xref: /kvmtool/builtin-run.c (revision 5b403dbfc4133e6d9ecb1fc8f2a88b3d245c37e6)
1 #include "kvm/builtin-run.h"
2 
3 #include "kvm/builtin-setup.h"
4 #include "kvm/virtio-balloon.h"
5 #include "kvm/virtio-console.h"
6 #include "kvm/parse-options.h"
7 #include "kvm/8250-serial.h"
8 #include "kvm/framebuffer.h"
9 #include "kvm/disk-image.h"
10 #include "kvm/threadpool.h"
11 #include "kvm/virtio-scsi.h"
12 #include "kvm/virtio-blk.h"
13 #include "kvm/virtio-net.h"
14 #include "kvm/virtio-rng.h"
15 #include "kvm/ioeventfd.h"
16 #include "kvm/virtio-9p.h"
17 #include "kvm/barrier.h"
18 #include "kvm/kvm-cpu.h"
19 #include "kvm/ioport.h"
20 #include "kvm/symbol.h"
21 #include "kvm/i8042.h"
22 #include "kvm/mutex.h"
23 #include "kvm/term.h"
24 #include "kvm/util.h"
25 #include "kvm/strbuf.h"
26 #include "kvm/vesa.h"
27 #include "kvm/irq.h"
28 #include "kvm/kvm.h"
29 #include "kvm/pci.h"
30 #include "kvm/rtc.h"
31 #include "kvm/sdl.h"
32 #include "kvm/vnc.h"
33 #include "kvm/guest_compat.h"
34 #include "kvm/pci-shmem.h"
35 #include "kvm/kvm-ipc.h"
36 #include "kvm/builtin-debug.h"
37 
38 #include <linux/types.h>
39 #include <linux/err.h>
40 
41 #include <sys/utsname.h>
42 #include <sys/types.h>
43 #include <sys/stat.h>
44 #include <termios.h>
45 #include <signal.h>
46 #include <stdlib.h>
47 #include <string.h>
48 #include <unistd.h>
49 #include <ctype.h>
50 #include <stdio.h>
51 
52 #define MB_SHIFT		(20)
53 #define KB_SHIFT		(10)
54 #define GB_SHIFT		(30)
55 
56 __thread struct kvm_cpu *current_kvm_cpu;
57 
58 static int  kvm_run_wrapper;
59 
60 bool do_debug_print = false;
61 
62 extern char _binary_guest_init_start;
63 extern char _binary_guest_init_size;
64 
65 static const char * const run_usage[] = {
66 	"lkvm run [<options>] [<kernel image>]",
67 	NULL
68 };
69 
70 enum {
71 	KVM_RUN_DEFAULT,
72 	KVM_RUN_SANDBOX,
73 };
74 
75 static int img_name_parser(const struct option *opt, const char *arg, int unset)
76 {
77 	char path[PATH_MAX];
78 	struct stat st;
79 
80 	snprintf(path, PATH_MAX, "%s%s", kvm__get_dir(), arg);
81 
82 	if ((stat(arg, &st) == 0 && S_ISDIR(st.st_mode)) ||
83 	   (stat(path, &st) == 0 && S_ISDIR(st.st_mode)))
84 		return virtio_9p_img_name_parser(opt, arg, unset);
85 	return disk_img_name_parser(opt, arg, unset);
86 }
87 
88 void kvm_run_set_wrapper_sandbox(void)
89 {
90 	kvm_run_wrapper = KVM_RUN_SANDBOX;
91 }
92 
93 #define BUILD_OPTIONS(name, cfg, kvm)					\
94 	struct option name[] = {					\
95 	OPT_GROUP("Basic options:"),					\
96 	OPT_STRING('\0', "name", &(cfg)->guest_name, "guest name",	\
97 			"A name for the guest"),			\
98 	OPT_INTEGER('c', "cpus", &(cfg)->nrcpus, "Number of CPUs"),	\
99 	OPT_U64('m', "mem", &(cfg)->ram_size, "Virtual machine memory"	\
100 		" size in MiB."),					\
101 	OPT_CALLBACK('\0', "shmem", NULL,				\
