From: Sean Christopherson Date: Fri, 19 Sep 2025 00:32:59 +0000 (-0700) Subject: KVM: s390/vfio-ap: Use kvm_is_gpa_in_memslot() instead of open coded equivalent X-Git-Tag: v6.18-rc1~55^2~4 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=15463eece957be34da64b4d6fe18fc98981bf487;p=thirdparty%2Flinux.git KVM: s390/vfio-ap: Use kvm_is_gpa_in_memslot() instead of open coded equivalent Use kvm_is_gpa_in_memslot() to check the validity of the notification indicator byte address instead of open coding equivalent logic in the VFIO AP driver. Opportunistically use a dedicated wrapper that exists and is exported expressly for the VFIO AP module. kvm_is_gpa_in_memslot() is generally unsuitable for use outside of KVM; other drivers typically shouldn't rely on KVM's memslots, and using the API requires kvm->srcu (or slots_lock) to be held for the entire duration of the usage, e.g. to avoid TOCTOU bugs. handle_pqap() is a bit of a special case, as it's explicitly invoked from KVM with kvm->srcu already held, and the VFIO AP driver is in many ways an extension of KVM that happens to live in a separate module. Providing a dedicated API for the VFIO AP driver will allow restricting the vast majority of generic KVM's exports to KVM submodules (e.g. to x86's kvm-{amd,intel}.ko vendor mdoules). No functional change intended. Acked-by: Anthony Krowiak Reviewed-by: Christian Borntraeger Link: https://lore.kernel.org/r/20250919003303.1355064-2-seanjc@google.com Signed-off-by: Sean Christopherson Signed-off-by: Paolo Bonzini --- diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h index 95d15416c39d..c2ba3d4398c5 100644 --- a/arch/s390/include/asm/kvm_host.h +++ b/arch/s390/include/asm/kvm_host.h @@ -722,6 +722,8 @@ extern int kvm_s390_enter_exit_sie(struct kvm_s390_sie_block *scb, extern int kvm_s390_gisc_register(struct kvm *kvm, u32 gisc); extern int kvm_s390_gisc_unregister(struct kvm *kvm, u32 gisc); +bool kvm_s390_is_gpa_in_memslot(struct kvm *kvm, gpa_t gpa); + static inline void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot) {} static inline void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen) {} diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c index 9253c70897a8..9a71b6e00948 100644 --- a/arch/s390/kvm/priv.c +++ b/arch/s390/kvm/priv.c @@ -605,6 +605,14 @@ static int handle_io_inst(struct kvm_vcpu *vcpu) } } +#if IS_ENABLED(CONFIG_VFIO_AP) +bool kvm_s390_is_gpa_in_memslot(struct kvm *kvm, gpa_t gpa) +{ + return kvm_is_gpa_in_memslot(kvm, gpa); +} +EXPORT_SYMBOL_FOR_MODULES(kvm_s390_is_gpa_in_memslot, "vfio_ap"); +#endif + /* * handle_pqap: Handling pqap interception * @vcpu: the vcpu having issue the pqap instruction diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c index 766557547f83..eb5ff49f6fe7 100644 --- a/drivers/s390/crypto/vfio_ap_ops.c +++ b/drivers/s390/crypto/vfio_ap_ops.c @@ -354,7 +354,7 @@ static int vfio_ap_validate_nib(struct kvm_vcpu *vcpu, dma_addr_t *nib) if (!*nib) return -EINVAL; - if (kvm_is_error_hva(gfn_to_hva(vcpu->kvm, *nib >> PAGE_SHIFT))) + if (!kvm_s390_is_gpa_in_memslot(vcpu->kvm, *nib)) return -EINVAL; return 0;