[PATCH 7/7] KVM: selftests: x86: Add test for KVM_MAP_MEMORY

[Paolo Bonzini <pbonzini@redhat.com>]

From: Isaku Yamahata <isaku.yamahata@intel.com>

Add a test case to exercise KVM_MAP_MEMORY and run the guest to access the
pre-populated area.  It tests KVM_MAP_MEMORY ioctl for KVM_X86_DEFAULT_VM
and KVM_X86_SW_PROTECTED_VM.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Message-ID: <32427791ef42e5efaafb05d2ac37fa4372715f47.1712785629.git.isaku.yamahata@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 tools/include/uapi/linux/kvm.h                |   8 ++
 tools/testing/selftests/kvm/Makefile          |   1 +
 tools/testing/selftests/kvm/map_memory_test.c | 135 ++++++++++++++++++
 3 files changed, 144 insertions(+)
 create mode 100644 tools/testing/selftests/kvm/map_memory_test.c

diff --git a/tools/include/uapi/linux/kvm.h b/tools/include/uapi/linux/kvm.h
index c3308536482b..69a43c5ae33c 100644
--- a/tools/include/uapi/linux/kvm.h
+++ b/tools/include/uapi/linux/kvm.h
@@ -2227,4 +2227,12 @@ struct kvm_create_guest_memfd {
 	__u64 reserved[6];
 };
 
+#define KVM_MAP_MEMORY	_IOWR(KVMIO, 0xd5, struct kvm_map_memory)
+
+struct kvm_map_memory {
+	__u64 base_address;
+	__u64 size;
+	__u64 flags;
+};
+
 #endif /* __LINUX_KVM_H */
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 871e2de3eb05..41def90f7dfb 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -144,6 +144,7 @@ TEST_GEN_PROGS_x86_64 += set_memory_region_test
 TEST_GEN_PROGS_x86_64 += steal_time
 TEST_GEN_PROGS_x86_64 += kvm_binary_stats_test
 TEST_GEN_PROGS_x86_64 += system_counter_offset_test
+TEST_GEN_PROGS_x86_64 += map_memory_test
 
 # Compiled outputs used by test targets
 TEST_GEN_PROGS_EXTENDED_x86_64 += x86_64/nx_huge_pages_test
diff --git a/tools/testing/selftests/kvm/map_memory_test.c b/tools/testing/selftests/kvm/map_memory_test.c
new file mode 100644
index 000000000000..e52e33145f01
--- /dev/null
+++ b/tools/testing/selftests/kvm/map_memory_test.c
@@ -0,0 +1,135 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2024, Intel, Inc
+ *
+ * Author:
+ * Isaku Yamahata <isaku.yamahata at gmail.com>
+ */
+#include <linux/sizes.h>
+
+#include <test_util.h>
+#include <kvm_util.h>
+#include <processor.h>
+
+/* Arbitrarily chosen values */
+#define TEST_SIZE		(SZ_2M + PAGE_SIZE)
+#define TEST_NPAGES		(TEST_SIZE / PAGE_SIZE)
+#define TEST_SLOT		10
+
+static void guest_code(uint64_t base_gpa)
+{
+	volatile uint64_t val __used;
+	int i;
+
+	for (i = 0; i < TEST_NPAGES; i++) {
+		uint64_t *src = (uint64_t *)(base_gpa + i * PAGE_SIZE);
+
+		val = *src;
+	}
+
+	GUEST_DONE();
+}
+
+static void map_memory(struct kvm_vcpu *vcpu, u64 base_address, u64 size,
+		       bool should_succeed)
+{
+	struct kvm_map_memory mapping = {
+		.base_address = base_address,
+		.size = size,
+		.flags = 0,
+	};
+	int ret;
+
+	do {
+		ret = __vcpu_ioctl(vcpu, KVM_MAP_MEMORY, &mapping);
+	} while (ret >= 0 && mapping.size);
+
+	if (should_succeed)
+		__TEST_ASSERT_VM_VCPU_IOCTL(!ret, "KVM_MAP_MEMORY", ret, vcpu->vm);
+	else
+		/* No memory slot causes RET_PF_EMULATE. it results in -EINVAL. */
+		__TEST_ASSERT_VM_VCPU_IOCTL(ret && errno == EINVAL,
+					    "KVM_MAP_MEMORY", ret, vcpu->vm);
+}
+
+static void __test_map_memory(unsigned long vm_type, bool private)
+{
+	const struct vm_shape shape = {
+		.mode = VM_MODE_DEFAULT,
+		.type = vm_type,
+	};
+	struct kvm_vcpu *vcpu;
+	struct kvm_run *run;
+	struct kvm_vm *vm;
+	struct ucall uc;
+
+	uint64_t guest_test_phys_mem;
+	uint64_t guest_test_virt_mem;
+	uint64_t alignment, guest_page_size;
+
+	vm = vm_create_shape_with_one_vcpu(shape, &vcpu, guest_code);
+
+	alignment = guest_page_size = vm_guest_mode_params[VM_MODE_DEFAULT].page_size;
+	guest_test_phys_mem = (vm->max_gfn - TEST_NPAGES) * guest_page_size;
+#ifdef __s390x__
+	alignment = max(0x100000UL, guest_page_size);
+#else
+	alignment = SZ_2M;
+#endif
+	guest_test_phys_mem = align_down(guest_test_phys_mem, alignment);
+	guest_test_virt_mem = guest_test_phys_mem;
+
+	vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
+				    guest_test_phys_mem, TEST_SLOT, TEST_NPAGES,
+				    private ? KVM_MEM_GUEST_MEMFD : 0);
+	virt_map(vm, guest_test_virt_mem, guest_test_phys_mem, TEST_NPAGES);
+
+	if (private)
+		vm_mem_set_private(vm, guest_test_phys_mem, TEST_SIZE);
+	map_memory(vcpu, guest_test_phys_mem, SZ_2M, true);
+	map_memory(vcpu, guest_test_phys_mem + SZ_2M, PAGE_SIZE, true);
+	map_memory(vcpu, guest_test_phys_mem + TEST_SIZE, PAGE_SIZE, false);
+
+	vcpu_args_set(vcpu, 1, guest_test_virt_mem);
+	vcpu_run(vcpu);
+
+	run = vcpu->run;
+	TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
+		    "Wanted KVM_EXIT_IO, got exit reason: %u (%s)",
+		    run->exit_reason, exit_reason_str(run->exit_reason));
+
+	switch (get_ucall(vcpu, &uc)) {
+	case UCALL_ABORT:
+		REPORT_GUEST_ASSERT(uc);
+		break;
+	case UCALL_DONE:
+		break;
+	default:
+		TEST_FAIL("Unknown ucall 0x%lx.", uc.cmd);
+		break;
+	}
+
+	kvm_vm_free(vm);
+}
+
+static void test_map_memory(unsigned long vm_type, bool private)
+{
+	if (vm_type && !(kvm_check_cap(KVM_CAP_VM_TYPES) & BIT(vm_type))) {
+		pr_info("Skipping tests for vm_type 0x%lx\n", vm_type);
+		return;
+	}
+
+	__test_map_memory(vm_type, private);
+}
+
+int main(int argc, char *argv[])
+{
+	TEST_REQUIRE(kvm_check_cap(KVM_CAP_MAP_MEMORY));
+
+	test_map_memory(0, false);
+#ifdef __x86_64__
+	test_map_memory(KVM_X86_SW_PROTECTED_VM, false);
+	test_map_memory(KVM_X86_SW_PROTECTED_VM, true);
+#endif
+	return 0;
+}
-- 
2.43.0