Make it easier to simulate the Dell Equallogic iSCSI with its
unusual 15M preferred and maximum unmap and write zero sizing,
or to simulate Linux loopback block devices enforcing a small
max_transfer of 64k, by allowing blkdebug to wrap any other
device with further restrictions on various alignments.
Signed-off-by: Eric Blake <ebl...@redhat.com>
---
qapi/block-core.json | 27 ++++++++++++++-
block/blkdebug.c | 97 ++++++++++++++++++++++++++++++++++++++++++++++++++--
2 files changed, 121 insertions(+), 3 deletions(-)
diff --git a/qapi/block-core.json b/qapi/block-core.json
index c29bef7..26f3e9f 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -2068,6 +2068,29 @@
# @align: #optional required alignment for requests in bytes,
# must be power of 2, or 0 for default
#
+# @max-transfer: #optional maximum size for I/O transfers in bytes,
+# must be multiple of the larger of @align and and 512
+# (but need not be a power of 2), or 0 for default
+# (since 2.9)
+#
+# @opt-write-zero: #optional preferred alignment for write zero requests
+# in bytes, must be multiple of the larger of @align
+# and 512 (but need not be a power of 2), or 0 for
+# default (since 2.9)
+#
+# @max-write-zero: #optional maximum size for write zero requests in bytes,
+# must be multiple of the larger of @align and 512 (but
+# need not be a power of 2), or 0 for default (since 2.9)
+#
+# @opt-discard: #optional preferred alignment for discard requests
+# in bytes, must be multiple of the larger of @align
+# and 512 (but need not be a power of 2), or 0 for
+# default (since 2.9)
+#
+# @max-discard: #optional maximum size for discard requests in bytes,
+# must be multiple of the larger of @align and 512 (but
+# need not be a power of 2), or 0 for default (since 2.9)
+#
# @inject-error: #optional array of error injection descriptions
#
# @set-state: #optional array of state-change descriptions
@@ -2077,7 +2100,9 @@
{ 'struct': 'BlockdevOptionsBlkdebug',
'data': { 'image': 'BlockdevRef',
'*config': 'str',
- '*align': 'int',
+ '*align': 'int', '*max-transfer': 'int32',
+ '*opt-write-zero': 'int32', '*max-write-zero': 'int32',
+ '*opt-discard': 'int32', '*max-discard': 'int32',
'*inject-error': ['BlkdebugInjectErrorOptions'],
'*set-state': ['BlkdebugSetStateOptions'] } }
diff --git a/block/blkdebug.c b/block/blkdebug.c
index d45826d..3ba7a96 100644
--- a/block/blkdebug.c
+++ b/block/blkdebug.c
@@ -39,6 +39,11 @@ typedef struct BDRVBlkdebugState {
int state;
int new_state;
int align;
+ int max_transfer;
+ int opt_write_zero;
+ int max_write_zero;
+ int opt_discard;
+ int max_discard;
/* For blkdebug_refresh_filename() */
char *config_file;
@@ -344,6 +349,31 @@ static QemuOptsList runtime_opts = {
.type = QEMU_OPT_SIZE,
.help = "Required alignment in bytes",
},
+ {
+ .name = "max-transfer",
+ .type = QEMU_OPT_SIZE,
+ .help = "Maximum transfer size in bytes",
+ },
+ {
+ .name = "opt-write-zero",
+ .type = QEMU_OPT_SIZE,
+ .help = "Optimum write zero size in bytes",
+ },
+ {
+ .name = "max-write-zero",
+ .type = QEMU_OPT_SIZE,
+ .help = "Maximum write zero size in bytes",
+ },
+ {
+ .name = "opt-discard",
+ .type = QEMU_OPT_SIZE,
+ .help = "Optimum discard size in bytes",
