diff options
author | Rusty Russell <rusty@rustcorp.com.au> | 2009-07-30 18:03:45 -0400 |
---|---|---|
committer | Rusty Russell <rusty@rustcorp.com.au> | 2009-07-30 02:33:45 -0400 |
commit | 2e04ef76916d1e29a077ea9d0f2003c8fd86724d (patch) | |
tree | 2ff8d625d6e467be9f9f1b67a3674cb6e125e970 /Documentation | |
parent | e969fed542cae08cb11d666efac4f7c5d624d09f (diff) |
lguest: fix comment style
I don't really notice it (except to begrudge the extra vertical
space), but Ingo does. And he pointed out that one excuse of lguest
is as a teaching tool, it should set a good example.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@redhat.com>
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/lguest/lguest.c | 540 |
1 files changed, 349 insertions, 191 deletions
diff --git a/Documentation/lguest/lguest.c b/Documentation/lguest/lguest.c index 45d7d6dcae7a..aa66a52b73e9 100644 --- a/Documentation/lguest/lguest.c +++ b/Documentation/lguest/lguest.c | |||
@@ -1,7 +1,9 @@ | |||
1 | /*P:100 This is the Launcher code, a simple program which lays out the | 1 | /*P:100 |
2 | * "physical" memory for the new Guest by mapping the kernel image and | 2 | * This is the Launcher code, a simple program which lays out the "physical" |
3 | * the virtual devices, then opens /dev/lguest to tell the kernel | 3 | * memory for the new Guest by mapping the kernel image and the virtual |
4 | * about the Guest and control it. :*/ | 4 | * devices, then opens /dev/lguest to tell the kernel about the Guest and |
5 | * control it. | ||
6 | :*/ | ||
5 | #define _LARGEFILE64_SOURCE | 7 | #define _LARGEFILE64_SOURCE |
6 | #define _GNU_SOURCE | 8 | #define _GNU_SOURCE |
7 | #include <stdio.h> | 9 | #include <stdio.h> |
@@ -46,13 +48,15 @@ | |||
46 | #include "linux/virtio_rng.h" | 48 | #include "linux/virtio_rng.h" |
47 | #include "linux/virtio_ring.h" | 49 | #include "linux/virtio_ring.h" |
48 | #include "asm/bootparam.h" | 50 | #include "asm/bootparam.h" |
49 | /*L:110 We can ignore the 39 include files we need for this program, but I do | 51 | /*L:110 |
50 | * want to draw attention to the use of kernel-style types. | 52 | * We can ignore the 39 include files we need for this program, but I do want |
53 | * to draw attention to the use of kernel-style types. | ||
51 | * | 54 | * |
52 | * As Linus said, "C is a Spartan language, and so should your naming be." I | 55 | * As Linus said, "C is a Spartan language, and so should your naming be." I |
53 | * like these abbreviations, so we define them here. Note that u64 is always | 56 | * like these abbreviations, so we define them here. Note that u64 is always |
54 | * unsigned long long, which works on all Linux systems: this means that we can | 57 | * unsigned long long, which works on all Linux systems: this means that we can |
55 | * use %llu in printf for any u64. */ | 58 | * use %llu in printf for any u64. |
59 | */ | ||
56 | typedef unsigned long long u64; | 60 | typedef unsigned long long u64; |
57 | typedef uint32_t u32; | 61 | typedef uint32_t u32; |
58 | typedef uint16_t u16; | 62 | typedef uint16_t u16; |
@@ -69,8 +73,10 @@ typedef uint8_t u8; | |||
69 | /* This will occupy 3 pages: it must be a power of 2. */ | 73 | /* This will occupy 3 pages: it must be a power of 2. */ |
70 | #define VIRTQUEUE_NUM 256 | 74 | #define VIRTQUEUE_NUM 256 |
71 | 75 | ||
72 | /*L:120 verbose is both a global flag and a macro. The C preprocessor allows | 76 | /*L:120 |
73 | * this, and although I wouldn't recommend it, it works quite nicely here. */ | 77 | * verbose is both a global flag and a macro. The C preprocessor allows |
78 | * this, and although I wouldn't recommend it, it works quite nicely here. | ||
79 | */ | ||
74 | static bool verbose; | 80 | static bool verbose; |
75 | #define verbose(args...) \ | 81 | #define verbose(args...) \ |
76 | do { if (verbose) printf(args); } while(0) | 82 | do { if (verbose) printf(args); } while(0) |
@@ -100,8 +106,7 @@ struct device_list | |||
100 | 106 | ||
101 | /* A single linked list of devices. */ | 107 | /* A single linked list of devices. */ |
102 | struct device *dev; | 108 | struct device *dev; |
103 | /* And a pointer to the last device for easy append and also for | 109 | /* And a pointer to the last device for easy append. */ |
104 | * configuration appending. */ | ||
105 | struct device *lastdev; | 110 | struct device *lastdev; |
106 | }; | 111 | }; |
107 | 112 | ||
@@ -168,20 +173,24 @@ static char **main_args; | |||
168 | /* The original tty settings to restore on exit. */ | 173 | /* The original tty settings to restore on exit. */ |
169 | static struct termios orig_term; | 174 | static struct termios orig_term; |
170 | 175 | ||
171 | /* We have to be careful with barriers: our devices are all run in separate | 176 | /* |
177 | * We have to be careful with barriers: our devices are all run in separate | ||
172 | * threads and so we need to make sure that changes visible to the Guest happen | 178 | * threads and so we need to make sure that changes visible to the Guest happen |
173 | * in precise order. */ | 179 | * in precise order. |
180 | */ | ||
174 | #define wmb() __asm__ __volatile__("" : : : "memory") | 181 | #define wmb() __asm__ __volatile__("" : : : "memory") |
175 | #define mb() __asm__ __volatile__("" : : : "memory") | 182 | #define mb() __asm__ __volatile__("" : : : "memory") |
176 | 183 | ||
177 | /* Convert an iovec element to the given type. | 184 | /* |
185 | * Convert an iovec element to the given type. | ||
178 | * | 186 | * |
179 | * This is a fairly ugly trick: we need to know the size of the type and | 187 | * This is a fairly ugly trick: we need to know the size of the type and |
180 | * alignment requirement to check the pointer is kosher. It's also nice to | 188 | * alignment requirement to check the pointer is kosher. It's also nice to |
181 | * have the name of the type in case we report failure. | 189 | * have the name of the type in case we report failure. |
182 | * | 190 | * |
183 | * Typing those three things all the time is cumbersome and error prone, so we | 191 | * Typing those three things all the time is cumbersome and error prone, so we |
184 | * have a macro which sets them all up and passes to the real function. */ | 192 | * have a macro which sets them all up and passes to the real function. |
193 | */ | ||
185 | #define convert(iov, type) \ | 194 | #define convert(iov, type) \ |
186 | ((type *)_convert((iov), sizeof(type), __alignof__(type), #type)) | 195 | ((type *)_convert((iov), sizeof(type), __alignof__(type), #type)) |
187 | 196 | ||
@@ -198,8 +207,10 @@ static void *_convert(struct iovec *iov, size_t size, size_t align, | |||
198 | /* Wrapper for the last available index. Makes it easier to change. */ | 207 | /* Wrapper for the last available index. Makes it easier to change. */ |
199 | #define lg_last_avail(vq) ((vq)->last_avail_idx) | 208 | #define lg_last_avail(vq) ((vq)->last_avail_idx) |
200 | 209 | ||
201 | /* The virtio configuration space is defined to be little-endian. x86 is | 210 | /* |
202 | * little-endian too, but it's nice to be explicit so we have these helpers. */ | 211 | * The virtio configuration space is defined to be little-endian. x86 is |
212 | * little-endian too, but it's nice to be explicit so we have these helpers. | ||
213 | */ | ||
203 | #define cpu_to_le16(v16) (v16) | 214 | #define cpu_to_le16(v16) (v16) |
204 | #define cpu_to_le32(v32) (v32) | 215 | #define cpu_to_le32(v32) (v32) |
205 | #define cpu_to_le64(v64) (v64) | 216 | #define cpu_to_le64(v64) (v64) |
@@ -241,11 +252,12 @@ static u8 *get_feature_bits(struct device *dev) | |||
241 | + dev->num_vq * sizeof(struct lguest_vqconfig); | 252 | + dev->num_vq * sizeof(struct lguest_vqconfig); |
242 | } | 253 | } |
243 | 254 | ||
244 | /*L:100 The Launcher code itself takes us out into userspace, that scary place | 255 | /*L:100 |
245 | * where pointers run wild and free! Unfortunately, like most userspace | 256 | * The Launcher code itself takes us out into userspace, that scary place where |
246 | * programs, it's quite boring (which is why everyone likes to hack on the | 257 | * pointers run wild and free! Unfortunately, like most userspace programs, |
247 | * kernel!). Perhaps if you make up an Lguest Drinking Game at this point, it | 258 | * it's quite boring (which is why everyone likes to hack on the kernel!). |
248 | * will get you through this section. Or, maybe not. | 259 | * Perhaps if you make up an Lguest Drinking Game at this point, it will get |
260 | * you through this section. Or, maybe not. | ||
249 | * | 261 | * |
250 | * The Launcher sets up a big chunk of memory to be the Guest's "physical" | 262 | * The Launcher sets up a big chunk of memory to be the Guest's "physical" |
251 | * memory and stores it in "guest_base". In other words, Guest physical == | 263 | * memory and stores it in "guest_base". In other words, Guest physical == |
@@ -253,7 +265,8 @@ static u8 *get_feature_bits(struct device *dev) | |||
253 | * | 265 | * |
254 | * This can be tough to get your head around, but usually it just means that we | 266 | * This can be tough to get your head around, but usually it just means that we |
255 | * use these trivial conversion functions when the Guest gives us it's | 267 | * use these trivial conversion functions when the Guest gives us it's |
256 | * "physical" addresses: */ | 268 | * "physical" addresses: |
269 | */ | ||
257 | static void *from_guest_phys(unsigned long addr) | 270 | static void *from_guest_phys(unsigned long addr) |
258 | { | 271 | { |
259 | return guest_base + addr; | 272 | return guest_base + addr; |
