Opened 13 years ago
Closed 13 years ago
#9941 closed defect (fixed)
fixed in svn: pxe boot fails if vt-x/amd-v is enabled
| Reported by: | Christoph Thielecke | Owned by: | |
|---|---|---|---|
| Component: | VMM/HWACCM | Version: | VirtualBox 4.1.6 |
| Keywords: | pxe hang, vt-x | Cc: | |
| Guest type: | other | Host type: | Linux |
Description (last modified by )
if vt-x/amd-v is enabled pxe hangs. I bridged eth0 with the client network card.
see attached image.
Attachments (4)
Change History (10)
by , 13 years ago
| Attachment: | vbox_pxe_boot_hang.png added |
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by , 13 years ago
| Attachment: | vbox_pxe_boot_boot2.png added |
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successful pxe boot if if vt-x/amd-v is disabled
follow-up: 4 comment:3 by , 13 years ago
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 by , 13 years ago
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.
by , 13 years ago
comment:5 by , 13 years ago
| Component: | network → VMM/HWACCM |
|---|---|
| Description: | modified (diff) |
| Guest type: | Linux → other |
| Keywords: | vt-x added; vt-x/amd-v removed |
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 by , 13 years ago
| Resolution: | → fixed |
|---|---|
| Status: | new → closed |
| Summary: | pxe boot fails if vt-x/amd-v is enabled → 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.
vbox mainwindow showing where pxe boot hangs