Re: [PATCH] hw/i386/pc: fix max_used_gpa for 32-bit systems

[David Hildenbrand <david@redhat.com>]

On 18.09.23 17:56, Ani Sinha wrote:
> On Mon, Sep 18, 2023 at 8:59 PM David Hildenbrand <david@redhat.com> wrote:
>>
>> On 18.09.23 17:22, Ani Sinha wrote:
>>> On Mon, Sep 18, 2023 at 7:25 PM Ani Sinha <anisinha@redhat.com> wrote:
>>>>
>>>> 32-bit systems do not have a reserved memory for hole64 but they may have a
>>>> reserved memory space for memory hotplug. Since, hole64 starts after the
>>>> reserved hotplug memory, the unaligned hole64 start address gives us the
>>>> end address for this memory hotplug region that the processor may use.
>>>> Fix this. This ensures that the physical address space bound checking works
>>>> correctly for 32-bit systems as well.
>>>
>>> This patch breaks some unit tests. I am not sure why it did not catch
>>> it when I tested it before sending.
>>> Will have to resend after fixing the tests.
>>
>> Probably because they supply more memory than the system can actually
>> handle? (e.g., -m 4g on 32bit)?
> 
> cxl tests are failing for example.
> 
> $ ./qemu-system-i386 -display none -machine q35,cxl=on
> qemu-system-i386: Address space limit 0xffffffff < 0x1000fffff
> phys-bits too low (32)

CXL with 32bit CPUs ... it might be reasonably to just disable such 
tests. Certainly does not exist in real HW ... :)

-- 
Cheers,

David / dhildenb