@@ -268,7 +281,8 @@ static unsigned long to_guest_phys(const void *addr) | |||
268 | * Loading the Kernel. | 281 | * Loading the Kernel. |
269 | * | 282 | * |
270 | * We start with couple of simple helper routines. open_or_die() avoids | 283 | * We start with couple of simple helper routines. open_or_die() avoids |
271 | * error-checking code cluttering the callers: */ | 284 | * error-checking code cluttering the callers: |
285 | */ | ||
272 | static int open_or_die(const char *name, int flags) | 286 | static int open_or_die(const char *name, int flags) |
273 | { | 287 | { |
274 | int fd = open(name, flags); | 288 | int fd = open(name, flags); |
@@ -283,8 +297,10 @@ static void *map_zeroed_pages(unsigned int num) | |||
283 | int fd = open_or_die("/dev/zero", O_RDONLY); | 297 | int fd = open_or_die("/dev/zero", O_RDONLY); |
284 | void *addr; | 298 | void *addr; |
285 | 299 | ||
286 | /* We use a private mapping (ie. if we write to the page, it will be | 300 | /* |
287 | * copied). */ | 301 | * We use a private mapping (ie. if we write to the page, it will be |
302 | * copied). | ||
303 | */ | ||
288 | addr = mmap(NULL, getpagesize() * num, | 304 | addr = mmap(NULL, getpagesize() * num, |
289 | PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, fd, 0); | 305 | PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, fd, 0); |
290 | if (addr == MAP_FAILED) | 306 | if (addr == MAP_FAILED) |
@@ -305,20 +321,24 @@ static void *get_pages(unsigned int num) | |||
305 | return addr; | 321 | return addr; |
306 | } | 322 | } |
307 | 323 | ||
308 | /* This routine is used to load the kernel or initrd. It tries mmap, but if | 324 | /* |
325 | * This routine is used to load the kernel or initrd. It tries mmap, but if | ||
309 | * that fails (Plan 9's kernel file isn't nicely aligned on page boundaries), | 326 | * that fails (Plan 9's kernel file isn't nicely aligned on page boundaries), |
310 | * it falls back to reading the memory in. */ | 327 | * it falls back to reading the memory in. |
328 | */ | ||
311 | static void map_at(int fd, void *addr, unsigned long offset, unsigned long len) | 329 | static void map_at(int fd, void *addr, unsigned long offset, unsigned long len) |
312 | { | 330 | { |
313 | ssize_t r; | 331 | ssize_t r; |
314 | 332 | ||
315 | /* We map writable even though for some segments are marked read-only. | 333 | /* |
334 | * We map writable even though for some segments are marked read-only. | ||
316 | * The kernel really wants to be writable: it patches its own | 335 | * The kernel really wants to be writable: it patches its own |
317 | * instructions. | 336 | * instructions. |
318 | * | 337 | * |
319 | * MAP_PRIVATE means that the page won't be copied until a write is | 338 | * MAP_PRIVATE means that the page won't be copied until a write is |
320 | * done to it. This allows us to share untouched memory between | 339 | * done to it. This allows us to share untouched memory between |
321 | * Guests. */ | 340 | * Guests. |
341 | */ | ||
322 | if (mmap(addr, len, PROT_READ|PROT_WRITE|PROT_EXEC, | 342 | if (mmap(addr, len, PROT_READ|PROT_WRITE|PROT_EXEC, |
323 | MAP_FIXED|MAP_PRIVATE, fd, offset) != MAP_FAILED) | 343 | MAP_FIXED|MAP_PRIVATE, fd, offset) != MAP_FAILED) |
324 | return; | 344 | return; |
@@ -329,7 +349,8 @@ static void map_at(int fd, void *addr, unsigned long offset, unsigned long len) | |||
329 | err(1, "Reading offset %lu len %lu gave %zi", offset, len, r); | 349 | err(1, "Reading offset %lu len %lu gave %zi", offset, len, r); |
330 | } | 350 | } |
331 | 351 | ||
332 | /* This routine takes an open vmlinux image, which is in ELF, and maps it into | 352 | /* |
353 | * This routine takes an open vmlinux image, which is in ELF, and maps it into | ||
333 | * the Guest memory. ELF = Embedded Linking Format, which is the format used | 354 | * the Guest memory. ELF = Embedded Linking Format, which is the format used |
334 | * by all modern binaries on Linux including the kernel. | 355 | * by all modern binaries on Linux including the kernel. |
335 | * | 356 | * |
@@ -337,23 +358,28 @@ static void map_at(int fd, void *addr, unsigned long offset, unsigned long len) | |||
337 | * address. We use the physical address; the Guest will map itself to the | 358 | * address. We use the physical address; the Guest will map itself to the |
338 | * virtual address. | 359 | * virtual address. |
339 | * | 360 | * |
340 | * We return the starting address. */ | 361 | * We return the starting address. |
362 | */ | ||
341 | static unsigned long map_elf(int elf_fd, const Elf32_Ehdr *ehdr) | 363 | static unsigned long map_elf(int elf_fd, const Elf32_Ehdr *ehdr) |
342 | { | 364 | { |
343 | Elf32_Phdr phdr[ehdr->e_phnum]; | 365 | Elf32_Phdr phdr[ehdr->e_phnum]; |
344 | unsigned int i; | 366 | unsigned int i; |
345 | 367 | ||
346 | /* Sanity checks on the main ELF header: an x86 executable with a | 368 | /* |
347 | * reasonable number of correctly-sized program headers. */ | 369 | * Sanity checks on the main ELF header: an x86 executable with a |
370 | * reasonable number of correctly-sized program headers. | ||
371 | */ | ||
348 | if (ehdr->e_type != ET_EXEC | 372 | if (ehdr->e_type != ET_EXEC |
349 | || ehdr->e_machine != EM_386 | 373 | || ehdr->e_machine != EM_386 |
350 | || ehdr->e_phentsize != sizeof(Elf32_Phdr) | 374 | || ehdr->e_phentsize != sizeof(Elf32_Phdr) |
351 | || ehdr->e_phnum < 1 || ehdr->e_phnum > 65536U/sizeof(Elf32_Phdr)) | 375 | || ehdr->e_phnum < 1 || ehdr->e_phnum > 65536U/sizeof(Elf32_Phdr)) |
352 | errx(1, "Malformed elf header"); | 376 | errx(1, "Malformed elf header"); |
353 | 377 | ||
354 | /* An ELF executable contains an ELF header and a number of "program" | 378 | /* |
379 | * An ELF executable contains an ELF header and a number of "program" | ||
355 | * headers which indicate which parts ("segments") of the program to | 380 | * headers which indicate which parts ("segments") of the program to |
356 | * load where. */ | 381 | * load where. |
382 | */ | ||
357 | 383 | ||
358 | /* We read in all the program headers at once: */ | 384 | /* We read in all the program headers at once: */ |
359 | if (lseek(elf_fd, ehdr->e_phoff, SEEK_SET) < 0) | 385 | if (lseek(elf_fd, ehdr->e_phoff, SEEK_SET) < 0) |
@@ -361,8 +387,10 @@ static unsigned long map_elf(int elf_fd, const Elf32_Ehdr *ehdr) | |||
361 | if (read(elf_fd, phdr, sizeof(phdr)) != sizeof(phdr)) | 387 | if (read(elf_fd, phdr, sizeof(phdr)) != sizeof(phdr)) |
362 | err(1, "Reading program headers"); | 388 | err(1, "Reading program headers"); |
363 | 389 | ||
364 | /* Try all the headers: there are usually only three. A read-only one, | 390 | /* |
365 | * a read-write one, and a "note" section which we don't load. */ | 391 | * Try all the headers: there are usually only three. A read-only one, |
392 | * a read-write one, and a "note" section which we don't load. | ||
393 | */ | ||
366 | for (i = 0; i < ehdr->e_phnum; i++) { | 394 | for (i = 0; i < ehdr->e_phnum; i++) { |
367 | /* If this isn't a loadable segment, we ignore it */ | 395 | /* If this isn't a loadable segment, we ignore it */ |
368 | if (phdr[i].p_type != PT_LOAD) | 396 | if (phdr[i].p_type != PT_LOAD) |
@@ -380,13 +408,15 @@ static unsigned long map_elf(int elf_fd, const Elf32_Ehdr *ehdr) | |||
380 | return ehdr->e_entry; | 408 | return ehdr->e_entry; |
381 | } | 409 | } |
382 | 410 | ||
383 | /*L:150 A bzImage, unlike an ELF file, is not meant to be loaded. You're | 411 | /*L:150 |
384 | * supposed to jump into it and it will unpack itself. We used to have to | 412 | * A bzImage, unlike an ELF file, is not meant to be loaded. You're supposed |
385 | * perform some hairy magic because the unpacking code scared me. | 413 | * to jump into it and it will unpack itself. We used to have to perform some |
414 | * hairy magic because the unpacking code scared me. | ||
386 | * | 415 | * |
387 | * Fortunately, Jeremy Fitzhardinge convinced me it wasn't that hard and wrote | 416 | * Fortunately, Jeremy Fitzhardinge convinced me it wasn't that hard and wrote |
388 | * a small patch to jump over the tricky bits in the Guest, so now we just read | 417 | * a small patch to jump over the tricky bits in the Guest, so now we just read |
389 | * the funky header so we know where in the file to load, and away we go! */ | 418 | * the funky header so we know where in the file to load, and away we go! |
419 | */ | ||
390 | static unsigned long load_bzimage(int fd) | 420 | static unsigned long load_bzimage(int fd) |
391 | { | 421 | { |
392 | struct boot_params boot; | 422 | struct boot_params boot; |
@@ -394,8 +424,10 @@ static unsigned long load_bzimage(int fd) | |||
394 | /* Modern bzImages get loaded at 1M. */ | 424 | /* Modern bzImages get loaded at 1M. */ |
395 | void *p = from_guest_phys(0x100000); | 425 | void *p = from_guest_phys(0x100000); |
396 | 426 | ||
397 | /* Go back to the start of the file and read the header. It should be | 427 | /* |
398 | * a Linux boot header (see Documentation/x86/i386/boot.txt) */ | 428 | * Go back to the start of the file and read the header. It should be |
429 | * a Linux boot header (see Documentation/x86/i386/boot.txt) | ||
430 | */ | ||
399 | lseek(fd, 0, SEEK_SET); | 431 | lseek(fd, 0, SEEK_SET); |
400 | read(fd, &boot, sizeof(boot)); | 432 | read(fd, &boot, sizeof(boot)); |
401 | 433 | ||
@@ -414,9 +446,11 @@ static unsigned long load_bzimage(int fd) | |||
414 | return boot.hdr.code32_start; | 446 | return boot.hdr.code32_start; |
415 | } | 447 | } |
416 | 448 | ||
417 | /*L:140 Loading the kernel is easy when it's a "vmlinux", but most kernels | 449 | /*L:140 |
