Re: [PATCH v14 23/44] arm64: RMI: Handle RMI_EXIT_RIPAS_CHANGE

[Steven Price]

On 19/05/2026 10:40, Aneesh Kumar K.V wrote:
> Steven Price <steven.price@xxxxxxx> writes:
> 
> ...
> 
>> +void kvm_realm_unmap_range(struct kvm *kvm, unsigned long start,
>> +			   unsigned long size, bool unmap_private,
>> +			   bool may_block)
>> +{
>> +	unsigned long end = start + size;
>> +	struct realm *realm = &kvm->arch.realm;
>> +
>> +	if (!kvm_realm_is_created(kvm))
>> +		return;
>> +
>> +	end = min(BIT(realm->ia_bits - 1), end);
>> +
>> +	realm_unmap_shared_range(kvm, start, end, may_block);
>> +	if (unmap_private)
>> +		realm_unmap_private_range(kvm, start, end, may_block);
>> +}
>> +
>  
> kvm_gmem_invalidate_begin() indicates a private-only invalidation. How
> is that supported?

Because we treat the private and shared spaces are aliasing we don't
really support a "private-only" invalidation. So the shared space will
be invalidated as well. Something has gone wrong if we've ended up with
the 'same' IPA being used in both the private and shared spaces.

Private has to be treated slightly specially because removing a private
mapping is observable by the guest (the page can't be reinserted without
the guest agreeing and the contents being wiped). For shared mappings
the page can simply be refaulted.

That said, I'll look into Wei-Lin's suggestion to use
kvm_gfn_range_filter which would allow all three combinations of
private-only, shared-only and private+shared.

Thanks,
Steve