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/*
* Copyright 2017 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include <errno.h>
#include <fcntl.h>
#include <linux/memfd.h>
#include <pthread.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/eventfd.h>
#include <sys/mman.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <time.h>
#include <unistd.h>
#include "crosvm.h"
#ifndef F_LINUX_SPECIFIC_BASE
#define F_LINUX_SPECIFIC_BASE 1024
#endif
#ifndef F_ADD_SEALS
#define F_ADD_SEALS (F_LINUX_SPECIFIC_BASE + 9)
#endif
#ifndef F_SEAL_SHRINK
#define F_SEAL_SHRINK 0x0002
#endif
#define SERIAL_ADDRESS 0x3f8
#define KILL_ADDRESS 0x3f9
static char g_serial_out[16];
static int g_next_evt;
static int g_kill_evt;
static bool g_paused;
static bool g_exit_loop;
static pthread_mutex_t g_pause_mutex = PTHREAD_MUTEX_INITIALIZER;
static pthread_cond_t g_pause_cond = PTHREAD_COND_INITIALIZER;
static volatile int count;
static void *vcpu_thread_fn(void *arg) {
struct crosvm_vcpu *vcpu = arg;
struct crosvm_vcpu_event evt;
int i = 0;
while (crosvm_vcpu_wait(vcpu, &evt) == 0) {
if (evt.kind == CROSVM_VCPU_EVENT_KIND_INIT) {
struct kvm_sregs sregs;
crosvm_vcpu_get_sregs(vcpu, &sregs);
sregs.cs.base = 0;
sregs.cs.selector = 0;
sregs.es.base = KILL_ADDRESS;
sregs.es.selector = 0;
crosvm_vcpu_set_sregs(vcpu, &sregs);
struct kvm_regs regs;
crosvm_vcpu_get_regs(vcpu, ®s);
regs.rip = 0x1000;
regs.rax = 2;
regs.rbx = 7;
regs.rflags = 2;
crosvm_vcpu_set_regs(vcpu, ®s);
/* Signal the main thread that init is done */
uint64_t dummy = 1;
write(g_next_evt, &dummy, sizeof(dummy));
}
else if (evt.kind == CROSVM_VCPU_EVENT_KIND_IO_ACCESS &&
evt.io_access.address_space == CROSVM_ADDRESS_SPACE_IOPORT &&
evt.io_access.address == KILL_ADDRESS &&
evt.io_access.is_write &&
evt.io_access.length == 1 &&
evt.io_access.data[0] == 1) {
uint64_t dummy = 1;
write(g_kill_evt, &dummy, sizeof(dummy));
return NULL;
}
else if (evt.kind == CROSVM_VCPU_EVENT_KIND_PAUSED) {
/* Signal that we paused */
uint64_t dummy = 1;
write(g_next_evt, &dummy, sizeof(dummy));
/* Wait till we can continue again */
pthread_mutex_lock(&g_pause_mutex);
while (g_paused)
pthread_cond_wait(&g_pause_cond, &g_pause_mutex);
/* Kick the VM from infinite loop if requested */
if (g_exit_loop) {
struct kvm_regs regs;
crosvm_vcpu_get_regs(vcpu, ®s);
regs.rbx = 1;
crosvm_vcpu_set_regs(vcpu, ®s);
}
/* Signal that we are no longer paused */
write(g_next_evt, &dummy, sizeof(dummy));
pthread_mutex_unlock(&g_pause_mutex);
}
crosvm_vcpu_resume(vcpu);
}
return NULL;
}
static int signal_pause(struct crosvm *crosvm) {
pthread_mutex_lock(&g_pause_mutex);
g_paused = true;
pthread_mutex_unlock(&g_pause_mutex);
return crosvm_pause_vcpus(crosvm, 1, NULL);
}
static void signal_unpause(struct crosvm *crosvm, bool exit_loop) {
pthread_mutex_lock(&g_pause_mutex);
g_paused = false;
g_exit_loop = exit_loop;
pthread_cond_broadcast(&g_pause_cond);
pthread_mutex_unlock(&g_pause_mutex);
}
int main(int argc, char** argv) {
const uint8_t code[] = {
/*
0000 00D8 add al,bl
0002 80FB01 cmp bl, 0x1
0005 75F9 jne 0x0
0007 BAF903 mov dx,0x3f8
000A B001 mov al,0x1
000C EE out dx,al
000D F4 hlt
*/
0x00, 0xd8,
0x80, 0xfb, 0x01,
0x75, 0xf9,
0xba, 0xf9, 0x03,
0xb0, 0x01,
0xee,
0xf4
};
g_next_evt = eventfd(0, 0);
