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From 780fbdf04884188eca3d5891faa2b2417a88ef14 Mon Sep 17 00:00:00 2001
From: Maxim Levitsky <mlevitsk@redhat.com>
Date: Tue, 24 Sep 2019 21:11:51 +0100
Subject: [PATCH 3/4] block/qcow2: refactor encryption code
RH-Author: Maxim Levitsky <mlevitsk@redhat.com>
Message-id: <20190924211152.13461-4-mlevitsk@redhat.com>
Patchwork-id: 90876
O-Subject: [RHEL-AV-8.1.0 qemu-kvm PATCH v2 3/4] block/qcow2: refactor encryption code
Bugzilla: 1745922
RH-Acked-by: John Snow <jsnow@redhat.com>
RH-Acked-by: Max Reitz <mreitz@redhat.com>
RH-Acked-by: Danilo de Paula <ddepaula@redhat.com>
* Change the qcow2_co_{encrypt|decrypt} to just receive full host and
guest offsets and use this function directly instead of calling
do_perform_cow_encrypt (which is removed by that patch).
* Adjust qcow2_co_encdec to take full host and guest offsets as well.
* Document the qcow2_co_{encrypt|decrypt} arguments
to prevent the bug fixed in former commit from hopefully
happening again.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-id: 20190915203655.21638-3-mlevitsk@redhat.com
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
[mreitz: Let perform_cow() return the error value returned by
qcow2_co_encrypt(), as proposed by Vladimir]
Signed-off-by: Max Reitz <mreitz@redhat.com>
(cherry picked from commit 603fbd076c76438b15ec842f0e2d1ba4867dfd00)
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>
---
block/qcow2-cluster.c | 41 +++++++++++----------------------
block/qcow2-threads.c | 63 +++++++++++++++++++++++++++++++++++++++------------
block/qcow2.c | 5 ++--
block/qcow2.h | 8 +++----
4 files changed, 69 insertions(+), 48 deletions(-)
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index 11e5a92..b30fd12 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -461,28 +461,6 @@ static int coroutine_fn do_perform_cow_read(BlockDriverState *bs,
return 0;
}
-static bool coroutine_fn do_perform_cow_encrypt(BlockDriverState *bs,
- uint64_t src_cluster_offset,
- uint64_t cluster_offset,
- unsigned offset_in_cluster,
- uint8_t *buffer,
- unsigned bytes)
-{
- if (bytes && bs->encrypted) {
- BDRVQcow2State *s = bs->opaque;
- assert(QEMU_IS_ALIGNED(offset_in_cluster, BDRV_SECTOR_SIZE));
- assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE));
- assert(s->crypto);
- if (qcow2_co_encrypt(bs,
- start_of_cluster(s, cluster_offset + offset_in_cluster),
- src_cluster_offset + offset_in_cluster,
- buffer, bytes) < 0) {
- return false;
- }
- }
- return true;
-}
-
static int coroutine_fn do_perform_cow_write(BlockDriverState *bs,
uint64_t cluster_offset,
unsigned offset_in_cluster,
@@ -887,12 +865,19 @@ static int perform_cow(BlockDriverState *bs, QCowL2Meta *m)
/* Encrypt the data if necessary before writing it */
if (bs->encrypted) {
- if (!do_perform_cow_encrypt(bs, m->offset, m->alloc_offset,
- start->offset, start_buffer,
- start->nb_bytes) ||
- !do_perform_cow_encrypt(bs, m->offset, m->alloc_offset,
- end->offset, end_buffer, end->nb_bytes)) {
- ret = -EIO;
+ ret = qcow2_co_encrypt(bs,
+ m->alloc_offset + start->offset,
+ m->offset + start->offset,
+ start_buffer, start->nb_bytes);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ ret = qcow2_co_encrypt(bs,
+ m->alloc_offset + end->offset,
+ m->offset + end->offset,
+ end_buffer, end->nb_bytes);
+ if (ret < 0) {
goto fail;
}
}
diff --git a/block/qcow2-threads.c b/block/qcow2-threads.c
index 3b1e63f..8f5a0d1 100644
--- a/block/qcow2-threads.c
+++ b/block/qcow2-threads.c
@@ -234,35 +234,70 @@ static int qcow2_encdec_pool_func(void *opaque)
}
static int coroutine_fn
-qcow2_co_encdec(BlockDriverState *bs, uint64_t file_cluster_offset,
- uint64_t offset, void *buf, size_t len, Qcow2EncDecFunc func)
+qcow2_co_encdec(BlockDriverState *bs, uint64_t host_offset,
+ uint64_t guest_offset, void *buf, size_t len,
+ Qcow2EncDecFunc func)
{
BDRVQcow2State *s = bs->opaque;
Qcow2EncDecData arg = {
.block = s->crypto,
- .offset = s->crypt_physical_offset ?
