According to the release notes, nested VT-x for Intel CPUs has been available from VirtualBox 6.1 for Intel >= gen 5 CPUs. However the "Enabled Nested VT-x/AMD-V" checkbox in the Processor settings is greyed out for me. Am I missing something here, or this not available on Mac OS hosts?
Host HW: MacBook Pro 13" 2016 with i7-6567U CPU
Host OS: Mac OS Catalina 10.15.2
VBox Ver: 6.1.2 r135662 (Qt5.6.3)
Guest: Debian 10 (Buster)
"Enabled Nested VT-x/AMD-V" option greyed out on Mac OS host
"Enabled Nested VT-x/AMD-V" option greyed out on Mac OS host
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GregoryYoung
- Posts: 1
- Joined: 21. Jan 2020, 04:49
Re: "Enabled Nested VT-x/AMD-V" option greyed out on Mac OS host
Nope. It's not enabled on Mac. I tried in vain to get it to work using the CLI, but it looks like even though nested VT-x is available in the CPU, either Apple has it disabled in the UEFI config (which surprise, we can't access), or something in MacOS Catalina is using nested virtualisation already, so it can't be released for Virtualbox to use with VMs.
Re: "Enabled Nested VT-x/AMD-V" option greyed out on Mac OS host
I don't think this would be the case. The option in BIOS/UEFI is to enable or disable the VT-x extension to the host's OS. There is no option (that I have seen) in BIOSs for nested virtualisation. From what I understand this would be managed on the OS side.GregoryYoung wrote:either Apple has it disabled in the UEFI config
I doubt this also. If something in MacOS was using the VT-x extension of the CPU, then you wouldn't even be able to run VirtualBox (at the same time VT-x was being used by the other process).GregoryYoung wrote:something in MacOS Catalina is using nested virtualisation already
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the1andonlydave
- Posts: 1
- Joined: 11. Feb 2020, 14:15
Re: "Enabled Nested VT-x/AMD-V" option greyed out on Mac OS host
I guess it's disabled due to some bugs or because it is very unstable.
I enabled it via commandline, also on macOS Catalina.
Then in my linux VM i loaded the kvm module (modprobe kvm_intel) and after that i started applications which need vt-x. On 5 of 6 tries the VM locked totally up within minutes. On the other try the whole VM became unusable with a "Guru Meditation" Errorstate. If i boot and load kvm in a similar VM in VMware Fusion on the same host i have no issues, so i think it's VirtualBox, not the guest VM.
Sadly it looks like there are no newer builds we could try out.
I enabled it via commandline, also on macOS Catalina.
Then in my linux VM i loaded the kvm module (modprobe kvm_intel) and after that i started applications which need vt-x. On 5 of 6 tries the VM locked totally up within minutes. On the other try the whole VM became unusable with a "Guru Meditation" Errorstate. If i boot and load kvm in a similar VM in VMware Fusion on the same host i have no issues, so i think it's VirtualBox, not the guest VM.
Sadly it looks like there are no newer builds we could try out.