Re: [PATCH v1 1/6] xen/arm: Decrease size of the 2nd ram bank

["Edgar E. Iglesias" <edgar.iglesias@xxxxxxxxx>]

On Tue, Sep 24, 2024 at 04:34:16PM -0700, Stefano Stabellini wrote:
> On Tue, 24 Sep 2024, Julien Grall wrote:
> > Hi Edgar,
> > 
> > On 24/09/2024 17:23, Edgar E. Iglesias wrote:
> > > From: "Edgar E. Iglesias" <edgar.iglesias@xxxxxxx>
> > > 
> > > The address range between 4G (32bit) and 1TB (40bit) is fully
> > > allocated. There's no more room for devices on ARM systems with
> > > 40-bit physicall address width.
> > > > This decreases the size of the second RAM bank to free up space
> > > in preparation for virtio-pci and for future use-cases.
> > 
> > I don't think we should reduce the amount of RAM supported in the default
> > case. Instead, I think it is time to support a more dynamic layout so we 
> > still
> > allow 1TB guest when QEMU is not emulated a virtual PCI hostbridge.
> 
> Edgar, do you think it would be possible for QEMU to take the virtio-pci
> address ranges and SPIs on the command line? If yes, I think that would
> solve the problem on the QEMU side.

Yes, that is already done on the QEMU side, all addresses and sizes are
passed on the command-line.


> On the Xen side, you have already added "virtio-pci-ranges" as dom0less
> property and that's all we need as far as I can tell.
> 
> Then you can remove patch #1 and patch #2 from this series?

I didn't think of that but yes, that should actually work, good point.

Cheers,
Edgar