102 		     "[pci:]<addr>:<size>[:handle=<handle>][:create]",	\
103 		     "Share host shmem with guest via pci device",	\
104 		     shmem_parser, NULL),				\
105 	OPT_CALLBACK('d', "disk", kvm, "image or rootfs_dir", "Disk "	\
106 			" image or rootfs directory", img_name_parser,	\
107 			kvm),						\
108 	OPT_BOOLEAN('\0', "balloon", &(cfg)->balloon, "Enable virtio"	\
109 			" balloon"),					\
110 	OPT_BOOLEAN('\0', "vnc", &(cfg)->vnc, "Enable VNC framebuffer"),\
111 	OPT_BOOLEAN('\0', "sdl", &(cfg)->sdl, "Enable SDL framebuffer"),\
112 	OPT_BOOLEAN('\0', "rng", &(cfg)->virtio_rng, "Enable virtio"	\
113 			" Random Number Generator"),			\
114 	OPT_CALLBACK('\0', "9p", NULL, "dir_to_share,tag_name",		\
115 		     "Enable virtio 9p to share files between host and"	\
116 		     " guest", virtio_9p_rootdir_parser, kvm),		\
117 	OPT_STRING('\0', "console", &(cfg)->console, "serial, virtio or"\
118 			" hv", "Console to use"),			\
119 	OPT_STRING('\0', "dev", &(cfg)->dev, "device_file",		\
120 			"KVM device file"),				\
121 	OPT_CALLBACK('\0', "tty", NULL, "tty id",			\
122 		     "Remap guest TTY into a pty on the host",		\
123 		     tty_parser, NULL),					\
124 	OPT_STRING('\0', "sandbox", &(cfg)->sandbox, "script",		\
125 			"Run this script when booting into custom"	\
126 			" rootfs"),					\
127 	OPT_STRING('\0', "hugetlbfs", &(cfg)->hugetlbfs_path, "path",	\
128 			"Hugetlbfs path"),				\
129 									\
130 	OPT_GROUP("Kernel options:"),					\
131 	OPT_STRING('k', "kernel", &(cfg)->kernel_filename, "kernel",	\
132 			"Kernel to boot in virtual machine"),		\
133 	OPT_STRING('i', "initrd", &(cfg)->initrd_filename, "initrd",	\
134 			"Initial RAM disk image"),			\
135 	OPT_STRING('p', "params", &(cfg)->kernel_cmdline, "params",	\
136 			"Kernel command line arguments"),		\
137 	OPT_STRING('f', "firmware", &(cfg)->firmware_filename, "firmware",\
138 			"Firmware image to boot in virtual machine"),	\
139 									\
140 	OPT_GROUP("Networking options:"),				\
141 	OPT_CALLBACK_DEFAULT('n', "network", NULL, "network params",	\
142 		     "Create a new guest NIC",				\
143 		     netdev_parser, NULL, kvm),				\
144 	OPT_BOOLEAN('\0', "no-dhcp", &(cfg)->no_dhcp, "Disable kernel"	\
145 			" DHCP in rootfs mode"),			\
146 									\
147 	OPT_GROUP("BIOS options:"),					\
148 	OPT_INTEGER('\0', "vidmode", &(cfg)->vidmode,			\
149 		    "Video mode"),					\
150 									\
151 	OPT_GROUP("Debug options:"),					\
152 	OPT_BOOLEAN('\0', "debug", &do_debug_print,			\
153 			"Enable debug messages"),			\
154 	OPT_BOOLEAN('\0', "debug-single-step", &(cfg)->single_step,	\
155 			"Enable single stepping"),			\
156 	OPT_BOOLEAN('\0', "debug-ioport", &(cfg)->ioport_debug,		\
157 			"Enable ioport debugging"),			\
158 	OPT_BOOLEAN('\0', "debug-mmio", &(cfg)->mmio_debug,		\
159 			"Enable MMIO debugging"),			\
160 	OPT_INTEGER('\0', "debug-iodelay", &(cfg)->debug_iodelay,	\
161 			"Delay IO by millisecond"),			\
162 	OPT_END()							\
163 	};
164 
165 static void handle_sigalrm(int sig, siginfo_t *si, void *uc)
166 {
167 	struct kvm *kvm = si->si_value.sival_ptr;
168 
169 	kvm__arch_periodic_poll(kvm);
170 }
171 
172 static void *kvm_cpu_thread(void *arg)
173 {
174 	char name[16];
175 
176 	current_kvm_cpu = arg;
177 
178 	sprintf(name, "kvm-vcpu-%lu", current_kvm_cpu->cpu_id);
179 	kvm__set_thread_name(name);
180 
181 	if (kvm_cpu__start(current_kvm_cpu))
182 		goto panic_kvm;
183 
184 	return (void *) (intptr_t) 0;
185 
186 panic_kvm:
187 	fprintf(stderr, "KVM exit reason: %u (\"%s\")\n",
188 		current_kvm_cpu->kvm_run->exit_reason,
189 		kvm_exit_reasons[current_kvm_cpu->kvm_run->exit_reason]);
190 	if (current_kvm_cpu->kvm_run->exit_reason == KVM_EXIT_UNKNOWN)
191 		fprintf(stderr, "KVM exit code: 0x%Lu\n",
192 			current_kvm_cpu->kvm_run->hw.hardware_exit_reason);
193 
194 	kvm_cpu__set_debug_fd(STDOUT_FILENO);
195 	kvm_cpu__show_registers(current_kvm_cpu);
196 	kvm_cpu__show_code(current_kvm_cpu);
197 	kvm_cpu__show_page_tables(current_kvm_cpu);
198 
199 	return (void *) (intptr_t) 1;
200 }
201 
202 static char kernel[PATH_MAX];
203 
204 static const char *host_kernels[] = {
205 	"/boot/vmlinuz",
206 	"/boot/bzImage",
207 	NULL
208 };
209 
210 static const char *default_kernels[] = {
211 	"./bzImage",
212 	"arch/" BUILD_ARCH "/boot/bzImage",
213 	"../../arch/" BUILD_ARCH "/boot/bzImage",
214 	NULL
215 };
216 
217 static const char *default_vmlinux[] = {
218 	"vmlinux",
219 	"../../../vmlinux",
220 	"../../vmlinux",
221 	NULL
222 };
223 
224 static void kernel_usage_with_options(void)
225 {
226 	const char **k;
227 	struct utsname uts;
228 
229 	fprintf(stderr, "Fatal: could not find default kernel image in:\n");
230 	k = &default_kernels[0];
231 	while (*k) {
232 		fprintf(stderr, "\t%s\n", *k);
233 		k++;
234 	}
235 
236 	if (uname(&uts) < 0)
237 		return;
238 
239 	k = &host_kernels[0];
240 	while (*k) {
241 		if (snprintf(kernel, PATH_MAX, "%s-%s", *k, uts.release) < 0)
242 			return;
243 		fprintf(stderr, "\t%s\n", kernel);
244 		k++;
245 	}
246 	fprintf(stderr, "\nPlease see '%s run --help' for more options.\n\n",
247 		KVM_BINARY_NAME);
248 }
249 
250 static u64 host_ram_size(void)
251 {
252 	long page_size;
253 	long nr_pages;
254 
255 	nr_pages	= sysconf(_SC_PHYS_PAGES);
256 	if (nr_pages < 0) {
257 		pr_warning("sysconf(_SC_PHYS_PAGES) failed");
258 		return 0;
259 	}
260 
261 	page_size	= sysconf(_SC_PAGE_SIZE);
262 	if (page_size < 0) {
263 		pr_warning("sysconf(_SC_PAGE_SIZE) failed");
264 		return 0;
265 	}
266 
267 	return (nr_pages * page_size) >> MB_SHIFT;
268 }
269 
270 /*
271  * If user didn't specify how much memory it wants to allocate for the guest,
272  * avoid filling the whole host RAM.
