--- /dev/null
+/*
+ * Block driver for Conectix/Microsoft Virtual PC images
+ *
+ * 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.
+ */
+#include "vl.h"
+#include "block_int.h"
+
+/**************************************************************/
+
+#define HEADER_SIZE 512
+
+//#define CACHE
+
+// always big-endian
+struct vpc_subheader {
+ char magic[8]; // "conectix" / "cxsparse"
+ union {
+ struct {
+ uint32_t unk1[2];
+ uint32_t unk2; // always zero?
+ uint32_t subheader_offset;
+ uint32_t unk3; // some size?
+ char creator[4]; // "vpc "
+ uint16_t major;
+ uint16_t minor;
+ char guest[4]; // "Wi2k"
+ uint32_t unk4[7];
+ uint8_t vnet_id[16]; // virtual network id, purpose unknown
+ // next 16 longs are used, but dunno the purpose
+ // next 6 longs unknown, following 7 long maybe a serial
+ char padding[HEADER_SIZE - 84];
+ } main;
+ struct {
+ uint32_t unk1[2]; // all bits set
+ uint32_t unk2; // always zero?
+ uint32_t pagetable_offset;
+ uint32_t unk3;
+ uint32_t pagetable_entries; // 32bit/entry
+ uint32_t pageentry_size; // 512*8*512
+ uint32_t nb_sectors;
+ char padding[HEADER_SIZE - 40];
+ } sparse;
+ char padding[HEADER_SIZE - 8];
+ } type;
+};
+
+typedef struct BDRVVPCState {
+ int fd;
+
+ int pagetable_entries;
+ uint32_t *pagetable;
+
+ uint32_t pageentry_size;
+#ifdef CACHE
+ uint8_t *pageentry_u8;
+ uint32_t *pageentry_u32;
+ uint16_t *pageentry_u16;
+
+ uint64_t last_bitmap;
+#endif
+} BDRVVPCState;
+
+static int vpc_probe(const uint8_t *buf, int buf_size, const char *filename)
+{
+ if (!strncmp(buf, "conectix", 8))
+ return 100;
+
+ return 0;
+}
+
+static int vpc_open(BlockDriverState *bs, const char *filename)
+{
+ BDRVVPCState *s = bs->opaque;
+ int fd, i;
+ struct vpc_subheader header;
+
+ 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, &header, HEADER_SIZE) != HEADER_SIZE)
+ goto fail;
+
+ if (strncmp(header.magic, "conectix", 8))
+ goto fail;
+ lseek(s->fd, be32_to_cpu(header.type.main.subheader_offset), SEEK_SET);
+
+ if (read(fd, &header, HEADER_SIZE) != HEADER_SIZE)
+ goto fail;
+
+ if (strncmp(header.magic, "cxsparse", 8))
+ goto fail;
+
+ bs->total_sectors = ((uint64_t)be32_to_cpu(header.type.sparse.pagetable_entries) *
+ be32_to_cpu(header.type.sparse.pageentry_size)) / 512;
+
+ lseek(s->fd, be32_to_cpu(header.type.sparse.pagetable_offset), SEEK_SET);
+
+ s->pagetable_entries = be32_to_cpu(header.type.sparse.pagetable_entries);
+ s->pagetable = qemu_malloc(s->pagetable_entries * 4);
+ if (!s->pagetable)
+ goto fail;
+ if (read(s->fd, s->pagetable, s->pagetable_entries * 4) !=
+ s->pagetable_entries * 4)
+ goto fail;
+ for (i = 0; i < s->pagetable_entries; i++)
+ be32_to_cpus(&s->pagetable[i]);
+
+ s->pageentry_size = be32_to_cpu(header.type.sparse.pageentry_size);
+#ifdef CACHE
+ s->pageentry_u8 = qemu_malloc(512);
+ if (!s->pageentry_u8)
+ goto fail;
+ s->pageentry_u32 = s->pageentry_u8;
+ s->pageentry_u16 = s->pageentry_u8;
+ s->last_pagetable = -1;
+#endif
+
+ return 0;
+ fail:
+ close(fd);
+ return -1;
+}
+
+static inline int seek_to_sector(BlockDriverState *bs, int64_t sector_num)
+{
+ BDRVVPCState *s = bs->opaque;
+ uint64_t offset = sector_num * 512;
+ uint64_t bitmap_offset, block_offset;
+ uint32_t pagetable_index, pageentry_index;
+
+ pagetable_index = offset / s->pageentry_size;
+ pageentry_index = (offset % s->pageentry_size) / 512;
+
+ if (pagetable_index > s->pagetable_entries || s->pagetable[pagetable_index] == 0xffffffff)
+ return -1; // not allocated
+
+ bitmap_offset = 512 * s->pagetable[pagetable_index];
+ block_offset = bitmap_offset + 512 + (512 * pageentry_index);
+
+// printf("sector: %llx, index: %x, offset: %x, bioff: %llx, bloff: %llx\n",
+// sector_num, pagetable_index, pageentry_index,
+// bitmap_offset, block_offset);
+
+// disabled by reason
+#if 0
+#ifdef CACHE
+ if (bitmap_offset != s->last_bitmap)
+ {
+ lseek(s->fd, bitmap_offset, SEEK_SET);
+
+ s->last_bitmap = bitmap_offset;
+
+ // Scary! Bitmap is stored as big endian 32bit entries,
+ // while we used to look it up byte by byte
+ read(s->fd, s->pageentry_u8, 512);
+ for (i = 0; i < 128; i++)
+ be32_to_cpus(&s->pageentry_u32[i]);
+ }
+
+ if ((s->pageentry_u8[pageentry_index / 8] >> (pageentry_index % 8)) & 1)
+ return -1;
+#else
+ lseek(s->fd, bitmap_offset + (pageentry_index / 8), SEEK_SET);
+
+ read(s->fd, &bitmap_entry, 1);
+
+ if ((bitmap_entry >> (pageentry_index % 8)) & 1)
+ return -1; // not allocated
+#endif
+#endif
+ lseek(s->fd, block_offset, SEEK_SET);
+
+ return 0;
+}
+
+static int vpc_read(BlockDriverState *bs, int64_t sector_num,
+ uint8_t *buf, int nb_sectors)
+{
+ BDRVVPCState *s = bs->opaque;
+ int ret;
+
+ 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 vpc_close(BlockDriverState *bs)
+{
+ BDRVVPCState *s = bs->opaque;
+ qemu_free(s->pagetable);
+#ifdef CACHE
+ qemu_free(s->pageentry_u8);
+#endif
+ close(s->fd);
+}
+
+BlockDriver bdrv_vpc = {
+ "vpc",
+ sizeof(BDRVVPCState),
+ vpc_probe,
+ vpc_open,
+ vpc_read,
+ NULL,
+ vpc_close,
+};
projects / qemu / commitdiff