ESXi 5.5 Nested Virtualization and PCI Passthrough

[mlombz]

Good evening to everyone,

this is my first time that i write here in community forum, sorry to everyone for my bad English I'm come from Italy.

I have a problem with ESXi 5.5 last update with vCenter, the host is a Dell C1100 with 36GB DDr3, two xeon L5520 with an ati Radeon 6450 in the PCI express slot.

All components are working, BIOS version is 1.84 I have set all the settings on the BiOS for PCI passthrough and Nested Virtualization.

I Have created a Virtual Machine with 8 GB vRAM and 8 vCPU and the OS is Windows Server 2012 R2, network card is the VMXNET3 and no problems with networking.

Now the problem.

Before the hyper v role installation, I have set the PCI passthrough to the virtual machine and the systems detect correctly the card and no problems with driver installation.

But when I try to install hyper v role (installations gone fine but the problem appears after reboot), the ESXi system crash with a PSOD. I have a picture of the screen, i have attach it here with the post.

I tried to deactivate the PCI passthrough on the VM and it boot correctly without create any PSOD, hyper v working without problems, I can create nested virtual machine x64 too.

So if I try to activate the PCI passthrough of the Ati 6450 on the hyper v virtual machine the system crash.

All the operations are made with vSphere Web Client.

Thank you very much to everyone.

[a_p_]

Discussion moved from VMware ESXi 5 to Nested Virtualization

[mlombz]

Good Morning to everyone,

i want to give an update for this problem, i have notify that currently i receive the PSOD exactly when i add the "hypervisor.cpuid.v0" row to vmx file to enable the hyper-v role on the Windows Server 2012 R2 Vm.

Now i have try the same procedure in a Dell R710 ESXi 5.5 (custom Dell image) and i receive the same PSOD screen when i Passthrough the ATI 6450 and enable "hypervisor.cpuid.v0" on the virtual machine.

I am unable to download the dump file, because no dump file show when this PSOD happen.

Thank you to everyone.

Marco

[joadswe]

Hi, I have almost the same problem. The difference is that I get no PSOD, my host reboots during the Windows guest starts.

All works well until installing Hyper-V on my Windows 2012 R2. And to the install Hyper-V I need to add "hypervisor.cpuid.v0" = FALSE

Have you found a solution?

[admin]

Nested pass-through is not likely to work with Intel CPUs, because the shadow nested page table forces all memory in the nested guest to writeback.  This may work with AMD CPUs.

[admin]

Actually, nested virtualization and PCI pass-through are incompatible, since we cannot snoop on DMA to the guest hypervisor's nested page tables.  This configuration should be disallowed.

[joadswe]

Okay, then I know. Thanks for your reply.

/ Johan