Re: [Qemu-devel] [RFC 0/9] Introduce light weight PC platform pc-lite

[Dr. David Alan Gilbert]

* Paolo Bonzini (address@hidden) wrote:
> 
> 
> On 17/06/2016 10:14, Chao Peng wrote:
> > Basically:
> > - it removes old ISA devices and support only PCI devices;
> 
> I think you need to keep at least the RTC, otherwise where does Linux
> get the time of day from?
> 
> > - it removes 8259, instead use MSI as much as possible. IOAPIC and PCI
> >   PIN are still kept to support ACPI SCI;
> > - it supports PCIE ( you can use MMFG instead of 0xcf8/0xcfc port
> >   access);
> > - it gets rid of legacy firmware interfaces and supports ACPI tables;
> > - it supports CPU/memory/PCI hotplug;
> > - it supports Linux-guest only at present;
> > - You may need carefully configure guest kernel;
> > - You are forced to use virtio-serial-pci, old 8250/16550 is not there;
> 
> It doesn't support PCIe hotplug though, I think? (Because it doesn't
> support PCI bridges and PCIe hotplug doesn't work for root complex
> devices).  So is it ACPI-based hotplug?
> 
> Lack of 8250/16550 means lack of earlyprintk.  I know the driver is slow
> though, so I understand that.

You could always define a different way to get early debug; for example
a chunk of RAM at a known address seems fine for a VM.

Dave
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK