Invalid number of CPU cores detected => Fixed in SVN

[Rafcio]

I'm getting "Invalid settings detected" message is the Settings dialog. It says that more virtual CPUs are assigned than the number of physical CPUs. The laptop has 4 cores, which I believe are equivalent to stand alone CPUs. However, the message indicates that only 2 physical CPUs are detected. This is strange, because on the processor tab the green bar ends at 4 CPUs, and that is exactly how many are assigned to the VM.

[Rafcio]

Logs

[Frank Mehnert]

Sorry to say but your CPU has only 2 physical cores, see ​here. Hyperthreads don't count.

[Rafcio]

You are correct. My employer is a cheap one and the new laptops it provides are lousy. I thought there were 4 single threaded cores, but my assumption was incorrect. Anyway, why is the green bar on the processor tab up to 4 CPUs? This is inconsistent. If only physical CPUs (cores) count, then this fact should be reflected on the processor tab as well. Green means good, right? Perhaps 3 colors should be used? Green for the number of actual CPUs (cores), yellow for the available threads and red (pink?) for whatever that color is used for now.
I'm not trying to be a pain..., but clearly a green setting shouldn't generate a warning. I'm just pointing this out and making a suggestion. Go ahead and close the ticket again.

[Frank Mehnert]

You are right, the colors are not consistent to the actual warnings. The reason is that in 4.3.x we don't use the number of physical processors consistently in the VM settings dialog. This will be fixed in the next maintenance release and there is no additional color change necessary.

[Frank Mehnert]

Fix is part of VBox 4.3.6.

[mizzao]

task manager CPU info

[mizzao]

warning in vbox 4.3.6

[mizzao]

I'm using VBox 4.3.6 and this is not fixed.

I have a dual-core processor with hyperthreading (pretty common these days.) I have a Windows 8.1 64-bit host and a Linux guest. If I select four processors, I get the warning, but the Linux guest works normally (a native installation would show four listings in 'cat /proc/cpuinfo'). If I select two processors, the Linux guest sees two cores but I don't think it has access to the hyper-threads.

Anyway, this warning should be fixed for different numbers of cores and hyperthreads. Screenshots of processor monitor and virtualbox attached.

[Frank Mehnert]

No, that works like intended. Passing 4 virtual CPUs on a dual-core machine with 2 hyperthreads per machine does not make sense. VirtualBox does not emulate hyperthreads but only physical cores.

[PepeN]

Hi,

I'm install 4.3.8.

I have 2 x Intel® Xeon® Processor L5420 (​http://ark.intel.com/products/33929/Intel-Xeon-Processor-L5420-12M-Cache-2_50-GHz-1333-MHz-FSB)

• of Cores ‡ 4
• Intel® Hyper-Threading Technology ‡ No

system have 2 x 4 = 8 physical CPUs cores

but VBox detect:

number of physical CPUs on the host system (2) - not physical CPUs cores (8)

[Frank Mehnert]

PepeN, please attach the VBox.log file of a VM session. It will provide all information I need.

[PepeN]

previous version

[PepeN]

current version

[PepeN]

Frank, I hope this information will help.

[Frank Mehnert]

Thanks for these logs. Could you also attach the output of the following commands:

uname -a
ls -ld /sys/devices/system/cpu/cpu*
cat /sys/devices/system/cpu/cpu*/topology/core_id
cat /sys/devices/system/cpu/cpu*/topology/physical_package_id

Thank you!

[PepeN]

I apologize for the carelessness. My mistake, I have

Host type: Windows
Guest type: Linux

My information relates (https://www.virtualbox.org/ticket/12726)

[Frank Mehnert]

The problem is that on Windows we depend on the GetLogicalProcessorInformation() which apparently returns wrong information on your host. The VBox source code for the Windows function can be found here.

[Mihai Hanor]

PepeN, I think this may be relevant to your host OS (win2003) and the GetLogicalProcessorInformation issue:
​http://support.microsoft.com/kb/932370

[Frank Mehnert]

Replying to mhanor:

PepeN, I think this may be relevant to your host OS (win2003) and the GetLogicalProcessorInformation issue:
​http://support.microsoft.com/kb/932370

Very right, thanks for pointing this out!

[PepeN]

Replying to mhanor:

PepeN, I think this may be relevant to your host OS (win2003) and the GetLogicalProcessorInformation issue:
​http://support.microsoft.com/kb/932370

Yes, you were right! Thank you!

[zogoibi]

Hi. This is somewhat old topic, but I've found the same issue on my system. Running Windows 7 Home Premium on a Toshiba Portégé Z830 with Intel i5-2467M dual-core multithreaded (Windows 7 reports 4 CPUs). My VBox version is 4.2.30, and whenever I setup a guest, it only reports one (1) core. If I try to set two, system complaints "more virtual CPUs in the guest than actual number of physical CPUs in the host", which isn't true. Some workaround? Some hint or help? If more information is needed please ask.

[Mihai Hanor]

Run VBoxManage list hostinfo and coreinfo -cglnsm and attach here the output of these commands. Get Coreinfo from ​here

[zogoibi]

Thank you. I already found the answer: for some reason my system was running with only one CPU. I fixed it and now VirtualBox detects the two multithreaded cores correctly.

[Klaus Espenlaub]

No valid open issues left, closing the ticket again.