From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37600) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dtxZE-0002oZ-9B for qemu-devel@nongnu.org; Mon, 18 Sep 2017 11:02:44 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dtxZ4-0002R5-N7 for qemu-devel@nongnu.org; Mon, 18 Sep 2017 11:02:36 -0400 Date: Mon, 18 Sep 2017 16:02:13 +0100 From: "Daniel P. Berrange" Message-ID: <20170918150213.GJ2951@redhat.com> Reply-To: "Daniel P. Berrange" References: <20170912112855.24269-1-berrange@redhat.com> <20170912112855.24269-5-berrange@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Subject: Re: [Qemu-devel] [PATCH v3 4/7] block: don't use constant 512 as sector size in crypto driver List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Max Reitz Cc: qemu-devel@nongnu.org, qemu-block@nongnu.org, Kevin Wolf , Eric Blake , Stefan Hajnoczi On Sat, Sep 16, 2017 at 06:24:56PM +0200, Max Reitz wrote: > On 2017-09-12 13:28, Daniel P. Berrange wrote: > > Use the qcrypto_block_get_sector_size() value in the block > > crypto driver instead of hardcoding 512 as the sector size. > > > > Signed-off-by: Daniel P. Berrange > > --- > > block/crypto.c | 34 ++++++++++++++++++---------------- > > 1 file changed, 18 insertions(+), 16 deletions(-) > > > > diff --git a/block/crypto.c b/block/crypto.c > > index d68cbac2ac..49d6d4c058 100644 > > --- a/block/crypto.c > > +++ b/block/crypto.c > > @@ -392,8 +392,9 @@ block_crypto_co_readv(BlockDriverState *bs, int64_t sector_num, > > uint8_t *cipher_data = NULL; > > QEMUIOVector hd_qiov; > > int ret = 0; > > + uint64_t sector_size = qcrypto_block_get_sector_size(crypto->block); > > uint64_t payload_offset = > > - qcrypto_block_get_payload_offset(crypto->block) / 512; > > + qcrypto_block_get_payload_offset(crypto->block) / sector_size; > > assert(payload_offset < (INT64_MAX / 512)); > > > > qemu_iovec_init(&hd_qiov, qiov->niov); > > @@ -401,9 +402,9 @@ block_crypto_co_readv(BlockDriverState *bs, int64_t sector_num, > > /* Bounce buffer because we don't wish to expose cipher text > > * in qiov which points to guest memory. > > */ > > - cipher_data = > > - qemu_try_blockalign(bs->file->bs, MIN(BLOCK_CRYPTO_MAX_SECTORS * 512, > > - qiov->size)); > > + cipher_data = qemu_try_blockalign( > > + bs->file->bs, MIN(BLOCK_CRYPTO_MAX_SECTORS * sector_size, > > + qiov->size)); > > if (cipher_data == NULL) { > > ret = -ENOMEM; > > goto cleanup; > > @@ -417,7 +418,7 @@ block_crypto_co_readv(BlockDriverState *bs, int64_t sector_num, > > } > > > > qemu_iovec_reset(&hd_qiov); > > - qemu_iovec_add(&hd_qiov, cipher_data, cur_nr_sectors * 512); > > + qemu_iovec_add(&hd_qiov, cipher_data, cur_nr_sectors * sector_size); > > cur_nr_sectors is based on remaining_sectors; which in turn is a > parameter to this function and comes from the block layer. Therefore > its unit is BDRV_SECTOR_SIZE and not the crypto driver's sector size. > > Same in the hunk below, and in block_crypto_co_writev(). > > > > > ret = bdrv_co_readv(bs->file, > > payload_offset + sector_num, > > Same thing here, albeit in a different variation: The unit of this > parameter of bdrv_co_readv() (start sector index) is a block layer > sector, whose size is always BDRV_SECTOR_SIZE. > > Therefore you cannot divide the result from > qcrypto_block_get_payload_offset() by the crypto driver's sector size > and then use it as a sector index here. > > Same in block_crypto_co_writev(). > > > I assume that you fix this in the next patch, but for now it's just wrong. Yeah, in retrospect I should have kept this patch using BDRV_SECTOR_SIZE throughout as previous versions had it, so I'm going to go back to doing that. Only use the encryption sector size in a later patch where we have already switched to doing byte based I/O. Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|