// SPDX-License-Identifier: GPL-2.0
/*
* steal/stolen time test
*
* Copyright (C) 2020, Red Hat, Inc.
*/
#include <stdio.h>
#include <time.h>
#include <sched.h>
#include <pthread.h>
#include <linux/kernel.h>
#include <asm/kvm.h>
#ifdef __riscv
#include "sbi.h"
#else
#include <asm/kvm_para.h>
#endif
#include "test_util.h"
#include "kvm_util.h"
#include "processor.h"
#include "ucall_common.h"
#define NR_VCPUS 4
#define ST_GPA_BASE (1 << 30)
static void *st_gva[NR_VCPUS];
static uint64_t guest_stolen_time[NR_VCPUS];
#if defined(__x86_64__)
/* steal_time must have 64-byte alignment */
#define STEAL_TIME_SIZE ((sizeof(struct kvm_steal_time) + 63) & ~63)
static void check_status(struct kvm_steal_time *st)
{
GUEST_ASSERT(!(READ_ONCE(st->version) & 1));
GUEST_ASSERT_EQ(READ_ONCE(st->flags), 0);
GUEST_ASSERT_EQ(READ_ONCE(st->preempted), 0);
}
static void guest_code(int cpu)
{
struct kvm_steal_time *st = st_gva[cpu];
uint32_t version;
GUEST_ASSERT_EQ(rdmsr(MSR_KVM_STEAL_TIME), ((uint64_t)st_gva[cpu] | KVM_MSR_ENABLED));
memset(st, 0, sizeof(*st));
GUEST_SYNC(0);
check_status(st);
WRITE_ONCE(guest_stolen_time[cpu], st->steal);
version = READ_ONCE(st->version);
check_status(st);
GUEST_SYNC(1);
check_status(st);
GUEST_ASSERT(version < READ_ONCE(st->version));
WRITE_ONCE(guest_stolen_time[cpu], st->steal);
check_status(st);
GUEST_DONE();
}
static bool is_steal_time_supported(struct kvm_vcpu *vcpu)
{
return kvm_cpu_has(X86_FEATURE_KVM_STEAL_TIME);
}
static void steal_time_init(struct kvm_vcpu *vcpu, uint32_t i)
{
int ret;
/* ST_GPA_BASE is identity mapped */
st_gva[i] = (void *)(ST_GPA_BASE + i * STEAL_TIME_SIZE);
sync_global_to_guest(vcpu->vm, st_gva[i]);
ret = _vcpu_set_msr(vcpu, MSR_KVM_STEAL_TIME,
(ulong)st_gva[i] | KVM_STEAL_RESERVED_MASK);
TEST_ASSERT(ret == 0, "Bad GPA didn't fail");
vcpu_set_msr(vcpu, MSR_KVM_STEAL_TIME, (ulong)st_gva[i] | KVM_MSR_ENABLED);
}
static void steal_time_dump(struct kvm_vm *vm, uint32_t vcpu_idx)
{
struct kvm_steal_time *st = addr_gva2hva(vm, (ulong)st_gva[vcpu_idx]);
ksft_print_msg("VCPU%d:\n", vcpu_idx);
ksft_print_msg(" steal: %lld\n", st->steal);
ksft_print_msg(" version: %d\n", st->version);
ksft_print_msg(" flags: %d\n", st->flags);
ksft_print_msg(" preempted: %d\n", st->preempted);
ksft_print_msg(" u8_pad: %d %d %d\n",
st->u8_pad[0], st->u8_pad[1], st->u8_pad[2]);
ksft_print_msg(" pad: %d %d %d %d %d %d %d %d %d %d %d\n",
st->pad[0], st->pad[1], st->pad[2], st->pad[3],
st->pad[4], st->pad[5], st->pad[6], st->pad[7],
st->pad[8], st->pad[9], st->pad[10]);
}
#elif defined(__aarch64__)
/* PV_TIME_ST must have 64-byte alignment */
#define STEAL_TIME_SIZE ((sizeof(struct st_time) + 63) & ~63)