450 | * Loading the kernel is easy when it's a "vmlinux", but most kernels | ||
418 | * come wrapped up in the self-decompressing "bzImage" format. With a little | 451 | * come wrapped up in the self-decompressing "bzImage" format. With a little |
419 | * work, we can load those, too. */ | 452 | * work, we can load those, too. |
453 | */ | ||
420 | static unsigned long load_kernel(int fd) | 454 | static unsigned long load_kernel(int fd) |
421 | { | 455 | { |
422 | Elf32_Ehdr hdr; | 456 | Elf32_Ehdr hdr; |
@@ -433,24 +467,28 @@ static unsigned long load_kernel(int fd) | |||
433 | return load_bzimage(fd); | 467 | return load_bzimage(fd); |
434 | } | 468 | } |
435 | 469 | ||
436 | /* This is a trivial little helper to align pages. Andi Kleen hated it because | 470 | /* |
471 | * This is a trivial little helper to align pages. Andi Kleen hated it because | ||
437 | * it calls getpagesize() twice: "it's dumb code." | 472 | * it calls getpagesize() twice: "it's dumb code." |
438 | * | 473 | * |
439 | * Kernel guys get really het up about optimization, even when it's not | 474 | * Kernel guys get really het up about optimization, even when it's not |
440 | * necessary. I leave this code as a reaction against that. */ | 475 | * necessary. I leave this code as a reaction against that. |
476 | */ | ||
441 | static inline unsigned long page_align(unsigned long addr) | 477 | static inline unsigned long page_align(unsigned long addr) |
442 | { | 478 | { |
443 | /* Add upwards and truncate downwards. */ | 479 | /* Add upwards and truncate downwards. */ |
444 | return ((addr + getpagesize()-1) & ~(getpagesize()-1)); | 480 | return ((addr + getpagesize()-1) & ~(getpagesize()-1)); |
445 | } | 481 | } |
446 | 482 | ||
447 | /*L:180 An "initial ram disk" is a disk image loaded into memory along with | 483 | /*L:180 |
448 | * the kernel which the kernel can use to boot from without needing any | 484 | * An "initial ram disk" is a disk image loaded into memory along with the |
449 | * drivers. Most distributions now use this as standard: the initrd contains | 485 | * kernel which the kernel can use to boot from without needing any drivers. |
450 | * the code to load the appropriate driver modules for the current machine. | 486 | * Most distributions now use this as standard: the initrd contains the code to |
487 | * load the appropriate driver modules for the current machine. | ||
451 | * | 488 | * |
452 | * Importantly, James Morris works for RedHat, and Fedora uses initrds for its | 489 | * Importantly, James Morris works for RedHat, and Fedora uses initrds for its |
453 | * kernels. He sent me this (and tells me when I break it). */ | 490 | * kernels. He sent me this (and tells me when I break it). |
491 | */ | ||
454 | static unsigned long load_initrd(const char *name, unsigned long mem) | 492 | static unsigned long load_initrd(const char *name, unsigned long mem) |
455 | { | 493 | { |
456 | int ifd; | 494 | int ifd; |
@@ -462,12 +500,16 @@ static unsigned long load_initrd(const char *name, unsigned long mem) | |||
462 | if (fstat(ifd, &st) < 0) | 500 | if (fstat(ifd, &st) < 0) |
463 | err(1, "fstat() on initrd '%s'", name); | 501 | err(1, "fstat() on initrd '%s'", name); |
464 | 502 | ||
465 | /* We map the initrd at the top of memory, but mmap wants it to be | 503 | /* |
466 | * page-aligned, so we round the size up for that. */ | 504 | * We map the initrd at the top of memory, but mmap wants it to be |
505 | * page-aligned, so we round the size up for that. | ||
506 | */ | ||
467 | len = page_align(st.st_size); | 507 | len = page_align(st.st_size); |
468 | map_at(ifd, from_guest_phys(mem - len), 0, st.st_size); | 508 | map_at(ifd, from_guest_phys(mem - len), 0, st.st_size); |
469 | /* Once a file is mapped, you can close the file descriptor. It's a | 509 | /* |
470 | * little odd, but quite useful. */ | 510 | * Once a file is mapped, you can close the file descriptor. It's a |
511 | * little odd, but quite useful. | ||
512 | */ | ||
471 | close(ifd); | 513 | close(ifd); |
472 | verbose("mapped initrd %s size=%lu @ %p\n", name, len, (void*)mem-len); | 514 | verbose("mapped initrd %s size=%lu @ %p\n", name, len, (void*)mem-len); |
473 | 515 | ||
@@ -476,8 +518,10 @@ static unsigned long load_initrd(const char *name, unsigned long mem) | |||
476 | } | 518 | } |
477 | /*:*/ | 519 | /*:*/ |
478 | 520 | ||
479 | /* Simple routine to roll all the commandline arguments together with spaces | 521 | /* |
480 | * between them. */ | 522 | * Simple routine to roll all the commandline arguments together with spaces |
523 | * between them. | ||
524 | */ | ||
481 | static void concat(char *dst, char *args[]) | 525 | static void concat(char *dst, char *args[]) |
482 | { | 526 | { |
483 | unsigned int i, len = 0; | 527 | unsigned int i, len = 0; |
@@ -494,10 +538,12 @@ static void concat(char *dst, char *args[]) | |||
494 | dst[len] = '\0'; | 538 | dst[len] = '\0'; |
495 | } | 539 | } |
496 | 540 | ||
497 | /*L:185 This is where we actually tell the kernel to initialize the Guest. We | 541 | /*L:185 |
542 | * This is where we actually tell the kernel to initialize the Guest. We | ||
498 | * saw the arguments it expects when we looked at initialize() in lguest_user.c: | 543 | * saw the arguments it expects when we looked at initialize() in lguest_user.c: |
499 | * the base of Guest "physical" memory, the top physical page to allow and the | 544 | * the base of Guest "physical" memory, the top physical page to allow and the |
500 | * entry point for the Guest. */ | 545 | * entry point for the Guest. |
546 | */ | ||
501 | static void tell_kernel(unsigned long start) | 547 | static void tell_kernel(unsigned long start) |
502 | { | 548 | { |
503 | unsigned long args[] = { LHREQ_INITIALIZE, | 549 | unsigned long args[] = { LHREQ_INITIALIZE, |
@@ -522,20 +568,26 @@ static void tell_kernel(unsigned long start) | |||
522 | static void *_check_pointer(unsigned long addr, unsigned int size, | 568 | static void *_check_pointer(unsigned long addr, unsigned int size, |
523 | unsigned int line) | 569 | unsigned int line) |
524 | { | 570 | { |
525 | /* We have to separately check addr and addr+size, because size could | 571 | /* |
526 | * be huge and addr + size might wrap around. */ | 572 | * We have to separately check addr and addr+size, because size could |
573 | * be huge and addr + size might wrap around. | ||
574 | */ | ||
527 | if (addr >= guest_limit || addr + size >= guest_limit) | 575 | if (addr >= guest_limit || addr + size >= guest_limit) |
528 | errx(1, "%s:%i: Invalid address %#lx", __FILE__, line, addr); | 576 | errx(1, "%s:%i: Invalid address %#lx", __FILE__, line, addr); |
529 | /* We return a pointer for the caller's convenience, now we know it's | 577 | /* |
530 | * safe to use. */ | 578 | * We return a pointer for the caller's convenience, now we know it's |
579 | * safe to use. | ||
580 | */ | ||
531 | return from_guest_phys(addr); | 581 | return from_guest_phys(addr); |
532 | } | 582 | } |
533 | /* A macro which transparently hands the line number to the real function. */ | 583 | /* A macro which transparently hands the line number to the real function. */ |
534 | #define check_pointer(addr,size) _check_pointer(addr, size, __LINE__) | 584 | #define check_pointer(addr,size) _check_pointer(addr, size, __LINE__) |
535 | 585 | ||
536 | /* Each buffer in the virtqueues is actually a chain of descriptors. This | 586 | /* |
587 | * Each buffer in the virtqueues is actually a chain of descriptors. This | ||
537 | * function returns the next descriptor in the chain, or vq->vring.num if we're | 588 | * function returns the next descriptor in the chain, or vq->vring.num if we're |
538 | * at the end. */ | 589 | * at the end. |
590 | */ | ||
539 | static unsigned next_desc(struct vring_desc *desc, | 591 | static unsigned next_desc(struct vring_desc *desc, |
540 | unsigned int i, unsigned int max) | 592 | unsigned int i, unsigned int max) |
541 | { | 593 | { |
@@ -576,12 +628,14 @@ static void trigger_irq(struct virtqueue *vq) | |||
576 | err(1, "Triggering irq %i", vq->config.irq); | 628 | err(1, "Triggering irq %i", vq->config.irq); |
577 | } | 629 | } |
578 | 630 | ||
579 | /* This looks in the virtqueue and for the first available buffer, and converts | 631 | /* |
632 | * This looks in the virtqueue and for the first available buffer, and converts | ||
580 | * it to an iovec for convenient access. Since descriptors consist of some | 633 | * it to an iovec for convenient access. Since descriptors consist of some |
581 | * number of output then some number of input descriptors, it's actually two | 634 | * number of output then some number of input descriptors, it's actually two |
582 | * iovecs, but we pack them into one and note how many of each there were. | 635 | * iovecs, but we pack them into one and note how many of each there were. |
583 | * | 636 | * |
584 | * This function returns the descriptor number found. */ | 637 | * This function returns the descriptor number found. |
638 | */ | ||
585 | static unsigned wait_for_vq_desc(struct virtqueue *vq, | 639 | static unsigned wait_for_vq_desc(struct virtqueue *vq, |
586 | struct iovec iov[], | 640 | struct iovec iov[], |
587 | unsigned int *out_num, unsigned int *in_num) | 641 | unsigned int *out_num, unsigned int *in_num) |
@@ -599,8 +653,10 @@ static unsigned wait_for_vq_desc(struct virtqueue *vq, | |||
599 | /* OK, now we need to know about added descriptors. */ | 653 | /* OK, now we need to know about added descriptors. */ |
600 | vq->vring.used->flags &= ~VRING_USED_F_NO_NOTIFY; | 654 | vq->vring.used->flags &= ~VRING_USED_F_NO_NOTIFY; |
