[Solved] Problems with Windows 10 host/Windows 10 guest: crashes and unbootable VM

[fstx1]

Hi!

I have a new computer, and i am trying to install Windows 10 Enterprise N in a Virtual Box VM. The installation goes through the CD phase, but when it tries to reboot from the hd image, it sayas that it can\t find an operating system.

I also have had Virtual Box crash a few times. An example form the Event log. Alas, the message is in Swedish

Felet uppstod i programmet med namn: VirtualBox.exe, version 6.1.4.36177, tidsstämpel 0x5e4c1d2a
, felet uppstod i modulen med namn: VirtualBox.exe, version 6.1.4.36177, tidsstämpel 0x5e4c1d2a
Undantagskod: 0xc0000005
Felförskjutning: 0x00000000000251b7
Process-ID: 0x4b34
Programmets starttid: 0x01d5ff6dbade2a83
Sökväg till program: C:\Program Files\Oracle\VirtualBox\VirtualBox.exe
Sökväg till modul: C:\Program Files\Oracle\VirtualBox\VirtualBox.exe
Rapport-ID: fb62e9b1-ccd0-4381-be43-e4174f3a414f
Fullständigt namn på felaktigt paket:
Program-ID relativt till felaktigt paket:

[mpack]

One issue per topic please. I will only address the Windows 10 Enterprise install issue here.

Please provide a VM log file. With the VM fully shut down, right click it in the GUI. Select "Show Log" and save "VBox.log" (no other file) to a zip file. Attach the zip here.

Also, where did you get "Windows 10 Enterprise" from, and what version is it?

[fstx1]

Sorry for not replying promptly. I am running hardware diagnostics on the computer. So far I have not found any hardware problems.

Stupidly enough I removed the virtual machine, and when I recreate it I get a different problem earlier in the installation. I have attached log files from two different tries.

I got the Windows 10 Enterprise from my MSDN subscription. It is the 1909 Updated Feb 2020 version.
I have checked the SHA sum, and it seems te be correct.

[fstx1]

And here is the last logfile after I shut down the VM.

[mpack]

00:00:03.694248 HM: HMR3Init: Attempting fall back to NEM: VT-x is not available
00:00:03.778907 NEM: WHvCapabilityCodeHypervisorPresent is TRUE, so this might work...
00:00:03.778922 NEM: WHvCapabilityCodeExtendedVmExits = 0x0000000000000007

You have Hyper-v enabled on the host, that kills performance. VirtualBox attempts to use the Hyper-v API (NEM) to continue running, but that's a very poor option, especially as Microsoft keep changing how the API works.

Related FAQ: I have a 64bit host, but can't install 64bit guests. Especially posts #2 and beyond.

[fstx1]

Well, I tried to turn it off with bcdedit, but it turned out I had core isolation and kernel-dma protection enabled

I turned it off, and now the the log file says:

0:00:03.799347 HM: HMR3Init: VT-x w/ nested paging and unrestricted guest execution hw support

Does this mean that VirtualBox now has what it needs?

I'll retry the installation, and report back.

[fstx1]

It worked!

Thank you!

[fstx1]

The popup on the small cpu icon says 'Paravitualization interface: Hyper-V'. Execution engine is VT-x/AMD-V.

[mpack]

Paravirtualization is about what the guest sees. It has nothing to do with how VirtualBox works on the host. It's part of a modern virtual environment: there's a virtual disk, a virtual network and - a virtual hypervisor. A Windows 10 guest running on a Linux host still "sees" a Hyper-v API so thinks it's running under Hyper-v. Likewise a Linux guest running on a Windows host still "sees" a KVM hypervisor. That's because VirtualBox provides the appropriate API to each guest OS - at least those guests that know about hypervisors.

[fstx1]

I understand.

The other one, Execution engine is VT-x/AMD-V, does that mean that Virtualbox is able to use the better way and not the inferior Hyper-V way?

[mpack]

Execution engine is VT-x/AMD-V, does that mean that Virtualbox is able to use the better way and not the inferior Hyper-V way?

Yes, that's what it means, except... there's no need to butter me up with the "inferior" thing . At this precise minute the Hyper-v option provides an inferior user experience because the feature is immature/experimental/slow. Maybe in the future the issues will be fixed and the Hyper-v option will be a good one.