- file_cluster_offset + offset_into_cluster(s, offset) :
- offset,
+ .offset = s->crypt_physical_offset ? host_offset : guest_offset,
.buf = buf,
.len = len,
.func = func,
};
- return qcow2_co_process(bs, qcow2_encdec_pool_func, &arg);
+ assert(QEMU_IS_ALIGNED(guest_offset, BDRV_SECTOR_SIZE));
+ assert(QEMU_IS_ALIGNED(host_offset, BDRV_SECTOR_SIZE));
+ assert(QEMU_IS_ALIGNED(len, BDRV_SECTOR_SIZE));
+ assert(s->crypto);
+
+ return len == 0 ? 0 : qcow2_co_process(bs, qcow2_encdec_pool_func, &arg);
}
+/*
+ * qcow2_co_encrypt()
+ *
+ * Encrypts one or more contiguous aligned sectors
+ *
+ * @host_offset - underlying storage offset of the first sector of the
+ * data to be encrypted
+ *
+ * @guest_offset - guest (virtual) offset of the first sector of the
+ * data to be encrypted
+ *
+ * @buf - buffer with the data to encrypt, that after encryption
+ * will be written to the underlying storage device at
+ * @host_offset
+ *
+ * @len - length of the buffer (must be a BDRV_SECTOR_SIZE multiple)
+ *
+ * Depending on the encryption method, @host_offset and/or @guest_offset
+ * may be used for generating the initialization vector for
+ * encryption.
+ *
+ * Note that while the whole range must be aligned on sectors, it
+ * does not have to be aligned on clusters and can also cross cluster
+ * boundaries
+ */
int coroutine_fn
-qcow2_co_encrypt(BlockDriverState *bs, uint64_t file_cluster_offset,
- uint64_t offset, void *buf, size_t len)
+qcow2_co_encrypt(BlockDriverState *bs, uint64_t host_offset,
+ uint64_t guest_offset, void *buf, size_t len)
{
- return qcow2_co_encdec(bs, file_cluster_offset, offset, buf, len,
- qcrypto_block_encrypt);
+ return qcow2_co_encdec(bs, host_offset, guest_offset, buf, len,
+ qcrypto_block_encrypt);
}
+/*
+ * qcow2_co_decrypt()
+ *
+ * Decrypts one or more contiguous aligned sectors
+ * Similar to qcow2_co_encrypt
+ */
int coroutine_fn
-qcow2_co_decrypt(BlockDriverState *bs, uint64_t file_cluster_offset,
- uint64_t offset, void *buf, size_t len)
+qcow2_co_decrypt(BlockDriverState *bs, uint64_t host_offset,
+ uint64_t guest_offset, void *buf, size_t len)
{
- return qcow2_co_encdec(bs, file_cluster_offset, offset, buf, len,
- qcrypto_block_decrypt);
+ return qcow2_co_encdec(bs, host_offset, guest_offset, buf, len,
+ qcrypto_block_decrypt);
}
diff --git a/block/qcow2.c b/block/qcow2.c
index dc4302f..d4c4f24 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -2073,7 +2073,8 @@ static coroutine_fn int qcow2_co_preadv(BlockDriverState *bs, uint64_t offset,
assert(s->crypto);
assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE));
assert(QEMU_IS_ALIGNED(cur_bytes, BDRV_SECTOR_SIZE));
- if (qcow2_co_decrypt(bs, cluster_offset, offset,
+ if (qcow2_co_decrypt(bs, cluster_offset + offset_in_cluster,
+ offset,
cluster_data, cur_bytes) < 0) {
ret = -EIO;
goto fail;
@@ -2288,7 +2289,7 @@ static coroutine_fn int qcow2_co_pwritev(BlockDriverState *bs, uint64_t offset,
QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size);
qemu_iovec_to_buf(&hd_qiov, 0, cluster_data, hd_qiov.size);
- if (qcow2_co_encrypt(bs, cluster_offset, offset,
+ if (qcow2_co_encrypt(bs, cluster_offset + offset_in_cluster, offset,
cluster_data, cur_bytes) < 0) {
ret = -EIO;
goto out_unlocked;
diff --git a/block/qcow2.h b/block/qcow2.h
index fc1b0d3..b54e734 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -757,10 +757,10 @@ ssize_t coroutine_fn
qcow2_co_decompress(BlockDriverState *bs, void *dest, size_t dest_size,
const void *src, size_t src_size);
int coroutine_fn
-qcow2_co_encrypt(BlockDriverState *bs, uint64_t file_cluster_offset,
- uint64_t offset, void *buf, size_t len);
+qcow2_co_encrypt(BlockDriverState *bs, uint64_t host_offset,
+ uint64_t guest_offset, void *buf, size_t len);
int coroutine_fn
-qcow2_co_decrypt(BlockDriverState *bs, uint64_t file_cluster_offset,
- uint64_t offset, void *buf, size_t len);
+qcow2_co_decrypt(BlockDriverState *bs, uint64_t host_offset,
+ uint64_t guest_offset, void *buf, size_t len);
#endif
--
1.8.3.1
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