601 | 655 | ||
602 | /* They could have slipped one in as we were doing that: make | 656 | /* |
603 | * sure it's written, then check again. */ | 657 | * They could have slipped one in as we were doing that: make |
658 | * sure it's written, then check again. | ||
659 | */ | ||
604 | mb(); | 660 | mb(); |
605 | if (last_avail != vq->vring.avail->idx) { | 661 | if (last_avail != vq->vring.avail->idx) { |
606 | vq->vring.used->flags |= VRING_USED_F_NO_NOTIFY; | 662 | vq->vring.used->flags |= VRING_USED_F_NO_NOTIFY; |
@@ -620,8 +676,10 @@ static unsigned wait_for_vq_desc(struct virtqueue *vq, | |||
620 | errx(1, "Guest moved used index from %u to %u", | 676 | errx(1, "Guest moved used index from %u to %u", |
621 | last_avail, vq->vring.avail->idx); | 677 | last_avail, vq->vring.avail->idx); |
622 | 678 | ||
623 | /* Grab the next descriptor number they're advertising, and increment | 679 | /* |
624 | * the index we've seen. */ | 680 | * Grab the next descriptor number they're advertising, and increment |
681 | * the index we've seen. | ||
682 | */ | ||
625 | head = vq->vring.avail->ring[last_avail % vq->vring.num]; | 683 | head = vq->vring.avail->ring[last_avail % vq->vring.num]; |
626 | lg_last_avail(vq)++; | 684 | lg_last_avail(vq)++; |
627 | 685 | ||
@@ -636,8 +694,10 @@ static unsigned wait_for_vq_desc(struct virtqueue *vq, | |||
636 | desc = vq->vring.desc; | 694 | desc = vq->vring.desc; |
637 | i = head; | 695 | i = head; |
638 | 696 | ||
639 | /* If this is an indirect entry, then this buffer contains a descriptor | 697 | /* |
640 | * table which we handle as if it's any normal descriptor chain. */ | 698 | * If this is an indirect entry, then this buffer contains a descriptor |
699 | * table which we handle as if it's any normal descriptor chain. | ||
700 | */ | ||
641 | if (desc[i].flags & VRING_DESC_F_INDIRECT) { | 701 | if (desc[i].flags & VRING_DESC_F_INDIRECT) { |
642 | if (desc[i].len % sizeof(struct vring_desc)) | 702 | if (desc[i].len % sizeof(struct vring_desc)) |
643 | errx(1, "Invalid size for indirect buffer table"); | 703 | errx(1, "Invalid size for indirect buffer table"); |
@@ -656,8 +716,10 @@ static unsigned wait_for_vq_desc(struct virtqueue *vq, | |||
656 | if (desc[i].flags & VRING_DESC_F_WRITE) | 716 | if (desc[i].flags & VRING_DESC_F_WRITE) |
657 | (*in_num)++; | 717 | (*in_num)++; |
658 | else { | 718 | else { |
659 | /* If it's an output descriptor, they're all supposed | 719 | /* |
660 | * to come before any input descriptors. */ | 720 | * If it's an output descriptor, they're all supposed |
721 | * to come before any input descriptors. | ||
722 | */ | ||
661 | if (*in_num) | 723 | if (*in_num) |
662 | errx(1, "Descriptor has out after in"); | 724 | errx(1, "Descriptor has out after in"); |
663 | (*out_num)++; | 725 | (*out_num)++; |
@@ -671,14 +733,18 @@ static unsigned wait_for_vq_desc(struct virtqueue *vq, | |||
671 | return head; | 733 | return head; |
672 | } | 734 | } |
673 | 735 | ||
674 | /* After we've used one of their buffers, we tell them about it. We'll then | 736 | /* |
675 | * want to send them an interrupt, using trigger_irq(). */ | 737 | * After we've used one of their buffers, we tell them about it. We'll then |
738 | * want to send them an interrupt, using trigger_irq(). | ||
739 | */ | ||
676 | static void add_used(struct virtqueue *vq, unsigned int head, int len) | 740 | static void add_used(struct virtqueue *vq, unsigned int head, int len) |
677 | { | 741 | { |
678 | struct vring_used_elem *used; | 742 | struct vring_used_elem *used; |
679 | 743 | ||
680 | /* The virtqueue contains a ring of used buffers. Get a pointer to the | 744 | /* |
681 | * next entry in that used ring. */ | 745 | * The virtqueue contains a ring of used buffers. Get a pointer to the |
746 | * next entry in that used ring. | ||
747 | */ | ||
682 | used = &vq->vring.used->ring[vq->vring.used->idx % vq->vring.num]; | 748 | used = &vq->vring.used->ring[vq->vring.used->idx % vq->vring.num]; |
683 | used->id = head; | 749 | used->id = head; |
684 | used->len = len; | 750 | used->len = len; |
@@ -698,7 +764,8 @@ static void add_used_and_trigger(struct virtqueue *vq, unsigned head, int len) | |||
698 | /* | 764 | /* |
699 | * The Console | 765 | * The Console |
700 | * | 766 | * |
701 | * We associate some data with the console for our exit hack. */ | 767 | * We associate some data with the console for our exit hack. |
768 | */ | ||
702 | struct console_abort | 769 | struct console_abort |
703 | { | 770 | { |
704 | /* How many times have they hit ^C? */ | 771 | /* How many times have they hit ^C? */ |
@@ -725,20 +792,24 @@ static void console_input(struct virtqueue *vq) | |||
725 | if (len <= 0) { | 792 | if (len <= 0) { |
726 | /* Ran out of input? */ | 793 | /* Ran out of input? */ |
727 | warnx("Failed to get console input, ignoring console."); | 794 | warnx("Failed to get console input, ignoring console."); |
728 | /* For simplicity, dying threads kill the whole Launcher. So | 795 | /* |
729 | * just nap here. */ | 796 | * For simplicity, dying threads kill the whole Launcher. So |
797 | * just nap here. | ||
798 | */ | ||
730 | for (;;) | 799 | for (;;) |
731 | pause(); | 800 | pause(); |
732 | } | 801 | } |
733 | 802 | ||
734 | add_used_and_trigger(vq, head, len); | 803 | add_used_and_trigger(vq, head, len); |
735 | 804 | ||
736 | /* Three ^C within one second? Exit. | 805 | /* |
806 | * Three ^C within one second? Exit. | ||
737 | * | 807 | * |
738 | * This is such a hack, but works surprisingly well. Each ^C has to | 808 | * This is such a hack, but works surprisingly well. Each ^C has to |
739 | * be in a buffer by itself, so they can't be too fast. But we check | 809 | * be in a buffer by itself, so they can't be too fast. But we check |
740 | * that we get three within about a second, so they can't be too | 810 | * that we get three within about a second, so they can't be too |
741 | * slow. */ | 811 | * slow. |
812 | */ | ||
742 | if (len != 1 || ((char *)iov[0].iov_base)[0] != 3) { | 813 | if (len != 1 || ((char *)iov[0].iov_base)[0] != 3) { |
743 | abort->count = 0; | 814 | abort->count = 0; |
744 | return; | 815 | return; |
@@ -809,8 +880,7 @@ static bool will_block(int fd) | |||
809 | return select(fd+1, &fdset, NULL, NULL, &zero) != 1; | 880 | return select(fd+1, &fdset, NULL, NULL, &zero) != 1; |
810 | } | 881 | } |
811 | 882 | ||
812 | /* This is where we handle packets coming in from the tun device to our | 883 | /* This handles packets coming in from the tun device to our Guest. */ |
813 | * Guest. */ | ||
814 | static void net_input(struct virtqueue *vq) | 884 | static void net_input(struct virtqueue *vq) |
815 | { | 885 | { |
816 | int len; | 886 | int len; |
@@ -842,8 +912,10 @@ static int do_thread(void *_vq) | |||
842 | return 0; | 912 | return 0; |
843 | } | 913 | } |
844 | 914 | ||
845 | /* When a child dies, we kill our entire process group with SIGTERM. This | 915 | /* |
846 | * also has the side effect that the shell restores the console for us! */ | 916 | * When a child dies, we kill our entire process group with SIGTERM. This |
917 | * also has the side effect that the shell restores the console for us! | ||
918 | */ | ||
847 | static void kill_launcher(int signal) | 919 | static void kill_launcher(int signal) |
848 | { | 920 | { |
849 | kill(0, SIGTERM); | 921 | kill(0, SIGTERM); |
@@ -880,9 +952,10 @@ static void reset_device(struct device *dev) | |||
880 | 952 | ||
881 | static void create_thread(struct virtqueue *vq) | 953 | static void create_thread(struct virtqueue *vq) |
882 | { | 954 | { |
883 | /* Create stack for thread and run it. Since stack grows | 955 | /* |
884 | * upwards, we point the stack pointer to the end of this | 956 | * Create stack for thread and run it. Since the stack grows upwards, |
885 | * region. */ | 957 | * we point the stack pointer to the end of this region. |
958 | */ | ||
886 | char *stack = malloc(32768); | 959 | char *stack = malloc(32768); |
887 | unsigned long args[] = { LHREQ_EVENTFD, | 960 | unsigned long args[] = { LHREQ_EVENTFD, |
888 | vq->config.pfn*getpagesize(), 0 }; | 961 | vq->config.pfn*getpagesize(), 0 }; |
@@ -981,8 +1054,11 @@ static void handle_output(unsigned long addr) | |||
981 | } | 1054 | } |
982 | } | 1055 | } |
983 | 1056 | ||
984 | /* Early console write is done using notify on a nul-terminated string | 1057 | /* |
985 | * in Guest memory. */ | 1058 | * Early console write is done using notify on a nul-terminated string |
1059 | * in Guest memory. It's also great for hacking debugging messages | ||
1060 | * into a Guest. | ||
1061 | */ | ||
986 | if (addr >= guest_limit) | 1062 | if (addr >= guest_limit) |
987 | errx(1, "Bad NOTIFY %#lx", addr); | 1063 | errx(1, "Bad NOTIFY %#lx", addr); |
988 | 1064 | ||
@@ -998,10 +1074,12 @@ static void handle_output(unsigned long addr) | |||
998 | * routines to allocate and manage them. | 1074 | * routines to allocate and manage them. |
999 | */ | 1075 | */ |
1000 | 1076 | ||
1001 | /* The layout of the device page is a "struct lguest_device_desc" followed by a | 1077 | /* |
1078 | * The layout of the device page is a "struct lguest_device_desc" followed by a | ||
1002 | * number of virtqueue descriptors, then two sets of feature bits, then an | 1079 | * number of virtqueue descriptors, then two sets of feature bits, then an |
1003 | * array of configuration bytes. This routine returns the configuration | 1080 | * array of configuration bytes. This routine returns the configuration |
1004 | * pointer. */ | 1081 | * pointer. |
1082 | */ | ||