273  */
274 #define RAM_SIZE_RATIO		0.8
275 
276 static u64 get_ram_size(int nr_cpus)
277 {
278 	u64 available;
279 	u64 ram_size;
280 
281 	ram_size	= 64 * (nr_cpus + 3);
282 
283 	available	= host_ram_size() * RAM_SIZE_RATIO;
284 	if (!available)
285 		available = MIN_RAM_SIZE_MB;
286 
287 	if (ram_size > available)
288 		ram_size	= available;
289 
290 	return ram_size;
291 }
292 
293 static const char *find_kernel(void)
294 {
295 	const char **k;
296 	struct stat st;
297 	struct utsname uts;
298 
299 	k = &default_kernels[0];
300 	while (*k) {
301 		if (stat(*k, &st) < 0 || !S_ISREG(st.st_mode)) {
302 			k++;
303 			continue;
304 		}
305 		strncpy(kernel, *k, PATH_MAX);
306 		return kernel;
307 	}
308 
309 	if (uname(&uts) < 0)
310 		return NULL;
311 
312 	k = &host_kernels[0];
313 	while (*k) {
314 		if (snprintf(kernel, PATH_MAX, "%s-%s", *k, uts.release) < 0)
315 			return NULL;
316 
317 		if (stat(kernel, &st) < 0 || !S_ISREG(st.st_mode)) {
318 			k++;
319 			continue;
320 		}
321 		return kernel;
322 
323 	}
324 	return NULL;
325 }
326 
327 static const char *find_vmlinux(void)
328 {
329 	const char **vmlinux;
330 
331 	vmlinux = &default_vmlinux[0];
332 	while (*vmlinux) {
333 		struct stat st;
334 
335 		if (stat(*vmlinux, &st) < 0 || !S_ISREG(st.st_mode)) {
336 			vmlinux++;
337 			continue;
338 		}
339 		return *vmlinux;
340 	}
341 	return NULL;
342 }
343 
344 void kvm_run_help(void)
345 {
346 	struct kvm *kvm = NULL;
347 
348 	BUILD_OPTIONS(options, &kvm->cfg, kvm);
349 	usage_with_options(run_usage, options);
350 }
351 
352 static int kvm_setup_guest_init(struct kvm *kvm)
353 {
354 	const char *rootfs = kvm->cfg.custom_rootfs_name;
355 	char tmp[PATH_MAX];
356 	size_t size;
357 	int fd, ret;
358 	char *data;
359 
360 	/* Setup /virt/init */
361 	size = (size_t)&_binary_guest_init_size;
362 	data = (char *)&_binary_guest_init_start;
363 	snprintf(tmp, PATH_MAX, "%s%s/virt/init", kvm__get_dir(), rootfs);
364 	remove(tmp);
365 	fd = open(tmp, O_CREAT | O_WRONLY, 0755);
366 	if (fd < 0)
367 		die("Fail to setup %s", tmp);
368 	ret = xwrite(fd, data, size);
369 	if (ret < 0)
370 		die("Fail to setup %s", tmp);
371 	close(fd);
372 
373 	return 0;
374 }
375 
376 static int kvm_run_set_sandbox(struct kvm *kvm)
377 {
378 	const char *guestfs_name = kvm->cfg.custom_rootfs_name;
379 	char path[PATH_MAX], script[PATH_MAX], *tmp;
380 
381 	snprintf(path, PATH_MAX, "%s%s/virt/sandbox.sh", kvm__get_dir(), guestfs_name);
382 
383 	remove(path);
384 
385 	if (kvm->cfg.sandbox == NULL)
386 		return 0;
387 
388 	tmp = realpath(kvm->cfg.sandbox, NULL);
389 	if (tmp == NULL)
390 		return -ENOMEM;
391 
392 	snprintf(script, PATH_MAX, "/host/%s", tmp);
393 	free(tmp);
394 
395 	return symlink(script, path);
396 }
397 
398 static void kvm_write_sandbox_cmd_exactly(int fd, const char *arg)
399 {
400 	const char *single_quote;
401 
402 	if (!*arg) { /* zero length string */
403 		if (write(fd, "''", 2) <= 0)
404 			die("Failed writing sandbox script");
