Re: [PATCH v7] xen: allow up to 16383 cpus

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 10/05/2024 10:08 pm, Julien Grall wrote:
> Hi Juergen,
>
> On 10/05/2024 15:16, Juergen Gross wrote:
>> With lock handling now allowing up to 16384 cpus (spinlocks can handle
>> 65535 cpus, rwlocks can handle 16384 cpus), raise the allowed limit for
>> the number of cpus to be configured to 16383.
>>
>> The new limit is imposed by IOMMU_CMD_BUFFER_MAX_ENTRIES and
>> QINVAL_MAX_ENTRY_NR required to be larger than 2 * CONFIG_NR_CPUS.
>>
>> Add a support limit of physical CPUs to SUPPORT.md (4096 on x86, 128
>> on ARM).
>>
>> Signed-off-by: Juergen Gross <jgross@suse.com>
>> Acked-by: Jan Beulich <jbeulich@suse.com>
>
> I am a bit surprised that this is kept given you added SUPPORT.md. I'd
> like Jan (or other x86 maintainers) to confirm they are happy with the
> proposed x86 security supported limit the SUPPORT.md.
>
> For Arm (only):
>
> Acked-by: Julien Grall <jgrall@amazon.com>

XenServer is currently at 2k and we're waiting on this series to move to 4k.

I'm happy with this being the security statement for now.

~Andrew