*/
#include "qemu/osdep.h"
+#include "block/block_int-common.h"
#include "sysemu/blockdev.h"
#include "sysemu/block-backend.h"
#include "hw/block/block.h"
#include "qapi/error.h"
#include "qapi/qapi-types-block.h"
-#include "qemu/error-report.h"
-void blkconf_blocksizes(BlockConf *conf)
+/*
+ * Read the non-zeroes parts of @blk into @buf
+ * Reading all of the @blk is expensive if the zeroes parts of @blk
+ * is large enough. Therefore check the block status and only write
+ * the non-zeroes block into @buf.
+ *
+ * Return 0 on success, non-zero on error.
+ */
+static int blk_pread_nonzeroes(BlockBackend *blk, hwaddr size, void *buf)
+{
+ int ret;
+ int64_t bytes, offset = 0;
+ BlockDriverState *bs = blk_bs(blk);
+
+ for (;;) {
+ bytes = MIN(size - offset, BDRV_REQUEST_MAX_BYTES);
+ if (bytes <= 0) {
+ return 0;
+ }
+ ret = bdrv_block_status(bs, offset, bytes, &bytes, NULL, NULL);
+ if (ret < 0) {
+ return ret;
+ }
+ if (!(ret & BDRV_BLOCK_ZERO)) {
+ ret = blk_pread(blk, offset, bytes, (uint8_t *) buf + offset, 0);
+ if (ret < 0) {
+ return ret;
+ }
+ }
+ offset += bytes;
+ }
+}
+
+/*
+ * Read the entire contents of @blk into @buf.
+ * @blk's contents must be @size bytes, and @size must be at most
+ * BDRV_REQUEST_MAX_BYTES.
+ * On success, return true.
+ * On failure, store an error through @errp and return false.
+ *
+ * This function not intended for actual block devices, which read on
+ * demand. It's for things like memory devices that (ab)use a block
+ * backend to provide persistence.
+ */
+bool blk_check_size_and_read_all(BlockBackend *blk, DeviceState *dev,
+ void *buf, hwaddr size, Error **errp)
+{
+ int64_t blk_len;
+ int ret;
+ g_autofree char *dev_id = NULL;
+
+ blk_len = blk_getlength(blk);
+ if (blk_len < 0) {
+ error_setg_errno(errp, -blk_len,
+ "can't get size of %s block backend", blk_name(blk));
+ return false;
+ }
+ if (blk_len != size) {
+ dev_id = qdev_get_human_name(dev);
+ error_setg(errp, "%s device '%s' requires %" HWADDR_PRIu
+ " bytes, %s block backend provides %" PRIu64 " bytes",
+ object_get_typename(OBJECT(dev)), dev_id, size,
+ blk_name(blk), blk_len);
+ return false;
+ }
+
+ /*
+ * We could loop for @size > BDRV_REQUEST_MAX_BYTES, but if we
+ * ever get to the point we want to read *gigabytes* here, we
+ * should probably rework the device to be more like an actual
+ * block device and read only on demand.
+ */
+ assert(size <= BDRV_REQUEST_MAX_BYTES);
+ ret = blk_pread_nonzeroes(blk, size, buf);
+ if (ret < 0) {
+ dev_id = qdev_get_human_name(dev);
+ error_setg_errno(errp, -ret, "can't read %s block backend"
+ " for %s device '%s'",
+ blk_name(blk), object_get_typename(OBJECT(dev)),
+ dev_id);
+ return false;
+ }
+ return true;
+}
+
+bool blkconf_blocksizes(BlockConf *conf, Error **errp)
{
BlockBackend *blk = conf->blk;
BlockSizes blocksizes;
- int backend_ret;
+ BlockDriverState *bs;
+ bool use_blocksizes;
+ bool use_bs;
+
+ switch (conf->backend_defaults) {
+ case ON_OFF_AUTO_AUTO:
+ use_blocksizes = !blk_probe_blocksizes(blk, &blocksizes);
+ use_bs = false;
+ break;
+
+ case ON_OFF_AUTO_ON:
+ use_blocksizes = !blk_probe_blocksizes(blk, &blocksizes);
+ bs = blk_bs(blk);
+ use_bs = bs;
+ break;
+
+ case ON_OFF_AUTO_OFF:
+ use_blocksizes = false;
+ use_bs = false;
+ break;
+
+ default:
+ abort();
+ }
- backend_ret = blk_probe_blocksizes(blk, &blocksizes);
/* fill in detected values if they are not defined via qemu command line */
if (!conf->physical_block_size) {
- if (!backend_ret) {
+ if (use_blocksizes) {
conf->physical_block_size = blocksizes.phys;
} else {
conf->physical_block_size = BDRV_SECTOR_SIZE;
}
}
if (!conf->logical_block_size) {
- if (!backend_ret) {
+ if (use_blocksizes) {
conf->logical_block_size = blocksizes.log;
} else {
conf->logical_block_size = BDRV_SECTOR_SIZE;
}
}
+ if (use_bs) {
+ if (!conf->opt_io_size) {
+ conf->opt_io_size = bs->bl.opt_transfer;
+ }
+ if (conf->discard_granularity == -1) {
+ if (bs->bl.pdiscard_alignment) {
+ conf->discard_granularity = bs->bl.pdiscard_alignment;
+ } else if (bs->bl.request_alignment != 1) {
+ conf->discard_granularity = bs->bl.request_alignment;
+ }
+ }
+ }
+
+ if (conf->logical_block_size > conf->physical_block_size) {
+ error_setg(errp,
+ "logical_block_size > physical_block_size not supported");
+ return false;
+ }
+
+ if (!QEMU_IS_ALIGNED(conf->min_io_size, conf->logical_block_size)) {
+ error_setg(errp,
+ "min_io_size must be a multiple of logical_block_size");
+ return false;
+ }
+
+ /*
+ * all devices which support min_io_size (scsi and virtio-blk) expose it to
+ * the guest as a uint16_t in units of logical blocks
+ */
+ if (conf->min_io_size / conf->logical_block_size > UINT16_MAX) {
+ error_setg(errp, "min_io_size must not exceed %u logical blocks",
+ UINT16_MAX);
+ return false;
+ }
+
+ if (!QEMU_IS_ALIGNED(conf->opt_io_size, conf->logical_block_size)) {
+ error_setg(errp,
+ "opt_io_size must be a multiple of logical_block_size");
+ return false;
+ }
+
+ if (conf->discard_granularity != -1 &&
+ !QEMU_IS_ALIGNED(conf->discard_granularity,
+ conf->logical_block_size)) {
+ error_setg(errp, "discard_granularity must be "
+ "a multiple of logical_block_size");
+ return false;
+ }
+
+ return true;
}
bool blkconf_apply_backend_options(BlockConf *conf, bool readonly,
perm |= BLK_PERM_WRITE;
}
- shared_perm = BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE_UNCHANGED |
- BLK_PERM_GRAPH_MOD;
+ shared_perm = BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE_UNCHANGED;
if (resizable) {
shared_perm |= BLK_PERM_RESIZE;
}
blk_set_enable_write_cache(blk, wce);
blk_set_on_error(blk, rerror, werror);
+ block_acct_setup(blk_get_stats(blk), conf->account_invalid,
+ conf->account_failed);
return true;
}
projects / mirror_qemu.git / blobdiff