405 		return;
406 	}
407 
408 	while (*arg) {
409 		single_quote = strchrnul(arg, '\'');
410 
411 		/* write non-single-quote string as #('string') */
412 		if (arg != single_quote) {
413 			if (write(fd, "'", 1) <= 0 ||
414 			    write(fd, arg, single_quote - arg) <= 0 ||
415 			    write(fd, "'", 1) <= 0)
416 				die("Failed writing sandbox script");
417 		}
418 
419 		/* write single quote as #("'") */
420 		if (*single_quote) {
421 			if (write(fd, "\"'\"", 3) <= 0)
422 				die("Failed writing sandbox script");
423 		} else
424 			break;
425 
426 		arg = single_quote + 1;
427 	}
428 }
429 
430 static void resolve_program(const char *src, char *dst, size_t len)
431 {
432 	struct stat st;
433 	int err;
434 
435 	err = stat(src, &st);
436 
437 	if (!err && S_ISREG(st.st_mode)) {
438 		char resolved_path[PATH_MAX];
439 
440 		if (!realpath(src, resolved_path))
441 			die("Unable to resolve program %s: %s\n", src, strerror(errno));
442 
443 		snprintf(dst, len, "/host%s", resolved_path);
444 	} else
445 		strncpy(dst, src, len);
446 }
447 
448 static void kvm_run_write_sandbox_cmd(struct kvm *kvm, const char **argv, int argc)
449 {
450 	const char script_hdr[] = "#! /bin/bash\n\n";
451 	char program[PATH_MAX];
452 	int fd;
453 
454 	remove(kvm->cfg.sandbox);
455 
456 	fd = open(kvm->cfg.sandbox, O_RDWR | O_CREAT, 0777);
457 	if (fd < 0)
458 		die("Failed creating sandbox script");
459 
460 	if (write(fd, script_hdr, sizeof(script_hdr) - 1) <= 0)
461 		die("Failed writing sandbox script");
462 
463 	resolve_program(argv[0], program, PATH_MAX);
464 	kvm_write_sandbox_cmd_exactly(fd, program);
465 
466 	argv++;
467 	argc--;
468 
469 	while (argc) {
470 		if (write(fd, " ", 1) <= 0)
471 			die("Failed writing sandbox script");
472 
473 		kvm_write_sandbox_cmd_exactly(fd, argv[0]);
474 		argv++;
475 		argc--;
476 	}
477 	if (write(fd, "\n", 1) <= 0)
478 		die("Failed writing sandbox script");
479 
480 	close(fd);
481 }
482 
483 static struct kvm *kvm_cmd_run_init(int argc, const char **argv)
484 {
485 	static char real_cmdline[2048], default_name[20];
486 	unsigned int nr_online_cpus;
487 	struct sigaction sa;
488 	struct kvm *kvm = kvm__new();
489 
490 	if (IS_ERR(kvm))
491 		return kvm;
492 
493 	sa.sa_flags = SA_SIGINFO;
494 	sa.sa_sigaction = handle_sigalrm;
495 	sigemptyset(&sa.sa_mask);
496 	sigaction(SIGALRM, &sa, NULL);
497 
498 	nr_online_cpus = sysconf(_SC_NPROCESSORS_ONLN);
499 	kvm->cfg.custom_rootfs_name = "default";
500 
501 	while (argc != 0) {
502 		BUILD_OPTIONS(options, &kvm->cfg, kvm);
503 		argc = parse_options(argc, argv, options, run_usage,
504 				PARSE_OPT_STOP_AT_NON_OPTION |
505 				PARSE_OPT_KEEP_DASHDASH);
506 		if (argc != 0) {
507 			/* Cusrom options, should have been handled elsewhere */
508 			if (strcmp(argv[0], "--") == 0) {
509 				if (kvm_run_wrapper == KVM_RUN_SANDBOX) {
510 					kvm->cfg.sandbox = DEFAULT_SANDBOX_FILENAME;
511 					kvm_run_write_sandbox_cmd(kvm, argv+1, argc-1);
512 					break;
513 				}
514 			}
