Re: HYPERVISOR_console_io + CONSOLEIO_write needs COPY_flush_dcache

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Thu, 11 Jun 2020, Julien Grall wrote:
> > Probably my use-case should be somewhere documented, so another time someone
> > steps into similar issues it is explained.
> 
> You would have the exact same issue if you don't use hypercalls but modify a
> buffer with MMU off and then expect it to read the content correctly after
> turning on the MMU. That's even on baremetal! (see [1])
> 
> I am afraid you have to know how the cache works when writing code that will
> run with MMU off.
> 
> Therefore I don't think it is Xen Project to document how an architecture
> works. Instead this should be a tutorial for anyone wanting to write its own
> OS.

We could have a page on wiki.xenproject.org on the topic if Oleksandr
wants to write it. (Adding George in case Oleksandr wants to write the
and he doesn't have access to the wiki yet.)