1 files changed, 92 insertions, 0 deletions
diff --git a/arch/s390/kvm/faultin.h b/arch/s390/kvm/faultin.h
new file mode 100644
index 000000000000..f86176d2769c
--- /dev/null
+++ b/arch/s390/kvm/faultin.h
@@ -0,0 +1,92 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ *  KVM guest fault handling.
+ *
+ *    Copyright IBM Corp. 2025
+ *    Author(s): Claudio Imbrenda <imbrenda@linux.ibm.com>
+ */
+
+#ifndef __KVM_S390_FAULTIN_H
+#define __KVM_S390_FAULTIN_H
+
+#include <linux/kvm_host.h>
+
+#include "dat.h"
+
+int kvm_s390_faultin_gfn(struct kvm_vcpu *vcpu, struct kvm *kvm, struct guest_fault *f);
+int kvm_s390_get_guest_page(struct kvm *kvm, struct guest_fault *f, gfn_t gfn, bool w);
+
+static inline int kvm_s390_faultin_gfn_simple(struct kvm_vcpu *vcpu, struct kvm *kvm,
+					      gfn_t gfn, bool wr)
+{
+	struct guest_fault f = { .gfn = gfn, .write_attempt = wr, };
+
+	return kvm_s390_faultin_gfn(vcpu, kvm, &f);
+}
+
+static inline int kvm_s390_get_guest_page_and_read_gpa(struct kvm *kvm, struct guest_fault *f,
+						       gpa_t gaddr, unsigned long *val)
+{
+	int rc;
+
+	rc = kvm_s390_get_guest_page(kvm, f, gpa_to_gfn(gaddr), false);
+	if (rc)
+		return rc;
+
+	*val = *(unsigned long *)phys_to_virt(pfn_to_phys(f->pfn) | offset_in_page(gaddr));
+
+	return 0;
+}
+
+static inline void kvm_s390_release_multiple(struct kvm *kvm, struct guest_fault *guest_faults,
+					     int n, bool ignore)
+{
+	int i;
+
+	for (i = 0; i < n; i++) {
+		kvm_release_faultin_page(kvm, guest_faults[i].page, ignore,
+					 guest_faults[i].write_attempt);
+		guest_faults[i].page = NULL;
+	}
+}
+
+static inline bool kvm_s390_multiple_faults_need_retry(struct kvm *kvm, unsigned long seq,
+						       struct guest_fault *guest_faults, int n,
+						       bool unsafe)
+{
+	int i;
+
+	for (i = 0; i < n; i++) {
+		if (!guest_faults[i].valid)
+			continue;
+		if (unsafe && mmu_invalidate_retry_gfn_unsafe(kvm, seq, guest_faults[i].gfn))
+			return true;
+		if (!unsafe && mmu_invalidate_retry_gfn(kvm, seq, guest_faults[i].gfn))
+			return true;
+	}
+	return false;
+}
+
+static inline int kvm_s390_get_guest_pages(struct kvm *kvm, struct guest_fault *guest_faults,
+					   gfn_t start, int n_pages, bool write_attempt)
+{
+	int i, rc;
+
+	for (i = 0; i < n_pages; i++) {
+		rc = kvm_s390_get_guest_page(kvm, guest_faults + i, start + i, write_attempt);
+		if (rc)
+			break;
+	}
+	return rc;
+}
+
+#define kvm_s390_release_faultin_array(kvm, array, ignore) \
+	kvm_s390_release_multiple(kvm, array, ARRAY_SIZE(array), ignore)
+
+#define kvm_s390_array_needs_retry_unsafe(kvm, seq, array) \
+	kvm_s390_multiple_faults_need_retry(kvm, seq, array, ARRAY_SIZE(array), true)
+
+#define kvm_s390_array_needs_retry_safe(kvm, seq, array) \
+	kvm_s390_multiple_faults_need_retry(kvm, seq, array, ARRAY_SIZE(array), false)
+
+#endif /* __KVM_S390_FAULTIN_H */