515 
516 			if ((kvm_run_wrapper == KVM_RUN_DEFAULT && kvm->cfg.kernel_filename) ||
517 				(kvm_run_wrapper == KVM_RUN_SANDBOX && kvm->cfg.sandbox)) {
518 				fprintf(stderr, "Cannot handle parameter: "
519 						"%s\n", argv[0]);
520 				usage_with_options(run_usage, options);
521 				free(kvm);
522 				return ERR_PTR(-EINVAL);
523 			}
524 			if (kvm_run_wrapper == KVM_RUN_SANDBOX) {
525 				/*
526 				 * first unhandled parameter is treated as
527 				 * sandbox command
528 				 */
529 				kvm->cfg.sandbox = DEFAULT_SANDBOX_FILENAME;
530 				kvm_run_write_sandbox_cmd(kvm, argv, argc);
531 			} else {
532 				/*
533 				 * first unhandled parameter is treated as a kernel
534 				 * image
535 				 */
536 				kvm->cfg.kernel_filename = argv[0];
537 			}
538 			argv++;
539 			argc--;
540 		}
541 
542 	}
543 
544 	kvm->nr_disks = kvm->cfg.image_count;
545 
546 	if (!kvm->cfg.kernel_filename)
547 		kvm->cfg.kernel_filename = find_kernel();
548 
549 	if (!kvm->cfg.kernel_filename) {
550 		kernel_usage_with_options();
551 		return ERR_PTR(-EINVAL);
552 	}
553 
554 	kvm->cfg.vmlinux_filename = find_vmlinux();
555 	kvm->vmlinux = kvm->cfg.vmlinux_filename;
556 
557 	if (kvm->cfg.nrcpus == 0)
558 		kvm->cfg.nrcpus = nr_online_cpus;
559 
560 	if (!kvm->cfg.ram_size)
561 		kvm->cfg.ram_size = get_ram_size(kvm->cfg.nrcpus);
562 
563 	if (kvm->cfg.ram_size < MIN_RAM_SIZE_MB)
564 		die("Not enough memory specified: %lluMB (min %lluMB)", kvm->cfg.ram_size, MIN_RAM_SIZE_MB);
565 
566 	if (kvm->cfg.ram_size > host_ram_size())
567 		pr_warning("Guest memory size %lluMB exceeds host physical RAM size %lluMB", kvm->cfg.ram_size, host_ram_size());
568 
569 	kvm->cfg.ram_size <<= MB_SHIFT;
570 
571 	if (!kvm->cfg.dev)
572 		kvm->cfg.dev = DEFAULT_KVM_DEV;
573 
574 	if (!kvm->cfg.console)
575 		kvm->cfg.console = DEFAULT_CONSOLE;
576 
577 	if (!strncmp(kvm->cfg.console, "virtio", 6))
578 		kvm->cfg.active_console  = CONSOLE_VIRTIO;
579 	else if (!strncmp(kvm->cfg.console, "serial", 6))
580 		kvm->cfg.active_console  = CONSOLE_8250;
581 	else if (!strncmp(kvm->cfg.console, "hv", 2))
582 		kvm->cfg.active_console = CONSOLE_HV;
583 	else
584 		pr_warning("No console!");
585 
586 	if (!kvm->cfg.host_ip)
587 		kvm->cfg.host_ip = DEFAULT_HOST_ADDR;
588 
589 	if (!kvm->cfg.guest_ip)
590 		kvm->cfg.guest_ip = DEFAULT_GUEST_ADDR;
591 
592 	if (!kvm->cfg.guest_mac)
593 		kvm->cfg.guest_mac = DEFAULT_GUEST_MAC;
594 
595 	if (!kvm->cfg.host_mac)
596 		kvm->cfg.host_mac = DEFAULT_HOST_MAC;
597 
598 	if (!kvm->cfg.script)
599 		kvm->cfg.script = DEFAULT_SCRIPT;
600 
601 	if (!kvm->cfg.vidmode)
602 		kvm->cfg.vidmode = -1;
603 
604 	/* vidmode should be either specified or set by default */
605 	if (kvm->cfg.vnc || kvm->cfg.sdl) {
606 		if (kvm->cfg.vidmode == -1)
607 			kvm->cfg.vidmode = 0x312;
608 	} else {
609 		kvm->cfg.vidmode = 0;
610 	}
611 
612 	if (!kvm->cfg.network)
613                 kvm->cfg.network = DEFAULT_NETWORK;
614 
615 	memset(real_cmdline, 0, sizeof(real_cmdline));