#define SMCCC_ARCH_FEATURES 0x80000001
#define PV_TIME_FEATURES 0xc5000020
#define PV_TIME_ST 0xc5000021
struct st_time {
uint32_t rev;
uint32_t attr;
uint64_t st_time;
};
static int64_t smccc(uint32_t func, uint64_t arg)
{
struct arm_smccc_res res;
smccc_hvc(func, arg, 0, 0, 0, 0, 0, 0, &res);
return res.a0;
}
static void check_status(struct st_time *st)
{
GUEST_ASSERT_EQ(READ_ONCE(st->rev), 0);
GUEST_ASSERT_EQ(READ_ONCE(st->attr), 0);
}
static void guest_code(int cpu)
{
struct st_time *st;
int64_t status;
status = smccc(SMCCC_ARCH_FEATURES, PV_TIME_FEATURES);
GUEST_ASSERT_EQ(status, 0);
status = smccc(PV_TIME_FEATURES, PV_TIME_FEATURES);
GUEST_ASSERT_EQ(status, 0);
status = smccc(PV_TIME_FEATURES, PV_TIME_ST);
GUEST_ASSERT_EQ(status, 0);
status = smccc(PV_TIME_ST, 0);
GUEST_ASSERT_NE(status, -1);
GUEST_ASSERT_EQ(status, (ulong)st_gva[cpu]);
st = (struct st_time *)status;
GUEST_SYNC(0);
check_status(st);
WRITE_ONCE(guest_stolen_time[cpu], st->st_time);
GUEST_SYNC(1);
check_status(st);
WRITE_ONCE(guest_stolen_time[cpu], st->st_time);
GUEST_DONE();
}
static bool is_steal_time_supported(struct kvm_vcpu *vcpu)
{
struct kvm_device_attr dev = {
.group = KVM_ARM_VCPU_PVTIME_CTRL,
.attr = KVM_ARM_VCPU_PVTIME_IPA,
};
return !__vcpu_ioctl(vcpu, KVM_HAS_DEVICE_ATTR, &dev);
}
static void steal_time_init(struct kvm_vcpu *vcpu, uint32_t i)
{
struct kvm_vm *vm = vcpu->vm;
uint64_t st_ipa;
int ret;
struct kvm_device_attr dev = {
.group = KVM_ARM_VCPU_PVTIME_CTRL,
.attr = KVM_ARM_VCPU_PVTIME_IPA,
.addr = (uint64_t)&st_ipa,
};
vcpu_ioctl(vcpu, KVM_HAS_DEVICE_ATTR, &dev);
/* ST_GPA_BASE is identity mapped */
st_gva[i] = (void *)(ST_GPA_BASE + i * STEAL_TIME_SIZE);
sync_global_to_guest(vm, st_gva[i]);
st_ipa = (ulong)st_gva[i] | 1;
ret = __vcpu_ioctl(vcpu, KVM_SET_DEVICE_ATTR, &dev);
TEST_ASSERT(ret == -1 && errno == EINVAL, "Bad IPA didn't report EINVAL");
st_ipa = (ulong)st_gva[i];
vcpu_ioctl(vcpu, KVM_SET_DEVICE_ATTR, &dev);
ret = __vcpu_ioctl(vcpu, KVM_SET_DEVICE_ATTR, &dev);
TEST_ASSERT(ret == -1 && errno == EEXIST, "Set IPA twice without EEXIST");
}
static void steal_time_dump(struct kvm_vm *vm, uint32_t vcpu_idx)
{
struct st_time *st = addr_gva2hva(vm, (ulong)st_gva[vcpu_idx]);
ksft_print_msg("VCPU%d:\n", vcpu_idx);
ksft_print_msg(" rev: %d\n", st->rev);
ksft_print_msg(" attr: %d\n", st->attr);
ksft_print_msg(" st_time: %ld\n", st->st_time);
}
#elif defined(__riscv)
/* SBI STA shmem must have 64-byte alignment */
#define STEAL_TIME_SIZE ((sizeof(struct sta_struct) + 63) & ~63)
static vm_paddr_t st_gpa[NR_VCPUS];
struct sta_struct {
uint32_t sequence;
uint32_t flags;
uint64_t steal;
uint8_t preempted;
