I'd recommend you implement all hypercalls while you are looking at it. After that it's other support code (gnttab, evtchn? Unsure how hvm event channels work...mapped to irq+bitmap perhaps? Would want to take a polled approach since EFI is only allowed to have a timer interrupt). I recommend looking at MiniOS under Xen extras for PV support implementation details).
On Jul 29, 2011 1:25 PM, "Tim Deegan" <Tim.Deegan@citrix.com
> At 19:11 +0100 on 29 Jul (1311966704), Jordan Justen wrote:
>> I'm a little concerned about OvmfPkg/Include/Protocol/Hypercall.h. I
>> think some content may have been copied from the Xen project here (the
>> comments like: /* compat since 0x00030101 */). We need to make
>> certain that this code can be BSD licensed. I think our code style
>> generally would use an enum in this scenario as well.
> Things copied from Xen's "public" header files should be OK -- those
> particular files are explicitly licensed so as to allow BSD and other
> users to copy them:
> In fact we rather hope that you do copy them verbatim, so you can more
> easily keep your version up to date.
> Tim Deegan <Tim.Deegan@citrix.com
> Principal Software Engineer, Xen Platform Team
> Citrix Systems UK Ltd. (Company #02937203, SL9 0BG)