616 	kvm__arch_set_cmdline(real_cmdline, kvm->cfg.vnc || kvm->cfg.sdl);
617 
618 	if (strlen(real_cmdline) > 0)
619 		strcat(real_cmdline, " ");
620 
621 	if (kvm->cfg.kernel_cmdline)
622 		strlcat(real_cmdline, kvm->cfg.kernel_cmdline, sizeof(real_cmdline));
623 
624 	if (!kvm->cfg.guest_name) {
625 		if (kvm->cfg.custom_rootfs) {
626 			kvm->cfg.guest_name = kvm->cfg.custom_rootfs_name;
627 		} else {
628 			sprintf(default_name, "guest-%u", getpid());
629 			kvm->cfg.guest_name = default_name;
630 		}
631 	}
632 
633 	if (!kvm->cfg.using_rootfs && !kvm->cfg.disk_image[0].filename && !kvm->cfg.initrd_filename) {
634 		char tmp[PATH_MAX];
635 
636 		kvm_setup_create_new(kvm->cfg.custom_rootfs_name);
637 		kvm_setup_resolv(kvm->cfg.custom_rootfs_name);
638 
639 		snprintf(tmp, PATH_MAX, "%s%s", kvm__get_dir(), "default");
640 		if (virtio_9p__register(kvm, tmp, "/dev/root") < 0)
641 			die("Unable to initialize virtio 9p");
642 		if (virtio_9p__register(kvm, "/", "hostfs") < 0)
643 			die("Unable to initialize virtio 9p");
644 		kvm->cfg.using_rootfs = kvm->cfg.custom_rootfs = 1;
645 	}
646 
647 	if (kvm->cfg.using_rootfs) {
648 		strcat(real_cmdline, " root=/dev/root rw rootflags=rw,trans=virtio,version=9p2000.L rootfstype=9p");
649 		if (kvm->cfg.custom_rootfs) {
650 			kvm_run_set_sandbox(kvm);
651 
652 			strcat(real_cmdline, " init=/virt/init");
653 
654 			if (!kvm->cfg.no_dhcp)
655 				strcat(real_cmdline, "  ip=dhcp");
656 			if (kvm_setup_guest_init(kvm))
657 				die("Failed to setup init for guest.");
658 		}
659 	} else if (!strstr(real_cmdline, "root=")) {
660 		strlcat(real_cmdline, " root=/dev/vda rw ", sizeof(real_cmdline));
661 	}
662 
663 	kvm->cfg.real_cmdline = real_cmdline;
664 
665 	printf("  # %s run -k %s -m %Lu -c %d --name %s\n", KVM_BINARY_NAME,
666 		kvm->cfg.kernel_filename, kvm->cfg.ram_size / 1024 / 1024, kvm->cfg.nrcpus, kvm->cfg.guest_name);
667 
668 	if (init_list__init(kvm) < 0)
669 		die ("Initialisation failed");
670 
671 	return kvm;
672 }
673 
674 static int kvm_cmd_run_work(struct kvm *kvm)
675 {
676 	int i;
677 	void *ret = NULL;
678 
679 	for (i = 0; i < kvm->nrcpus; i++) {
680 		if (pthread_create(&kvm->cpus[i]->thread, NULL, kvm_cpu_thread, kvm->cpus[i]) != 0)
681 			die("unable to create KVM VCPU thread");
682 	}
683 
684 	/* Only VCPU #0 is going to exit by itself when shutting down */
685 	return pthread_join(kvm->cpus[0]->thread, &ret);
686 }
687 
688 static void kvm_cmd_run_exit(struct kvm *kvm, int guest_ret)
689 {
690 	compat__print_all_messages();
691 
692 	init_list__exit(kvm);
693 
694 	if (guest_ret == 0)
695 		printf("\n  # KVM session ended normally.\n");
696 }
697 
698 int kvm_cmd_run(int argc, const char **argv, const char *prefix)
699 {
700 	int ret = -EFAULT;
701 	struct kvm *kvm;
702 
703 	kvm = kvm_cmd_run_init(argc, argv);
704 	if (IS_ERR(kvm))
705 		return PTR_ERR(kvm);
706 
707 	ret = kvm_cmd_run_work(kvm);
708 	kvm_cmd_run_exit(kvm, ret);
709 
710 	return ret;
711 }
712