kvm: selftests: add API testing infrastructure

Testsuite contributed by Google and cleaned up by myself for
inclusion in Linux.

Signed-off-by: Ken Hofsass <hofsass@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

tools/testing/selftests/Makefile

@@ -14,6 +14,7 @@ TARGETS += gpio
 TARGETS += intel_pstate
 TARGETS += ipc
 TARGETS += kcmp
+TARGETS += kvm
 TARGETS += lib
 TARGETS += membarrier
 TARGETS += memfd

tools/testing/selftests/kvm/Makefile

@@ -0,0 +1,38 @@
+all:
+
+top_srcdir = ../../../../
+UNAME_M := $(shell uname -m)
+
+LIBKVM = lib/assert.c lib/kvm_util.c lib/sparsebit.c
+LIBKVM_x86_64 = lib/x86.c
+
+TEST_GEN_PROGS_x86_64 = set_sregs_test
+
+TEST_GEN_PROGS += $(TEST_GEN_PROGS_$(UNAME_M))
+LIBKVM += $(LIBKVM_$(UNAME_M))
+
+INSTALL_HDR_PATH = $(top_srcdir)/usr
+LINUX_HDR_PATH = $(INSTALL_HDR_PATH)/include/
+CFLAGS += -O2 -g -I$(LINUX_HDR_PATH) -Iinclude -I$(<D)
+
+# After inclusion, $(OUTPUT) is defined and
+# $(TEST_GEN_PROGS) starts with $(OUTPUT)/
+include ../lib.mk
+
+STATIC_LIBS := $(OUTPUT)/libkvm.a
+LIBKVM_OBJ := $(patsubst %.c, $(OUTPUT)/%.o, $(LIBKVM))
+EXTRA_CLEAN += $(LIBKVM_OBJ) $(STATIC_LIBS)
+
+x := $(shell mkdir -p $(sort $(dir $(LIBKVM_OBJ))))
+$(LIBKVM_OBJ): $(OUTPUT)/%.o: %.c
+	$(CC) $(CFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -c $< -o $@
+
+$(OUTPUT)/libkvm.a: $(LIBKVM_OBJ)
+	$(AR) crs $@ $^
+
+$(LINUX_HDR_PATH):
+	make -C $(top_srcdir) headers_install
+
+all: $(STATIC_LIBS) $(LINUX_HDR_PATH)
+$(TEST_GEN_PROGS): $(STATIC_LIBS)
+$(TEST_GEN_PROGS) $(LIBKVM_OBJ): | $(LINUX_HDR_PATH)

