Re: [PATCH] mem/x86: add processor address space check for VM memory

[Ani Sinha]

On Mon, 18 Sept, 2023, 3:03 pm David Hildenbrand, <david@redhat.com> wrote:

>>
>>>> /*
>>>> * The 64bit pci hole starts after "above 4G RAM" and
>>>> * potentially the space reserved for memory hotplug.
>>>> */
>>>>
>>>> There is the
>>>>    ROUND_UP(hole64_start, 1 * GiB);
>>>> in there that is not really required for the !hole64 case. It
>>>> shouldn't matter much in practice I think (besides an aligned value
>>>> showing up in the error message).
>>>>
>>>> We could factor out most of that calculation into a
>>>> separate function, skipping that alignment to make that
>>>> clearer.
>>> Yeah this whole memory segmentation is quite complicated and might benefit from a qemu doc or a refactoring.
>>
>> Absolutely. Do you have time to work on that (including the updated fix?).
>
> Other than the fix you proposed I am not sure if we need to fix anything else atm. Seems physical address space bound checks are already in place.
> Re: doc, maybe. I will add it to my TODO list.

Will you send a proper patch, ideally not using pc_pci_hole64_start()
but instead the same logic without the final alignment to 1 GiB?

I'll send. No problem. Could you answer my other question please ?

I can also do it, but might take a bit longer.

--
Cheers,

David / dhildenb