[RFC PATCH 04/11] KVM: selftests: Test transferring private memory to another VM

[Ackerley Tng <ackerleytng@google.com>]

Signed-off-by: Ackerley Tng <ackerleytng@google.com>
---
 tools/testing/selftests/kvm/Makefile          |  1 +
 .../kvm/x86_64/private_mem_migrate_tests.c    | 87 +++++++++++++++++++
 2 files changed, 88 insertions(+)
 create mode 100644 tools/testing/selftests/kvm/x86_64/private_mem_migrate_tests.c

diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index cb9450022302..d348ff56c92b 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -82,6 +82,7 @@ TEST_GEN_PROGS_x86_64 += x86_64/platform_info_test
 TEST_GEN_PROGS_x86_64 += x86_64/pmu_event_filter_test
 TEST_GEN_PROGS_x86_64 += x86_64/private_mem_conversions_test
 TEST_GEN_PROGS_x86_64 += x86_64/private_mem_kvm_exits_test
+TEST_GEN_PROGS_x86_64 += x86_64/private_mem_migrate_tests
 TEST_GEN_PROGS_x86_64 += x86_64/set_boot_cpu_id
 TEST_GEN_PROGS_x86_64 += x86_64/set_sregs_test
 TEST_GEN_PROGS_x86_64 += x86_64/smaller_maxphyaddr_emulation_test
diff --git a/tools/testing/selftests/kvm/x86_64/private_mem_migrate_tests.c b/tools/testing/selftests/kvm/x86_64/private_mem_migrate_tests.c
new file mode 100644
index 000000000000..4226de3ebd41
--- /dev/null
+++ b/tools/testing/selftests/kvm/x86_64/private_mem_migrate_tests.c
@@ -0,0 +1,87 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "kvm_util_base.h"
+#include "test_util.h"
+#include "ucall_common.h"
+#include <linux/kvm.h>
+#include <linux/sizes.h>
+
+#define TRANSFER_PRIVATE_MEM_TEST_SLOT 10
+#define TRANSFER_PRIVATE_MEM_GPA ((uint64_t)(1ull << 32))
+#define TRANSFER_PRIVATE_MEM_GVA TRANSFER_PRIVATE_MEM_GPA
+#define TRANSFER_PRIVATE_MEM_VALUE 0xdeadbeef
+
+static void transfer_private_mem_guest_code_src(void)
+{
+	uint64_t volatile *const ptr = (uint64_t *)TRANSFER_PRIVATE_MEM_GVA;
+
+	*ptr = TRANSFER_PRIVATE_MEM_VALUE;
+
+	GUEST_SYNC1(*ptr);
+}
+
+static void transfer_private_mem_guest_code_dst(void)
+{
+	uint64_t volatile *const ptr = (uint64_t *)TRANSFER_PRIVATE_MEM_GVA;
+
+	GUEST_SYNC1(*ptr);
+}
+
+static void test_transfer_private_mem(void)
+{
+	struct kvm_vm *src_vm, *dst_vm;
+	struct kvm_vcpu *src_vcpu, *dst_vcpu;
+	int src_memfd, dst_memfd;
+	struct ucall uc;
+
+	const struct vm_shape shape = {
+		.mode = VM_MODE_DEFAULT,
+		.type = KVM_X86_SW_PROTECTED_VM,
+	};
+
+	/* Build the source VM, use it to write to private memory */
+	src_vm = __vm_create_shape_with_one_vcpu(
+		shape, &src_vcpu, 0, transfer_private_mem_guest_code_src);
+	src_memfd = vm_create_guest_memfd(src_vm, SZ_4K, 0);
+
+	vm_mem_add(src_vm, DEFAULT_VM_MEM_SRC, TRANSFER_PRIVATE_MEM_GPA,
+		   TRANSFER_PRIVATE_MEM_TEST_SLOT, 1, KVM_MEM_PRIVATE,
+		   src_memfd, 0);
+
+	virt_map(src_vm, TRANSFER_PRIVATE_MEM_GVA, TRANSFER_PRIVATE_MEM_GPA, 1);
+	vm_set_memory_attributes(src_vm, TRANSFER_PRIVATE_MEM_GPA, SZ_4K,
+				 KVM_MEMORY_ATTRIBUTE_PRIVATE);
+
+	vcpu_run(src_vcpu);
+	TEST_ASSERT_KVM_EXIT_REASON(src_vcpu, KVM_EXIT_IO);
+	get_ucall(src_vcpu, &uc);
+	TEST_ASSERT(uc.args[0] == TRANSFER_PRIVATE_MEM_VALUE,
+		    "Source VM should be able to write to private memory");
+
+	/* Build the destination VM with linked fd */
+	dst_vm = __vm_create_shape_with_one_vcpu(
+		shape, &dst_vcpu, 0, transfer_private_mem_guest_code_dst);
+	dst_memfd = vm_link_guest_memfd(dst_vm, src_memfd, 0);
+
+	vm_mem_add(dst_vm, DEFAULT_VM_MEM_SRC, TRANSFER_PRIVATE_MEM_GPA,
+		   TRANSFER_PRIVATE_MEM_TEST_SLOT, 1, KVM_MEM_PRIVATE,
+		   dst_memfd, 0);
+
+	virt_map(dst_vm, TRANSFER_PRIVATE_MEM_GVA, TRANSFER_PRIVATE_MEM_GPA, 1);
+	vm_set_memory_attributes(dst_vm, TRANSFER_PRIVATE_MEM_GPA, SZ_4K,
+				 KVM_MEMORY_ATTRIBUTE_PRIVATE);
+
+	vcpu_run(dst_vcpu);
+	TEST_ASSERT_KVM_EXIT_REASON(dst_vcpu, KVM_EXIT_IO);
+	get_ucall(dst_vcpu, &uc);
+	TEST_ASSERT(uc.args[0] == TRANSFER_PRIVATE_MEM_VALUE,
+		    "Destination VM should be able to read value transferred");
+}
+
+int main(int argc, char *argv[])
+{
+	TEST_REQUIRE(kvm_check_cap(KVM_CAP_VM_TYPES) & BIT(KVM_X86_SW_PROTECTED_VM));
+
+	test_transfer_private_mem();
+
+	return 0;
+}
-- 
2.41.0.640.ga95def55d0-goog