Re: [PATCH 3/3] arm, arm64: KVM: handle potential incoherency of readonly memslots

Paolo Bonzini
2014-11-17T15:29:58Z

On 17/11/2014 15:58, Ard Biesheuvel wrote:
> Readonly memslots are often used to implement emulation of ROMs and
> NOR flashes, in which case the guest may legally map these regions as
> uncached.
> To deal with the incoherency associated with uncached guest mappings,
> treat all readonly memslots as incoherent, and ensure that pages that
> belong to regions tagged as such are flushed to DRAM before being passed
> to the guest.

On x86, the processor combines the cacheability values from the two
levels of page tables. Is there no way to do the same on ARM?

Paolo