* [Qemu-devel] [PATCH 1/2] Refactor CHS guessing to be usable outside of IDE
@ 2007-12-05 16:24 Anthony Liguori
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From: Anthony Liguori @ 2007-12-05 16:24 UTC (permalink / raw)
To: qemu-devel
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The next patch I post will require this patch. It refactors the CHS
guessing so it can be used by devices other than IDE.
Regards,
Anthony Liguori
[-- Attachment #2: bdrv-guess-geometry.diff --]
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Index: qemu/block.c
===================================================================
--- qemu.orig/block.c 2007-12-04 16:18:46.000000000 -0600
+++ qemu/block.c 2007-12-04 16:19:08.000000000 -0600
@@ -738,6 +738,122 @@
memset(bs->boot_sector_data + size, 0, 512 - size);
}
+struct partition {
+ uint8_t boot_ind; /* 0x80 - active */
+ uint8_t head; /* starting head */
+ uint8_t sector; /* starting sector */
+ uint8_t cyl; /* starting cylinder */
+ uint8_t sys_ind; /* What partition type */
+ uint8_t end_head; /* end head */
+ uint8_t end_sector; /* end sector */
+ uint8_t end_cyl; /* end cylinder */
+ uint32_t start_sect; /* starting sector counting from 0 */
+ uint32_t nr_sects; /* nr of sectors in partition */
+} __attribute__((packed));
+
+/* try to guess the disk logical geometry from the MSDOS partition table. Return 0 if OK, -1 if could not guess */
+static int guess_disk_lchs(BlockDriverState *bs,
+ int *pcylinders, int *pheads, int *psectors)
+{
+ uint8_t buf[512];
+ int ret, i, heads, sectors, cylinders;
+ struct partition *p;
+ uint32_t nr_sects;
+ int64_t nb_sectors;
+
+ bdrv_get_geometry(bs, &nb_sectors);
+
+ ret = bdrv_read(bs, 0, buf, 1);
+ if (ret < 0)
+ return -1;
+ /* test msdos magic */
+ if (buf[510] != 0x55 || buf[511] != 0xaa)
+ return -1;
+ for(i = 0; i < 4; i++) {
+ p = ((struct partition *)(buf + 0x1be)) + i;
+ nr_sects = le32_to_cpu(p->nr_sects);
+ if (nr_sects && p->end_head) {
+ /* We make the assumption that the partition terminates on
+ a cylinder boundary */
+ heads = p->end_head + 1;
+ sectors = p->end_sector & 63;
+ if (sectors == 0)
+ continue;
+ cylinders = nb_sectors / (heads * sectors);
+ if (cylinders < 1 || cylinders > 16383)
+ continue;
+ *pheads = heads;
+ *psectors = sectors;
+ *pcylinders = cylinders;
+#if 0
+ printf("guessed geometry: LCHS=%d %d %d\n",
+ cylinders, heads, sectors);
+#endif
+ return 0;
+ }
+ }
+ return -1;
+}
+
+void bdrv_guess_geometry(BlockDriverState *bs, int *pcyls, int *pheads, int *psecs)
+{
+ int translation, lba_detected = 0;
+ int cylinders, heads, secs;
+ int64_t nb_sectors;
+
+ /* if a geometry hint is available, use it */
+ bdrv_get_geometry(bs, &nb_sectors);
+ bdrv_get_geometry_hint(bs, &cylinders, &heads, &secs);
+ translation = bdrv_get_translation_hint(bs);
+ if (cylinders != 0) {
+ *pcyls = cylinders;
+ *pheads = heads;
+ *psecs = secs;
+ } else {
+ if (guess_disk_lchs(bs, &cylinders, &heads, &secs) == 0) {
+ if (heads > 16) {
+ /* if heads > 16, it means that a BIOS LBA
+ translation was active, so the default
+ hardware geometry is OK */
+ lba_detected = 1;
+ goto default_geometry;
+ } else {
+ *pcyls = cylinders;
+ *pheads = heads;
+ *psecs = secs;
+ /* disable any translation to be in sync with
+ the logical geometry */
+ if (translation == BIOS_ATA_TRANSLATION_AUTO) {
+ bdrv_set_translation_hint(bs,
+ BIOS_ATA_TRANSLATION_NONE);
+ }
+ }
+ } else {
+ default_geometry:
+ /* if no geometry, use a standard physical disk geometry */
+ cylinders = nb_sectors / (16 * 63);
+
+ if (cylinders > 16383)
+ cylinders = 16383;
+ else if (cylinders < 2)
+ cylinders = 2;
+ *pcyls = cylinders;
+ *pheads = 16;
+ *psecs = 63;
+ if ((lba_detected == 1) && (translation == BIOS_ATA_TRANSLATION_AUTO)) {
+ if ((*pcyls * *pheads) <= 131072) {
+ bdrv_set_translation_hint(bs,
+ BIOS_ATA_TRANSLATION_LARGE);
+ } else {
+ bdrv_set_translation_hint(bs,
+ BIOS_ATA_TRANSLATION_LBA);
+ }
+ }
+ }
+ bdrv_set_geometry_hint(bs, *pcyls, *pheads, *psecs);
+ }
+}
+
void bdrv_set_geometry_hint(BlockDriverState *bs,
int cyls, int heads, int secs)
{
Index: qemu/block.h
===================================================================
--- qemu.orig/block.h 2007-12-04 16:18:46.000000000 -0600
+++ qemu/block.h 2007-12-04 16:19:08.000000000 -0600
@@ -73,6 +73,7 @@
int bdrv_truncate(BlockDriverState *bs, int64_t offset);
int64_t bdrv_getlength(BlockDriverState *bs);
