Re: Summary of LPC guest MSI discussion in Santa Fe

From: Joerg Roedel
Date: Thu Nov 10 2016 - 10:19:59 EST


On Wed, Nov 09, 2016 at 08:11:16PM +0000, Robin Murphy wrote:
> When we *are* in full control of the IOVA space, we just carve out what
> we can find as best we can - see iova_reserve_pci_windows() in
> dma-iommu.c, which isn't really all that different to what x86 does
> (e.g. init_reserved_iova_ranges() in amd-iommu.c).

Yeah, that code was actually written with a look at what the Intel
driver does. I don't really like that it goes over all resources and
reserves them individually (not only because it is not hotplug-safe).

I have to check whether there is a nice and generic way to find out the
root-bridge windows and just reserve them in the iova-space. That would
be easier and more reliable.


Joerg