1005 | static u8 *device_config(const struct device *dev) | 1083 | static u8 *device_config(const struct device *dev) |
1006 | { | 1084 | { |
1007 | return (void *)(dev->desc + 1) | 1085 | return (void *)(dev->desc + 1) |
@@ -1009,9 +1087,11 @@ static u8 *device_config(const struct device *dev) | |||
1009 | + dev->feature_len * 2; | 1087 | + dev->feature_len * 2; |
1010 | } | 1088 | } |
1011 | 1089 | ||
1012 | /* This routine allocates a new "struct lguest_device_desc" from descriptor | 1090 | /* |
1091 | * This routine allocates a new "struct lguest_device_desc" from descriptor | ||
1013 | * table page just above the Guest's normal memory. It returns a pointer to | 1092 | * table page just above the Guest's normal memory. It returns a pointer to |
1014 | * that descriptor. */ | 1093 | * that descriptor. |
1094 | */ | ||
1015 | static struct lguest_device_desc *new_dev_desc(u16 type) | 1095 | static struct lguest_device_desc *new_dev_desc(u16 type) |
1016 | { | 1096 | { |
1017 | struct lguest_device_desc d = { .type = type }; | 1097 | struct lguest_device_desc d = { .type = type }; |
@@ -1032,8 +1112,10 @@ static struct lguest_device_desc *new_dev_desc(u16 type) | |||
1032 | return memcpy(p, &d, sizeof(d)); | 1112 | return memcpy(p, &d, sizeof(d)); |
1033 | } | 1113 | } |
1034 | 1114 | ||
1035 | /* Each device descriptor is followed by the description of its virtqueues. We | 1115 | /* |
1036 | * specify how many descriptors the virtqueue is to have. */ | 1116 | * Each device descriptor is followed by the description of its virtqueues. We |
1117 | * specify how many descriptors the virtqueue is to have. | ||
1118 | */ | ||
1037 | static void add_virtqueue(struct device *dev, unsigned int num_descs, | 1119 | static void add_virtqueue(struct device *dev, unsigned int num_descs, |
1038 | void (*service)(struct virtqueue *)) | 1120 | void (*service)(struct virtqueue *)) |
1039 | { | 1121 | { |
@@ -1061,10 +1143,12 @@ static void add_virtqueue(struct device *dev, unsigned int num_descs, | |||
1061 | /* Initialize the vring. */ | 1143 | /* Initialize the vring. */ |
1062 | vring_init(&vq->vring, num_descs, p, LGUEST_VRING_ALIGN); | 1144 | vring_init(&vq->vring, num_descs, p, LGUEST_VRING_ALIGN); |
1063 | 1145 | ||
1064 | /* Append virtqueue to this device's descriptor. We use | 1146 | /* |
1147 | * Append virtqueue to this device's descriptor. We use | ||
1065 | * device_config() to get the end of the device's current virtqueues; | 1148 | * device_config() to get the end of the device's current virtqueues; |
1066 | * we check that we haven't added any config or feature information | 1149 | * we check that we haven't added any config or feature information |
1067 | * yet, otherwise we'd be overwriting them. */ | 1150 | * yet, otherwise we'd be overwriting them. |
1151 | */ | ||
1068 | assert(dev->desc->config_len == 0 && dev->desc->feature_len == 0); | 1152 | assert(dev->desc->config_len == 0 && dev->desc->feature_len == 0); |
1069 | memcpy(device_config(dev), &vq->config, sizeof(vq->config)); | 1153 | memcpy(device_config(dev), &vq->config, sizeof(vq->config)); |
1070 | dev->num_vq++; | 1154 | dev->num_vq++; |
@@ -1072,14 +1156,18 @@ static void add_virtqueue(struct device *dev, unsigned int num_descs, | |||
1072 | 1156 | ||
1073 | verbose("Virtqueue page %#lx\n", to_guest_phys(p)); | 1157 | verbose("Virtqueue page %#lx\n", to_guest_phys(p)); |
1074 | 1158 | ||
1075 | /* Add to tail of list, so dev->vq is first vq, dev->vq->next is | 1159 | /* |
1076 | * second. */ | 1160 | * Add to tail of list, so dev->vq is first vq, dev->vq->next is |
1161 | * second. | ||
1162 | */ | ||
1077 | for (i = &dev->vq; *i; i = &(*i)->next); | 1163 | for (i = &dev->vq; *i; i = &(*i)->next); |
1078 | *i = vq; | 1164 | *i = vq; |
1079 | } | 1165 | } |
1080 | 1166 | ||
1081 | /* The first half of the feature bitmask is for us to advertise features. The | 1167 | /* |
1082 | * second half is for the Guest to accept features. */ | 1168 | * The first half of the feature bitmask is for us to advertise features. The |
1169 | * second half is for the Guest to accept features. | ||
1170 | */ | ||
1083 | static void add_feature(struct device *dev, unsigned bit) | 1171 | static void add_feature(struct device *dev, unsigned bit) |
1084 | { | 1172 | { |
1085 | u8 *features = get_feature_bits(dev); | 1173 | u8 *features = get_feature_bits(dev); |
@@ -1093,9 +1181,11 @@ static void add_feature(struct device *dev, unsigned bit) | |||
1093 | features[bit / CHAR_BIT] |= (1 << (bit % CHAR_BIT)); | 1181 | features[bit / CHAR_BIT] |= (1 << (bit % CHAR_BIT)); |
1094 | } | 1182 | } |
1095 | 1183 | ||
1096 | /* This routine sets the configuration fields for an existing device's | 1184 | /* |
1185 | * This routine sets the configuration fields for an existing device's | ||
1097 | * descriptor. It only works for the last device, but that's OK because that's | 1186 | * descriptor. It only works for the last device, but that's OK because that's |
1098 | * how we use it. */ | 1187 | * how we use it. |
1188 | */ | ||
1099 | static void set_config(struct device *dev, unsigned len, const void *conf) | 1189 | static void set_config(struct device *dev, unsigned len, const void *conf) |
1100 | { | 1190 | { |
1101 | /* Check we haven't overflowed our single page. */ | 1191 | /* Check we haven't overflowed our single page. */ |
@@ -1110,10 +1200,12 @@ static void set_config(struct device *dev, unsigned len, const void *conf) | |||
1110 | assert(dev->desc->config_len == len); | 1200 | assert(dev->desc->config_len == len); |
1111 | } | 1201 | } |
1112 | 1202 | ||
1113 | /* This routine does all the creation and setup of a new device, including | 1203 | /* |
1204 | * This routine does all the creation and setup of a new device, including | ||
1114 | * calling new_dev_desc() to allocate the descriptor and device memory. | 1205 | * calling new_dev_desc() to allocate the descriptor and device memory. |
1115 | * | 1206 | * |
1116 | * See what I mean about userspace being boring? */ | 1207 | * See what I mean about userspace being boring? |
1208 | */ | ||
1117 | static struct device *new_device(const char *name, u16 type) | 1209 | static struct device *new_device(const char *name, u16 type) |
1118 | { | 1210 | { |
1119 | struct device *dev = malloc(sizeof(*dev)); | 1211 | struct device *dev = malloc(sizeof(*dev)); |
@@ -1126,10 +1218,12 @@ static struct device *new_device(const char *name, u16 type) | |||
1126 | dev->num_vq = 0; | 1218 | dev->num_vq = 0; |
1127 | dev->running = false; | 1219 | dev->running = false; |
1128 | 1220 | ||
1129 | /* Append to device list. Prepending to a single-linked list is | 1221 | /* |
1222 | * Append to device list. Prepending to a single-linked list is | ||
1130 | * easier, but the user expects the devices to be arranged on the bus | 1223 | * easier, but the user expects the devices to be arranged on the bus |
1131 | * in command-line order. The first network device on the command line | 1224 | * in command-line order. The first network device on the command line |
1132 | * is eth0, the first block device /dev/vda, etc. */ | 1225 | * is eth0, the first block device /dev/vda, etc. |
1226 | */ | ||
1133 | if (devices.lastdev) | 1227 | if (devices.lastdev) |
1134 | devices.lastdev->next = dev; | 1228 | devices.lastdev->next = dev; |
1135 | else | 1229 | else |
@@ -1139,8 +1233,10 @@ static struct device *new_device(const char *name, u16 type) | |||
1139 | return dev; | 1233 | return dev; |
1140 | } | 1234 | } |
1141 | 1235 | ||
1142 | /* Our first setup routine is the console. It's a fairly simple device, but | 1236 | /* |
1143 | * UNIX tty handling makes it uglier than it could be. */ | 1237 | * Our first setup routine is the console. It's a fairly simple device, but |
1238 | * UNIX tty handling makes it uglier than it could be. | ||
1239 | */ | ||
1144 | static void setup_console(void) | 1240 | static void setup_console(void) |
1145 | { | 1241 | { |
1146 | struct device *dev; | 1242 | struct device *dev; |
@@ -1148,8 +1244,10 @@ static void setup_console(void) | |||
1148 | /* If we can save the initial standard input settings... */ | 1244 | /* If we can save the initial standard input settings... */ |
1149 | if (tcgetattr(STDIN_FILENO, &orig_term) == 0) { | 1245 | if (tcgetattr(STDIN_FILENO, &orig_term) == 0) { |
1150 | struct termios term = orig_term; | 1246 | struct termios term = orig_term; |
1151 | /* Then we turn off echo, line buffering and ^C etc. We want a | 1247 | /* |
1152 | * raw input stream to the Guest. */ | 1248 | * Then we turn off echo, line buffering and ^C etc: We want a |
1249 | * raw input stream to the Guest. | ||
1250 | */ | ||
1153 | term.c_lflag &= ~(ISIG|ICANON|ECHO); | 1251 | term.c_lflag &= ~(ISIG|ICANON|ECHO); |
1154 | tcsetattr(STDIN_FILENO, TCSANOW, &term); | 1252 | tcsetattr(STDIN_FILENO, TCSANOW, &term); |
1155 | } | 1253 | } |
@@ -1160,10 +1258,12 @@ static void setup_console(void) | |||
1160 | dev->priv = malloc(sizeof(struct console_abort)); | 1258 | dev->priv = malloc(sizeof(struct console_abort)); |
1161 | ((struct console_abort *)dev->priv)->count = 0; | 1259 | ((struct console_abort *)dev->priv)->count = 0; |
1162 | 1260 | ||
1163 | /* The console needs two virtqueues: the input then the output. When | 1261 | /* |
1262 | * The console needs two virtqueues: the input then the output. When | ||
1164 | * they put something the input queue, we make sure we're listening to | 1263 | * they put something the input queue, we make sure we're listening to |
1165 | * stdin. When they put something in the output queue, we write it to | 1264 | * stdin. When they put something in the output queue, we write it to |
