1 files changed, 402 insertions, 0 deletions

diff --git a/tools/testing/selftests/kvm/get-reg-list.c b/tools/testing/selftests/kvm/get-reg-list.c
new file mode 100644
index 000000000000..91f05f78e824
--- /dev/null
+++ b/tools/testing/selftests/kvm/get-reg-list.c
@@ -0,0 +1,402 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Check for KVM_GET_REG_LIST regressions.
+ *
+ * Copyright (C) 2020, Red Hat, Inc.
+ *
+ * When attempting to migrate from a host with an older kernel to a host
+ * with a newer kernel we allow the newer kernel on the destination to
+ * list new registers with get-reg-list. We assume they'll be unused, at
+ * least until the guest reboots, and so they're relatively harmless.
+ * However, if the destination host with the newer kernel is missing
+ * registers which the source host with the older kernel has, then that's
+ * a regression in get-reg-list. This test checks for that regression by
+ * checking the current list against a blessed list. We should never have
+ * missing registers, but if new ones appear then they can probably be
+ * added to the blessed list. A completely new blessed list can be created
+ * by running the test with the --list command line argument.
+ *
+ * The blessed list should be created from the oldest possible kernel.
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include "kvm_util.h"
+#include "test_util.h"
+#include "processor.h"
+
+static struct kvm_reg_list *reg_list;
+static __u64 *blessed_reg, blessed_n;
+
+extern struct vcpu_reg_list *vcpu_configs[];
+extern int vcpu_configs_n;
+
+#define for_each_reg(i)								\
+	for ((i) = 0; (i) < reg_list->n; ++(i))
+
+#define for_each_reg_filtered(i)						\
+	for_each_reg(i)								\
+		if (!filter_reg(reg_list->reg[i]))
+
+#define for_each_missing_reg(i)							\
+	for ((i) = 0; (i) < blessed_n; ++(i))					\
+		if (!find_reg(reg_list->reg, reg_list->n, blessed_reg[i]))	\
+			if (check_supported_reg(vcpu, blessed_reg[i]))
+
+#define for_each_new_reg(i)							\
+	for_each_reg_filtered(i)						\
+		if (!find_reg(blessed_reg, blessed_n, reg_list->reg[i]))
+
+#define for_each_present_blessed_reg(i)						\
+	for_each_reg(i)								\
+		if (find_reg(blessed_reg, blessed_n, reg_list->reg[i]))
+
+static const char *config_name(struct vcpu_reg_list *c)
+{
+	struct vcpu_reg_sublist *s;
+	int len = 0;
+
+	if (c->name)
+		return c->name;
+
+	for_each_sublist(c, s)
+		len += strlen(s->name) + 1;
+
+	c->name = malloc(len);
+
+	len = 0;
+	for_each_sublist(c, s) {
+		if (!strcmp(s->name, "base"))
+			continue;
+		if (len)
+			c->name[len++] = '+';
+		strcpy(c->name + len, s->name);
+		len += strlen(s->name);
+	}
+	c->name[len] = '\0';
+
+	return c->name;
+}
+
+bool __weak check_supported_reg(struct kvm_vcpu *vcpu, __u64 reg)
+{
+	return true;
+}
+
+bool __weak filter_reg(__u64 reg)
+{
+	return false;
+}
+
+static bool find_reg(__u64 regs[], __u64 nr_regs, __u64 reg)
+{
+	int i;
+
+	for (i = 0; i < nr_regs; ++i)
+		if (reg == regs[i])
+			return true;
+	return false;
+}
+
+void __weak print_reg(const char *prefix, __u64 id)
+{
+	printf("\t0x%llx,\n", id);
+}
+
+bool __weak check_reject_set(int err)
+{
+	return true;
+}
+
+void __weak finalize_vcpu(struct kvm_vcpu *vcpu, struct vcpu_reg_list *c)
+{
+}
+
+#ifdef __aarch64__
+static void prepare_vcpu_init(struct vcpu_reg_list *c, struct kvm_vcpu_init *init)
+{
+	struct vcpu_reg_sublist *s;
+
+	for_each_sublist(c, s)
+		if (s->capability)
+			init->features[s->feature / 32] |= 1 << (s->feature % 32);
+}
+
+static struct kvm_vcpu *vcpu_config_get_vcpu(struct vcpu_reg_list *c, struct kvm_vm *vm)
