Re: [PATCH v2] xen/device-tree: Allow region overlapping with /memreserve/ ranges

[Julien Grall <julien@xxxxxxx>]

Hi,

On 16/11/2024 10:18, Julien Grall wrote:
> On 14/11/2024 10:28, Luca Fancellu wrote:
> > There are some cases where the device tree exposes a memory range
> > in both /memreserve/ and reserved-memory node, in this case the
> > current code will stop Xen to boot since it will find that the
> > latter range is clashing with the already recorded /memreserve/
> > ranges.
> >
> > Furthermore, u-boot lists boot modules ranges, such as ramdisk,
> > in the /memreserve/ part and even in this case this will prevent
> > Xen to boot since it will see that the module memory range that
> > it is going to add in 'add_boot_module' clashes with a /memreserve/
> > range.
> >
> > When Xen populate the data structure that tracks the memory ranges,
> > it also adds a memory type described in 'enum membank_type', so
> > in order to fix this behavior, allow overlapping with the /memreserve/
> > ranges in the 'check_reserved_regions_overlap' function when a flag
> > is set.
> >
> > In order to implement this solution, there is a distinction between
> > the 'struct membanks *' handled by meminfo_overlap_check(...) that
> > needs to be done, because the static shared memory banks doesn't have
> > a usable bank[].type field and so it can't be accessed, hence now
> > the 'struct membanks_hdr' have a 'enum region_type type' field in order
> > to be able to identify static shared memory banks in 
> > meminfo_overlap_check(...).
> > While there, set a type for the memory recorded using meminfo_add_bank()
> > from efi-boot.h.
> >
> > Fixes: 53dc37829c31 ("xen/arm: Add DT reserve map regions to 
> > bootinfo.reserved_mem")
> > Reported-by: Shawn Anastasio <sanastasio@xxxxxxxxxxxxxxxxxxxxx>
> > Reported-by: Grygorii Strashko <grygorii_strashko@xxxxxxxx>
> > Signed-off-by: Luca Fancellu <luca.fancellu@xxxxxxx>
> Reviewed-by: Julien Grall <jgrall@xxxxxxxxxx>
>
> I will give a few days for the others to review and Shawn to comment 
> whether it fixes his issue (I can't remember if it was already done).
This is now committed.

Cheers,

--
Julien Grall