tools/testing/selftests/kvm/include/kvm_util.h

@@ -0,0 +1,139 @@
+/*
+ * tools/testing/selftests/kvm/include/kvm_util.h
+ *
+ * Copyright (C) 2018, Google LLC.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ *
+ */
+#ifndef SELFTEST_KVM_UTIL_H
+#define SELFTEST_KVM_UTIL_H 1
+
+#include "test_util.h"
+
+#include "asm/kvm.h"
+#include "linux/kvm.h"
+#include <sys/ioctl.h>
+
+#include "sparsebit.h"
+
+/*
+ * Memslots can't cover the gfn starting at this gpa otherwise vCPUs can't be
+ * created. Only applies to VMs using EPT.
+ */
+#define KVM_DEFAULT_IDENTITY_MAP_ADDRESS 0xfffbc000ul
+
+
+/* Callers of kvm_util only have an incomplete/opaque description of the
+ * structure kvm_util is using to maintain the state of a VM.
+ */
+struct kvm_vm;
+
+typedef uint64_t vm_paddr_t; /* Virtual Machine (Guest) physical address */
+typedef uint64_t vm_vaddr_t; /* Virtual Machine (Guest) virtual address */
+
+/* Minimum allocated guest virtual and physical addresses */
+#define KVM_UTIL_MIN_VADDR 0x2000
+
+#define DEFAULT_GUEST_PHY_PAGES		512
+#define DEFAULT_GUEST_STACK_VADDR_MIN	0xab6000
+#define DEFAULT_STACK_PGS               5
+
+enum vm_guest_mode {
+	VM_MODE_FLAT48PG,
+};
+
+enum vm_mem_backing_src_type {
+	VM_MEM_SRC_ANONYMOUS,
+	VM_MEM_SRC_ANONYMOUS_THP,
+	VM_MEM_SRC_ANONYMOUS_HUGETLB,
+};
+
+int kvm_check_cap(long cap);
+
+struct kvm_vm *vm_create(enum vm_guest_mode mode, uint64_t phy_pages, int perm);
+void kvm_vm_free(struct kvm_vm *vmp);
+
+int kvm_memcmp_hva_gva(void *hva,
+	struct kvm_vm *vm, const vm_vaddr_t gva, size_t len);
+
+void vm_dump(FILE *stream, struct kvm_vm *vm, uint8_t indent);
+void vcpu_dump(FILE *stream, struct kvm_vm *vm,
+	uint32_t vcpuid, uint8_t indent);
+
+void vm_create_irqchip(struct kvm_vm *vm);
+
+void vm_userspace_mem_region_add(struct kvm_vm *vm,
+	enum vm_mem_backing_src_type src_type,
+	uint64_t guest_paddr, uint32_t slot, uint64_t npages,
+	uint32_t flags);
+
+void vcpu_ioctl(struct kvm_vm *vm,
+	uint32_t vcpuid, unsigned long ioctl, void *arg);
+void vm_ioctl(struct kvm_vm *vm, unsigned long ioctl, void *arg);
+void vm_mem_region_set_flags(struct kvm_vm *vm, uint32_t slot, uint32_t flags);
+void vm_vcpu_add(struct kvm_vm *vm, uint32_t vcpuid);
+vm_vaddr_t vm_vaddr_alloc(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min,
+	uint32_t data_memslot, uint32_t pgd_memslot);
+void *addr_gpa2hva(struct kvm_vm *vm, vm_paddr_t gpa);
+void *addr_gva2hva(struct kvm_vm *vm, vm_vaddr_t gva);
+vm_paddr_t addr_hva2gpa(struct kvm_vm *vm, void *hva);
+vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva);
+
+struct kvm_run *vcpu_state(struct kvm_vm *vm, uint32_t vcpuid);
+void vcpu_run(struct kvm_vm *vm, uint32_t vcpuid);
+int _vcpu_run(struct kvm_vm *vm, uint32_t vcpuid);
+void vcpu_set_mp_state(struct kvm_vm *vm, uint32_t vcpuid,
+	struct kvm_mp_state *mp_state);
+void vcpu_regs_get(struct kvm_vm *vm,
+	uint32_t vcpuid, struct kvm_regs *regs);
+void vcpu_regs_set(struct kvm_vm *vm,
+	uint32_t vcpuid, struct kvm_regs *regs);
+void vcpu_args_set(struct kvm_vm *vm, uint32_t vcpuid, unsigned int num, ...);
+void vcpu_sregs_get(struct kvm_vm *vm,
+	uint32_t vcpuid, struct kvm_sregs *sregs);
+void vcpu_sregs_set(struct kvm_vm *vm,
+	uint32_t vcpuid, struct kvm_sregs *sregs);
+int _vcpu_sregs_set(struct kvm_vm *vm,
+	uint32_t vcpuid, struct kvm_sregs *sregs);
+void vcpu_events_get(struct kvm_vm *vm, uint32_t vcpuid,
+			  struct kvm_vcpu_events *events);
+void vcpu_events_set(struct kvm_vm *vm, uint32_t vcpuid,
+			  struct kvm_vcpu_events *events);
+
+const char *exit_reason_str(unsigned int exit_reason);
+
+void virt_pgd_alloc(struct kvm_vm *vm, uint32_t pgd_memslot);
+void virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
+	uint32_t pgd_memslot);
+vm_paddr_t vm_phy_page_alloc(struct kvm_vm *vm,
+	vm_paddr_t paddr_min, uint32_t memslot);
+
+void kvm_get_supported_cpuid(struct kvm_cpuid2 *cpuid);
+void vcpu_set_cpuid(
+	struct kvm_vm *vm, uint32_t vcpuid, struct kvm_cpuid2 *cpuid);
+
+struct kvm_cpuid2 *allocate_kvm_cpuid2(void);
+struct kvm_cpuid_entry2 *
+find_cpuid_index_entry(struct kvm_cpuid2 *cpuid, uint32_t function,
+		       uint32_t index);
+
+static inline struct kvm_cpuid_entry2 *
+find_cpuid_entry(struct kvm_cpuid2 *cpuid, uint32_t function)
+{
+	return find_cpuid_index_entry(cpuid, function, 0);
+}
+
+struct kvm_vm *vm_create_default(uint32_t vcpuid, void *guest_code);
+void vm_vcpu_add_default(struct kvm_vm *vm, uint32_t vcpuid, void *guest_code);
+
+struct kvm_userspace_memory_region *
+kvm_userspace_memory_region_find(struct kvm_vm *vm, uint64_t start,
+				 uint64_t end);
+
+struct kvm_dirty_log *
+allocate_kvm_dirty_log(struct kvm_userspace_memory_region *region);
+
+int vm_create_device(struct kvm_vm *vm, struct kvm_create_device *cd);
+
+#endif /* SELFTEST_KVM_UTIL_H */