+{
+	struct kvm_vcpu_init init = { .target = -1, };
+	struct kvm_vcpu *vcpu;
+
+	prepare_vcpu_init(c, &init);
+	vcpu = __vm_vcpu_add(vm, 0);
+	aarch64_vcpu_setup(vcpu, &init);
+
+	return vcpu;
+}
+#else
+static struct kvm_vcpu *vcpu_config_get_vcpu(struct vcpu_reg_list *c, struct kvm_vm *vm)
+{
+	return __vm_vcpu_add(vm, 0);
+}
+#endif
+
+static void check_supported(struct vcpu_reg_list *c)
+{
+	struct vcpu_reg_sublist *s;
+
+	for_each_sublist(c, s) {
+		if (!s->capability)
+			continue;
+
+		__TEST_REQUIRE(kvm_has_cap(s->capability),
+			       "%s: %s not available, skipping tests",
+			       config_name(c), s->name);
+	}
+}
+
+static bool print_list;
+static bool print_filtered;
+
+static void run_test(struct vcpu_reg_list *c)
+{
+	int new_regs = 0, missing_regs = 0, i, n;
+	int failed_get = 0, failed_set = 0, failed_reject = 0;
+	int skipped_set = 0;
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm;
+	struct vcpu_reg_sublist *s;
+
+	check_supported(c);
+
+	vm = vm_create_barebones();
+	vcpu = vcpu_config_get_vcpu(c, vm);
+	finalize_vcpu(vcpu, c);
+
+	reg_list = vcpu_get_reg_list(vcpu);
+
+	if (print_list || print_filtered) {
+		putchar('\n');
+		for_each_reg(i) {
+			__u64 id = reg_list->reg[i];
+			if ((print_list && !filter_reg(id)) ||
+			    (print_filtered && filter_reg(id)))
+				print_reg(config_name(c), id);
+		}
+		putchar('\n');
+		return;
+	}
+
+	for_each_sublist(c, s)
+		blessed_n += s->regs_n;
+	blessed_reg = calloc(blessed_n, sizeof(__u64));
+
+	n = 0;
+	for_each_sublist(c, s) {
+		for (i = 0; i < s->regs_n; ++i)
+			blessed_reg[n++] = s->regs[i];
+	}
+
+	/*
+	 * We only test that we can get the register and then write back the
+	 * same value. Some registers may allow other values to be written
+	 * back, but others only allow some bits to be changed, and at least
+	 * for ID registers set will fail if the value does not exactly match
+	 * what was returned by get. If registers that allow other values to
+	 * be written need to have the other values tested, then we should
+	 * create a new set of tests for those in a new independent test
+	 * executable.
+	 *
+	 * Only do the get/set tests on present, blessed list registers,
+	 * since we don't know the capabilities of any new registers.
+	 */
+	for_each_present_blessed_reg(i) {
+		uint8_t addr[2048 / 8];
+		struct kvm_one_reg reg = {
+			.id = reg_list->reg[i],
+			.addr = (__u64)&addr,
+		};
+		bool reject_reg = false, skip_reg = false;
+		int ret;
+
+		ret = __vcpu_get_reg(vcpu, reg_list->reg[i], &addr);
+		if (ret) {
+			printf("%s: Failed to get ", config_name(c));
+			print_reg(config_name(c), reg.id);
+			putchar('\n');
+			++failed_get;
+		}
+
+		for_each_sublist(c, s) {
+			/* rejects_set registers are rejected for set operation */
+			if (s->rejects_set && find_reg(s->rejects_set, s->rejects_set_n, reg.id)) {
+				reject_reg = true;
+				ret = __vcpu_ioctl(vcpu, KVM_SET_ONE_REG, &reg);
+				if (ret != -1 || !check_reject_set(errno)) {
+					printf("%s: Failed to reject (ret=%d, errno=%d) ", config_name(c), ret, errno);
+					print_reg(config_name(c), reg.id);
+					putchar('\n');
+					++failed_reject;
+				}
+				break;
+			}
+
+			/* skips_set registers are skipped for set operation */
+			if (s->skips_set && find_reg(s->skips_set, s->skips_set_n, reg.id)) {
+				skip_reg = true;
+				++skipped_set;
+				break;
+			}
+		}
+
+		if (!reject_reg && !skip_reg) {
+			ret = __vcpu_ioctl(vcpu, KVM_SET_ONE_REG, &reg);
+			if (ret) {
+				printf("%s: Failed to set ", config_name(c));
+				print_reg(config_name(c), reg.id);