1166 | * stdout. */ | 1265 | * stdout. |
1266 | */ | ||
1167 | add_virtqueue(dev, VIRTQUEUE_NUM, console_input); | 1267 | add_virtqueue(dev, VIRTQUEUE_NUM, console_input); |
1168 | add_virtqueue(dev, VIRTQUEUE_NUM, console_output); | 1268 | add_virtqueue(dev, VIRTQUEUE_NUM, console_output); |
1169 | 1269 | ||
@@ -1171,7 +1271,8 @@ static void setup_console(void) | |||
1171 | } | 1271 | } |
1172 | /*:*/ | 1272 | /*:*/ |
1173 | 1273 | ||
1174 | /*M:010 Inter-guest networking is an interesting area. Simplest is to have a | 1274 | /*M:010 |
1275 | * Inter-guest networking is an interesting area. Simplest is to have a | ||
1175 | * --sharenet=<name> option which opens or creates a named pipe. This can be | 1276 | * --sharenet=<name> option which opens or creates a named pipe. This can be |
1176 | * used to send packets to another guest in a 1:1 manner. | 1277 | * used to send packets to another guest in a 1:1 manner. |
1177 | * | 1278 | * |
@@ -1185,7 +1286,8 @@ static void setup_console(void) | |||
1185 | * multiple inter-guest channels behind one interface, although it would | 1286 | * multiple inter-guest channels behind one interface, although it would |
1186 | * require some manner of hotplugging new virtio channels. | 1287 | * require some manner of hotplugging new virtio channels. |
1187 | * | 1288 | * |
1188 | * Finally, we could implement a virtio network switch in the kernel. :*/ | 1289 | * Finally, we could implement a virtio network switch in the kernel. |
1290 | :*/ | ||
1189 | 1291 | ||
1190 | static u32 str2ip(const char *ipaddr) | 1292 | static u32 str2ip(const char *ipaddr) |
1191 | { | 1293 | { |
@@ -1210,11 +1312,13 @@ static void str2mac(const char *macaddr, unsigned char mac[6]) | |||
1210 | mac[5] = m[5]; | 1312 | mac[5] = m[5]; |
1211 | } | 1313 | } |
1212 | 1314 | ||
1213 | /* This code is "adapted" from libbridge: it attaches the Host end of the | 1315 | /* |
1316 | * This code is "adapted" from libbridge: it attaches the Host end of the | ||
1214 | * network device to the bridge device specified by the command line. | 1317 | * network device to the bridge device specified by the command line. |
1215 | * | 1318 | * |
1216 | * This is yet another James Morris contribution (I'm an IP-level guy, so I | 1319 | * This is yet another James Morris contribution (I'm an IP-level guy, so I |
1217 | * dislike bridging), and I just try not to break it. */ | 1320 | * dislike bridging), and I just try not to break it. |
1321 | */ | ||
1218 | static void add_to_bridge(int fd, const char *if_name, const char *br_name) | 1322 | static void add_to_bridge(int fd, const char *if_name, const char *br_name) |
1219 | { | 1323 | { |
1220 | int ifidx; | 1324 | int ifidx; |
@@ -1234,9 +1338,11 @@ static void add_to_bridge(int fd, const char *if_name, const char *br_name) | |||
1234 | err(1, "can't add %s to bridge %s", if_name, br_name); | 1338 | err(1, "can't add %s to bridge %s", if_name, br_name); |
1235 | } | 1339 | } |
1236 | 1340 | ||
1237 | /* This sets up the Host end of the network device with an IP address, brings | 1341 | /* |
1342 | * This sets up the Host end of the network device with an IP address, brings | ||
1238 | * it up so packets will flow, the copies the MAC address into the hwaddr | 1343 | * it up so packets will flow, the copies the MAC address into the hwaddr |
1239 | * pointer. */ | 1344 | * pointer. |
1345 | */ | ||
1240 | static void configure_device(int fd, const char *tapif, u32 ipaddr) | 1346 | static void configure_device(int fd, const char *tapif, u32 ipaddr) |
1241 | { | 1347 | { |
1242 | struct ifreq ifr; | 1348 | struct ifreq ifr; |
@@ -1263,10 +1369,12 @@ static int get_tun_device(char tapif[IFNAMSIZ]) | |||
1263 | /* Start with this zeroed. Messy but sure. */ | 1369 | /* Start with this zeroed. Messy but sure. */ |
1264 | memset(&ifr, 0, sizeof(ifr)); | 1370 | memset(&ifr, 0, sizeof(ifr)); |
1265 | 1371 | ||
1266 | /* We open the /dev/net/tun device and tell it we want a tap device. A | 1372 | /* |
1373 | * We open the /dev/net/tun device and tell it we want a tap device. A | ||
1267 | * tap device is like a tun device, only somehow different. To tell | 1374 | * tap device is like a tun device, only somehow different. To tell |
1268 | * the truth, I completely blundered my way through this code, but it | 1375 | * the truth, I completely blundered my way through this code, but it |
1269 | * works now! */ | 1376 | * works now! |
1377 | */ | ||
1270 | netfd = open_or_die("/dev/net/tun", O_RDWR); | 1378 | netfd = open_or_die("/dev/net/tun", O_RDWR); |
1271 | ifr.ifr_flags = IFF_TAP | IFF_NO_PI | IFF_VNET_HDR; | 1379 | ifr.ifr_flags = IFF_TAP | IFF_NO_PI | IFF_VNET_HDR; |
1272 | strcpy(ifr.ifr_name, "tap%d"); | 1380 | strcpy(ifr.ifr_name, "tap%d"); |
@@ -1277,18 +1385,22 @@ static int get_tun_device(char tapif[IFNAMSIZ]) | |||
1277 | TUN_F_CSUM|TUN_F_TSO4|TUN_F_TSO6|TUN_F_TSO_ECN) != 0) | 1385 | TUN_F_CSUM|TUN_F_TSO4|TUN_F_TSO6|TUN_F_TSO_ECN) != 0) |
1278 | err(1, "Could not set features for tun device"); | 1386 | err(1, "Could not set features for tun device"); |
1279 | 1387 | ||
1280 | /* We don't need checksums calculated for packets coming in this | 1388 | /* |
1281 | * device: trust us! */ | 1389 | * We don't need checksums calculated for packets coming in this |
1390 | * device: trust us! | ||
1391 | */ | ||
1282 | ioctl(netfd, TUNSETNOCSUM, 1); | 1392 | ioctl(netfd, TUNSETNOCSUM, 1); |
1283 | 1393 | ||
1284 | memcpy(tapif, ifr.ifr_name, IFNAMSIZ); | 1394 | memcpy(tapif, ifr.ifr_name, IFNAMSIZ); |
1285 | return netfd; | 1395 | return netfd; |
1286 | } | 1396 | } |
1287 | 1397 | ||
1288 | /*L:195 Our network is a Host<->Guest network. This can either use bridging or | 1398 | /*L:195 |
1399 | * Our network is a Host<->Guest network. This can either use bridging or | ||
1289 | * routing, but the principle is the same: it uses the "tun" device to inject | 1400 | * routing, but the principle is the same: it uses the "tun" device to inject |
1290 | * packets into the Host as if they came in from a normal network card. We | 1401 | * packets into the Host as if they came in from a normal network card. We |
1291 | * just shunt packets between the Guest and the tun device. */ | 1402 | * just shunt packets between the Guest and the tun device. |
1403 | */ | ||
1292 | static void setup_tun_net(char *arg) | 1404 | static void setup_tun_net(char *arg) |
1293 | { | 1405 | { |
1294 | struct device *dev; | 1406 | struct device *dev; |
@@ -1305,13 +1417,14 @@ static void setup_tun_net(char *arg) | |||
1305 | dev = new_device("net", VIRTIO_ID_NET); | 1417 | dev = new_device("net", VIRTIO_ID_NET); |
1306 | dev->priv = net_info; | 1418 | dev->priv = net_info; |
1307 | 1419 | ||
1308 | /* Network devices need a receive and a send queue, just like | 1420 | /* Network devices need a recv and a send queue, just like console. */ |
1309 | * console. */ | ||
1310 | add_virtqueue(dev, VIRTQUEUE_NUM, net_input); | 1421 | add_virtqueue(dev, VIRTQUEUE_NUM, net_input); |
1311 | add_virtqueue(dev, VIRTQUEUE_NUM, net_output); | 1422 | add_virtqueue(dev, VIRTQUEUE_NUM, net_output); |
1312 | 1423 | ||
1313 | /* We need a socket to perform the magic network ioctls to bring up the | 1424 | /* |
1314 | * tap interface, connect to the bridge etc. Any socket will do! */ | 1425 | * We need a socket to perform the magic network ioctls to bring up the |
1426 | * tap interface, connect to the bridge etc. Any socket will do! | ||
1427 | */ | ||
1315 | ipfd = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP); | 1428 | ipfd = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP); |
1316 | if (ipfd < 0) | 1429 | if (ipfd < 0) |
1317 | err(1, "opening IP socket"); | 1430 | err(1, "opening IP socket"); |
@@ -1366,7 +1479,8 @@ static void setup_tun_net(char *arg) | |||
1366 | devices.device_num, tapif, arg); | 1479 | devices.device_num, tapif, arg); |
1367 | } | 1480 | } |
1368 | 1481 | ||
1369 | /* Our block (disk) device should be really simple: the Guest asks for a block | 1482 | /* |
1483 | * Our block (disk) device should be really simple: the Guest asks for a block | ||
1370 | * number and we read or write that position in the file. Unfortunately, that | 1484 | * number and we read or write that position in the file. Unfortunately, that |
1371 | * was amazingly slow: the Guest waits until the read is finished before | 1485 | * was amazingly slow: the Guest waits until the read is finished before |
1372 | * running anything else, even if it could have been doing useful work. | 1486 | * running anything else, even if it could have been doing useful work. |
@@ -1374,7 +1488,9 @@ static void setup_tun_net(char *arg) | |||
1374 | * We could use async I/O, except it's reputed to suck so hard that characters | 1488 | * We could use async I/O, except it's reputed to suck so hard that characters |
1375 | * actually go missing from your code when you try to use it. | 1489 | * actually go missing from your code when you try to use it. |
1376 | * | 1490 | * |
1377 | * So we farm the I/O out to thread, and communicate with it via a pipe. */ | 1491 | * So this was one reason why lguest now does all virtqueue servicing in |
1492 | * separate threads: it's more efficient and more like a real device. | ||
1493 | */ | ||
1378 | 1494 | ||
1379 | /* This hangs off device->priv. */ | 1495 | /* This hangs off device->priv. */ |
1380 | struct vblk_info | 1496 | struct vblk_info |
@@ -1412,9 +1528,11 @@ static void blk_request(struct virtqueue *vq) | |||