tools/testing/selftests/kvm/include/sparsebit.h

@@ -0,0 +1,75 @@
+/*
+ * tools/testing/selftests/kvm/include/sparsebit.h
+ *
+ * Copyright (C) 2018, Google LLC.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ *
+ *
+ * Header file that describes API to the sparsebit library.
+ * This library provides a memory efficient means of storing
+ * the settings of bits indexed via a uint64_t.  Memory usage
+ * is reasonable, significantly less than (2^64 / 8) bytes, as
+ * long as bits that are mostly set or mostly cleared are close
+ * to each other.  This library is efficient in memory usage
+ * even in the case where most bits are set.
+ */
+
+#ifndef _TEST_SPARSEBIT_H_
+#define _TEST_SPARSEBIT_H_
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct sparsebit;
+typedef uint64_t sparsebit_idx_t;
+typedef uint64_t sparsebit_num_t;
+
+struct sparsebit *sparsebit_alloc(void);
+void sparsebit_free(struct sparsebit **sbitp);
+void sparsebit_copy(struct sparsebit *dstp, struct sparsebit *src);
+
+bool sparsebit_is_set(struct sparsebit *sbit, sparsebit_idx_t idx);
+bool sparsebit_is_set_num(struct sparsebit *sbit,
+			  sparsebit_idx_t idx, sparsebit_num_t num);
+bool sparsebit_is_clear(struct sparsebit *sbit, sparsebit_idx_t idx);
+bool sparsebit_is_clear_num(struct sparsebit *sbit,
+			    sparsebit_idx_t idx, sparsebit_num_t num);
+sparsebit_num_t sparsebit_num_set(struct sparsebit *sbit);
+bool sparsebit_any_set(struct sparsebit *sbit);
+bool sparsebit_any_clear(struct sparsebit *sbit);
+bool sparsebit_all_set(struct sparsebit *sbit);
+bool sparsebit_all_clear(struct sparsebit *sbit);
+sparsebit_idx_t sparsebit_first_set(struct sparsebit *sbit);
+sparsebit_idx_t sparsebit_first_clear(struct sparsebit *sbit);
+sparsebit_idx_t sparsebit_next_set(struct sparsebit *sbit, sparsebit_idx_t prev);
+sparsebit_idx_t sparsebit_next_clear(struct sparsebit *sbit, sparsebit_idx_t prev);
+sparsebit_idx_t sparsebit_next_set_num(struct sparsebit *sbit,
+				       sparsebit_idx_t start, sparsebit_num_t num);
+sparsebit_idx_t sparsebit_next_clear_num(struct sparsebit *sbit,
+					 sparsebit_idx_t start, sparsebit_num_t num);
+
+void sparsebit_set(struct sparsebit *sbitp, sparsebit_idx_t idx);
+void sparsebit_set_num(struct sparsebit *sbitp, sparsebit_idx_t start,
+		       sparsebit_num_t num);
+void sparsebit_set_all(struct sparsebit *sbitp);
+
+void sparsebit_clear(struct sparsebit *sbitp, sparsebit_idx_t idx);
+void sparsebit_clear_num(struct sparsebit *sbitp,
+			 sparsebit_idx_t start, sparsebit_num_t num);
+void sparsebit_clear_all(struct sparsebit *sbitp);
+
+void sparsebit_dump(FILE *stream, struct sparsebit *sbit,
+		    unsigned int indent);
+void sparsebit_validate_internal(struct sparsebit *sbit);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _TEST_SPARSEBIT_H_ */

