGS, MO_SET_TARGET_PGS et al. */
+            req->cmd.xfer = cmd[9] | (cmd[8] << 8) |
+                            (cmd[7] << 16) | (cmd[6] << 24);
+        } else {
+            /* GPCMD_REPORT_KEY and GPCMD_SEND_KEY from multi media commands */
+            req->cmd.xfer = cmd[9] | (cmd[8] << 8);
+        }
+        break;
     }

Do you have a problem with leaving this reassignment in for TYPE_ROM..?

Best,

--nab