if (g_next_evt == -1) {
fprintf(stderr, "failed to create eventfd: %d\n", errno);
return 1;
}
struct crosvm *crosvm;
int ret = crosvm_connect(&crosvm);
if (ret) {
fprintf(stderr, "failed to connect to crosvm: %d\n", ret);
return 1;
}
/* We needs this eventfd to know when to exit before being killed. */
g_kill_evt = crosvm_get_shutdown_eventfd(crosvm);
if (g_kill_evt < 0) {
fprintf(stderr, "failed to get kill eventfd: %d\n", g_kill_evt);
return 1;
}
ret = crosvm_reserve_range(crosvm, CROSVM_ADDRESS_SPACE_IOPORT,
KILL_ADDRESS, 1);
if (ret) {
fprintf(stderr, "failed to reserve mmio range: %d\n", ret);
return 1;
}
int mem_size = 0x2000;
int mem_fd = syscall(SYS_memfd_create,
"guest_mem", MFD_CLOEXEC | MFD_ALLOW_SEALING);
if (mem_fd < 0) {
fprintf(stderr, "failed to create guest memfd: %d\n", errno);
return 1;
}
ret = ftruncate(mem_fd, mem_size);
if (ret) {
fprintf(stderr, "failed to set size of guest memory: %d\n", errno);
return 1;
}
uint8_t *mem = mmap(NULL, mem_size, PROT_READ | PROT_WRITE, MAP_SHARED,
mem_fd, 0x1000);
if (mem == MAP_FAILED) {
fprintf(stderr, "failed to mmap guest memory: %d\n", errno);
return 1;
}
fcntl(mem_fd, F_ADD_SEALS, F_SEAL_SHRINK);
memcpy(mem, code, sizeof(code));
struct crosvm_memory *mem_obj;
ret = crosvm_create_memory(crosvm, mem_fd, 0x1000, 0x1000, 0x1000,
false, false, &mem_obj);
if (ret) {
fprintf(stderr, "failed to create memory in crosvm: %d\n", ret);
return 1;
}
/* get and create a thread for the vcpu */
struct crosvm_vcpu *vcpu;
ret = crosvm_get_vcpu(crosvm, 0, &vcpu);
if (ret) {
fprintf(stderr, "error while getting vcpu: %d\n", ret);
return 1;
}
pthread_t vcpu_thread;
ret = pthread_create(&vcpu_thread, NULL, vcpu_thread_fn, vcpu);
if (ret) {
fprintf(stderr, "failed to createvcpu thread\n");
return 1;
}
ret = crosvm_start(crosvm);
if (ret) {
fprintf(stderr, "failed to tell crosvm to start: %d\n", ret);
return 1;
}
/* Wait till VCPU thread tells us that its initialization is done */
uint64_t dummy;
read(g_next_evt, &dummy, sizeof(dummy));
ret = signal_pause(crosvm);
if (ret) {
fprintf(stderr, "failed to pause vcpus (1st time): %d\n", ret);
return 1;
}
/* Wait till VCPU thread tells us it is paused */
read(g_next_evt, &dummy, sizeof(dummy));
/* Try pausing VCPUs 2nd time to make sure we do not deadlock */
ret = signal_pause(crosvm);
if (ret) {
fprintf(stderr, "failed to pause vcpus (2nd time): %d\n", ret);
return 1;
}
signal_unpause(crosvm, false);
/* Wait until VCPU thread tells us that it is no longer paused */
read(g_next_evt, &dummy, sizeof(dummy));
/*
* Try pausing VCPUs 3rd time to see if we will miss pause
* request as we are exiting previous pause.
*/
ret = signal_pause(crosvm);
if (ret) {
fprintf(stderr, "failed to pause vcpus (2nd time): %d\n", ret);
return 1;
}
signal_unpause(crosvm, true);
/* Wait for crosvm to request that we exit otherwise we will be killed. */
read(g_kill_evt, &dummy, sizeof(dummy));
ret = crosvm_destroy_memory(crosvm, &mem_obj);
if (ret) {
fprintf(stderr, "failed to destroy memory in crosvm: %d\n", ret);
return 1;
}
ret = crosvm_reserve_range(crosvm, CROSVM_ADDRESS_SPACE_IOPORT,
KILL_ADDRESS, 0);
if (ret) {
fprintf(stderr, "failed to unreserve mmio range: %d\n", ret);
return 1;
}
return 0;
}
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