New vIOMMU setting in machines menu

[Sp00nman]

Morning all,

What does this new setting do?

TIA

 

[Sp00nman]

Found it: https://michael2012z.medium.com/virtio-iommu-789369049443

 

[leesteken]

It's also in the manual: https://pve.proxmox.com/pve-docs/pve-admin-guide.html#qm_pci_viommu
Note that Proxmox made the very common mistake about amd_iommu=on, which does not exist because it's on by default.

 

[dcsapak]

Note that Proxmox made the very common mistake about amd_iommu=on, which does not exist because it's on by default.

thanks for noticing, i sent a fix for the docs: https://lists.proxmox.com/pipermail/pve-devel/2024-April/063688.html

 

[guruevi]

Note that for Windows guest (where machine type is q35 + [version], changing the setting fails because "machine does not match the regexp"

 

[dcsapak]

Note that for Windows guest (where machine type is q35 + [version], changing the setting fails because "machine does not match the regexp"

which setting are you talking about exactly?

how does your config look like? (qm config ID) ?

 

[guruevi]

@dcsapak:
This is the setting I'm talking about
machine: pc-q35-8.1

If the machine is:
machine: q35
It works

But machine: pc-q35-8.1 (versions differ) is automatically set when OS Type is set to Windows instead of Linux under Options -> OS Type

 

[gfngfn256]

thanks for noticing, i sent a fix for the docs: https://lists.proxmox.com/pipermail/pve-devel/2024-April/063688.html

From the above link:

-* Add `intel_iommu=on` or `amd_iommu=on` depending on your CPU to your kernel command line.
+* Add `intel_iommu=on` depending on your CPU to your kernel command line.

That should probably be:

+* Add `intel_iommu=on` for your Intel CPU to your kernel command line.

 

[dcsapak]

But machine: pc-q35-8.1 (versions differ) is automatically set when OS Type is set to Windows instead of Linux under Options -> OS Type

that works here without problem (setting any version) that the version is set to a fixed one for windows is by design, since windows does not like hardware changes (which the machine version sometimes does)
can you post the output of 'pveversion -v' ? and maybe a screenshot of the error?

 

[guruevi]

@dcsapak: Seems to have been resolved in the latest version, I am able to change the setting now.