"The upper MMIO region" error if -HighMemoryMappedIoSpace parameter exceeds 512MB

Evgenii 1 Reputation point
2020-08-24T12:03:21.567+00:00

I'm using Windows 10 2004 host and Windows 10 2004 Hyper-V guest Gen2 VM "W102004_01".

The following command is issued in Powershell for Guest VM: 

$vm = "W102004_01"  
Set-VM -LowMemoryMappedIoSpace 3072MB -VMName $vm  
Set-VM -HighMemoryMappedIoSpace 512MB -VMName $vm

If -HighMemoryMappedIoSpace parameter value exceeds 512MB even by 1 MB, then the errors occur during Guest VM startup.

For example:
Set-VM -HighMemoryMappedIoSpace 1GB -VMName $vm
Error during VM startup:
The upper MMIO region (0x000000101ffff000) is above the supported physical address range.
Make sure that the upper MMIO region is below 0x0000001000000000.

Set-VM -HighMemoryMappedIoSpace 750MB -VMName $vm
Error during VM startup:
The upper MMIO region (0x000000100edff000) is above the supported physical address range.
Make sure that the upper MMIO region is below 0x0000001000000000.

Set-VM -HighMemoryMappedIoSpace 513MB -VMName $vm
Error during VM startup:
The upper MMIO region (0x00000010001ff000) is above the supported physical address range.
Make sure that the upper MMIO region is below 0x0000001000000000.

It seems that the system doesn't allow to increase upper MMIO region above default 512MB value.

Guest VM parameters are attached.19897-vm-parameters.txt

The same errors exist also for Gen1 VM.

Hyper-V
Hyper-V
A Windows technology providing a hypervisor-based virtualization solution enabling customers to consolidate workloads onto a single server.
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  1. Xiaowei He 9,866 Reputation points
    2020-08-25T09:05:44.997+00:00

    Hi,

    I have seen this post, while I may need some time to do research on this issue, if I get any useful informaiton, I will feedback as soon as possible. Thanks for your understanding!

    Best Regards,
    Anne

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  2. Miroslav 1 Reputation point
    2021-08-23T11:06:57.167+00:00

    I don't know what host CPU was used by @Evgenii , but I think it's a problem of old architectures. I had this with a i7-3770, @Hassan-2674 has a e3-1270v2 (both Ivy Bridge). When I upgraded to a new Ryzen, the problem was gone. I also talked to a guy who had this problem with a i7-4770 (Haswell) and also for him an upgrade to a new CPU solved the problem.