// 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, ®);
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, ®);
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;
}
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