1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Check for KVM_GET_REG_LIST regressions.
4 *
5 * Copyright (C) 2020, Red Hat, Inc.
6 *
7 * When attempting to migrate from a host with an older kernel to a host
8 * with a newer kernel we allow the newer kernel on the destination to
9 * list new registers with get-reg-list. We assume they'll be unused, at
10 * least until the guest reboots, and so they're relatively harmless.
11 * However, if the destination host with the newer kernel is missing
12 * registers which the source host with the older kernel has, then that's
13 * a regression in get-reg-list. This test checks for that regression by
14 * checking the current list against a blessed list. We should never have
15 * missing registers, but if new ones appear then they can probably be
16 * added to the blessed list. A completely new blessed list can be created
17 * by running the test with the --list command line argument.
18 *
19 * The blessed list should be created from the oldest possible kernel.
20 */
21#include <stdio.h>
22#include <stdlib.h>
23#include <string.h>
24#include <unistd.h>
25#include <sys/types.h>
26#include <sys/wait.h>
27#include "kvm_util.h"
28#include "test_util.h"
29#include "processor.h"
30
31static struct kvm_reg_list *reg_list;
32static __u64 *blessed_reg, blessed_n;
33
34extern struct vcpu_reg_list *vcpu_configs[];
35extern int vcpu_configs_n;
36
37#define for_each_reg(i)								\
38	for ((i) = 0; (i) < reg_list->n; ++(i))
39
40#define for_each_reg_filtered(i)						\
41	for_each_reg(i)								\
42		if (!filter_reg(reg_list->reg[i]))
43
44#define for_each_missing_reg(i)							\
45	for ((i) = 0; (i) < blessed_n; ++(i))					\
46		if (!find_reg(reg_list->reg, reg_list->n, blessed_reg[i]))	\
47			if (check_supported_reg(vcpu, blessed_reg[i]))
48
49#define for_each_new_reg(i)							\
50	for_each_reg_filtered(i)						\
51		if (!find_reg(blessed_reg, blessed_n, reg_list->reg[i]))
52
53#define for_each_present_blessed_reg(i)						\
54	for_each_reg(i)								\
55		if (find_reg(blessed_reg, blessed_n, reg_list->reg[i]))
56
57static const char *config_name(struct vcpu_reg_list *c)
58{
59	struct vcpu_reg_sublist *s;
60	int len = 0;
61
62	if (c->name)
63		return c->name;
64
65	for_each_sublist(c, s)
66		len += strlen(s->name) + 1;
67
68	c->name = malloc(len);
69
70	len = 0;
71	for_each_sublist(c, s) {
72		if (!strcmp(s->name, "base"))
73			continue;
74		if (len)
75			c->name[len++] = '+';
76		strcpy(c->name + len, s->name);
77		len += strlen(s->name);
78	}
79	c->name[len] = '\0';
80
81	return c->name;
82}
83
84bool __weak check_supported_reg(struct kvm_vcpu *vcpu, __u64 reg)
85{
86	return true;
87}
88
89bool __weak filter_reg(__u64 reg)
90{
91	return false;
92}
93
94static bool find_reg(__u64 regs[], __u64 nr_regs, __u64 reg)
95{
96	int i;
97
98	for (i = 0; i < nr_regs; ++i)
99		if (reg == regs[i])
100			return true;
101	return false;
102}
103
104void __weak print_reg(const char *prefix, __u64 id)
105{
106	printf("\t0x%llx,\n", id);
107}
108
109bool __weak check_reject_set(int err)
110{
111	return true;
112}
113
114void __weak finalize_vcpu(struct kvm_vcpu *vcpu, struct vcpu_reg_list *c)
115{
116}
117
118#ifdef __aarch64__
119static void prepare_vcpu_init(struct vcpu_reg_list *c, struct kvm_vcpu_init *init)
120{
121	struct vcpu_reg_sublist *s;
122
123	for_each_sublist(c, s)
124		if (s->capability)
125			init->features[s->feature / 32] |= 1 << (s->feature % 32);
126}
127
128static struct kvm_vcpu *vcpu_config_get_vcpu(struct vcpu_reg_list *c, struct kvm_vm *vm)
129{
130	struct kvm_vcpu_init init = { .target = -1, };
131	struct kvm_vcpu *vcpu;
132
133	prepare_vcpu_init(c, &init);
134	vcpu = __vm_vcpu_add(vm, 0);
135	aarch64_vcpu_setup(vcpu, &init);
136
