Re: run time memory trap question

[Julien Grall <julien.grall@linaro.org>]

On 02/17/2014 11:33 AM, Andrii Tseglytskyi wrote:
> Hi,

Hello Andrii,

> Can anyone clarify - is it possible to make a run time memory trap in
> Xen hypervisor?

I guess you are talking about ARM? If so, it's not possible right now.

> To be more specific - I see the following function:
> *int handle_mmio(mmio_info_t *info)*, which is called from *static
> void do_trap_data_abort_guest(struct cpu_user_regs *regs, union hsr
> hsr)*
> Using these calls I can define memory region and create a trap for it.
> But in current implementation I can do it only during compile time.
> Is there any way to do similar in runtime - i.e. calculate memory
> region value in code and add an entry to mmio_handlers[] ?
> Is it a good idea - just to modify/extend existing code in
> xen/arch/arm/io.c file to make it possible ?

I think yes, we might need that for a couple of new features in Xen such
as: clock drivers and multiple devices in a same page (see UARTs on
cubieboard 2).

Regards,

-- 
Julien Grall