1412 | /* Get the next request. */ | 1528 | /* Get the next request. */ |
1413 | head = wait_for_vq_desc(vq, iov, &out_num, &in_num); | 1529 | head = wait_for_vq_desc(vq, iov, &out_num, &in_num); |
1414 | 1530 | ||
1415 | /* Every block request should contain at least one output buffer | 1531 | /* |
1532 | * Every block request should contain at least one output buffer | ||
1416 | * (detailing the location on disk and the type of request) and one | 1533 | * (detailing the location on disk and the type of request) and one |
1417 | * input buffer (to hold the result). */ | 1534 | * input buffer (to hold the result). |
1535 | */ | ||
1418 | if (out_num == 0 || in_num == 0) | 1536 | if (out_num == 0 || in_num == 0) |
1419 | errx(1, "Bad virtblk cmd %u out=%u in=%u", | 1537 | errx(1, "Bad virtblk cmd %u out=%u in=%u", |
1420 | head, out_num, in_num); | 1538 | head, out_num, in_num); |
@@ -1423,33 +1541,41 @@ static void blk_request(struct virtqueue *vq) | |||
1423 | in = convert(&iov[out_num+in_num-1], u8); | 1541 | in = convert(&iov[out_num+in_num-1], u8); |
1424 | off = out->sector * 512; | 1542 | off = out->sector * 512; |
1425 | 1543 | ||
1426 | /* The block device implements "barriers", where the Guest indicates | 1544 | /* |
1545 | * The block device implements "barriers", where the Guest indicates | ||
1427 | * that it wants all previous writes to occur before this write. We | 1546 | * that it wants all previous writes to occur before this write. We |
1428 | * don't have a way of asking our kernel to do a barrier, so we just | 1547 | * don't have a way of asking our kernel to do a barrier, so we just |
1429 | * synchronize all the data in the file. Pretty poor, no? */ | 1548 | * synchronize all the data in the file. Pretty poor, no? |
1549 | */ | ||
1430 | if (out->type & VIRTIO_BLK_T_BARRIER) | 1550 | if (out->type & VIRTIO_BLK_T_BARRIER) |
1431 | fdatasync(vblk->fd); | 1551 | fdatasync(vblk->fd); |
1432 | 1552 | ||
1433 | /* In general the virtio block driver is allowed to try SCSI commands. | 1553 | /* |
1434 | * It'd be nice if we supported eject, for example, but we don't. */ | 1554 | * In general the virtio block driver is allowed to try SCSI commands. |
1555 | * It'd be nice if we supported eject, for example, but we don't. | ||
1556 | */ | ||
1435 | if (out->type & VIRTIO_BLK_T_SCSI_CMD) { | 1557 | if (out->type & VIRTIO_BLK_T_SCSI_CMD) { |
1436 | fprintf(stderr, "Scsi commands unsupported\n"); | 1558 | fprintf(stderr, "Scsi commands unsupported\n"); |
1437 | *in = VIRTIO_BLK_S_UNSUPP; | 1559 | *in = VIRTIO_BLK_S_UNSUPP; |
1438 | wlen = sizeof(*in); | 1560 | wlen = sizeof(*in); |
1439 | } else if (out->type & VIRTIO_BLK_T_OUT) { | 1561 | } else if (out->type & VIRTIO_BLK_T_OUT) { |
1440 | /* Write */ | 1562 | /* |
1441 | 1563 | * Write | |
1442 | /* Move to the right location in the block file. This can fail | 1564 | * |
1443 | * if they try to write past end. */ | 1565 | * Move to the right location in the block file. This can fail |
1566 | * if they try to write past end. | ||
1567 | */ | ||
1444 | if (lseek64(vblk->fd, off, SEEK_SET) != off) | 1568 | if (lseek64(vblk->fd, off, SEEK_SET) != off) |
1445 | err(1, "Bad seek to sector %llu", out->sector); | 1569 | err(1, "Bad seek to sector %llu", out->sector); |
1446 | 1570 | ||
1447 | ret = writev(vblk->fd, iov+1, out_num-1); | 1571 | ret = writev(vblk->fd, iov+1, out_num-1); |
1448 | verbose("WRITE to sector %llu: %i\n", out->sector, ret); | 1572 | verbose("WRITE to sector %llu: %i\n", out->sector, ret); |
1449 | 1573 | ||
1450 | /* Grr... Now we know how long the descriptor they sent was, we | 1574 | /* |
1575 | * Grr... Now we know how long the descriptor they sent was, we | ||
1451 | * make sure they didn't try to write over the end of the block | 1576 | * make sure they didn't try to write over the end of the block |
1452 | * file (possibly extending it). */ | 1577 | * file (possibly extending it). |
1578 | */ | ||
1453 | if (ret > 0 && off + ret > vblk->len) { | 1579 | if (ret > 0 && off + ret > vblk->len) { |
1454 | /* Trim it back to the correct length */ | 1580 | /* Trim it back to the correct length */ |
1455 | ftruncate64(vblk->fd, vblk->len); | 1581 | ftruncate64(vblk->fd, vblk->len); |
@@ -1459,10 +1585,12 @@ static void blk_request(struct virtqueue *vq) | |||
1459 | wlen = sizeof(*in); | 1585 | wlen = sizeof(*in); |
1460 | *in = (ret >= 0 ? VIRTIO_BLK_S_OK : VIRTIO_BLK_S_IOERR); | 1586 | *in = (ret >= 0 ? VIRTIO_BLK_S_OK : VIRTIO_BLK_S_IOERR); |
1461 | } else { | 1587 | } else { |
1462 | /* Read */ | 1588 | /* |
1463 | 1589 | * Read | |
1464 | /* Move to the right location in the block file. This can fail | 1590 | * |
1465 | * if they try to read past end. */ | 1591 | * Move to the right location in the block file. This can fail |
1592 | * if they try to read past end. | ||
1593 | */ | ||
1466 | if (lseek64(vblk->fd, off, SEEK_SET) != off) | 1594 | if (lseek64(vblk->fd, off, SEEK_SET) != off) |
1467 | err(1, "Bad seek to sector %llu", out->sector); | 1595 | err(1, "Bad seek to sector %llu", out->sector); |
1468 | 1596 | ||
@@ -1477,10 +1605,12 @@ static void blk_request(struct virtqueue *vq) | |||
1477 | } | 1605 | } |
1478 | } | 1606 | } |
1479 | 1607 | ||
1480 | /* OK, so we noted that it was pretty poor to use an fdatasync as a | 1608 | /* |
1609 | * OK, so we noted that it was pretty poor to use an fdatasync as a | ||
1481 | * barrier. But Christoph Hellwig points out that we need a sync | 1610 | * barrier. But Christoph Hellwig points out that we need a sync |
1482 | * *afterwards* as well: "Barriers specify no reordering to the front | 1611 | * *afterwards* as well: "Barriers specify no reordering to the front |
1483 | * or the back." And Jens Axboe confirmed it, so here we are: */ | 1612 | * or the back." And Jens Axboe confirmed it, so here we are: |
1613 | */ | ||
1484 | if (out->type & VIRTIO_BLK_T_BARRIER) | 1614 | if (out->type & VIRTIO_BLK_T_BARRIER) |
1485 | fdatasync(vblk->fd); | 1615 | fdatasync(vblk->fd); |
1486 | 1616 | ||
@@ -1494,7 +1624,7 @@ static void setup_block_file(const char *filename) | |||
1494 | struct vblk_info *vblk; | 1624 | struct vblk_info *vblk; |
1495 | struct virtio_blk_config conf; | 1625 | struct virtio_blk_config conf; |
1496 | 1626 | ||
1497 | /* The device responds to return from I/O thread. */ | 1627 | /* Creat the device. */ |
1498 | dev = new_device("block", VIRTIO_ID_BLOCK); | 1628 | dev = new_device("block", VIRTIO_ID_BLOCK); |
1499 | 1629 | ||
1500 | /* The device has one virtqueue, where the Guest places requests. */ | 1630 | /* The device has one virtqueue, where the Guest places requests. */ |
@@ -1513,8 +1643,10 @@ static void setup_block_file(const char *filename) | |||
1513 | /* Tell Guest how many sectors this device has. */ | 1643 | /* Tell Guest how many sectors this device has. */ |
1514 | conf.capacity = cpu_to_le64(vblk->len / 512); | 1644 | conf.capacity = cpu_to_le64(vblk->len / 512); |
1515 | 1645 | ||
1516 | /* Tell Guest not to put in too many descriptors at once: two are used | 1646 | /* |
1517 | * for the in and out elements. */ | 1647 | * Tell Guest not to put in too many descriptors at once: two are used |
1648 | * for the in and out elements. | ||
1649 | */ | ||
1518 | add_feature(dev, VIRTIO_BLK_F_SEG_MAX); | 1650 | add_feature(dev, VIRTIO_BLK_F_SEG_MAX); |
1519 | conf.seg_max = cpu_to_le32(VIRTQUEUE_NUM - 2); | 1651 | conf.seg_max = cpu_to_le32(VIRTQUEUE_NUM - 2); |
1520 | 1652 | ||
@@ -1525,16 +1657,18 @@ static void setup_block_file(const char *filename) | |||
1525 | ++devices.device_num, le64_to_cpu(conf.capacity)); | 1657 | ++devices.device_num, le64_to_cpu(conf.capacity)); |
1526 | } | 1658 | } |
1527 | 1659 | ||
1528 | struct rng_info { | 1660 | /*L:211 |
1529 | int rfd; | 1661 | * Our random number generator device reads from /dev/random into the Guest's |
1530 | }; | ||
1531 | |||
1532 | /* Our random number generator device reads from /dev/random into the Guest's | ||
1533 | * input buffers. The usual case is that the Guest doesn't want random numbers | 1662 | * input buffers. The usual case is that the Guest doesn't want random numbers |
1534 | * and so has no buffers although /dev/random is still readable, whereas | 1663 | * and so has no buffers although /dev/random is still readable, whereas |
1535 | * console is the reverse. | 1664 | * console is the reverse. |
1536 | * | 1665 | * |
1537 | * The same logic applies, however. */ | 1666 | * The same logic applies, however. |
1667 | */ | ||
1668 | struct rng_info { | ||
1669 | int rfd; | ||
1670 | }; | ||
1671 | |||
1538 | static void rng_input(struct virtqueue *vq) | 1672 | static void rng_input(struct virtqueue *vq) |
1539 | { | 1673 | { |
1540 | int len; | 1674 | int len; |
@@ -1547,9 +1681,11 @@ static void rng_input(struct virtqueue *vq) | |||
1547 | if (out_num) | 1681 | if (out_num) |
1548 | errx(1, "Output buffers in rng?"); | 1682 | errx(1, "Output buffers in rng?"); |
1549 | 1683 | ||
1550 | /* This is why we convert to iovecs: the readv() call uses them, and so | 1684 | /* |
1685 | * This is why we convert to iovecs: the readv() call uses them, and so | ||
1551 | * it reads straight into the Guest's buffer. We loop to make sure we | 1686 | * it reads straight into the Guest's buffer. We loop to make sure we |
1552 | * fill it. */ | 1687 | * fill it. |
1688 | */ | ||
1553 | while (!iov_empty(iov, in_num)) { | 1689 | while (!iov_empty(iov, in_num)) { |
1554 | len = readv(rng_info->rfd, iov, in_num); | 1690 | len = readv(rng_info->rfd, iov, in_num); |
1555 | if (len <= 0) | 1691 | if (len <= 0) |
@@ -1562,15 +1698,18 @@ static void rng_input(struct virtqueue *vq) | |||