uint8_t pad[47];
} __packed;
static void sta_set_shmem(vm_paddr_t gpa, unsigned long flags)
{
unsigned long lo = (unsigned long)gpa;
#if __riscv_xlen == 32
unsigned long hi = (unsigned long)(gpa >> 32);
#else
unsigned long hi = gpa == -1 ? -1 : 0;
#endif
struct sbiret ret = sbi_ecall(SBI_EXT_STA, 0, lo, hi, flags, 0, 0, 0);
GUEST_ASSERT(ret.value == 0 && ret.error == 0);
}
static void check_status(struct sta_struct *st)
{
GUEST_ASSERT(!(READ_ONCE(st->sequence) & 1));
GUEST_ASSERT(READ_ONCE(st->flags) == 0);
GUEST_ASSERT(READ_ONCE(st->preempted) == 0);
}
static void guest_code(int cpu)
{
struct sta_struct *st = st_gva[cpu];
uint32_t sequence;
long out_val = 0;
bool probe;
probe = guest_sbi_probe_extension(SBI_EXT_STA, &out_val);
GUEST_ASSERT(probe && out_val == 1);
sta_set_shmem(st_gpa[cpu], 0);
GUEST_SYNC(0);
check_status(st);
WRITE_ONCE(guest_stolen_time[cpu], st->steal);
sequence = READ_ONCE(st->sequence);
check_status(st);
GUEST_SYNC(1);
check_status(st);
GUEST_ASSERT(sequence < READ_ONCE(st->sequence));
WRITE_ONCE(guest_stolen_time[cpu], st->steal);
check_status(st);
GUEST_DONE();
}
static bool is_steal_time_supported(struct kvm_vcpu *vcpu)
{
uint64_t id = RISCV_SBI_EXT_REG(KVM_RISCV_SBI_EXT_STA);
unsigned long enabled;
vcpu_get_reg(vcpu, id, &enabled);
TEST_ASSERT(enabled == 0 || enabled == 1, "Expected boolean result");
return enabled;
}
static void steal_time_init(struct kvm_vcpu *vcpu, uint32_t i)
{
/* ST_GPA_BASE is identity mapped */
st_gva[i] = (void *)(ST_GPA_BASE + i * STEAL_TIME_SIZE);
st_gpa[i] = addr_gva2gpa(vcpu->vm, (vm_vaddr_t)st_gva[i]);
sync_global_to_guest(vcpu->vm, st_gva[i]);
sync_global_to_guest(vcpu->vm, st_gpa[i]);
}
static void steal_time_dump(struct kvm_vm *vm, uint32_t vcpu_idx)
{
struct sta_struct *st = addr_gva2hva(vm, (ulong)st_gva[vcpu_idx]);
int i;
pr_info("VCPU%d:\n", vcpu_idx);
pr_info(" sequence: %d\n", st->sequence);
pr_info(" flags: %d\n", st->flags);
pr_info(" steal: %"PRIu64"\n", st->steal);
pr_info(" preempted: %d\n", st->preempted);
pr_info(" pad: ");
for (i = 0; i < 47; ++i)
pr_info("%d", st->pad[i]);
pr_info("\n");
}
#endif
static void *do_steal_time(void *arg)
{
struct timespec ts, stop;
clock_gettime(CLOCK_MONOTONIC, &ts);
stop = timespec_add_ns(ts, MIN_RUN_DELAY_NS);
while (1) {
clock_gettime(CLOCK_MONOTONIC, &ts);
if (timespec_to_ns(timespec_sub(ts, stop)) >= 0)
break;
}
return NULL;
}
static void run_vcpu(struct kvm_vcpu *vcpu)
{
struct ucall uc;
vcpu_run(vcpu);
switch (get_ucall(vcpu, &uc)) {
case UCALL_SYNC:
case UCALL_DONE:
break;
case UCALL_ABORT:
REPORT_GUEST_ASSERT(uc);
default:
TEST_ASSERT(false, "Unexpected exit: %s",
exit_reason_str(vcpu->run->exit_reason));