+ },
+ {
+ .name = "max-discard",
+ .type = QEMU_OPT_SIZE,
+ .help = "Maximum discard size in bytes",
+ },
{ /* end of list */ }
},
};
@@ -354,7 +384,8 @@ static int blkdebug_open(BlockDriverState *bs, QDict
*options, int flags,
BDRVBlkdebugState *s = bs->opaque;
QemuOpts *opts;
Error *local_err = NULL;
- uint64_t align;
+ uint64_t align, max_transfer;
+ uint64_t opt_write_zero, max_write_zero, opt_discard, max_discard;
int ret;
opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
@@ -389,7 +420,7 @@ static int blkdebug_open(BlockDriverState *bs, QDict
*options, int flags,
bs->supported_zero_flags = (BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP) &
bs->file->bs->supported_zero_flags;
- /* Set request alignment */
+ /* Set alignment overrides */
align = qemu_opt_get_size(opts, "align", 0);
if (align < INT_MAX && is_power_of_2(align)) {
s->align = align;
@@ -398,6 +429,53 @@ static int blkdebug_open(BlockDriverState *bs, QDict
*options, int flags,
ret = -EINVAL;
goto fail_unref;
}
+ max_transfer = qemu_opt_get_size(opts, "max-transfer", 0);
+ if (max_transfer < INT_MAX &&
+ QEMU_IS_ALIGNED(max_transfer, MAX(align, BDRV_SECTOR_SIZE))) {
+ s->max_transfer = max_transfer;
+ } else if (max_transfer) {
+ error_setg(errp, "Invalid argument");
+ ret = -EINVAL;
+ goto fail_unref;
+ }
+ opt_write_zero = qemu_opt_get_size(opts, "opt-write-zero", 0);
+ if (opt_write_zero < INT_MAX &&
+ QEMU_IS_ALIGNED(opt_write_zero, MAX(align, BDRV_SECTOR_SIZE))) {
+ s->opt_write_zero = opt_write_zero;
+ } else if (opt_write_zero) {
+ error_setg(errp, "Invalid argument");
+ ret = -EINVAL;
+ goto fail_unref;
+ }
+ max_write_zero = qemu_opt_get_size(opts, "max-write-zero", 0);
+ if (max_write_zero < INT_MAX &&
+ QEMU_IS_ALIGNED(max_write_zero, MAX(opt_write_zero,
+ MAX(align, BDRV_SECTOR_SIZE)))) {
+ s->max_write_zero = max_write_zero;
+ } else if (max_write_zero) {
+ error_setg(errp, "Invalid argument");
+ ret = -EINVAL;
+ goto fail_unref;
+ }
+ opt_discard = qemu_opt_get_size(opts, "opt-discard", 0);
+ if (opt_discard < INT_MAX &&
+ QEMU_IS_ALIGNED(opt_discard, MAX(align, BDRV_SECTOR_SIZE))) {
+ s->opt_discard = opt_discard;
+ } else if (opt_discard) {
+ error_setg(errp, "Invalid argument");
+ ret = -EINVAL;
+ goto fail_unref;
+ }
+ max_discard = qemu_opt_get_size(opts, "max-discard", 0);
+ if (max_discard < INT_MAX &&
+ QEMU_IS_ALIGNED(max_discard, MAX(opt_discard,
+ MAX(align, BDRV_SECTOR_SIZE)))) {
+ s->max_discard = max_discard;
+ } else if (max_discard) {
+ error_setg(errp, "Invalid argument");
+ ret = -EINVAL;
+ goto fail_unref;
+ }
ret = 0;
goto out;
@@ -807,6 +885,21 @@ static void blkdebug_refresh_limits(BlockDriverState *bs,
Error **errp)
if (s->align) {
bs->bl.request_alignment = s->align;
}
+ if (s->max_transfer) {
+ bs->bl.max_transfer = s->max_transfer;
+ }
+ if (s->opt_write_zero) {
+ bs->bl.pwrite_zeroes_alignment = s->opt_write_zero;
+ }
+ if (s->max_write_zero) {
+ bs->bl.max_pwrite_zeroes = s->max_write_zero;
+ }
+ if (s->opt_discard) {
+ bs->bl.pdiscard_alignment = s->opt_discard;
+ }
+ if (s->max_discard) {
+ bs->bl.max_pdiscard = s->max_discard;
+ }
}
static int blkdebug_reopen_prepare(BDRVReopenState *reopen_state,
--
2.7.4