1562 | add_used(vq, head, totlen); | 1698 | add_used(vq, head, totlen); |
1563 | } | 1699 | } |
1564 | 1700 | ||
1565 | /* And this creates a "hardware" random number device for the Guest. */ | 1701 | /*L:199 |
1702 | * This creates a "hardware" random number device for the Guest. | ||
1703 | */ | ||
1566 | static void setup_rng(void) | 1704 | static void setup_rng(void) |
1567 | { | 1705 | { |
1568 | struct device *dev; | 1706 | struct device *dev; |
1569 | struct rng_info *rng_info = malloc(sizeof(*rng_info)); | 1707 | struct rng_info *rng_info = malloc(sizeof(*rng_info)); |
1570 | 1708 | ||
1709 | /* Our device's privat info simply contains the /dev/random fd. */ | ||
1571 | rng_info->rfd = open_or_die("/dev/random", O_RDONLY); | 1710 | rng_info->rfd = open_or_die("/dev/random", O_RDONLY); |
1572 | 1711 | ||
1573 | /* The device responds to return from I/O thread. */ | 1712 | /* Create the new device. */ |
1574 | dev = new_device("rng", VIRTIO_ID_RNG); | 1713 | dev = new_device("rng", VIRTIO_ID_RNG); |
1575 | dev->priv = rng_info; | 1714 | dev->priv = rng_info; |
1576 | 1715 | ||
@@ -1586,8 +1725,10 @@ static void __attribute__((noreturn)) restart_guest(void) | |||
1586 | { | 1725 | { |
1587 | unsigned int i; | 1726 | unsigned int i; |
1588 | 1727 | ||
1589 | /* Since we don't track all open fds, we simply close everything beyond | 1728 | /* |
1590 | * stderr. */ | 1729 | * Since we don't track all open fds, we simply close everything beyond |
1730 | * stderr. | ||
1731 | */ | ||
1591 | for (i = 3; i < FD_SETSIZE; i++) | 1732 | for (i = 3; i < FD_SETSIZE; i++) |
1592 | close(i); | 1733 | close(i); |
1593 | 1734 | ||
@@ -1598,8 +1739,10 @@ static void __attribute__((noreturn)) restart_guest(void) | |||
1598 | err(1, "Could not exec %s", main_args[0]); | 1739 | err(1, "Could not exec %s", main_args[0]); |
1599 | } | 1740 | } |
1600 | 1741 | ||
1601 | /*L:220 Finally we reach the core of the Launcher which runs the Guest, serves | 1742 | /*L:220 |
1602 | * its input and output, and finally, lays it to rest. */ | 1743 | * Finally we reach the core of the Launcher which runs the Guest, serves |
1744 | * its input and output, and finally, lays it to rest. | ||
1745 | */ | ||
1603 | static void __attribute__((noreturn)) run_guest(void) | 1746 | static void __attribute__((noreturn)) run_guest(void) |
1604 | { | 1747 | { |
1605 | for (;;) { | 1748 | for (;;) { |
@@ -1634,7 +1777,7 @@ static void __attribute__((noreturn)) run_guest(void) | |||
1634 | * | 1777 | * |
1635 | * Are you ready? Take a deep breath and join me in the core of the Host, in | 1778 | * Are you ready? Take a deep breath and join me in the core of the Host, in |
1636 | * "make Host". | 1779 | * "make Host". |
1637 | :*/ | 1780 | :*/ |
1638 | 1781 | ||
1639 | static struct option opts[] = { | 1782 | static struct option opts[] = { |
1640 | { "verbose", 0, NULL, 'v' }, | 1783 | { "verbose", 0, NULL, 'v' }, |
@@ -1655,8 +1798,7 @@ static void usage(void) | |||
1655 | /*L:105 The main routine is where the real work begins: */ | 1798 | /*L:105 The main routine is where the real work begins: */ |
1656 | int main(int argc, char *argv[]) | 1799 | int main(int argc, char *argv[]) |
1657 | { | 1800 | { |
1658 | /* Memory, top-level pagetable, code startpoint and size of the | 1801 | /* Memory, code startpoint and size of the (optional) initrd. */ |
1659 | * (optional) initrd. */ | ||
1660 | unsigned long mem = 0, start, initrd_size = 0; | 1802 | unsigned long mem = 0, start, initrd_size = 0; |
1661 | /* Two temporaries. */ | 1803 | /* Two temporaries. */ |
1662 | int i, c; | 1804 | int i, c; |
@@ -1668,24 +1810,30 @@ int main(int argc, char *argv[]) | |||
1668 | /* Save the args: we "reboot" by execing ourselves again. */ | 1810 | /* Save the args: we "reboot" by execing ourselves again. */ |
1669 | main_args = argv; | 1811 | main_args = argv; |
1670 | 1812 | ||
1671 | /* First we initialize the device list. We keep a pointer to the last | 1813 | /* |
1814 | * First we initialize the device list. We keep a pointer to the last | ||
1672 | * device, and the next interrupt number to use for devices (1: | 1815 | * device, and the next interrupt number to use for devices (1: |
1673 | * remember that 0 is used by the timer). */ | 1816 | * remember that 0 is used by the timer). |
1817 | */ | ||
1674 | devices.lastdev = NULL; | 1818 | devices.lastdev = NULL; |
1675 | devices.next_irq = 1; | 1819 | devices.next_irq = 1; |
1676 | 1820 | ||
1677 | cpu_id = 0; | 1821 | cpu_id = 0; |
1678 | /* We need to know how much memory so we can set up the device | 1822 | /* |
1823 | * We need to know how much memory so we can set up the device | ||
1679 | * descriptor and memory pages for the devices as we parse the command | 1824 | * descriptor and memory pages for the devices as we parse the command |
1680 | * line. So we quickly look through the arguments to find the amount | 1825 | * line. So we quickly look through the arguments to find the amount |
1681 | * of memory now. */ | 1826 | * of memory now. |
1827 | */ | ||
1682 | for (i = 1; i < argc; i++) { | 1828 | for (i = 1; i < argc; i++) { |
1683 | if (argv[i][0] != '-') { | 1829 | if (argv[i][0] != '-') { |
1684 | mem = atoi(argv[i]) * 1024 * 1024; | 1830 | mem = atoi(argv[i]) * 1024 * 1024; |
1685 | /* We start by mapping anonymous pages over all of | 1831 | /* |
1832 | * We start by mapping anonymous pages over all of | ||
1686 | * guest-physical memory range. This fills it with 0, | 1833 | * guest-physical memory range. This fills it with 0, |
1687 | * and ensures that the Guest won't be killed when it | 1834 | * and ensures that the Guest won't be killed when it |
1688 | * tries to access it. */ | 1835 | * tries to access it. |
1836 | */ | ||
1689 | guest_base = map_zeroed_pages(mem / getpagesize() | 1837 | guest_base = map_zeroed_pages(mem / getpagesize() |
1690 | + DEVICE_PAGES); | 1838 | + DEVICE_PAGES); |
1691 | guest_limit = mem; | 1839 | guest_limit = mem; |
@@ -1718,8 +1866,10 @@ int main(int argc, char *argv[]) | |||
1718 | usage(); | 1866 | usage(); |
1719 | } | 1867 | } |
1720 | } | 1868 | } |
1721 | /* After the other arguments we expect memory and kernel image name, | 1869 | /* |
1722 | * followed by command line arguments for the kernel. */ | 1870 | * After the other arguments we expect memory and kernel image name, |
1871 | * followed by command line arguments for the kernel. | ||
1872 | */ | ||
1723 | if (optind + 2 > argc) | 1873 | if (optind + 2 > argc) |
1724 | usage(); | 1874 | usage(); |
1725 | 1875 | ||
@@ -1737,20 +1887,26 @@ int main(int argc, char *argv[]) | |||
1737 | /* Map the initrd image if requested (at top of physical memory) */ | 1887 | /* Map the initrd image if requested (at top of physical memory) */ |
1738 | if (initrd_name) { | 1888 | if (initrd_name) { |
1739 | initrd_size = load_initrd(initrd_name, mem); | 1889 | initrd_size = load_initrd(initrd_name, mem); |
1740 | /* These are the location in the Linux boot header where the | 1890 | /* |
1741 | * start and size of the initrd are expected to be found. */ | 1891 | * These are the location in the Linux boot header where the |
1892 | * start and size of the initrd are expected to be found. | ||
1893 | */ | ||
1742 | boot->hdr.ramdisk_image = mem - initrd_size; | 1894 | boot->hdr.ramdisk_image = mem - initrd_size; |
1743 | boot->hdr.ramdisk_size = initrd_size; | 1895 | boot->hdr.ramdisk_size = initrd_size; |
1744 | /* The bootloader type 0xFF means "unknown"; that's OK. */ | 1896 | /* The bootloader type 0xFF means "unknown"; that's OK. */ |
1745 | boot->hdr.type_of_loader = 0xFF; | 1897 | boot->hdr.type_of_loader = 0xFF; |
1746 | } | 1898 | } |
1747 | 1899 | ||
1748 | /* The Linux boot header contains an "E820" memory map: ours is a | 1900 | /* |
1749 | * simple, single region. */ | 1901 | * The Linux boot header contains an "E820" memory map: ours is a |
1902 | * simple, single region. | ||
1903 | */ | ||
1750 | boot->e820_entries = 1; | 1904 | boot->e820_entries = 1; |
1751 | boot->e820_map[0] = ((struct e820entry) { 0, mem, E820_RAM }); | 1905 | boot->e820_map[0] = ((struct e820entry) { 0, mem, E820_RAM }); |
1752 | /* The boot header contains a command line pointer: we put the command | 1906 | /* |
1753 | * line after the boot header. */ | 1907 | * The boot header contains a command line pointer: we put the command |
1908 | * line after the boot header. | ||
1909 | */ | ||
1754 | boot->hdr.cmd_line_ptr = to_guest_phys(boot + 1); | 1910 | boot->hdr.cmd_line_ptr = to_guest_phys(boot + 1); |
1755 | /* We use a simple helper to copy the arguments separated by spaces. */ | 1911 | /* We use a simple helper to copy the arguments separated by spaces. */ |
1756 | concat((char *)(boot + 1), argv+optind+2); | 1912 | concat((char *)(boot + 1), argv+optind+2); |
@@ -1764,8 +1920,10 @@ int main(int argc, char *argv[]) | |||
1764 | /* Tell the entry path not to try to reload segment registers. */ | 1920 | /* Tell the entry path not to try to reload segment registers. */ |
1765 | boot->hdr.loadflags |= KEEP_SEGMENTS; | 1921 | boot->hdr.loadflags |= KEEP_SEGMENTS; |
1766 | 1922 | ||
1767 | /* We tell the kernel to initialize the Guest: this returns the open | 1923 | /* |
1768 | * /dev/lguest file descriptor. */ | 1924 | * We tell the kernel to initialize the Guest: this returns the open |
1925 | * /dev/lguest file descriptor. | ||
1926 | */ | ||
1769 | tell_kernel(start); | 1927 | tell_kernel(start); |
1770 | 1928 | ||
1771 | /* Ensure that we terminate if a child dies. */ | 1929 | /* Ensure that we terminate if a child dies. */ |