VirtualBox

Ticket #9941 (closed defect: fixed)

Opened 2 years ago

Last modified 2 years ago

fixed in svn: pxe boot fails if vt-x/amd-v is enabled

Reported by: crissi Owned by:
Priority: major Component: VMM/HWACCM
Version: VirtualBox 4.1.6 Keywords: pxe hang, vt-x
Cc: Guest type: other
Host type: Linux

Description (last modified by michaln) (diff)

if vt-x/amd-v is enabled pxe hangs. I bridged eth0 with the client network card.

see attached image.

Attachments

vbox_pxe_boot_hang.png Download (20.5 KB) - added by crissi 2 years ago.
vbox mainwindow showing where pxe boot hangs
vbox_pxe_boot_boot2.png Download (23.3 KB) - added by crissi 2 years ago.
successful pxe boot if if vt-x/amd-v is disabled
VBox.log Download (81.6 KB) - added by crissi 2 years ago.
TFTP.tar.gz Download (69.2 KB) - added by michaln 2 years ago.
TFTP files needed to reproduce problem

Change History

Changed 2 years ago by crissi

vbox mainwindow showing where pxe boot hangs

comment:1 Changed 2 years ago by crissi

if if vt-x/amd-v is disabled pxe does boot fine.

Changed 2 years ago by crissi

successful pxe boot if if vt-x/amd-v is disabled

comment:2 follow-up: ↓ 3 Changed 2 years ago by Hachiman

Could you please attach the log of hanging session?

comment:3 in reply to: ↑ 2 ; follow-up: ↓ 4 Changed 2 years ago by crissi

Replying to Hachiman:

Could you please attach the log of hanging session?

what log? nicetrace? if you want that, tell me a mail where i have send directly.

comment:4 in reply to: ↑ 3 Changed 2 years ago by Hachiman

Replying to crissi:

Replying to Hachiman:

Could you please attach the log of hanging session?

what log? nicetrace? if you want that, tell me a mail where i have send directly.

please look at  http://www.virtualbox.org/manual/ch12.html#idp10077472 for more details.

Changed 2 years ago by crissi

Changed 2 years ago by michaln

TFTP files needed to reproduce problem

comment:5 Changed 2 years ago by michaln

  • Keywords vt-x added; vt-x/amd-v removed
  • Component changed from network to VMM/HWACCM
  • Description modified (diff)
  • Guest type changed from Linux to other

User crissi provided files needed to reproduce the problem. That was very helpful. Confirmed the hang here with PXE over NAT.

The actual problem is completely unrelated to networking. It's greatly contributed to gPXE's creative use of big real mode, A20 control, and similar horrors.

From what I can tell, gPXE sets up big real mode which doesn't work quite right in VirtualBox only on Intel CPUs with old VT-x implementations with no unrestricted execution support (when VT-x is used). I haven't tried but doubt that AMD-V is affected.

I changed the ticket to reflect the situation. The guest type is in fact not Linux here, it's gPXE doing awful things to the poor little CPU.

comment:6 Changed 2 years ago by michaln

  • Status changed from new to closed
  • Resolution set to fixed
  • Summary changed from pxe boot fails if vt-x/amd-v is enabled to fixed in svn: pxe boot fails if vt-x/amd-v is enabled

This is now fixed but not yet part of any official release.

As I noted in the previous comment, the issue has nothing to do with networking or PXE, it's specific to unreal mode handling on older VT-x capable CPUs.

Note: See TracTickets for help on using tickets.

www.oracle.com
ContactPrivacy policyTerms of Use