kern/142724: [ada] camcontrol readcap shows inadequately high numbers in VBox

[pluknet]

>Number:         142724
>Category:       kern
>Synopsis:       [ada] camcontrol readcap shows inadequately high numbers in VBox
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Mon Jan 11 19:10:07 UTC 2010
>Closed-Date:
>Last-Modified:
>Originator:     pluknet
>Release:        8.0-STABLE, 9.0-CURRENT
>Organization:
>Environment:
c8-vb.h3 8.0-STABLE #0: Web Dec 30
c9-vb.h3 9.0-CURRENT #0: Sat Jan 9
>Description:
camcontrol readcap shows inadequately high numbers in VirtualBox
when using with ada disks.

dmesg shows correct disk size:

c9-vb# camcontrol readcap ada0
Last Block: 539522796, Block Length: 3216968941 bytes
c9-vb# dmesg | grep ada
ada0 at ahcich0 bus 0 scbus0 target 0 lun 0
ada0: <VBOX HARDDISK 1.0> ATA-6 SATA 2.x device
ada0: 300.000MB/s transfers (SATA 2.x, UDMA6, PIO size 8192bytes)
ada0: Command Queueing enabled
ada0: 10240MB (20971520 512 byte sectors: 16H 63S/T 16383C)

Though, if running without ahci driver (in legacy ata mode, where
ada0 became ad4), a similar atacontrol command prints correct
(it equals to detected disk size above for ada0):

c8-vb# atacontrol cap ad4 | grep sectors$
lba supported        20971520 sectors
lba48 supported        20971520 sectors

The behavior is identical on both 8.0-STABLE and current.
>How-To-Repeat:
VBox guest with installed FreeBSD 8.0 or above
camcontrol readcap ada0
>Fix:


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