137	return vcpu;
138}
139#else
140static struct kvm_vcpu *vcpu_config_get_vcpu(struct vcpu_reg_list *c, struct kvm_vm *vm)
141{
142	return __vm_vcpu_add(vm, 0);
143}
144#endif
145
146static void check_supported(struct vcpu_reg_list *c)
147{
148	struct vcpu_reg_sublist *s;
149
150	for_each_sublist(c, s) {
151		if (!s->capability)
152			continue;
153
154		__TEST_REQUIRE(kvm_has_cap(s->capability),
155			       "%s: %s not available, skipping tests",
156			       config_name(c), s->name);
157	}
158}
159
160static bool print_list;
161static bool print_filtered;
162
163static void run_test(struct vcpu_reg_list *c)
164{
165	int new_regs = 0, missing_regs = 0, i, n;
166	int failed_get = 0, failed_set = 0, failed_reject = 0;
167	int skipped_set = 0;
168	struct kvm_vcpu *vcpu;
169	struct kvm_vm *vm;
170	struct vcpu_reg_sublist *s;
171
172	check_supported(c);
173
174	vm = vm_create_barebones();
175	vcpu = vcpu_config_get_vcpu(c, vm);
176	finalize_vcpu(vcpu, c);
177
178	reg_list = vcpu_get_reg_list(vcpu);
179
180	if (print_list || print_filtered) {
181		putchar('\n');
182		for_each_reg(i) {
183			__u64 id = reg_list->reg[i];
184			if ((print_list && !filter_reg(id)) ||
185			    (print_filtered && filter_reg(id)))
186				print_reg(config_name(c), id);
187		}
188		putchar('\n');
189		return;
190	}
191
192	for_each_sublist(c, s)
193		blessed_n += s->regs_n;
194	blessed_reg = calloc(blessed_n, sizeof(__u64));
195
196	n = 0;
197	for_each_sublist(c, s) {
198		for (i = 0; i < s->regs_n; ++i)
199			blessed_reg[n++] = s->regs[i];
200	}
201
202	/*
203	 * We only test that we can get the register and then write back the
204	 * same value. Some registers may allow other values to be written
205	 * back, but others only allow some bits to be changed, and at least
206	 * for ID registers set will fail if the value does not exactly match
207	 * what was returned by get. If registers that allow other values to
208	 * be written need to have the other values tested, then we should
209	 * create a new set of tests for those in a new independent test
210	 * executable.
211	 *
212	 * Only do the get/set tests on present, blessed list registers,
213	 * since we don't know the capabilities of any new registers.
214	 */
215	for_each_present_blessed_reg(i) {
216		uint8_t addr[2048 / 8];
217		struct kvm_one_reg reg = {
218			.id = reg_list->reg[i],
219			.addr = (__u64)&addr,
220		};
221		bool reject_reg = false, skip_reg = false;
222		int ret;
223
224		ret = __vcpu_get_reg(vcpu, reg_list->reg[i], &addr);
225		if (ret) {
226			printf("%s: Failed to get ", config_name(c));
227			print_reg(config_name(c), reg.id);
228			putchar('\n');
229			++failed_get;
230		}
231
232		for_each_sublist(c, s) {
233			/* rejects_set registers are rejected for set operation */
234			if (s->rejects_set && find_reg(s->rejects_set, s->rejects_set_n, reg.id)) {
235				reject_reg = true;
236				ret = __vcpu_ioctl(vcpu, KVM_SET_ONE_REG, &reg);
237				if (ret != -1 || !check_reject_set(errno)) {
238					printf("%s: Failed to reject (ret=%d, errno=%d) ", config_name(c), ret, errno);
239					print_reg(config_name(c), reg.id);
240					putchar('\n');
241					++failed_reject;
242				}
243				break;
244			}
245
246			/* skips_set registers are skipped for set operation */
247			if (s->skips_set && find_reg(s->skips_set, s->skips_set_n, reg.id)) {
248				skip_reg = true;
249				++skipped_set;
250				break;
251			}
252		}
253
254		if (!reject_reg && !skip_reg) {
255			ret = __vcpu_ioctl(vcpu, KVM_SET_ONE_REG, &reg);
256			if (ret) {
257				printf("%s: Failed to set ", config_name(c));
258				print_reg(config_name(c), reg.id);
259				putchar('\n');
260				++failed_set;
261			}
262		}
263	}
264
265	for_each_new_reg(i)
266		++new_regs;
267