}
}
int main(int ac, char **av)
{
struct kvm_vcpu *vcpus[NR_VCPUS];
struct kvm_vm *vm;
pthread_attr_t attr;
pthread_t thread;
cpu_set_t cpuset;
unsigned int gpages;
long stolen_time;
long run_delay;
bool verbose;
int i;
verbose = ac > 1 && (!strncmp(av[1], "-v", 3) || !strncmp(av[1], "--verbose", 10));
/* Set CPU affinity so we can force preemption of the VCPU */
CPU_ZERO(&cpuset);
CPU_SET(0, &cpuset);
pthread_attr_init(&attr);
pthread_attr_setaffinity_np(&attr, sizeof(cpu_set_t), &cpuset);
pthread_setaffinity_np(pthread_self(), sizeof(cpu_set_t), &cpuset);
/* Create a VM and an identity mapped memslot for the steal time structure */
vm = vm_create_with_vcpus(NR_VCPUS, guest_code, vcpus);
gpages = vm_calc_num_guest_pages(VM_MODE_DEFAULT, STEAL_TIME_SIZE * NR_VCPUS);
vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, ST_GPA_BASE, 1, gpages, 0);
virt_map(vm, ST_GPA_BASE, ST_GPA_BASE, gpages);
ksft_print_header();
TEST_REQUIRE(is_steal_time_supported(vcpus[0]));
ksft_set_plan(NR_VCPUS);
/* Run test on each VCPU */
for (i = 0; i < NR_VCPUS; ++i) {
steal_time_init(vcpus[i], i);
vcpu_args_set(vcpus[i], 1, i);
/* First VCPU run initializes steal-time */
run_vcpu(vcpus[i]);
/* Second VCPU run, expect guest stolen time to be <= run_delay */
run_vcpu(vcpus[i]);
sync_global_from_guest(vm, guest_stolen_time[i]);
stolen_time = guest_stolen_time[i];
run_delay = get_run_delay();
TEST_ASSERT(stolen_time <= run_delay,
"Expected stolen time <= %ld, got %ld",
run_delay, stolen_time);
/* Steal time from the VCPU. The steal time thread has the same CPU affinity as the VCPUs. */
run_delay = get_run_delay();
pthread_create(&thread, &attr, do_steal_time, NULL);
do
sched_yield();
while (get_run_delay() - run_delay < MIN_RUN_DELAY_NS);
pthread_join(thread, NULL);
run_delay = get_run_delay() - run_delay;
TEST_ASSERT(run_delay >= MIN_RUN_DELAY_NS,
"Expected run_delay >= %ld, got %ld",
MIN_RUN_DELAY_NS, run_delay);
/* Run VCPU again to confirm stolen time is consistent with run_delay */
run_vcpu(vcpus[i]);
sync_global_from_guest(vm, guest_stolen_time[i]);
stolen_time = guest_stolen_time[i] - stolen_time;
TEST_ASSERT(stolen_time >= run_delay,
"Expected stolen time >= %ld, got %ld",
run_delay, stolen_time);
if (verbose) {
ksft_print_msg("VCPU%d: total-stolen-time=%ld test-stolen-time=%ld%s\n",
i, guest_stolen_time[i], stolen_time,
stolen_time == run_delay ?
" (BONUS: guest test-stolen-time even exactly matches test-run_delay)" : "");
steal_time_dump(vm, i);
}
ksft_test_result_pass("vcpu%d\n", i);
}
/* Print results and exit() accordingly */
ksft_finished();
}
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