From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1DJdJc-000190-Dj for qemu-devel@nongnu.org; Thu, 07 Apr 2005 16:09:25 -0400 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1DJdJT-00011h-4n for qemu-devel@nongnu.org; Thu, 07 Apr 2005 16:09:15 -0400 Received: from [129.104.30.34] (helo=mx1.polytechnique.org) by monty-python.gnu.org with esmtp (Exim 4.34) id 1DJdbj-0003vI-Tr for qemu-devel@nongnu.org; Thu, 07 Apr 2005 16:28:08 -0400 Message-ID: <4255980A.6020300@bellard.org> Date: Thu, 07 Apr 2005 22:28:58 +0200 From: Fabrice Bellard MIME-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH] Bochs Redolog disk image support References: <20050317185244.7b9fdc20@caprice.artificis.hu> In-Reply-To: <20050317185244.7b9fdc20@caprice.artificis.hu> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: alex@fsn.hu Cc: qemu-devel@nongnu.org Hi, Supporting Bochs disk images is interesting. I can commit your patch if you suppress the unneeded mmap() usage. Fabrice. Alex Beregszaszi wrote: > Hi, > > Looks like I forgot to attach... > > attached is a patch and file adding read-only support for bochs > "growing" type of disk images. > > I wrote this for converting my bochs images into cow and I'm not > currently interested in adding write support. > > Also note that altought the bochs "redolog" disk format has more > subtypes, the growing one is the widely used one. Also there's a > different format called "sparse", which is not supported by this driver. > The "flat" format used by bochs is just raw. > > Also it could be speed up by several factors. > > > > ------------------------------------------------------------------------ > > /* > * Block driver for the various disk image formats used by Bochs > * Currently only for "growing" type in read-only mode > * > * Copyright (c) 2005 Alex Beregszaszi > * > * Permission is hereby granted, free of charge, to any person obtaining a copy > * of this software and associated documentation files (the "Software"), to deal > * in the Software without restriction, including without limitation the rights > * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell > * copies of the Software, and to permit persons to whom the Software is > * furnished to do so, subject to the following conditions: > * > * The above copyright notice and this permission notice shall be included in > * all copies or substantial portions of the Software. > * > * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR > * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, > * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL > * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER > * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, > * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN > * THE SOFTWARE. > */ > #ifndef _WIN32 > #include "vl.h" > #include "block_int.h" > #include > > /**************************************************************/ > > #define HEADER_MAGIC "Bochs Virtual HD Image" > #define HEADER_VERSION 0x00010000 > #define HEADER_SIZE 512 > > #define REDOLOG_TYPE "Redolog" > #define GROWING_TYPE "Growing" > > // not allocated: 0xffffffff > > // always little-endian > struct bochs_header { > char magic[32]; // "Bochs Virtual HD Image" > char type[16]; // "Redolog" > char subtype[16]; // "Undoable" / "Volatile" / "Growing" > uint32_t version; > uint32_t header; // size of header > > union { > struct { > uint32_t