Re: [PATCH v2 0/3] KVM: x86: KVM_MEM_PCI_HOLE memory

From: Gerd Hoffmann
Date: Fri Sep 18 2020 - 05:33:32 EST


Hi,

> > We could probably wire up ecam (arm/virt style) for pcie support, once
> > the acpi support for mictovm finally landed (we need acpi for that
> > because otherwise the kernel wouldn't find the pcie bus).
> >
> > Question is whenever there is a good reason to do so. Why would someone
> > prefer microvm with pcie support over q35?
>
> The usual reasons to use pcie apply to microvm just the same.
> E.g.: pass through of pcie devices?

Playground:
https://git.kraxel.org/cgit/qemu/log/?h=sirius/microvm-usb

Adds support for usb and pcie (use -machine microvm,usb=on,pcie=on
to enable). Reuses the gpex used on arm/aarch64. Seems to work ok
on a quick test.

Not fully sure how to deal correctly with ioports. The gpex device
has a mmio window for the io address space. Will that approach work
on x86 too? Anyway, just not having a ioport range seems to be a
valid configuation, so I've just disabled them for now ...

take care,
Gerd