Re: [Xen-devel] [PATCH] acpi: Switch to dynamic mapping at SYS_STATE_boot

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 31.01.17 at 16:52, <boris.ostrovsky@xxxxxxxxxx> wrote:
> On 01/31/2017 06:01 AM, Jan Beulich wrote:
>>>>> On 30.01.17 at 19:26, <boris.ostrovsky@xxxxxxxxxx> wrote:
>>> We can switch ACPI from using fixmap to dynamic mapping as soon as
>>> the system enters SYS_STATE_boot. This will allow us, for example,
>>> to map MADT on systems with large number of processors where the
>>> table might not fit into NUM_FIXMAP_ACPI_PAGES (currently set to 4).
>> I think this needs a little more care. While ARM switches to
>> SYS_STATE_boot after having called vm_init(), that's not the case
>> on x86. Granted there's no ACPI code being invoked in between,
>> but this would still be a latent bug (as soon as someone inserts any
>> code there).
> 
> Then acpi_os_map_memory() shouldn't rely on system_state at all.

Why?

> How about adding something like
> 
> static bool_t vm_ready()
> {
>     return !!vm_base[VMAP_DEFAULT];
> }

What's wrong with just swapping the order of the two things in
x86's setup.c?

Jan


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
https://lists.xen.org/xen-devel