[PATCH v2 19/30] KVM: arm64: Kill write_fault from kvm_s2_fault

[Anshuman Khandual]

On 27/03/26 5:06 PM, Marc Zyngier wrote:
> We already have kvm_is_write_fault() as a predicate indicating
> a S2 fault on a write, and we're better off just using that instead
> of duplicating the state.
> 
> Tested-by: Fuad Tabba <tabba at google.com>
> Reviewed-by: Fuad Tabba <tabba at google.com>
> Reviewed-by: Suzuki K Poulose <suzuki.poulose at arm.com>
> Signed-off-by: Marc Zyngier <maz at kernel.org>
> ---

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

>  arch/arm64/kvm/mmu.c | 11 +++--------
>  1 file changed, 3 insertions(+), 8 deletions(-)
> 
> diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
> index 981c04a74ab7a..7dab0c3faa5bf 100644
> --- a/arch/arm64/kvm/mmu.c
> +++ b/arch/arm64/kvm/mmu.c
> @@ -1711,7 +1711,6 @@ static short kvm_s2_resolve_vma_size(const struct kvm_s2_fault_desc *s2fd,
>  }
>  
>  struct kvm_s2_fault {
> -	bool write_fault;
>  	bool exec_fault;
>  	bool writable;
>  	bool topup_memcache;
> @@ -1799,7 +1798,7 @@ static int kvm_s2_fault_pin_pfn(const struct kvm_s2_fault_desc *s2fd,
>  		return ret;
>  
>  	fault->pfn = __kvm_faultin_pfn(s2fd->memslot, get_canonical_gfn(s2fd, fault),
> -				       fault->write_fault ? FOLL_WRITE : 0,
> +				       kvm_is_write_fault(s2fd->vcpu) ? FOLL_WRITE : 0,
>  				       &fault->writable, &fault->page);
>  	if (unlikely(is_error_noslot_pfn(fault->pfn))) {
>  		if (fault->pfn == KVM_PFN_ERR_HWPOISON) {
> @@ -1850,7 +1849,7 @@ static int kvm_s2_fault_compute_prot(const struct kvm_s2_fault_desc *s2fd,
>  			 */
>  			fault->s2_force_noncacheable = true;
>  		}
> -	} else if (fault->logging_active && !fault->write_fault) {
> +	} else if (fault->logging_active && !kvm_is_write_fault(s2fd->vcpu)) {
>  		/*
>  		 * Only actually map the page as writable if this was a write
>  		 * fault.
> @@ -1980,21 +1979,17 @@ static int kvm_s2_fault_map(const struct kvm_s2_fault_desc *s2fd,
>  static int user_mem_abort(const struct kvm_s2_fault_desc *s2fd)
>  {
>  	bool perm_fault = kvm_vcpu_trap_is_permission_fault(s2fd->vcpu);
> -	bool write_fault = kvm_is_write_fault(s2fd->vcpu);
>  	bool logging_active = memslot_is_logging(s2fd->memslot);
>  	struct kvm_s2_fault fault = {
>  		.logging_active = logging_active,
>  		.force_pte = logging_active,
>  		.prot = KVM_PGTABLE_PROT_R,
> -		.write_fault = write_fault,
>  		.exec_fault = kvm_vcpu_trap_is_exec_fault(s2fd->vcpu),
> -		.topup_memcache = !perm_fault || (logging_active && write_fault),
> +		.topup_memcache = !perm_fault || (logging_active && kvm_is_write_fault(s2fd->vcpu)),
>  	};
>  	void *memcache;
>  	int ret;
>  
> -	VM_WARN_ON_ONCE(fault.write_fault && fault.exec_fault);
> -
>  	/*
>  	 * Permission faults just need to update the existing leaf entry,
>  	 * and so normally don't require allocations from the memcache. The