Provide allocate() helpers so that tests can mimic a userspace that frees
private memory on conversion, e.g. to prioritize memory usage over
performance.

Signed-off-by: Vishal Annapurve <redacted>
Co-developed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: [ref]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 .../selftests/kvm/include/kvm_util_base.h     | 48 +++++++++++++++++++
 tools/testing/selftests/kvm/lib/kvm_util.c    | 28 +++++++++++
 2 files changed, 76 insertions(+)

diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h
index 9f861182c02a..1441fca6c273 100644
--- a/tools/testing/selftests/kvm/include/kvm_util_base.h
+++ b/tools/testing/selftests/kvm/include/kvm_util_base.h

@@ -333,6 +333,54 @@ static inline void vm_enable_cap(struct kvm_vm *vm, uint32_t cap, uint64_t arg0)
        vm_ioctl(vm, KVM_ENABLE_CAP, &enable_cap);
 }

+static inline void vm_set_memory_attributes(struct kvm_vm *vm, uint64_t gpa,
+                                           uint64_t size, uint64_t attributes)
+{
+       struct kvm_memory_attributes attr = {
+               .attributes = attributes,
+               .address = gpa,
+               .size = size,
+               .flags = 0,
+       };
+
+       /*
+        * KVM_SET_MEMORY_ATTRIBUTES overwrites _all_ attributes.  These flows
+        * need significant enhancements to support multiple attributes.
+        */
+       TEST_ASSERT(!attributes || attributes == KVM_MEMORY_ATTRIBUTE_PRIVATE,
+                   "Update me to support multiple attributes!");
+
+       vm_ioctl(vm, KVM_SET_MEMORY_ATTRIBUTES, &attr);
+}
+
+
+static inline void vm_mem_set_private(struct kvm_vm *vm, uint64_t gpa,
+                                     uint64_t size)
+{
+       vm_set_memory_attributes(vm, gpa, size, KVM_MEMORY_ATTRIBUTE_PRIVATE);
+}
+
+static inline void vm_mem_set_shared(struct kvm_vm *vm, uint64_t gpa,
+                                    uint64_t size)
+{
+       vm_set_memory_attributes(vm, gpa, size, 0);
+}
+
+void vm_guest_mem_fallocate(struct kvm_vm *vm, uint64_t gpa, uint64_t size,
+                           bool punch_hole);
+
+static inline void vm_guest_mem_punch_hole(struct kvm_vm *vm, uint64_t gpa,
+                                          uint64_t size)
+{
+       vm_guest_mem_fallocate(vm, gpa, size, true);
+}
+
+static inline void vm_guest_mem_allocate(struct kvm_vm *vm, uint64_t gpa,
+                                        uint64_t size)
+{
+       vm_guest_mem_fallocate(vm, gpa, size, false);
+}
+
 void vm_enable_dirty_ring(struct kvm_vm *vm, uint32_t ring_size);
 const char *vm_guest_mode_string(uint32_t i);

diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index b63500fca627..95a553400ea9 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c

@@ -1167,6 +1167,34 @@ void vm_mem_region_delete(struct kvm_vm *vm, uint32_t slot)
        __vm_mem_region_delete(vm, memslot2region(vm, slot), true);
 }

+void vm_guest_mem_fallocate(struct kvm_vm *vm, uint64_t base, uint64_t size,
+                           bool punch_hole)
+{
+       const int mode = FALLOC_FL_KEEP_SIZE | (punch_hole ? FALLOC_FL_PUNCH_HOLE : 0);
+       struct userspace_mem_region *region;
+       uint64_t end = base + size;
+       uint64_t gpa, len;
+       off_t fd_offset;
+       int ret;
+
+       for (gpa = base; gpa < end; gpa += len) {
+               uint64_t offset;
+
+               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);