PCIe Passthrough on VMs enabled through BIOS? (iommu?)


#1

I’m trying to get pass thru to work on a virtual machine. According to the documentation, this requires compatible motherboard and CPU support for iommu.

Does the latest Librem 13 allow for it? If so how is it done?

Ref:
"## Enable BIOS features_
To use PCIe Passthrough, you will need a compatible motherboard and CPU with support for iommu. Look up your motherboard manual on how to enable these features, but they are commonly named VT-d or AMD Vi."


#2

I don’t know about Librem 13’s, but FWIW on a Purism 15v4 with PureOS it seems to be enabled by default with the newest coreboot firmware:

$ sudo sudo dmesg|grep DMAR
[    0.008087] ACPI: DMAR 0x000000007AA9E300 000088 (v01 COREv4 COREBOOT 00000000 CORE 20190703)
[    0.366177] DMAR: Host address width 39
[    0.366178] DMAR: DRHD base: 0x000000fed90000 flags: 0x0
[    0.366182] DMAR: dmar0: reg_base_addr fed90000 ver 1:0 cap 1c0000c40660462 ecap 19e2ff0505e
[    0.366183] DMAR: RMRR base: 0x0000007b800000 end: 0x0000007fffffff
[    0.366183] DMAR: DRHD base: 0x000000fed91000 flags: 0x1
[    0.366186] DMAR: dmar1: reg_base_addr fed91000 ver 1:0 cap d2008c40660462 ecap f050da
[    0.366187] DMAR-IR: IOAPIC id 2 under DRHD base  0xfed91000 IOMMU 1
[    0.366188] DMAR-IR: HPET id 0 under DRHD base 0xfed91000
[    0.366188] DMAR-IR: Queued invalidation will be enabled to support x2apic and Intr-remapping.
[    0.368052] DMAR-IR: Enabled IRQ remapping in x2apic mode

#3

I found this link on the Arch Wiki VFIO page: https://en.wikipedia.org/wiki/List_of_IOMMU-supporting_hardware. Is the motherboard listed on this Wikipedia page?


#4

@Emily i noticed that you posted different questions about VMs lately so i’ve found this video on lbry that talks about KVM/QEMU/virt-manager (i assume you need a GUI right ?)

here > https://lbry.tv/@DistroTube:2/virt-manager-is-the-better-way-to-manage:b

the jist of it is that this combination is more powerful than VirtualBOX/GNOME-boxes AND it’s free software unlike VmWare

by the way KVM is very close to bare-metal performance if you run it in a CLI with no GUI. most PROFESSIONALS are using it this way … graphics is not really something free-software + virtualisation will give you satisfaction anyway … hope this helps !