Nested virtualization triggers an extreme amount of flushes

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Hexalt
Posts: 1
Joined: 8. Mar 2023, 17:01

Nested virtualization triggers an extreme amount of flushes

Post by Hexalt »

Versions:
Virtualbox: 7.0.6
Guest additions: 7.0.6r155176
About the VM:
Ubuntu: 20.04.05
Qemu: 4.2.1

Every time I try to start another VM inside my Ubuntu machine using Qemu, a flush message/error will appear repeatedly in the VBox.log file. It happens so frequently the log file will quickly reach an absurd size (over 30gb in less than an hour). The Qemu VMs seem to be running fine despite all this. I have been able to use them without issue.

Here is a sample of the flush message I am getting over and over:

Code: Select all

00:01:03.767220 *FLUSH* idCpu=3 idxLogger=1 idxBuffer=0 cbToFlush=0xeee fFlushed=false cbDropped=0x0
00:01:03.766932 pgmR0BthEPTProtNestedTrap0eHandler: rc=0 GCPhysNestedFault=0x0000000007fbcb42 (0x00000000461bc000) uErr=0x11 cs:rip=0008:07fbcb42
00:01:03.766945 pgmR0BthEPTProtNestedTrap0eHandler: rc=0 GCPhysNestedFault=0x0000000007fbcb42 (0x00000000461bc000) uErr=0x11 cs:rip=0008:07fbcb42
00:01:03.766958 pgmR0BthEPTProtNestedTrap0eHandler: rc=0 GCPhysNestedFault=0x0000000007fbcb42 (0x00000000461bc000) uErr=0x11 cs:rip=0008:07fbcb42
[...]
00:01:03.767232 *FLUSH DONE*

VBoxLogs.zip
(255.46 KiB) Downloaded 8 times
Unfortunately, I am unable to link the complete log despite zipping it (the log file is 10mb despite me running the Qemu VM for only 2 seconds). I removed a few of the repeated errors in the middle of the log file so I could link it here (don't be surprised if you see a jump in the timestamps).

Does anyone have an idea why this is happening? Thanks in advance!
fth0
Volunteer
Posts: 5668
Joined: 14. Feb 2019, 03:06
Primary OS: Mac OS X other
VBox Version: PUEL
Guest OSses: Linux, Windows 10, ...
Location: Germany

Re: Nested virtualization triggers an extreme amount of flushes

Post by fth0 »

Please create a ticket in the Bugtracker.
OlivierBourdy
Posts: 2
Joined: 14. Jun 2023, 14:08

Re: Nested virtualization triggers an extreme amount of flushes

Post by OlivierBourdy »

Hello, I encounter the very same issue with Virtualbox 7.0.8, cf. logs below.
There logs occurs when I try to launch a Qemu in my VM. They can occupy the whole space on my hard drive in one or two hours.

Is there a bug tracking this issue?

