[PATCH 00/17] KVM: arm64: More user_mem_abort() rework

[Suzuki K Poulose]

On 16/03/2026 17:54, Marc Zyngier wrote:
> Piqued by Fuad's initial set of patches[1] splitting user_mem_abort()
> into more "edible" functions, I've added my on take on top of it with
> a few goals in mind:
> 
> - contextualise the state by splitting kvm_s2_fault into more granular
>    structures
> 
> - reduce the amount of state that is visible and/or mutable by any
>    single function
> 
> - reduce the number of variable that simply cache state that is
>    already implicitly available (and often only a helper away)
> 
> I find the result reasonably attractive, and throwing it at a couple
> of machines didn't result in anything out of the ordinary.

Indeed a very nice cleanup both of you ! Thanks for making this
pleasing to the eyes and easier to reason about.

FWIW:

Reviewed-by: Suzuki K Poulose <suzuki.poulose at arm.com>


> 
> For those interested, I have stashed a branch at [2], and I'd
> appreciate some feedback on the outcome.
> 
> [1] https://lore.kernel.org/all/20260306140232.2193802-1-tabba@google.com/
> [2] https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git/log/?h=hack/user_mem_abort-rework
> 
> Marc Zyngier (17):
>    KVM: arm64: Kill fault->ipa
>    KVM: arm64: Make fault_ipa immutable
>    KVM: arm64: Move fault context to const structure
>    KVM: arm64: Replace fault_is_perm with a helper
>    KVM: arm64: Constrain fault_granule to kvm_s2_fault_map()
>    KVM: arm64: Kill write_fault from kvm_s2_fault
>    KVM: arm64: Kill exec_fault from kvm_s2_fault
>    KVM: arm64: Kill topup_memcache from kvm_s2_fault
>    KVM: arm64: Move VMA-related information to kvm_s2_fault_vma_info
>    KVM: arm64: Kill logging_active from kvm_s2_fault
>    KVM: arm64: Restrict the scope of the 'writable' attribute
>    KVM: arm64: Move kvm_s2_fault.{pfn,page} to kvm_s2_vma_info
>    KVM: arm64: Replace force_pte with a max_map_size attribute
>    KVM: arm64: Move device mapping management into kvm_s2_fault_pin_pfn()
>    KVM: arm64: Directly expose mapping prot and kill kvm_s2_fault
>    KVM: arm64: Simplify integration of adjust_nested_*_perms()
>    KVM: arm64: Convert gmem_abort() to struct kvm_s2_fault_desc
> 
>   arch/arm64/kvm/mmu.c | 428 ++++++++++++++++++++++---------------------
>   1 file changed, 223 insertions(+), 205 deletions(-)
>