Hi,
On 13/11/2024 14:19, Michal Orzel wrote:
On 13/11/2024 14:50, Julien Grall wrote:
Hi Michal,
On 06/11/2024 15:07, Michal Orzel wrote:
On 06/11/2024 14:41, 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 the 'check_reserved_regions_overlap'
function to check for exact memory range match given a specific memory
type; allowing reserved-memory node ranges and boot modules to have an
exact match with ranges from /memreserve/.
While there, set a type for the memory recorded during ACPI boot.
Fixes: 53dc37829c31 ("xen/arm: Add DT reserve map regions to
bootinfo.reserved_mem")
Reported-by: Shawn Anastasio <sanasta...@raptorengineering.com>
Reported-by: Grygorii Strashko <grygorii_stras...@epam.com>
Signed-off-by: Luca Fancellu <luca.fance...@arm.com>
---
I tested this patch adding the same range in a /memreserve/ entry and
/reserved-memory node, and by letting u-boot pass a ramdisk.
I've also tested that a configuration running static shared memory still works
fine.
---
So we have 2 separate issues. I don't particularly like the concept of
introducing MEMBANK_NONE
and the changes below look a bit too much for me, given that for boot modules
we can only have
/memreserve/ matching initrd.
How so? Is this an observation or part of a specification?
Not sure what specification you would want to see.
Anything that you bake your observation. My concern with observation is ...
It's all part of U-Boot and Linux behavior that is not documented
(except for code comments).
My statement is based on the U-Boot and Linux behavior. U-Boot part only
present for initrd:
https://github.com/u-boot/u-boot/blob/master/boot/fdt_support.c#L249
... a user is not forced to use U-boot. So this is not a good reason to
rely on it. If Linux starts to rely on it, then it is probably a better
argument, but first I would need to see the code. Can you paste a link?
For things that Xen can be interested in, only region for ramdisk for dom0 can
match the /memreserve/ region.
Providing a generic solution (like Luca did) would want providing an example of
sth else that can match which I'm not aware of.
I would argue this is the other way around. If we are not certain that
/memreserve/ will not be used for any other boot module, then we should
have a generic solution. Otherwise, we will end up with similar weird
issue in the future.
Cheers,
--
Julien Grall
