Re: [PATCH v2 14/30] KVM: arm64: Kill fault->ipa

[Anshuman Khandual <anshuman.khandual@arm.com>]

On 27/03/26 5:06 PM, Marc Zyngier wrote:
> fault->ipa, in a nested contest, represents the output of the guest's
> S2 translation for the fault->fault_ipa input, and is equal to
> fault->fault_ipa otherwise,
> 
> Given that this is readily available from kvm_s2_trans_output(),
> drop fault->ipa and directly compute fault->gfn instead, which
> is really what we want.
> 
> Tested-by: Fuad Tabba <tabba@google.com>
> Reviewed-by: Fuad Tabba <tabba@google.com>
> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
> Signed-off-by: Marc Zyngier <maz@kernel.org>

Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>

> ---
>  arch/arm64/kvm/mmu.c | 14 +++++---------
>  1 file changed, 5 insertions(+), 9 deletions(-)
> 
> diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
> index c6cd6ce5254be..67e5e867e01dc 100644
> --- a/arch/arm64/kvm/mmu.c
> +++ b/arch/arm64/kvm/mmu.c
> @@ -1643,7 +1643,7 @@ static short kvm_s2_resolve_vma_size(struct vm_area_struct *vma,
>  				     unsigned long hva,
>  				     struct kvm_memory_slot *memslot,
>  				     struct kvm_s2_trans *nested,
> -				     bool *force_pte, phys_addr_t *ipa)
> +				     bool *force_pte)
>  {
>  	short vma_shift;
>  
> @@ -1681,8 +1681,6 @@ static short kvm_s2_resolve_vma_size(struct vm_area_struct *vma,
>  
>  		max_map_size = *force_pte ? PAGE_SIZE : PUD_SIZE;
>  
> -		*ipa = kvm_s2_trans_output(nested);
> -
>  		/*
>  		 * If we're about to create a shadow stage 2 entry, then we
>  		 * can only create a block mapping if the guest stage 2 page
> @@ -1722,7 +1720,6 @@ struct kvm_s2_fault {
>  	bool is_vma_cacheable;
>  	bool s2_force_noncacheable;
>  	unsigned long mmu_seq;
> -	phys_addr_t ipa;
>  	gfn_t gfn;
>  	kvm_pfn_t pfn;
>  	bool logging_active;
> @@ -1738,6 +1735,7 @@ static int kvm_s2_fault_get_vma_info(struct kvm_s2_fault *fault)
>  {
>  	struct vm_area_struct *vma;
>  	struct kvm *kvm = fault->vcpu->kvm;
> +	phys_addr_t ipa;
>  
>  	mmap_read_lock(current->mm);
>  	vma = vma_lookup(current->mm, fault->hva);
> @@ -1748,8 +1746,7 @@ static int kvm_s2_fault_get_vma_info(struct kvm_s2_fault *fault)
>  	}
>  
>  	fault->vma_pagesize = 1UL << kvm_s2_resolve_vma_size(vma, fault->hva, fault->memslot,
> -							     fault->nested, &fault->force_pte,
> -							     &fault->ipa);
> +							     fault->nested, &fault->force_pte);
>  
>  	/*
>  	 * Both the canonical IPA and fault IPA must be aligned to the
> @@ -1757,9 +1754,9 @@ static int kvm_s2_fault_get_vma_info(struct kvm_s2_fault *fault)
>  	 * mapping in the right place.
>  	 */
>  	fault->fault_ipa = ALIGN_DOWN(fault->fault_ipa, fault->vma_pagesize);
> -	fault->ipa = ALIGN_DOWN(fault->ipa, fault->vma_pagesize);
> +	ipa = fault->nested ? kvm_s2_trans_output(fault->nested) : fault->fault_ipa;
> +	fault->gfn = ALIGN_DOWN(ipa, fault->vma_pagesize) >> PAGE_SHIFT;
>  
> -	fault->gfn = fault->ipa >> PAGE_SHIFT;
>  	fault->mte_allowed = kvm_vma_mte_allowed(vma);
>  
>  	fault->vm_flags = vma->vm_flags;
> @@ -1970,7 +1967,6 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
>  		.memslot = memslot,
>  		.hva = hva,
>  		.fault_is_perm = fault_is_perm,
> -		.ipa = fault_ipa,
>  		.logging_active = logging_active,
>  		.force_pte = logging_active,
>  		.prot = KVM_PGTABLE_PROT_R,