KVM selftests changes for 7.2

- Randomize the dirty log test's delay when reaping the bitmap on the first
    pass, as always waiting only 1ms hid a KVM RISC-V bug as the test reaped the
    bitmap before KVM could build up enough state to hit the bug.
 
  - A pile of one-off fixes and cleanups.
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Merge tag 'kvm-x86-selftests-7.2' of https://github.com/kvm-x86/linux into HEAD

KVM selftests changes for 7.2

 - Randomize the dirty log test's delay when reaping the bitmap on the first
   pass, as always waiting only 1ms hid a KVM RISC-V bug as the test reaped the
   bitmap before KVM could build up enough state to hit the bug.

 - A pile of one-off fixes and cleanups.

tools/testing/selftests/kvm/dirty_log_test.c

@@ -694,7 +694,17 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	pthread_create(&vcpu_thread, NULL, vcpu_worker, vcpu);
 
 	for (iteration = 1; iteration <= p->iterations; iteration++) {
-		unsigned long i;
+		unsigned long i, reap_i;
+
+		/*
+		 * Select a random point in the time interval to reap the dirty
+		 * bitmap/ring while the guest is running, i.e. randomize how
+		 * long the guest gets to initially run and thus how many pages
+		 * it can dirty, before collecting the dirty bitmap/ring.  See
+		 * the loop below for details.
+		 */
+		reap_i = random() % p->interval;
+		printf("Reaping after a %lu ms delay\n", reap_i);
 
 		sync_global_to_guest(vm, iteration);
 
@@ -729,13 +739,17 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 			 * that's effectively blocked.  Collecting while the
 			 * guest is running also verifies KVM doesn't lose any
 			 * state.
-			 *
+			 */
+			if (i < reap_i)
+				continue;
+
+			/*
 			 * For bitmap modes, KVM overwrites the entire bitmap,
 			 * i.e. collecting the bitmaps is destructive.  Collect
-			 * the bitmap only on the first pass, otherwise this
-			 * test would lose track of dirty pages.
+			 * the bitmap while the guest is running only once,
+			 * otherwise this test would lose track of dirty pages.
 			 */
-			if (i && host_log_mode != LOG_MODE_DIRTY_RING)
+			if (i > reap_i && host_log_mode != LOG_MODE_DIRTY_RING)
 				continue;
 
 			/*
@@ -745,7 +759,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 			 * the ring on every pass would make it unlikely the
 			 * vCPU would ever fill the fing).
 			 */
-			if (i && !READ_ONCE(dirty_ring_vcpu_ring_full))
+			if (i > reap_i && !READ_ONCE(dirty_ring_vcpu_ring_full))
 				continue;
 
 			log_mode_collect_dirty_pages(vcpu, TEST_MEM_SLOT_INDEX,

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

@@ -89,4 +89,10 @@ __KVM_SYSCALL_DEFINE(fallocate, 4, int, fd, int, mode, loff_t, offset, loff_t, l
 __KVM_SYSCALL_DEFINE(ftruncate, 2, unsigned int, fd, off_t, length);
 __KVM_SYSCALL_DEFINE(madvise, 3, void *, addr, size_t, length, int, advice);
 
+#define kvm_free_fd(fd)		\
+do {				\
+	kvm_close(fd);		\
+	(fd) = -1;		\
+} while (0)
+
 #endif /* SELFTEST_KVM_SYSCALLS_H */

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

@@ -876,7 +876,7 @@ static inline int vcpu_get_stats_fd(struct kvm_vcpu *vcpu)
 {
 	int fd = __vcpu_ioctl(vcpu, KVM_GET_STATS_FD, NULL);
 
-	TEST_ASSERT_VM_VCPU_IOCTL(fd >= 0, KVM_CHECK_EXTENSION, fd, vcpu->vm);
+	TEST_ASSERT_VM_VCPU_IOCTL(fd >= 0, KVM_GET_STATS_FD, fd, vcpu->vm);
 	return fd;
 }
 

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

@@ -77,7 +77,8 @@ static ssize_t get_module_param(const char *module_name, const char *param,
 	int fd, r;
 
 	/* Verify KVM is loaded, to provide a more helpful SKIP message. */
-	close(open_kvm_dev_path_or_exit());
+	fd = open_kvm_dev_path_or_exit();
+	kvm_free_fd(fd);
 
 	r = snprintf(path, path_size, "/sys/module/%s/parameters/%s",
 		     module_name, param);
@@ -90,8 +91,7 @@ static ssize_t get_module_param(const char *module_name, const char *param,
 	TEST_ASSERT(bytes_read > 0, "read(%s) returned %ld, wanted %ld bytes",
 		    path, bytes_read, buffer_size);
 