tools/testing/selftests/kvm/include/test_util.h

@@ -0,0 +1,45 @@
+/*
+ * tools/testing/selftests/kvm/include/test_util.h
+ *
+ * Copyright (C) 2018, Google LLC.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ *
+ */
+
+#ifndef TEST_UTIL_H
+#define TEST_UTIL_H 1
+
+#include <stdlib.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <inttypes.h>
+#include <errno.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+ssize_t test_write(int fd, const void *buf, size_t count);
+ssize_t test_read(int fd, void *buf, size_t count);
+int test_seq_read(const char *path, char **bufp, size_t *sizep);
+
+void test_assert(bool exp, const char *exp_str,
+		 const char *file, unsigned int line, const char *fmt, ...);
+
+#define ARRAY_SIZE(array) (sizeof(array) / sizeof((array)[0]))
+
+#define TEST_ASSERT(e, fmt, ...) \
+	test_assert((e), #e, __FILE__, __LINE__, fmt, ##__VA_ARGS__)
+
+#define ASSERT_EQ(a, b) do { \
+	typeof(a) __a = (a); \
+	typeof(b) __b = (b); \
+	TEST_ASSERT(__a == __b, \
+		    "ASSERT_EQ(%s, %s) failed.\n" \
+		    "\t%s is %#lx\n" \
+		    "\t%s is %#lx", \
+		    #a, #b, #a, (unsigned long) __a, #b, (unsigned long) __b); \
+} while (0)
+
+#endif /* TEST_UTIL_H */

tools/testing/selftests/kvm/lib/assert.c

@@ -0,0 +1,87 @@
+/*
+ * tools/testing/selftests/kvm/lib/assert.c
+ *
+ * Copyright (C) 2018, Google LLC.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ */
+
+#define _GNU_SOURCE /* for getline(3) and strchrnul(3)*/
+
+#include "test_util.h"
+
+#include <execinfo.h>
+#include <sys/syscall.h>
+
+/* Dumps the current stack trace to stderr. */
+static void __attribute__((noinline)) test_dump_stack(void);
+static void test_dump_stack(void)
+{
+	/*
+	 * Build and run this command:
+	 *
+	 *	addr2line -s -e /proc/$PPID/exe -fpai {backtrace addresses} | \
+	 *		grep -v test_dump_stack | cat -n 1>&2
+	 *
+	 * Note that the spacing is different and there's no newline.
+	 */
+	size_t i;
+	size_t n = 20;
+	void *stack[n];
+	const char *addr2line = "addr2line -s -e /proc/$PPID/exe -fpai";
+	const char *pipeline = "|cat -n 1>&2";
+	char cmd[strlen(addr2line) + strlen(pipeline) +
+		 /* N bytes per addr * 2 digits per byte + 1 space per addr: */
+		 n * (((sizeof(void *)) * 2) + 1) +
+		 /* Null terminator: */
+		 1];
+	char *c;
+
+	n = backtrace(stack, n);
+	c = &cmd[0];
+	c += sprintf(c, "%s", addr2line);
+	/*
+	 * Skip the first 3 frames: backtrace, test_dump_stack, and
+	 * test_assert. We hope that backtrace isn't inlined and the other two
+	 * we've declared noinline.
+	 */
+	for (i = 2; i < n; i++)
+		c += sprintf(c, " %lx", ((unsigned long) stack[i]) - 1);
+	c += sprintf(c, "%s", pipeline);
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wunused-result"
+	system(cmd);
+#pragma GCC diagnostic pop
+}
+
+static pid_t gettid(void)
+{
+	return syscall(SYS_gettid);
+}
+
+void __attribute__((noinline))
+test_assert(bool exp, const char *exp_str,
+	const char *file, unsigned int line, const char *fmt, ...)
+{
+	va_list ap;
+
+	if (!(exp)) {
+		va_start(ap, fmt);
+
+		fprintf(stderr, "==== Test Assertion Failure ====\n"
+			"  %s:%u: %s\n"
+			"  pid=%d tid=%d\n",
+			file, line, exp_str, getpid(), gettid());
+		test_dump_stack();
+		if (fmt) {
+			fputs("  ", stderr);
+			vfprintf(stderr, fmt, ap);
+			fputs("\n", stderr);
+		}
+		va_end(ap);
+
+		exit(254);
+	}
+
+	return;
+}