Code: Select all

00:05:54.165636 *FLUSH* idCpu=4 idxLogger=1 idxBuffer=3 cbToFlush=0xeee fFlushed=false cbDropped=0x0
00:05:54.165350 pgmR0BthEPTProtNestedTrap0eHandler: rc=0 GCPhysNestedFault=0x00000000bffbbab2 (0x00000002397bb000) uErr=0x11 cs:rip=0008:bffbbab2
00:05:54.165362 pgmR0BthEPTProtNestedTrap0eHandler: rc=0 GCPhysNestedFault=0x00000000bffbbab2 (0x00000002397bb000) uErr=0x11 cs:rip=0008:bffbbab2
00:05:54.165373 pgmR0BthEPTProtNestedTrap0eHandler: rc=0 GCPhysNestedFault=0x00000000bffbbab2 (0x00000002397bb000) uErr=0x11 cs:rip=0008:bffbbab2
00:05:54.165383 pgmR0BthEPTProtNestedTrap0eHandler: rc=0 GCPhysNestedFault=0x00000000bffbbab2 (0x00000002397bb000) uErr=0x11 cs:rip=0008:bffbbab2
00:05:54.165393 pgmR0BthEPTProtNestedTrap0eHandler: rc=0 GCPhysNestedFault=0x00000000bffbbab2 (0x00000002397bb000) uErr=0x11 cs:rip=0008:bffbbab2
00:05:54.165403 pgmR0BthEPTProtNestedTrap0eHandler: rc=0 GCPhysNestedFault=0x00000000bffbbab2 (0x00000002397bb000) uErr=0x11 cs:rip=0008:bffbbab2
00:05:54.165412 pgmR0BthEPTProtNestedTrap0eHandler: rc=0 GCPhysNestedFault=0x00000000bffbbab2 (0x00000002397bb000) uErr=0x11 cs:rip=0008:bffbbab2
00:05:54.165422 pgmR0BthEPTProtNestedTrap0eHandler: rc=0 GCPhysNestedFault=0x00000000bffbbab2 (0x00000002397bb000) uErr=0x11 cs:rip=0008:bffbbab2
00:05:54.165433 pgmR0BthEPTProtNestedTrap0eHandler: rc=0 GCPhysNestedFault=0x00000000bffbbab2 (0x00000002397bb000) uErr=0x11 cs:rip=0008:bffbbab2
00:05:54.165445 pgmR0BthEPTProtNestedTrap0eHandler: rc=0 GCPhysNestedFault=0x00000000bffbbab2 (0x00000002397bb000) uErr=0x11 cs:rip=0008:bffbbab2
00:05:54.165456 pgmR0BthEPTProtNestedTrap0eHandler: rc=0 GCPhysNestedFault=0x00000000bffbbab2 (0x00000002397bb000) uErr=0x11 cs:rip=0008:bffbbab2
00:05:54.165466 pgmR0BthEPTProtNestedTrap0eHandler: rc=0 GCPhysNestedFault=0x00000000bffbbab2 (0x00000002397bb000) uErr=0x11 cs:rip=0008:bffbbab2
00:05:54.165476 pgmR0BthEPTProtNestedTrap0eHandler: rc=0 GCPhysNestedFault=0x00000000bffbbab2 (0x00000002397bb000) uErr=0x11 cs:rip=0008:bffbbab2
00:05:54.165486 pgmR0BthEPTProtNestedTrap0eHandler: rc=0 GCPhysNestedFault=0x00000000bffbbab2 (0x00000002397bb000) uErr=0x11 cs:rip=0008:bffbbab2
00:05:54.165495 pgmR0BthEPTProtNestedTrap0eHandler: rc=0 GCPhysNestedFault=0x00000000bffbbab2 (0x00000002397bb000) uErr=0x11 cs:rip=0008:bffbbab2
00:05:54.165505 pgmR0BthEPTProtNestedTrap0eHandler: rc=0 GCPhysNestedFault=0x00000000bffbbab2 (0x00000002397bb000) uErr=0x11 cs:rip=0008:bffbbab2
00:05:54.165516 pgmR0BthEPTProtNestedTrap0eHandler: rc=0 GCPhysNestedFault=0x00000000bffbbab2 (0x00000002397bb000) uErr=0x11 cs:rip=0008:bffbbab2
00:05:54.165528 pgmR0BthEPTProtNestedTrap0eHandler: rc=0 GCPhysNestedFault=0x00000000bffbbab2 (0x00000002397bb000) uErr=0x11 cs:rip=0008:bffbbab2
00:05:54.165539 pgmR0BthEPTProtNestedTrap0eHandler: rc=0 GCPhysNestedFault=0x00000000bffbbab2 (0x00000002397bb000) uErr=0x11 cs:rip=0008:bffbbab2
00:05:54.165549 pgmR0BthEPTProtNestedTrap0eHandler: rc=0 GCPhysNestedFault=0x00000000bffbbab2 (0x00000002397bb000) uErr=0x11 cs:rip=0008:bffbbab2
00:05:54.165559 pgmR0BthEPTProtNestedTrap0eHandler: rc=0 GCPhysNestedFault=0x00000000bffbbab2 (0x00000002397bb000) uErr=0x11 cs:rip=0008:bffbbab2
00:05:54.165569 pgmR0BthEPTProtNestedTrap0eHandler: rc=0 GCPhysNestedFault=0x00000000bffbbab2 (0x00000002397bb000) uErr=0x11 cs:rip=0008:bffbbab2
00:05:54.165578 pgmR0BthEPTProtNestedTrap0eHandler: rc=0 GCPhysNestedFault=0x00000000bffbbab2 (0x00000002397bb000) uErr=0x11 cs:rip=0008:bffbbab2
00:05:54.165588 pgmR0BthEPTProtNestedTrap0eHandler: rc=0 GCPhysNestedFault=0x00000000bffbbab2 (0x00000002397bb000) uErr=0x11 cs:rip=0008:bffbbab2
00:05:54.165600 pgmR0BthEPTProtNestedTrap0eHandler: rc=0 GCPhysNestedFault=0x00000000bffbbab2 (0x00000002397bb000) uErr=0x11 cs:rip=0008:bffbbab2
00:05:54.165611 pgmR0BthEPTProtNestedTrap0eHandler: rc=0 GCPhysNestedFault=0x00000000bffbbab2 (0x00000002397bb000) uErr=0x11 cs:rip=0008:bffbbab2
00:05:54.165656 *FLUSH DONE*
fth0
Volunteer
Posts: 5668
Joined: 14. Feb 2019, 03:06
Primary OS: Mac OS X other
VBox Version: PUEL
Guest OSses: Linux, Windows 10, ...
Location: Germany

Re: Nested virtualization triggers an extreme amount of flushes

Post by fth0 »

OlivierBourdy wrote: 14. Jun 2023, 14:12 Is there a bug tracking this issue?
I've found 21551.
OlivierBourdy
Posts: 2
Joined: 14. Jun 2023, 14:08

Re: Nested virtualization triggers an extreme amount of flushes

Post by OlivierBourdy »

For information: I came back to VirtualBox version 6.1.44 (dated april 2023), and I don't encounter this logs issue anymore.
Ramshankar
Oracle Corporation
Posts: 793
Joined: 7. Jan 2008, 16:17

Re: Nested virtualization triggers an extreme amount of flushes

Post by Ramshankar »

Thank you for the report!

The bug should be fixed in the upcoming VirtualBox 7.0.x maintenance release.
Oracle Corp.
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