While investigating another bug report, I tried booting my WinXP VM with the CD assigned to the host and with pass-through enabled. The CD drive is empty. The typical 25-30 sec until the WinXP login prompt took more than 10 min! Taking a look at the log, I saw these messages:
followed by a barrage of messages that keep repeating for about 10 minutes:00:00:05.995355 PIIX3 ATA: LUN#2: CD-ROM passthrough cmd=0x28 sense=2 ASC=0x3a ASCQ=0x2 VERR_DEV_IO_ERROR ... 00:00:14.857562 PIIX3 ATA: LUN#2: CD-ROM passthrough cmd=0x5a sense=5 ASC=0x24 ASCQ=0x0 VERR_DEV_IO_ERROR
This happens with two of my guests, a WinXP and a WinNT4. Does not happen with W2K, Win7, Win8, Win10. It does not happen with OSX or Linux guests. Just these two VMs.00:00:43.913699 PIIX3 ATA: Ctl#1: RESET, DevSel=0 AIOIf=0 CmdIf0=0xa0 (3996390 usec ago) CmdIf1=0x00 (-1 usec ago) 00:00:43.913767 PIIX3 ATA: Ctl#1: finished processing RESET 00:00:43.913812 PIIX3 ATA: LUN#2: performing device RESET ... 00:10:19.913857 PIIX3 ATA: Ctl#1: RESET, DevSel=0 AIOIf=0 CmdIf0=0xa0 (3997062 usec ago) CmdIf1=0x00 (-1 usec ago) 00:10:19.913925 PIIX3 ATA: Ctl#1: finished processing RESET 00:10:19.913965 PIIX3 ATA: LUN#2: performing device RESET
Oh, I almost forgot. I went back several versions of VBox and I saw it happening all the way to 4.3(.0). It does not happen with 4.2.26. I didn't try any earlier versions. I'll keep on testing, including the remaining of my VMs (about 20) as well as different versions of VBox.
Attaching the logs from WinXP, one with pass-through enabled and one with it disabled. Anyone else has seen this?