passthrough: viommu: replace host requirement with reference to pcie passthrough

Enabling IOMMU on the host is not a requirement for vIOMMU. It is only
a requirement for passthrough. Add a sentence to clarify the need for
a configured PCI(e) passthrough on the host for passthrough to nested
VMs.

While at it also clarify that this does not only applies to PCI but
also PCIe here.

Suggested-by: Dominik Csapak <d.csapak@proxmox.com>
Signed-off-by: Markus Frank <m.frank@proxmox.com>
 [ TL: mention all changes and avoid overly long line with link ]
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
This commit is contained in:
Markus Frank 2024-07-26 10:21:12 +02:00 committed by Thomas Lamprecht
parent 9332980f31
commit 2173def643

View File

@ -505,15 +505,14 @@ vIOMMU (emulated IOMMU)
vIOMMU is the emulation of a hardware IOMMU within a virtual machine, providing
improved memory access control and security for virtualized I/O devices. Using
the vIOMMU option also allows you to pass through PCI devices to level-2 VMs in
level-1 VMs via https://pve.proxmox.com/wiki/Nested_Virtualization[Nested Virtualization].
the vIOMMU option also allows you to pass through PCI(e) devices to level-2 VMs
in level-1 VMs via
https://pve.proxmox.com/wiki/Nested_Virtualization[Nested Virtualization].
To pass through physical PCI(e) devices from the host to nested VMs, follow the
PCI(e) passthrough instructions.
There are currently two vIOMMU implementations available: Intel and VirtIO.
Host requirement:
* Add `intel_iommu=on` or `amd_iommu=on` depending on your CPU to your kernel
command line.
Intel vIOMMU
^^^^^^^^^^^^