This commit tries to clarify few function arguments, and add comments describing the encrypt/decrypt interface
Signed-off-by: Maxim Levitsky <mlevi...@redhat.com> --- block/qcow2-cluster.c | 8 +++--- block/qcow2-threads.c | 63 ++++++++++++++++++++++++++++++++++--------- 2 files changed, 54 insertions(+), 17 deletions(-) diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index f09cc992af..b95e64c237 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -463,8 +463,8 @@ static int coroutine_fn do_perform_cow_read(BlockDriverState *bs, } static bool coroutine_fn do_perform_cow_encrypt(BlockDriverState *bs, - uint64_t src_cluster_offset, - uint64_t cluster_offset, + uint64_t guest_cluster_offset, + uint64_t host_cluster_offset, unsigned offset_in_cluster, uint8_t *buffer, unsigned bytes) @@ -474,8 +474,8 @@ static bool coroutine_fn do_perform_cow_encrypt(BlockDriverState *bs, assert((offset_in_cluster & ~BDRV_SECTOR_MASK) == 0); assert((bytes & ~BDRV_SECTOR_MASK) == 0); assert(s->crypto); - if (qcow2_co_encrypt(bs, cluster_offset, - src_cluster_offset + offset_in_cluster, + if (qcow2_co_encrypt(bs, host_cluster_offset, + guest_cluster_offset + offset_in_cluster, buffer, bytes) < 0) { return false; } diff --git a/block/qcow2-threads.c b/block/qcow2-threads.c index 3b1e63fe41..6da1838e95 100644 --- a/block/qcow2-threads.c +++ b/block/qcow2-threads.c @@ -234,15 +234,19 @@ 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_cluster_offset, + uint64_t guest_offset, void *buf, size_t len, + Qcow2EncDecFunc func) { BDRVQcow2State *s = bs->opaque; + + uint64_t offset = s->crypt_physical_offset ? + host_cluster_offset + offset_into_cluster(s, guest_offset) : + guest_offset; + Qcow2EncDecData arg = { .block = s->crypto, - .offset = s->crypt_physical_offset ? - file_cluster_offset + offset_into_cluster(s, offset) : - offset, + .offset = offset, .buf = buf, .len = len, .func = func, @@ -251,18 +255,51 @@ qcow2_co_encdec(BlockDriverState *bs, uint64_t file_cluster_offset, return qcow2_co_process(bs, qcow2_encdec_pool_func, &arg); } + +/* + * qcow2_co_encrypt() + * + * Encrypts one or more contiguous aligned sectors + * + * @host_cluster_offset - underlying storage offset of the first cluster + * in which the encrypted data will be written + * Used as an initialization vector for encryption + * + * @guest_offset - guest (virtual) offset of the first sector of the + * data to be encrypted + * Used as an initialization vector for older, qcow2 native encryption + * + * @buf - buffer with the data to encrypt, that after encryption + * will be written to the underlying storage device at + * @host_cluster_offset + * + * @len - length of the buffer (in sector size multiplies) + * + * Note that the group of the sectors, don't have to be aligned + * on cluster boundary and can also cross a cluster boundary. + * + */ 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_cluster_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_cluster_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_cluster_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_cluster_offset, guest_offset, buf, len, + qcrypto_block_decrypt); } -- 2.17.2