tools/testing/selftests/kvm/lib/kvm_util_internal.h

@@ -0,0 +1,67 @@
+/*
+ * tools/testing/selftests/kvm/lib/kvm_util.c
+ *
+ * Copyright (C) 2018, Google LLC.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ */
+
+#ifndef KVM_UTIL_INTERNAL_H
+#define KVM_UTIL_INTERNAL_H 1
+
+#include "sparsebit.h"
+
+#ifndef BITS_PER_BYTE
+#define BITS_PER_BYTE           8
+#endif
+
+#ifndef BITS_PER_LONG
+#define BITS_PER_LONG (BITS_PER_BYTE * sizeof(long))
+#endif
+
+#define DIV_ROUND_UP(n, d)	(((n) + (d) - 1) / (d))
+#define BITS_TO_LONGS(nr)       DIV_ROUND_UP(nr, BITS_PER_LONG)
+
+/* Concrete definition of struct kvm_vm. */
+struct userspace_mem_region {
+	struct userspace_mem_region *next, *prev;
+	struct kvm_userspace_memory_region region;
+	struct sparsebit *unused_phy_pages;
+	int fd;
+	off_t offset;
+	void *host_mem;
+	void *mmap_start;
+	size_t mmap_size;
+};
+
+struct vcpu {
+	struct vcpu *next, *prev;
+	uint32_t id;
+	int fd;
+	struct kvm_run *state;
+};
+
+struct kvm_vm {
+	int mode;
+	int fd;
+	unsigned int page_size;
+	unsigned int page_shift;
+	uint64_t max_gfn;
+	struct vcpu *vcpu_head;
+	struct userspace_mem_region *userspace_mem_region_head;
+	struct sparsebit *vpages_valid;
+	struct sparsebit *vpages_mapped;
+	bool pgd_created;
+	vm_paddr_t pgd;
+};
+
+struct vcpu *vcpu_find(struct kvm_vm *vm,
+	uint32_t vcpuid);
+void vcpu_setup(struct kvm_vm *vm, int vcpuid);
+void virt_dump(FILE *stream, struct kvm_vm *vm, uint8_t indent);
+void regs_dump(FILE *stream, struct kvm_regs *regs,
+	uint8_t indent);
+void sregs_dump(FILE *stream, struct kvm_sregs *sregs,
+	uint8_t indent);
+
+#endif

tools/testing/selftests/kvm/set_sregs_test.c

@@ -0,0 +1,54 @@
+/*
+ * KVM_SET_SREGS tests
+ *
+ * Copyright (C) 2018, Google LLC.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ *
+ * This is a regression test for the bug fixed by the following commit:
+ * d3802286fa0f ("kvm: x86: Disallow illegal IA32_APIC_BASE MSR values")
+ *
+ * That bug allowed a user-mode program that called the KVM_SET_SREGS
+ * ioctl to put a VCPU's local APIC into an invalid state.
+ *
+ */
+#define _GNU_SOURCE /* for program_invocation_short_name */
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+
+#include "test_util.h"
+
+#include "kvm_util.h"
+#include "x86.h"
+
+#define VCPU_ID                  5
+
+int main(int argc, char *argv[])
+{
+	struct kvm_sregs sregs;
+	struct kvm_vm *vm;
+	int rc;
+
+	/* Tell stdout not to buffer its content */
+	setbuf(stdout, NULL);
+
+	/* Create VM */
+	vm = vm_create_default(VCPU_ID, NULL);
+
+	vcpu_sregs_get(vm, VCPU_ID, &sregs);
+	sregs.apic_base = 1 << 10;
+	rc = _vcpu_sregs_set(vm, VCPU_ID, &sregs);
+	TEST_ASSERT(rc, "Set IA32_APIC_BASE to %llx (invalid)",
+		    sregs.apic_base);
+	sregs.apic_base = 1 << 11;
+	rc = _vcpu_sregs_set(vm, VCPU_ID, &sregs);
+	TEST_ASSERT(!rc, "Couldn't set IA32_APIC_BASE to %llx (valid)",
+		    sregs.apic_base);
+
+	kvm_vm_free(vm);
+
+	return 0;
+}