virtualbox.org

Hi, I tried to enable VT-x in Ubuntu 16.04 virtual machine but it's always disabled. Could anyone can help me on this? Thanks.

virtualbox version: 5.1.18
Acceleration: VT-X/AMD-V (auto enabled in system config)

00:00:01.497632 HM: MSR_IA32_VMX_BASIC_INFO = 0xda040000000010
00:00:01.497641 HM: MSR_IA32_VMX_PINBASED_CTLS = 0x7f00000016
00:00:01.497645 HM: MSR_IA32_VMX_PROCBASED_CTLS = 0xfff9fffe0401e172
00:00:01.497660 HM: MSR_IA32_VMX_PROCBASED_CTLS2 = 0x8ff00000000
00:00:01.497672 HM: MSR_IA32_VMX_ENTRY_CTLS = 0xffff000011ff
00:00:01.497678 HM: MSR_IA32_VMX_EXIT_CTLS = 0x7fffff00036dff
00:00:01.497682 HM: SAVE_VMX_PREEMPT_TIMER
00:00:01.497683 HM: MSR_IA32_VMX_EPT_VPID_CAP = 0xf0106114141
00:00:01.497690 HM: MSR_IA32_VMX_MISC = 0x100401e5
00:00:01.497696 HM: MSR_IA32_VMX_CR0_FIXED0 = 0x80000021
00:00:01.497697 HM: MSR_IA32_VMX_CR0_FIXED1 = 0xffffffff
00:00:01.497698 HM: MSR_IA32_VMX_CR4_FIXED0 = 0x2000
00:00:01.497699 HM: MSR_IA32_VMX_CR4_FIXED1 = 0x1727ff
00:00:01.497699 HM: MSR_IA32_VMX_VMCS_ENUM = 0x2a
00:00:01.497717 HM: Enabled VMX
00:00:01.497726 HM: VPID flush type = VMXFLUSHVPID_SINGLE_CONTEXT
00:00:01.497727 HM: Enabled VMX-preemption timer (cPreemptTimerShift=5)
00:00:01.498544 VMX - Virtual Machine Extensions = 0 (1)

I'm not sure why you chose to look at that, but VT-x is available and enabled:

00:00:01.356429 HM: HMR3Init: VT-x w/ nested paging and unrestricted guest execution hw support
00:00:01.497625 HM: Using VT-x implementation 2.0
00:00:01.497728 HM: VT-x/AMD-V init method: GLOBAL

If you're talking about passing that VT-x capability in the guest, no, you can't. VirtualBox doesn't pass that flag in the guests.

PS. For future reference, please ZIP the log file before posting it. It saves a couple of virtual trees...

OK, so that means I can't create a virtual machine inside a guest system created by virtualbox, right?

Not if it requires VT-x.

I have same issue.

If I see the log, firstly:
00:00:02.998256 HM: Using VT-x implementation 2.0
...
00:00:02.998326 HM: VT-x/AMD-V init method: LOCAL
...
and after:
00:00:02.998494 VMX - Virtual Machine Extensions = 0 (1)

I'm trying with PARAVIRTUALIZATION INTERFACE = kvm but If I execute egrep -c '(vmx|svm)' /proc/cpuinfo on my Ubuntu guest, I get 0. No vt-x flag.

What about kvm paravirtualization? Virtualbox claims it is ready from 5.0.

1. What's "the same issue" that you're having? If is it nested virtualization, no.
2. What about KVM paravirtualization? It is ready since 5.0.x. From the User Manual, Ch. 10.4. Paravirtualization providers:

   VirtualBox allows exposing a paravirtualization interface to facilitate accurate and efficient execution of software within a virtual machine. These interfaces require the guest operating system to recognize their presence and make use of them in order to leverage the benefits of communicating with the VirtualBox hypervisor.

Moving to "Linux Guests" from "OSX Hosts".

Sorry, but I do not understand the difference. I read text that you quoted many times and I understood that KVM will be available (using VT-X in my INTEL CPU).
However, if I execute
I get I need kvm in order to execute Android Studio Emulator on my Ubuntu 17.04 32bits guest.

Thank you.

negas wrote:I read text that you quoted many times

I gave you a link to the related chapter. Did you read that too many times? Without reading what you'd want to "hear", but what it actually says? It says nowhere that KVM will be available in the guest.

OK, I can not use KVM in my Ubuntu guest, so what can I do inside Linux host with paravirtualization interfaces? What is paravirtualization useful for?