[RFC PATCH v11 21/29] KVM: selftests: Add helpers to convert guest memory b/w private and shared

[Sean Christopherson]

From: Vishal Annapurve <vannapurve at google.com>

Signed-off-by: Vishal Annapurve <vannapurve at google.com>
Co-developed-by: Sean Christopherson <seanjc at google.com>
Signed-off-by: Sean Christopherson <seanjc at google.com>
---
 .../selftests/kvm/include/kvm_util_base.h     | 48 +++++++++++++++++++
 tools/testing/selftests/kvm/lib/kvm_util.c    | 26 ++++++++++
 2 files changed, 74 insertions(+)

diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h
index f1de6a279561..1819787b773b 100644
--- a/tools/testing/selftests/kvm/include/kvm_util_base.h
+++ b/tools/testing/selftests/kvm/include/kvm_util_base.h
@@ -312,6 +312,54 @@ 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 b93717e62325..1283e24b76f1 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -1171,6 +1171,32 @@ 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 gpa, uint64_t size,
+			    bool punch_hole)
+{
+	struct userspace_mem_region *region;
+	uint64_t end = gpa + size - 1;
+	off_t fd_offset;
+	int mode, ret;
+
+	region = userspace_mem_region_find(vm, gpa, gpa);
+	TEST_ASSERT(region && region->region.flags & KVM_MEM_PRIVATE,
+		    "Private memory region not found for GPA 0x%lx", gpa);
+
+	TEST_ASSERT(region == userspace_mem_region_find(vm, end, end),
+		    "fallocate() for guest_memfd must act on a single memslot");
+
+	fd_offset = region->region.gmem_offset +
+		    (gpa - region->region.guest_phys_addr);
+
+	mode = FALLOC_FL_KEEP_SIZE | (punch_hole ? FALLOC_FL_PUNCH_HOLE : 0);
+
+	ret = fallocate(region->region.gmem_fd, mode, fd_offset, size);
+	TEST_ASSERT(!ret, "fallocate() failed to %s at %lx[%lu], fd = %d, mode = %x, offset = %lx\n",
+		     punch_hole ? "punch hole" : "allocate", gpa, size,
+		     region->region.gmem_fd, mode, fd_offset);
+}
+
 /* Returns the size of a vCPU's kvm_run structure. */
 static int vcpu_mmap_sz(void)
 {
-- 
2.41.0.255.g8b1d071c50-goog