catalog; // num of entries > uint32_t bitmap; // bitmap size > uint32_t extent; // extent size > uint64_t disk; // disk size > char padding[HEADER_SIZE - 64 - 8 - 20]; > } redolog; > char padding[HEADER_SIZE - 64 - 8]; > } extra; > }; > > typedef struct BDRVBochsState { > int fd; > uint32_t *catalog_bitmap; > int catalog_size; > int catalog_addr; > > int bitmap_blocks, extent_blocks, extent_size; > } BDRVBochsState; > > static int bochs_probe(const uint8_t *buf, int buf_size, const char *filename) > { > const struct bochs_header *bochs = (const void *)buf; > > if (buf_size < HEADER_SIZE) > return 0; > > if (!strcmp(bochs->magic, HEADER_MAGIC) && > !strcmp(bochs->type, REDOLOG_TYPE) && > !strcmp(bochs->subtype, GROWING_TYPE) && > (le32_to_cpu(bochs->version) == HEADER_VERSION)) > return 100; > > return 0; > } > > static int bochs_open(BlockDriverState *bs, const char *filename) > { > BDRVBochsState *s = bs->opaque; > int fd; > struct bochs_header bochs; > int64_t size; > > fd = open(filename, O_RDWR | O_BINARY | O_LARGEFILE); > if (fd < 0) { > fd = open(filename, O_RDONLY | O_BINARY | O_LARGEFILE); > if (fd < 0) > return -1; > } > > bs->read_only = 1; // no write support yet > > s->fd = fd; > > if (read(fd, &bochs, sizeof(bochs)) != sizeof(bochs)) { > goto fail; > } > > if (strcmp(bochs.magic, HEADER_MAGIC) || > strcmp(bochs.type, REDOLOG_TYPE) || > strcmp(bochs.subtype, GROWING_TYPE) || > (le32_to_cpu(bochs.version) != HEADER_VERSION)) { > goto fail; > } > > size = le64_to_cpu(bochs.extra.redolog.disk); > > bs->total_sectors = size / 512; > > s->catalog_size = le32_to_cpu(bochs.extra.redolog.catalog) * 4 + le32_to_cpu(bochs.header); > s->catalog_addr = mmap(get_mmap_addr(s->catalog_size), > s->catalog_size, > PROT_READ, > MAP_SHARED, s->fd, 0); > if (s->catalog_addr == MAP_FAILED) > goto fail; > s->catalog_bitmap = s->catalog_addr + le32_to_cpu(bochs.header); > > s->bitmap_blocks = 1 + (le32_to_cpu(bochs.extra.redolog.bitmap) - 1) / 512; > s->extent_blocks = 1 + (le32_to_cpu(bochs.extra.redolog.extent) - 1) / 512; > > s->extent_size = le32_to_cpu(bochs.extra.redolog.extent); > > return 0; > fail: > close(fd); > return -1; > } > > static inline int seek_to_sector(BlockDriverState *bs, int64_t sector_num) > { > BDRVBochsState *s = bs->opaque; > int64_t offset = sector_num * 512; > int64_t extent_index, extent_offset, bitmap_offset, block_offset; > char bitmap_entry; > > // seek to sector > extent_index = offset / s->extent_size; > extent_offset = (offset % s->extent_size) / 512; > > if (le32_to_cpu(s->catalog_bitmap[extent_index]) == 0xffffffff) > { > // fprintf(stderr, "page not allocated [%x - %x:%x]\n", > // sector_num, extent_index, extent_offset); > return -1; // not allocated > } > > bitmap_offset = s->catalog_size + (512 * le32_to_cpu(s->catalog_bitmap[extent_index]) * > (s->extent_blocks + s->bitmap_blocks)); > block_offset = bitmap_offset + (512 * (s->bitmap_blocks + extent_offset)); > > // fprintf(stderr, "sect: %x [ext i: %x o: %x] -> %x bitmap: %x block: %x\n", > // sector_num, extent_index, extent_offset, > // le32_to_cpu(s->catalog_bitmap[extent_index]), > // bitmap_offset, block_offset); > > // read in bitmap for current extent > lseek(s->fd, bitmap_offset + (extent_offset / 8), SEEK_SET); > > read(s->fd, &bitmap_entry, 1); > > if (!