Re: UEFI support in ARM DomUs

[Julien Grall <julien@xxxxxxx>]

Hi,

On 19/06/2020 13:51, Oleksandr Andrushchenko wrote:
> On 6/19/20 3:47 PM, Julien Grall wrote:
> > They will not be available from the fdt, but you can retrieve them with an 
> > hypervisor call (see HVM_PARAM_STORE_PFN, HVM_PARAM_CONSOLE_PFN).
> Yes, and it used in the relevant pieces of code (hyp calls)
> > One question though, why do you need to map them in advance? Couldn't you map 
> > them on demand?
> Well, we need to at least estimate the pg_table size so we can reserve and 
> allocate memory later,
Oh, so U-boot doesn't support runtime page-table table allocation. Is 
that right?
> so I have to provide memory range from either by coding a constant or looking 
> into the devtree at
>
> hypervisor { reg = <>; }. It is a bit tricky though
Looking for a node in the device-tree shouldn't be too difficult given 
that you have fdt_* available.
However, please not that <reg> doesn't refer to the guest magic pages. 
Instead, it provides a region you can use for mapping the grant-table frames
Cheers,

--
Julien Grall