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AVX and VirtualBox v6.1.18 r142142

Posted: 26. Feb 2021, 15:52
by texace
Hi. I need to use AVX instructions in my project on guest Ubuntu 18.04, but Ubuntu does't have them. I have Ryzen 1600 and according to the specification it has the necessary instructions. On my host machine(Win 10) all work fine.

The output of "cat /proc/cpuinfo":

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...
flags       : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx fxsr_opt rdtscp lm constant_tsc rep_good nopl nonstop_tsc cpuid extd_apicid tsc_known_freq pni ssse3 sse4_1 sse4_2 hypervisor lahf_lm cmp_legacy cr8_legacy 3dnowprefetch ssbd vmmcall fsgsbase arat
...
I tried to use this command on my host:

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VBoxManage setextradata "$vm_name" VBoxInternal/CPUM/IsaExts/AVX2 1
as said on askubuntu(i can't post links, but this is the last part of link - "questions/699077/how-to-enable-avx2-extensions-on-a-ubuntu-guest-in-virtualbox-5"), but nothing happened.

So, what should i do? Maybe someone has encountered this error?

Re: AVX and VirtualBox v6.1.18 r142142

Posted: 26. Feb 2021, 19:12
by fth0
Please post a zipped VBox.log file.

Re: AVX and VirtualBox v6.1.18 r142142

Posted: 27. Feb 2021, 07:27
by texace
Here

Re: AVX and VirtualBox v6.1.18 r142142

Posted: 27. Feb 2021, 14:05
by fth0
You have Hyper-V enabled on your host, and it blocks AVX and AVX2. See HMR3Init: Attempting fall back to NEM (Hyper-V is active), especially the bcdedit and shutdown commands.

Re: AVX and VirtualBox v6.1.18 r142142

Posted: 28. Feb 2021, 09:26
by texace
Thank you, it was really helpful.

Re: AVX and VirtualBox v6.1.18 r142142

Posted: 22. Jun 2022, 11:33
by Steve6375
I fixed the x86-64 v2 not supported issue by enabling Nested Paging in System - Acceleration