-	r = close(fd);
-	TEST_ASSERT(!r, "close(%s) failed", path);
+	kvm_free_fd(fd);
 	return bytes_read;
 }
 
@@ -160,7 +160,7 @@ unsigned int kvm_check_cap(long cap)
 	ret = __kvm_ioctl(kvm_fd, KVM_CHECK_EXTENSION, (void *)cap);
 	TEST_ASSERT(ret >= 0, KVM_IOCTL_ERROR(KVM_CHECK_EXTENSION, ret));
 
-	close(kvm_fd);
+	kvm_free_fd(kvm_fd);
 
 	return (unsigned int)ret;
 }
@@ -747,8 +747,7 @@ static void kvm_stats_release(struct kvm_binary_stats *stats)
 		stats->desc = NULL;
 	}
 
-	kvm_close(stats->fd);
-	stats->fd = -1;
+	kvm_free_fd(stats->fd);
 }
 
 __weak void vcpu_arch_free(struct kvm_vcpu *vcpu)
@@ -777,7 +776,7 @@ static void vm_vcpu_rm(struct kvm_vm *vm, struct kvm_vcpu *vcpu)
 
 	kvm_munmap(vcpu->run, vcpu_mmap_sz());
 
-	kvm_close(vcpu->fd);
+	kvm_free_fd(vcpu->fd);
 	kvm_stats_release(&vcpu->stats);
 
 	list_del(&vcpu->list);
@@ -793,8 +792,8 @@ void kvm_vm_release(struct kvm_vm *vmp)
 	list_for_each_entry_safe(vcpu, tmp, &vmp->vcpus, list)
 		vm_vcpu_rm(vmp, vcpu);
 
-	kvm_close(vmp->fd);
-	kvm_close(vmp->kvm_fd);
+	kvm_free_fd(vmp->fd);
+	kvm_free_fd(vmp->kvm_fd);
 
 	/* Free cached stats metadata and close FD */
 	kvm_stats_release(&vmp->stats);
@@ -815,10 +814,10 @@ static void __vm_mem_region_delete(struct kvm_vm *vm,
 	if (region->fd >= 0) {
 		/* There's an extra map when using shared memory. */
 		kvm_munmap(region->mmap_alias, region->mmap_size);
-		close(region->fd);
+		kvm_free_fd(region->fd);
 	}
-	if (region->region.guest_memfd >= 0)
-		close(region->region.guest_memfd);
+	if ((int)region->region.guest_memfd >= 0)
+		kvm_free_fd(region->region.guest_memfd);
 
 	free(region);
 }
@@ -1311,7 +1310,7 @@ static size_t vcpu_mmap_sz(void)
 	TEST_ASSERT(ret >= 0 && ret >= sizeof(struct kvm_run),
 		    KVM_IOCTL_ERROR(KVM_GET_VCPU_MMAP_SIZE, ret));
 
-	close(dev_fd);
+	kvm_free_fd(dev_fd);
 
 	return ret;
 }

tools/testing/selftests/kvm/memslot_perf_test.c

@@ -111,6 +111,7 @@ struct sync_area {
  */
 static_assert(ATOMIC_BOOL_LOCK_FREE == 2, "atomic bool is not lockless");
 
+static int wait_timeout = 10;
 static sem_t vcpu_ready;
 
 static bool map_unmap_verify;
@@ -418,7 +419,7 @@ static bool _guest_should_exit(void)
  */
 static noinline void host_perform_sync(struct sync_area *sync)
 {
-	alarm(10);
+	alarm(wait_timeout);
 
 	atomic_store_explicit(&sync->sync_flag, true, memory_order_release);
 	while (atomic_load_explicit(&sync->sync_flag, memory_order_acquire))
@@ -900,7 +901,7 @@ static void help(char *name, struct test_args *targs)
 {
 	int ctr;
 
-	pr_info("usage: %s [-h] [-v] [-d] [-s slots] [-f first_test] [-e last_test] [-l test_length] [-r run_count]\n",
+	pr_info("usage: %s [-h] [-v] [-d] [-s slots] [-f first_test] [-e last_test] [-l test_length] [-r run_count] [-t wait_timeout]\n",
 		name);
 	pr_info(" -h: print this help screen.\n");
 	pr_info(" -v: enable verbose mode (not for benchmarking).\n");
@@ -916,6 +917,8 @@ static void help(char *name, struct test_args *targs)
 		targs->seconds);
 	pr_info(" -r: specify the number of runs per test (currently: %i)\n",
 		targs->runs);
+	pr_info(" -t: specify the number of seconds for host wait timeout (currently: %i)\n",
+		wait_timeout);
 
 	pr_info("\nAvailable tests:\n");
 	for (ctr = 0; ctr < NTESTS; ctr++)
@@ -964,7 +967,7 @@ static bool parse_args(int argc, char *argv[],
 	u32 max_mem_slots;
 	int opt;
 
