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authorKevin Wolf <kwolf@redhat.com>2018-03-13 15:37:40 +0100
committerKevin Wolf <kwolf@redhat.com>2018-03-19 12:01:39 +0100
commit1cfeaf386e3727df0e057710d61593ca515dd07b (patch)
treef8ee76dbbcbfbde56fa50f27bc9fd0d8c7e2e0b5
parent182c8835506eabd8ead4ea140c9d6ef94351afd0 (diff)
vpc: Require aligned size in .bdrv_co_create
Perform the rounding to match a CHS geometry only in the legacy code path in .bdrv_co_create_opts. QMP now requires that the user already passes a CHS aligned image size, unless force-size=true is given. CHS alignment is required to make the image compatible with Virtual PC, but not for use with newer Microsoft hypervisors. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
-rw-r--r--block/vpc.c113
1 files changed, 82 insertions, 31 deletions
diff --git a/block/vpc.c b/block/vpc.c
index 8824211713..28ffa0d2f8 100644
--- a/block/vpc.c
+++ b/block/vpc.c
@@ -902,6 +902,62 @@ static int create_fixed_disk(BlockBackend *blk, uint8_t *buf,
return ret;
}
+static int calculate_rounded_image_size(BlockdevCreateOptionsVpc *vpc_opts,
+ uint16_t *out_cyls,
+ uint8_t *out_heads,
+ uint8_t *out_secs_per_cyl,
+ int64_t *out_total_sectors,
+ Error **errp)
+{
+ int64_t total_size = vpc_opts->size;
+ uint16_t cyls = 0;
+ uint8_t heads = 0;
+ uint8_t secs_per_cyl = 0;
+ int64_t total_sectors;
+ int i;
+
+ /*
+ * Calculate matching total_size and geometry. Increase the number of
+ * sectors requested until we get enough (or fail). This ensures that
+ * qemu-img convert doesn't truncate images, but rather rounds up.
+ *
+ * If the image size can't be represented by a spec conformant CHS geometry,
+ * we set the geometry to 65535 x 16 x 255 (CxHxS) sectors and use
+ * the image size from the VHD footer to calculate total_sectors.
+ */
+ if (vpc_opts->force_size) {
+ /* This will force the use of total_size for sector count, below */
+ cyls = VHD_CHS_MAX_C;
+ heads = VHD_CHS_MAX_H;
+ secs_per_cyl = VHD_CHS_MAX_S;
+ } else {
+ total_sectors = MIN(VHD_MAX_GEOMETRY, total_size / BDRV_SECTOR_SIZE);
+ for (i = 0; total_sectors > (int64_t)cyls * heads * secs_per_cyl; i++) {
+ calculate_geometry(total_sectors + i, &cyls, &heads, &secs_per_cyl);
+ }
+ }
+
+ if ((int64_t)cyls * heads * secs_per_cyl == VHD_MAX_GEOMETRY) {
+ total_sectors = total_size / BDRV_SECTOR_SIZE;
+ /* Allow a maximum disk size of 2040 GiB */
+ if (total_sectors > VHD_MAX_SECTORS) {
+ error_setg(errp, "Disk size is too large, max size is 2040 GiB");
+ return -EFBIG;
+ }
+ } else {
+ total_sectors = (int64_t) cyls * heads * secs_per_cyl;
+ }
+
+ *out_total_sectors = total_sectors;
+ if (out_cyls) {
+ *out_cyls = cyls;
+ *out_heads = heads;
+ *out_secs_per_cyl = secs_per_cyl;
+ }
+
+ return 0;
+}
+
static int coroutine_fn vpc_co_create(BlockdevCreateOptions *opts,
Error **errp)
{
@@ -911,7 +967,6 @@ static int coroutine_fn vpc_co_create(BlockdevCreateOptions *opts,
uint8_t buf[1024];
VHDFooter *footer = (VHDFooter *) buf;
- int i;
uint16_t cyls = 0;
uint8_t heads = 0;
uint8_t secs_per_cyl = 0;
@@ -953,38 +1008,22 @@ static int coroutine_fn vpc_co_create(BlockdevCreateOptions *opts,
}
blk_set_allow_write_beyond_eof(blk, true);
- /*
- * Calculate matching total_size and geometry. Increase the number of
- * sectors requested until we get enough (or fail). This ensures that
- * qemu-img convert doesn't truncate images, but rather rounds up.
- *
- * If the image size can't be represented by a spec conformant CHS geometry,
- * we set the geometry to 65535 x 16 x 255 (CxHxS) sectors and use
- * the image size from the VHD footer to calculate total_sectors.
- */
- if (vpc_opts->force_size) {
- /* This will force the use of total_size for sector count, below */
- cyls = VHD_CHS_MAX_C;
- heads = VHD_CHS_MAX_H;
- secs_per_cyl = VHD_CHS_MAX_S;
- } else {
- total_sectors = MIN(VHD_MAX_GEOMETRY, total_size / BDRV_SECTOR_SIZE);
- for (i = 0; total_sectors > (int64_t)cyls * heads * secs_per_cyl; i++) {
- calculate_geometry(total_sectors + i, &cyls, &heads, &secs_per_cyl);
- }
+ /* Get geometry and check that it matches the image size*/
+ ret = calculate_rounded_image_size(vpc_opts, &cyls, &heads, &secs_per_cyl,
+ &total_sectors, errp);
+ if (ret < 0) {
+ goto out;
}
- if ((int64_t)cyls * heads * secs_per_cyl == VHD_MAX_GEOMETRY) {
- total_sectors = total_size / BDRV_SECTOR_SIZE;
- /* Allow a maximum disk size of 2040 GiB */
- if (total_sectors > VHD_MAX_SECTORS) {
- error_setg(errp, "Disk size is too large, max size is 2040 GiB");
- ret = -EFBIG;
- goto out;
- }
- } else {
- total_sectors = (int64_t)cyls * heads * secs_per_cyl;
- total_size = total_sectors * BDRV_SECTOR_SIZE;
+ if (total_size != total_sectors * BDRV_SECTOR_SIZE) {
+ error_setg(errp, "The requested image size cannot be represented in "
+ "CHS geometry");
+ error_append_hint(errp, "Try size=%llu or force-size=on (the "
+ "latter makes the image incompatible with "
+ "Virtual PC)",
+ total_sectors * BDRV_SECTOR_SIZE);
+ ret = -EINVAL;
+ goto out;
}
/* Prepare the Hard Disk Footer */
@@ -1102,6 +1141,18 @@ static int coroutine_fn vpc_co_create_opts(const char *filename,
create_options->u.vpc.size =
ROUND_UP(create_options->u.vpc.size, BDRV_SECTOR_SIZE);
+ if (!create_options->u.vpc.force_size) {
+ int64_t total_sectors;
+ ret = calculate_rounded_image_size(&create_options->u.vpc, NULL, NULL,
+ NULL, &total_sectors, errp);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ create_options->u.vpc.size = total_sectors * BDRV_SECTOR_SIZE;
+ }
+
+
/* Create the vpc image (format layer) */
ret = vpc_co_create(create_options, errp);