268	for_each_missing_reg(i)
269		++missing_regs;
270
271	if (new_regs || missing_regs) {
272		n = 0;
273		for_each_reg_filtered(i)
274			++n;
275
276		printf("%s: Number blessed registers: %5lld\n", config_name(c), blessed_n);
277		printf("%s: Number registers:         %5lld (includes %lld filtered registers)\n",
278		       config_name(c), reg_list->n, reg_list->n - n);
279	}
280
281	if (new_regs) {
282		printf("\n%s: There are %d new registers.\n"
283		       "Consider adding them to the blessed reg "
284		       "list with the following lines:\n\n", config_name(c), new_regs);
285		for_each_new_reg(i)
286			print_reg(config_name(c), reg_list->reg[i]);
287		putchar('\n');
288	}
289
290	if (missing_regs) {
291		printf("\n%s: There are %d missing registers.\n"
292		       "The following lines are missing registers:\n\n", config_name(c), missing_regs);
293		for_each_missing_reg(i)
294			print_reg(config_name(c), blessed_reg[i]);
295		putchar('\n');
296	}
297
298	TEST_ASSERT(!missing_regs && !failed_get && !failed_set && !failed_reject,
299		    "%s: There are %d missing registers; %d registers failed get; "
300		    "%d registers failed set; %d registers failed reject; %d registers skipped set",
301		    config_name(c), missing_regs, failed_get, failed_set, failed_reject, skipped_set);
302
303	pr_info("%s: PASS\n", config_name(c));
304	blessed_n = 0;
305	free(blessed_reg);
306	free(reg_list);
307	kvm_vm_free(vm);
308}
309
310static void help(void)
311{
312	struct vcpu_reg_list *c;
313	int i;
314
315	printf(
316	"\n"
317	"usage: get-reg-list [--config=<selection>] [--list] [--list-filtered]\n\n"
318	" --config=<selection>        Used to select a specific vcpu configuration for the test/listing\n"
319	"                             '<selection>' may be\n");
320
321	for (i = 0; i < vcpu_configs_n; ++i) {
322		c = vcpu_configs[i];
323		printf(
324	"                               '%s'\n", config_name(c));
325	}
326
327	printf(
328	"\n"
329	" --list                      Print the register list rather than test it (requires --config)\n"
330	" --list-filtered             Print registers that would normally be filtered out (requires --config)\n"
331	"\n"
332	);
333}
334
335static struct vcpu_reg_list *parse_config(const char *config)
336{
337	struct vcpu_reg_list *c = NULL;
338	int i;
339
340	if (config[8] != '=')
341		help(), exit(1);
342
343	for (i = 0; i < vcpu_configs_n; ++i) {
344		c = vcpu_configs[i];
345		if (strcmp(config_name(c), &config[9]) == 0)
346			break;
347	}
348
349	if (i == vcpu_configs_n)
350		help(), exit(1);
351
352	return c;
353}
354
355int main(int ac, char **av)
356{
357	struct vcpu_reg_list *c, *sel = NULL;
358	int i, ret = 0;
359	pid_t pid;
360
361	for (i = 1; i < ac; ++i) {
362		if (strncmp(av[i], "--config", 8) == 0)
363			sel = parse_config(av[i]);
364		else if (strcmp(av[i], "--list") == 0)
365			print_list = true;
366		else if (strcmp(av[i], "--list-filtered") == 0)
367			print_filtered = true;
368		else if (strcmp(av[i], "--help") == 0 || strcmp(av[1], "-h") == 0)
369			help(), exit(0);
370		else
371			help(), exit(1);
372	}
373
374	if (print_list || print_filtered) {
375		/*
376		 * We only want to print the register list of a single config.
377		 */
378		if (!sel)
379			help(), exit(1);
380	}
381
382	for (i = 0; i < vcpu_configs_n; ++i) {
383		c = vcpu_configs[i];
384		if (sel && c != sel)
385			continue;
386
387		pid = fork();
388
389		if (!pid) {
390			run_test(c);
391			exit(0);
392		} else {
393			int wstatus;
394			pid_t wpid = wait(&wstatus);
395			TEST_ASSERT(wpid == pid && WIFEXITED(wstatus), "wait: Unexpected return");
396			if (WEXITSTATUS(wstatus) && WEXITSTATUS(wstatus) != KSFT_SKIP)
397				ret = KSFT_FAIL;
398		}
399	}
400
401	return ret;
402}
403