Re: [PATCH v5 2/5] KVM: arm64: Add pre_fault_memory implementation

["Thomson, Jack" <jackabt.amazon@gmail.com>]

Hi Vincent,

On 27/07/2026 12:11 pm, Vincent Donnefort wrote:
>> +	unsigned long		*page_size;
> 
> It looks a bit odd in that struct.
> 
> Also, transparent_hugepage_adjust() modifies pfn and gfn. So perhaps it'd be
> better to introduce a struct kvm_s2_fault_mapping that can be used to get what
> has actually been mapped in kvm_s2_fault_map()?
> 

Yeah that's much nicer I'll do that thanks for the suggestion!

>> +	if (vcpu_is_protected(vcpu))
>> +		return -EOPNOTSUPP;
> 
> It could just call pkvm_mem_abort() when the VM is protected?
> 

I see, I don't have a setup to test this properly myself, so at the
moment I left the protected vm's out and don't advertise the capability,
if there's a usecase happy to look at it as a follow-up.

>> +	/*
>> +	 * pKVM stage-2 mappings aren't directly walkable from the host; let
>> +	 * the fault path handle both new and existing mappings.
>> +	 */
> 
> pKVM has a host interval-tree where we keep track of what has been mapped and at
> what level. This tree is also protected with the mmu_lock.
> 

Thanks, that sounds better. I'll have a look at moving to that for v6 then.

-- 
Thanks,
Jack