void bdrv_get_geometry(BlockDriverState *bs, int64_t *nb_sectors_ptr);
+void bdrv_guess_geometry(BlockDriverState *bs, int *pcyls, int *pheads, int *psecs);
int bdrv_commit(BlockDriverState *bs);
void bdrv_set_boot_sector(BlockDriverState *bs, const uint8_t *data, int size);
/* async block I/O */
Index: qemu/hw/ide.c
===================================================================
--- qemu.orig/hw/ide.c 2007-12-04 16:18:46.000000000 -0600
+++ qemu/hw/ide.c 2007-12-04 16:19:08.000000000 -0600
@@ -2355,67 +2355,13 @@
s->media_changed = 0;
}
-struct partition {
- uint8_t boot_ind; /* 0x80 - active */
- uint8_t head; /* starting head */
- uint8_t sector; /* starting sector */
- uint8_t cyl; /* starting cylinder */
- uint8_t sys_ind; /* What partition type */
- uint8_t end_head; /* end head */
- uint8_t end_sector; /* end sector */
- uint8_t end_cyl; /* end cylinder */
- uint32_t start_sect; /* starting sector counting from 0 */
- uint32_t nr_sects; /* nr of sectors in partition */
-} __attribute__((packed));
-
-/* try to guess the disk logical geometry from the MSDOS partition table. Return 0 if OK, -1 if could not guess */
-static int guess_disk_lchs(IDEState *s,
- int *pcylinders, int *pheads, int *psectors)
-{
- uint8_t buf[512];
- int ret, i, heads, sectors, cylinders;
- struct partition *p;
- uint32_t nr_sects;
-
- ret = bdrv_read(s->bs, 0, buf, 1);
- if (ret < 0)
- return -1;
- /* test msdos magic */
- if (buf[510] != 0x55 || buf[511] != 0xaa)
- return -1;
- for(i = 0; i < 4; i++) {
- p = ((struct partition *)(buf + 0x1be)) + i;
- nr_sects = le32_to_cpu(p->nr_sects);
- if (nr_sects && p->end_head) {
- /* We make the assumption that the partition terminates on
- a cylinder boundary */
- heads = p->end_head + 1;
- sectors = p->end_sector & 63;
- if (sectors == 0)
- continue;
- cylinders = s->nb_sectors / (heads * sectors);
- if (cylinders < 1 || cylinders > 16383)
- continue;
- *pheads = heads;
- *psectors = sectors;
- *pcylinders = cylinders;
-#if 0
- printf("guessed geometry: LCHS=%d %d %d\n",
- cylinders, heads, sectors);
-#endif
- return 0;
- }
- }
- return -1;
-}
-
static void ide_init2(IDEState *ide_state,
BlockDriverState *hd0, BlockDriverState *hd1,
qemu_irq irq)
{
IDEState *s;
static int drive_serial = 1;
- int i, cylinders, heads, secs, translation, lba_detected = 0;
+ int i, cylinders, heads, secs;
int64_t nb_sectors;
for(i = 0; i < 2; i++) {
@@ -2426,56 +2372,12 @@
s->bs = hd1;
if (s->bs) {
bdrv_get_geometry(s->bs, &nb_sectors);
+ bdrv_guess_geometry(s->bs, &cylinders, &heads, &secs);
+ s->cylinders = cylinders;
+ s->heads = heads;
+ s->sectors = secs;
s->nb_sectors = nb_sectors;
- /* if a geometry hint is available, use it */
- bdrv_get_geometry_hint(s->bs, &cylinders, &heads, &secs);
- translation = bdrv_get_translation_hint(s->bs);
- if (cylinders != 0) {
- s->cylinders = cylinders;
- s->heads = heads;
- s->sectors = secs;
- } else {
- if (guess_disk_lchs(s, &cylinders, &heads, &secs) == 0) {
- if (heads > 16) {
- /* if heads > 16, it means that a BIOS LBA
- translation was active, so the default
- hardware geometry is OK */
- lba_detected = 1;
- goto default_geometry;
- } else {
- s->cylinders = cylinders;
- s->heads = heads;
- s->sectors = secs;
- /* disable any translation to be in sync with
- the logical geometry */
- if (translation == BIOS_ATA_TRANSLATION_AUTO) {
- bdrv_set_translation_hint(s->bs,
- BIOS_ATA_TRANSLATION_NONE);
- }
- }
- } else {
- default_geometry:
- /* if no geometry, use a standard physical disk geometry */
- cylinders = nb_sectors / (16 * 63);
- if (cylinders > 16383)
- cylinders = 16383;
- else if (cylinders < 2)
- cylinders = 2;
- s->cylinders = cylinders;
- s->heads = 16;
- s->sectors = 63;
- if ((lba_detected == 1) && (translation == BIOS_ATA_TRANSLATION_AUTO)) {
- if ((s->cylinders * s->heads) <= 131072) {
- bdrv_set_translation_hint(s->bs,
- BIOS_ATA_TRANSLATION_LARGE);
- } else {
- bdrv_set_translation_hint(s->bs,
- BIOS_ATA_TRANSLATION_LBA);
- }
- }
- }
- bdrv_set_geometry_hint(s->bs, s->cylinders, s->heads, s->sectors);
- }
+
if (bdrv_get_type_hint(s->bs) == BDRV_TYPE_CDROM) {
s->is_cdrom = 1;
bdrv_set_change_cb(s->bs, cdrom_change_cb, s);
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2007-12-05 16:24 [Qemu-devel] [PATCH 1/2] Refactor CHS guessing to be usable outside of IDE Anthony Liguori
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