((bitmap_entry >> (extent_offset % 8)) & 1)) > { > // fprintf(stderr, "sector (%x) in bitmap not allocated\n", > // sector_num); > return -1; // not allocated > } > > lseek(s->fd, block_offset, SEEK_SET); > > return 0; > } > > static int bochs_read(BlockDriverState *bs, int64_t sector_num, > uint8_t *buf, int nb_sectors) > { > BDRVBochsState *s = bs->opaque; > int ret, n; > > while (nb_sectors > 0) { > if (!seek_to_sector(bs, sector_num)) > { > ret = read(s->fd, buf, 512); > if (ret != 512) > return -1; > } > else > memset(buf, 0, 512); > nb_sectors--; > sector_num++; > buf += 512; > } > return 0; > } > > static void bochs_close(BlockDriverState *bs) > { > BDRVBochsState *s = bs->opaque; > munmap(s->catalog_addr, s->catalog_size); > close(s->fd); > } > > BlockDriver bdrv_bochs = { > "bochs", > sizeof(BDRVBochsState), > bochs_probe, > bochs_open, > bochs_read, > NULL, > bochs_close, > }; > #endif > > > ------------------------------------------------------------------------ > > ? block-bochs.c > ? block-bochs.diff > Index: Makefile > =================================================================== > RCS file: /cvsroot/qemu/qemu/Makefile,v > retrieving revision 1.82 > diff -u -r1.82 Makefile > --- Makefile 10 Feb 2005 21:48:51 -0000 1.82 > +++ Makefile 17 Mar 2005 17:27:00 -0000 > @@ -21,7 +21,7 @@ > $(MAKE) -C kqemu > endif > > -qemu-img$(EXESUF): qemu-img.c block.c block-cow.c block-qcow.c aes.c block-vmdk.c block-cloop.c block-dmg.c > +qemu-img$(EXESUF): qemu-img.c block.c block-cow.c block-qcow.c aes.c block-vmdk.c block-cloop.c block-dmg.c block-bochs.c > $(CC) -DQEMU_TOOL $(CFLAGS) $(LDFLAGS) $(DEFINES) -o $@ $^ -lz $(LIBS) > > dyngen$(EXESUF): dyngen.c > Index: Makefile.target > =================================================================== > RCS file: /cvsroot/qemu/qemu/Makefile.target,v > retrieving revision 1.62 > diff -u -r1.62 Makefile.target > --- Makefile.target 13 Mar 2005 16:52:10 -0000 1.62 > +++ Makefile.target 17 Mar 2005 17:27:00 -0000 > @@ -309,7 +309,7 @@ > > # must use static linking to avoid leaving stuff in virtual address space > VL_OBJS=vl.o osdep.o block.o readline.o monitor.o pci.o console.o > -VL_OBJS+=block-cow.o block-qcow.o aes.o block-vmdk.o block-cloop.o block-dmg.o > +VL_OBJS+=block-cow.o block-qcow.o aes.o block-vmdk.o block-cloop.o block-dmg.o block-bochs.o > > SOUND_HW = sb16.o > AUDIODRV = audio.o noaudio.o wavaudio.o > Index: block.c > =================================================================== > RCS file: /cvsroot/qemu/qemu/block.c,v > retrieving revision 1.16 > diff -u -r1.16 block.c > --- block.c 12 Dec 2004 11:24:44 -0000 1.16 > +++ block.c 17 Mar 2005 17:27:00 -0000 > @@ -608,4 +608,5 @@ > bdrv_register(&bdrv_vmdk); > bdrv_register(&bdrv_cloop); > bdrv_register(&bdrv_dmg); > + bdrv_register(&bdrv_bochs); > } > Index: vl.h > =================================================================== > RCS file: /cvsroot/qemu/qemu/vl.h,v > retrieving revision 1.69 > diff -u -r1.69 vl.h > --- vl.h 13 Mar 2005 09:43:36 -0000 1.69 > +++ vl.h 17 Mar 2005 17:27:01 -0000 > @@ -381,6 +381,7 @@ > extern BlockDriver bdrv_vmdk; > extern BlockDriver bdrv_cloop; > extern BlockDriver bdrv_dmg; > +extern BlockDriver bdrv_bochs; > > void bdrv_init(void); > BlockDriver *bdrv_find_format(const char *format_name); > > > ------------------------------------------------------------------------ > > _______________________________________________ > Qemu-devel mailing list > Qemu-devel@nongnu.org > http://lists.nongnu.org/mailman/listinfo/qemu-devel