virtio_blk: set the zone write granularitygrafted

virtblk_read_zoned_limits() reads the write granularity that the device
reports in virtio_blk_zoned_characteristics and assigns it to the
physical block size and to io_min, but never to the limit that is named
after it. queue_limits.zone_write_granularity is left at zero, so
blk_validate_zoned_limits() raises it to the logical block size:

	if (lim->zone_write_granularity < lim->logical_block_size)
		lim->zone_write_granularity = lim->logical_block_size;

A device that reports a granularity coarser than its logical block size,
which is what the field exists to express, therefore has it silently
reduced. A 512e host managed disk passed through to a guest reports a
logical block size of 512 and a write granularity of 4096, and the guest
ends up with a zone write granularity of 512.

bio_split_alignment() returns lim->zone_write_granularity if it is non-zero
and bio_split_io_at() may split a bio with as per bio_split_alignment().
This can real to the write getting rejected by the host drive, as the write
is not aligned to the physical block size.

zonefs also takes its block size from bdev_zone_write_granularity(), so it
would incorrectly use 512 on a disk that requires 4096.

sd_zbc_read_zones() sets the limit from the physical block size for the
same reason. NVMe ZNS and null_blk leave it unset, but the fallback
gives the right answer for them, as their write granularity is the
logical block size. virtio carries a separate value that may exceed it.

Set the zone write granularity from the value that the device reports.

Fixes: 95bfec41bd3d ("virtio-blk: add support for zoned block devices")
Signed-off-by: Niklas Cassel <cassel@kernel.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Link: https://patch.msgid.link/20260918140641.2031075-2-cassel@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 56 insertions, 0 deletions

diff --git a/include/crypto/internal/poly1305.h b/include/crypto/internal/poly1305.h
new file mode 100644
index 000000000..a72fff409
--- /dev/null
+++ b/include/crypto/internal/poly1305.h
@@ -0,0 +1,56 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Common values for the Poly1305 algorithm
+ */
+
+#ifndef _CRYPTO_INTERNAL_POLY1305_H
+#define _CRYPTO_INTERNAL_POLY1305_H
+
+#include <crypto/poly1305.h>
+#include <linux/types.h>
+
+/*
+ * Poly1305 core functions.  These only accept whole blocks; the caller must
+ * handle any needed block buffering and padding.  'hibit' must be 1 for any
+ * full blocks, or 0 for the final block if it had to be padded.  If 'nonce' is
+ * non-NULL, then it's added at the end to compute the Poly1305 MAC.  Otherwise,
+ * only the ε-almost-∆-universal hash function (not the full MAC) is computed.
+ */
+
+void poly1305_core_setkey(struct poly1305_core_key *key,
+			  const u8 raw_key[POLY1305_BLOCK_SIZE]);
+static inline void poly1305_core_init(struct poly1305_state *state)
+{
+	*state = (struct poly1305_state){};
+}
+
+void poly1305_core_blocks(struct poly1305_state *state,
+			  const struct poly1305_core_key *key, const void *src,
+			  unsigned int nblocks, u32 hibit);
+void poly1305_core_emit(const struct poly1305_state *state, const u32 nonce[4],
+			void *dst);
+
+static inline void
+poly1305_block_init_generic(struct poly1305_block_state *desc,
+			    const u8 raw_key[POLY1305_BLOCK_SIZE])
+{
+	poly1305_core_init(&desc->h);
+	poly1305_core_setkey(&desc->core_r, raw_key);
+}
+
+static inline void poly1305_blocks_generic(struct poly1305_block_state *state,
+					   const u8 *src, unsigned int len,
+					   u32 padbit)
+{
+	poly1305_core_blocks(&state->h, &state->core_r, src,
+			     len / POLY1305_BLOCK_SIZE, padbit);
+}
+
+static inline void poly1305_emit_generic(const struct poly1305_state *state,
+					 u8 digest[POLY1305_DIGEST_SIZE],
+					 const u32 nonce[4])
+{
+	poly1305_core_emit(state, nonce, digest);
+}
+
+#endif