[PATCH v11 40/46] KVM: selftests: Provide function to look up guest_memfd details from gpa

@@ -428,6 +428,9 @@ static inline void vm_enable_cap(struct kvm_vm *vm, u32 cap, u64 arg0)
 	vm_ioctl(vm, KVM_ENABLE_CAP, &enable_cap);
 }
 
+int kvm_gpa_to_guest_memfd(struct kvm_vm *vm, gpa_t gpa, off_t *fd_offset,
+			   size_t *nr_bytes);
+
 /*
  * KVM_SET_MEMORY_ATTRIBUTES{,2} overwrites _all_ attributes.  These
  * flows need significant enhancements to support multiple attributes.

@@ -1332,27 +1332,20 @@ void vm_guest_mem_fallocate(struct kvm_vm *vm, u64 base, u64 size,
 			    bool punch_hole)
 {
 	const int mode = FALLOC_FL_KEEP_SIZE | (punch_hole ? FALLOC_FL_PUNCH_HOLE : 0);
-	struct userspace_mem_region *region;
 	u64 end = base + size;
-	gpa_t gpa, len;
 	off_t fd_offset;
-	int ret;
+	int fd, ret;
+	size_t len;
+	gpa_t gpa;
 
 	for (gpa = base; gpa < end; gpa += len) {
-		u64 offset;
+		fd = kvm_gpa_to_guest_memfd(vm, gpa, &fd_offset, &len);
+		len = min(end - gpa, len);
 
-		region = userspace_mem_region_find(vm, gpa, gpa);
-		TEST_ASSERT(region && region->region.flags & KVM_MEM_GUEST_MEMFD,
-			    "Private memory region not found for GPA 0x%lx", gpa);
-
-		offset = gpa - region->region.guest_phys_addr;
-		fd_offset = region->region.guest_memfd_offset + offset;
-		len = min_t(u64, end - gpa, region->region.memory_size - offset);
-
-		ret = fallocate(region->region.guest_memfd, mode, fd_offset, len);
+		ret = fallocate(fd, mode, fd_offset, len);
 		TEST_ASSERT(!ret, "fallocate() failed to %s at %lx (len = %lu), fd = %d, mode = %x, offset = %lx",
 			    punch_hole ? "punch hole" : "allocate", gpa, len,
-			    region->region.guest_memfd, mode, fd_offset);
+			    fd, mode, fd_offset);
 	}
 }
 

@@ -1689,6 +1682,22 @@ void *addr_gpa2alias(struct kvm_vm *vm, gpa_t gpa)
 	return (void *) ((uintptr_t) region->host_alias + offset);
 }
 
+int kvm_gpa_to_guest_memfd(struct kvm_vm *vm, gpa_t gpa, off_t *fd_offset,
+			   size_t *nr_bytes)
+{
+	struct userspace_mem_region *region;
+	gpa_t gpa_offset;
+
+	region = userspace_mem_region_find(vm, gpa, gpa);
+	TEST_ASSERT(region && region->region.flags & KVM_MEM_GUEST_MEMFD,
+		    "guest_memfd memory region not found for GPA 0x%lx", gpa);
+
+	gpa_offset = gpa - region->region.guest_phys_addr;
+	*fd_offset = region->region.guest_memfd_offset + gpa_offset;
+	*nr_bytes = region->region.memory_size - gpa_offset;
+	return region->region.guest_memfd;
+}
+
 /* Create an interrupt controller chip for the specified VM. */
 void vm_create_irqchip(struct kvm_vm *vm)
 {