-	while ((opt = getopt(argc, argv, "hvdqs:f:e:l:r:")) != -1) {
+	while ((opt = getopt(argc, argv, "hvdqs:f:e:l:r:t:")) != -1) {
 		switch (opt) {
 		case 'h':
 		default:
@@ -1007,6 +1010,9 @@ static bool parse_args(int argc, char *argv[],
 		case 'r':
 			targs->runs = atoi_positive("Runs per test", optarg);
 			break;
+		case 't':
+			wait_timeout = atoi_positive("Host wait timeout", optarg);
+			break;
 		}
 	}
 

tools/testing/selftests/kvm/x86/hyperv_features.c

@@ -26,6 +26,7 @@ struct msr_data {
 	bool fault_expected;
 	bool write;
 	u64 write_val;
+	bool reset_expected;
 };
 
 struct hcall_data {
@@ -267,14 +268,9 @@ static void guest_test_msrs_access(void)
 		case 16:
 			msr->idx = HV_X64_MSR_RESET;
 			msr->write = true;
-			/*
-			 * TODO: the test only writes '0' to HV_X64_MSR_RESET
-			 * at the moment, writing some other value there will
-			 * trigger real vCPU reset and the code is not prepared
-			 * to handle it yet.
-			 */
-			msr->write_val = 0;
+			msr->write_val = 1;
 			msr->fault_expected = false;
+			msr->reset_expected = true;
 			break;
 
 		case 17:
@@ -457,7 +453,7 @@ static void guest_test_msrs_access(void)
 			msr->fault_expected = true;
 			break;
 		case 45:
-			/* MSR is vailable when CPUID feature bit is set */
+			/* MSR is available when CPUID feature bit is set */
 			if (!has_invtsc)
 				goto next_stage;
 			vcpu_set_cpuid_feature(vcpu, HV_ACCESS_TSC_INVARIANT);
@@ -497,6 +493,15 @@ static void guest_test_msrs_access(void)
 			 msr->idx, msr->write ? "write" : "read");
 
 		vcpu_run(vcpu);
+
+		if (msr->reset_expected) {
+			TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_SYSTEM_EVENT);
+			TEST_ASSERT(vcpu->run->system_event.type == KVM_SYSTEM_EVENT_RESET,
+				    "Expected reset system event, got type %u",
+				    vcpu->run->system_event.type);
+			goto next_stage;
+		}
+
 		TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);
 
 		switch (get_ucall(vcpu, &uc)) {

tools/testing/selftests/kvm/x86/hyperv_tlb_flush.c

@@ -141,17 +141,6 @@ static void swap_two_test_pages(gpa_t pte_gva1, gpa_t pte_gva2)
 	*(u64 *)pte_gva2 = tmp;
 }
 
-/*
- * TODO: replace the silly NOP loop with a proper udelay() implementation.
- */
-static inline void do_delay(void)
-{
-	int i;
-
-	for (i = 0; i < 1000000; i++)
-		asm volatile("nop");
-}
-
 /*
  * Prepare to test: 'disable' workers by setting the expectation to '0',
  * clear hypercall input page and then swap two test pages.
@@ -169,7 +158,7 @@ static inline void prepare_to_test(struct test_data *data)
 	wmb();
 
 	/* Make sure workers have enough time to notice */
-	do_delay();
+	udelay(100);
 
 	/* Swap test page mappings */
 	swap_two_test_pages(data->test_pages_pte[0], data->test_pages_pte[1]);
@@ -189,7 +178,7 @@ static inline void post_test(struct test_data *data, u64 exp1, u64 exp2)
 	set_expected_val((void *)data->test_pages, exp2, WORKER_VCPU_ID_2);
 
 	/* Make sure workers have enough time to test */
-	do_delay();
+	udelay(100);
 }
 
 #define TESTVAL1 0x0101010101010101

tools/testing/selftests/kvm/x86/sync_regs_test.c

@@ -255,7 +255,6 @@ KVM_ONE_VCPU_TEST(sync_regs_test, req_and_verify_all_valid, guest_code)
 	struct kvm_regs regs;
 
 	/* Request and verify all valid register sets. */
-	/* TODO: BUILD TIME CHECK: TEST_ASSERT(KVM_SYNC_X86_NUM_FIELDS != 3); */
 	run->kvm_valid_regs = TEST_SYNC_FIELDS;
 	vcpu_run(vcpu);
 	TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);