+				putchar('\n');
+				++failed_set;
+			}
+		}
+	}
+
+	for_each_new_reg(i)
+		++new_regs;
+
+	for_each_missing_reg(i)
+		++missing_regs;
+
+	if (new_regs || missing_regs) {
+		n = 0;
+		for_each_reg_filtered(i)
+			++n;
+
+		printf("%s: Number blessed registers: %5lld\n", config_name(c), blessed_n);
+		printf("%s: Number registers:         %5lld (includes %lld filtered registers)\n",
+		       config_name(c), reg_list->n, reg_list->n - n);
+	}
+
+	if (new_regs) {
+		printf("\n%s: There are %d new registers.\n"
+		       "Consider adding them to the blessed reg "
+		       "list with the following lines:\n\n", config_name(c), new_regs);
+		for_each_new_reg(i)
+			print_reg(config_name(c), reg_list->reg[i]);
+		putchar('\n');
+	}
+
+	if (missing_regs) {
+		printf("\n%s: There are %d missing registers.\n"
+		       "The following lines are missing registers:\n\n", config_name(c), missing_regs);
+		for_each_missing_reg(i)
+			print_reg(config_name(c), blessed_reg[i]);
+		putchar('\n');
+	}
+
+	TEST_ASSERT(!missing_regs && !failed_get && !failed_set && !failed_reject,
+		    "%s: There are %d missing registers; %d registers failed get; "
+		    "%d registers failed set; %d registers failed reject; %d registers skipped set",
+		    config_name(c), missing_regs, failed_get, failed_set, failed_reject, skipped_set);
+
+	pr_info("%s: PASS\n", config_name(c));
+	blessed_n = 0;
+	free(blessed_reg);
+	free(reg_list);
+	kvm_vm_free(vm);
+}
+
+static void help(void)
+{
+	struct vcpu_reg_list *c;
+	int i;
+
+	printf(
+	"\n"
+	"usage: get-reg-list [--config=<selection>] [--list] [--list-filtered]\n\n"
+	" --config=<selection>        Used to select a specific vcpu configuration for the test/listing\n"
+	"                             '<selection>' may be\n");
+
+	for (i = 0; i < vcpu_configs_n; ++i) {
+		c = vcpu_configs[i];
+		printf(
+	"                               '%s'\n", config_name(c));
+	}
+
+	printf(
+	"\n"
+	" --list                      Print the register list rather than test it (requires --config)\n"
+	" --list-filtered             Print registers that would normally be filtered out (requires --config)\n"
+	"\n"
+	);
+}
+
+static struct vcpu_reg_list *parse_config(const char *config)
+{
+	struct vcpu_reg_list *c = NULL;
+	int i;
+
+	if (config[8] != '=')
+		help(), exit(1);
+
+	for (i = 0; i < vcpu_configs_n; ++i) {
+		c = vcpu_configs[i];
+		if (strcmp(config_name(c), &config[9]) == 0)
+			break;
+	}
+
+	if (i == vcpu_configs_n)
+		help(), exit(1);
+
+	return c;
+}
+
+int main(int ac, char **av)
+{
+	struct vcpu_reg_list *c, *sel = NULL;
+	int i, ret = 0;
+	pid_t pid;
+
+	for (i = 1; i < ac; ++i) {
+		if (strncmp(av[i], "--config", 8) == 0)
+			sel = parse_config(av[i]);
+		else if (strcmp(av[i], "--list") == 0)
+			print_list = true;
+		else if (strcmp(av[i], "--list-filtered") == 0)
+			print_filtered = true;
+		else if (strcmp(av[i], "--help") == 0 || strcmp(av[1], "-h") == 0)
+			help(), exit(0);
+		else
+			help(), exit(1);
+	}
+
+	if (print_list || print_filtered) {
+		/*
+		 * We only want to print the register list of a single config.
+		 */
+		if (!sel)
+			help(), exit(1);
+	}
+
+	for (i = 0; i < vcpu_configs_n; ++i) {
+		c = vcpu_configs[i];
+		if (sel && c != sel)
+			continue;
+
+		pid = fork();
+
+		if (!pid) {
+			run_test(c);
+			exit(0);
+		} else {
+			int wstatus;
+			pid_t wpid = wait(&wstatus);
+			TEST_ASSERT(wpid == pid && WIFEXITED(wstatus), "wait: Unexpected return");
+			if (WEXITSTATUS(wstatus) && WEXITSTATUS(wstatus) != KSFT_SKIP)
+				ret = KSFT_FAIL;
+		}
+	}
+
+	return ret;
+}