kern/103130: reenable tagged queueing of VMware virtual SCSI disk.

[Shusuke SHINOMIYA]

>Number:         103130
>Category:       kern
>Synopsis:       reenable tagged queueing of VMware virtual SCSI disk.
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          update
>Submitter-Id:   current-users
>Arrival-Date:   Mon Sep 11 09:50:26 GMT 2006
>Closed-Date:
>Last-Modified:
>Originator:     Shusuke SHINOMIYA
>Release:        FreeBSD 5.5-STABLE
>Organization:
Tokyo Institute of Technology
>Environment:
FreeBSD attacker.noc.titech.ac.jp 5.5-STABLE FreeBSD 5.5-STABLE #16: Fri Sep  8 17:45:56 JST 2006     root at attacker.noc.titech.ac.jp:/usr/obj/usr/src/sys/VMWARE_FREEBSD5  i386

>Description:
 Tagged queueing feature of a VMware virtual disk connected with SCSI
has been disabled since the cam quirk was added at Jun 26 05:42:26 2006 in RELENG_5 branch.
# this quirk is needed to find the drive by SCSI HA.
>How-To-Repeat:
boot up a FreeBSD on a VMware Virtual Machine of which hard drive is connected with SCSI.

Tagged queueing feature is not available as shown the following.

da0 at mpt0 bus 0 target 0 lun 0
da0: <VMware Virtual disk 1.0> Fixed Direct Access SCSI-2 device
da0: 80.000MB/s transfers (40.000MHz, offset 127, 16bit)
da0: 8192MB (16777216 512 byte sectors: 255H 63S/T 1044C)

>Fix:
apply following patch to sys/cam/cam_xpt.c. this patch is for RELENG_5.

--- sys/cam/cam_xpt.c.orig      Fri Sep  8 18:10:14 2006
+++ sys/cam/cam_xpt.c   Fri Sep  8 17:43:57 2006
@@ -359,7 +359,7 @@
        {
                /* Does not support other than LUN 0 */
                { T_DIRECT, SIP_MEDIA_FIXED, "VMware*", "*", "*" },
-               CAM_QUIRK_NOLUNS, /*mintags*/0, /*maxtags*/0
+               CAM_QUIRK_NOLUNS, /*mintags*/2, /*maxtags*/255
        },


>Release-Note:
>Audit-Trail:
>Unformatted: