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2017-07-11qcow2: report encryption specific image informationDaniel P. Berrange
Currently 'qemu-img info' reports a simple "encrypted: yes" field. This is not very useful now that qcow2 can support multiple encryption formats. Users want to know which format is in use and some data related to it. Wire up usage of the qcrypto_block_get_info() method so that 'qemu-img info' can report about the encryption format and parameters in use $ qemu-img create \ --object secret,id=sec0,data=123456 \ -o encrypt.format=luks,encrypt.key-secret=sec0 \ -f qcow2 demo.qcow2 1G Formatting 'demo.qcow2', fmt=qcow2 size=1073741824 \ encryption=off encrypt.format=luks encrypt.key-secret=sec0 \ cluster_size=65536 lazy_refcounts=off refcount_bits=16 $ qemu-img info demo.qcow2 image: demo.qcow2 file format: qcow2 virtual size: 1.0G (1073741824 bytes) disk size: 480K encrypted: yes cluster_size: 65536 Format specific information: compat: 1.1 lazy refcounts: false refcount bits: 16 encrypt: ivgen alg: plain64 hash alg: sha256 cipher alg: aes-256 uuid: 3fa930c4-58c8-4ef7-b3c5-314bb5af21f3 format: luks cipher mode: xts slots: [0]: active: true iters: 1839058 key offset: 4096 stripes: 4000 [1]: active: false key offset: 262144 [2]: active: false key offset: 520192 [3]: active: false key offset: 778240 [4]: active: false key offset: 1036288 [5]: active: false key offset: 1294336 [6]: active: false key offset: 1552384 [7]: active: false key offset: 1810432 payload offset: 2068480 master key iters: 438487 corrupt: false With the legacy "AES" encryption we just report the format name $ qemu-img create \ --object secret,id=sec0,data=123456 \ -o encrypt.format=aes,encrypt.key-secret=sec0 \ -f qcow2 demo.qcow2 1G Formatting 'demo.qcow2', fmt=qcow2 size=1073741824 \ encryption=off encrypt.format=aes encrypt.key-secret=sec0 \ cluster_size=65536 lazy_refcounts=off refcount_bits=16 $ ./qemu-img info demo.qcow2 image: demo.qcow2 file format: qcow2 virtual size: 1.0G (1073741824 bytes) disk size: 196K encrypted: yes cluster_size: 65536 Format specific information: compat: 1.1 lazy refcounts: false refcount bits: 16 encrypt: format: aes corrupt: false Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-id: 20170623162419.26068-20-berrange@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11block: pass option prefix down to crypto layerDaniel P. Berrange
While the crypto layer uses a fixed option name "key-secret", the upper block layer may have a prefix on the options. e.g. "encrypt.key-secret", in order to avoid clashes between crypto option names & other block option names. To ensure the crypto layer can report accurate error messages, we must tell it what option name prefix was used. Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-id: 20170623162419.26068-19-berrange@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11block: remove all encryption handling APIsDaniel P. Berrange
Now that all encryption keys must be provided upfront via the QCryptoSecret API and associated block driver properties there is no need for any explicit encryption handling APIs in the block layer. Encryption can be handled transparently within the block driver. We only retain an API for querying whether an image is encrypted or not, since that is a potentially useful piece of metadata to report to the user. Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-id: 20170623162419.26068-18-berrange@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11qcow2: add support for LUKS encryption formatDaniel P. Berrange
This adds support for using LUKS as an encryption format with the qcow2 file, using the new encrypt.format parameter to request "luks" format. e.g. # qemu-img create --object secret,data=123456,id=sec0 \ -f qcow2 -o encrypt.format=luks,encrypt.key-secret=sec0 \ test.qcow2 10G The legacy "encryption=on" parameter still results in creation of the old qcow2 AES format (and is equivalent to the new 'encryption-format=aes'). e.g. the following are equivalent: # qemu-img create --object secret,data=123456,id=sec0 \ -f qcow2 -o encryption=on,encrypt.key-secret=sec0 \ test.qcow2 10G # qemu-img create --object secret,data=123456,id=sec0 \ -f qcow2 -o encryption-format=aes,encrypt.key-secret=sec0 \ test.qcow2 10G With the LUKS format it is necessary to store the LUKS partition header and key material in the QCow2 file. This data can be many MB in size, so cannot go into the QCow2 header region directly. Thus the spec defines a FDE (Full Disk Encryption) header extension that specifies the offset of a set of clusters to hold the FDE headers, as well as the length of that region. The LUKS header is thus stored in these extra allocated clusters before the main image payload. Aside from all the cryptographic differences implied by use of the LUKS format, there is one further key difference between the use of legacy AES and LUKS encryption in qcow2. For LUKS, the initialiazation vectors are generated using the host physical sector as the input, rather than the guest virtual sector. This guarantees unique initialization vectors for all sectors when qcow2 internal snapshots are used, thus giving stronger protection against watermarking attacks. Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-id: 20170623162419.26068-14-berrange@redhat.com Reviewed-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11qcow2: convert QCow2 to use QCryptoBlock for encryptionDaniel P. Berrange
This converts the qcow2 driver to make use of the QCryptoBlock APIs for encrypting image content, using the legacy QCow2 AES scheme. With this change it is now required to use the QCryptoSecret object for providing passwords, instead of the current block password APIs / interactive prompting. $QEMU \ -object secret,id=sec0,file=/home/berrange/encrypted.pw \ -drive file=/home/berrange/encrypted.qcow2,encrypt.key-secret=sec0 The test 087 could be simplified since there is no longer a difference in behaviour when using blockdev_add with encrypted images for the running vs stopped CPU state. Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-id: 20170623162419.26068-12-berrange@redhat.com Reviewed-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11qcow2: make qcow2_encrypt_sectors encrypt in placeDaniel P. Berrange
Instead of requiring separate input/output buffers for encrypting data, change qcow2_encrypt_sectors() to assume use of a single buffer, encrypting in place. The current callers all used the same buffer for input/output already. Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-id: 20170623162419.26068-11-berrange@redhat.com Reviewed-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11block: deprecate "encryption=on" in favor of "encrypt.format=aes"Daniel P. Berrange
Historically the qcow & qcow2 image formats supported a property "encryption=on" to enable their built-in AES encryption. We'll soon be supporting LUKS for qcow2, so need a more general purpose way to enable encryption, with a choice of formats. This introduces an "encrypt.format" option, which will later be joined by a number of other "encrypt.XXX" options. The use of a "encrypt." prefix instead of "encrypt-" is done to facilitate mapping to a nested QAPI schema at later date. e.g. the preferred syntax is now qemu-img create -f qcow2 -o encrypt.format=aes demo.qcow2 Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-id: 20170623162419.26068-8-berrange@redhat.com Reviewed-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-06-26block: change variable names in BlockDriverStateManos Pitsidianakis
Change the 'int count' parameter in *pwrite_zeros, *pdiscard related functions (and some others) to 'int bytes', as they both refer to bytes. This helps with code legibility. Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr> Message-id: 20170609101808.13506-1-el13635@mail.ntua.gr Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-06-26qcow2: Use offset_into_cluster() and offset_to_l2_index()Alberto Garcia
We already have functions for doing these calculations, so let's use them instead of doing everything by hand. This makes the code a bit more readable. Signed-off-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-06-26qcow2: Merge the writing of the COW regions with the guest dataAlberto Garcia
If the guest tries to write data that results on the allocation of a new cluster, instead of writing the guest data first and then the data from the COW regions, write everything together using one single I/O operation. This can improve the write performance by 25% or more, depending on several factors such as the media type, the cluster size and the I/O request size. Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-05-29qcow2: remove extra local_error variableAlberto Garcia
Commit d7086422b1c1e75e320519cfe26176db6ec97a37 added a local_err variable global to the qcow2_amend_options() function, so there's no need to have this other one. Signed-off-by: Alberto Garcia <berto@igalia.com> Message-id: 20170511150337.21470-1-berto@igalia.com Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-05-11qcow2: Discard/zero clusters by byte countEric Blake
Passing a byte offset, but sector count, when we ultimately want to operate on cluster granularity, is madness. Clean up the external interfaces to take both offset and count as bytes, while still keeping the assertion added previously that the caller must align the values to a cluster. Then rename things to make sure backports don't get confused by changed units: instead of qcow2_discard_clusters() and qcow2_zero_clusters(), we now have qcow2_cluster_discard() and qcow2_cluster_zeroize(). The internal functions still operate on clusters at a time, and return an int for number of cleared clusters; but on an image with 2M clusters, a single L2 table holds 256k entries that each represent a 2M cluster, totalling well over INT_MAX bytes if we ever had a request for that many bytes at once. All our callers currently limit themselves to 32-bit bytes (and therefore fewer clusters), but by making this function 64-bit clean, we have one less place to clean up if we later improve the block layer to support 64-bit bytes through all operations (with the block layer auto-fragmenting on behalf of more-limited drivers), rather than the current state where some interfaces are artificially limited to INT_MAX at a time. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 20170507000552.20847-13-eblake@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-05-11qcow2: Optimize write zero of unaligned tail clusterEric Blake
We've already improved discards to operate efficiently on the tail of an unaligned qcow2 image; it's time to make a similar improvement to write zeroes. The special case is only valid at the tail cluster of a file, where we must recognize that any sectors beyond the image end would implicitly read as zero, and therefore should not penalize our logic for widening a partial cluster into writing the whole cluster as zero. However, note that for now, the special case of end-of-file is only recognized if there is no backing file, or if the backing file has the same length; that's because when the backing file is shorter than the active layer, we don't have code in place to recognize that reads of a sector unallocated at the top and beyond the backing end-of-file are implicitly zero. It's not much of a real loss, because most people don't use images that aren't cluster-aligned, or where the active layer is a different size than the backing layer (especially where the difference falls within a single cluster). Update test 154 to cover the new scenarios, using two images of intentionally differing length. While at it, fix the test to gracefully skip when run as ./check -qcow2 -o compat=0.10 154 since the older format lacks zero clusters already required earlier in the test. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 20170507000552.20847-11-eblake@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-05-11qcow2: Make distinction between zero cluster types obviousEric Blake
Treat plain zero clusters differently from allocated ones, so that we can simplify the logic of checking whether an offset is present. Do this by splitting QCOW2_CLUSTER_ZERO into two new enums, QCOW2_CLUSTER_ZERO_PLAIN and QCOW2_CLUSTER_ZERO_ALLOC. I tried to arrange the enum so that we could use 'ret <= QCOW2_CLUSTER_ZERO_PLAIN' for all unallocated types, and 'ret >= QCOW2_CLUSTER_ZERO_ALLOC' for allocated types, although I didn't actually end up taking advantage of the layout. In many cases, this leads to simpler code, by properly combining cases (sometimes, both zero types pair together, other times, plain zero is more like unallocated while allocated zero is more like normal). Signed-off-by: Eric Blake <eblake@redhat.com> Message-id: 20170507000552.20847-7-eblake@redhat.com Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-05-11qcow2: Fix preallocation size formulaMax Reitz
When calculating the number of reftable entries, we should actually use the number of refblocks and not (wrongly[1]) re-calculate it. [1] "Wrongly" means: Dividing the number of clusters by the number of entries per refblock and rounding down instead of up. Reported-by: Eric Blake <eblake@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-05-09qobject: Use simpler QDict/QList scalar insertion macrosEric Blake
We now have macros in place to make it less verbose to add a scalar to QDict and QList, so use them. Patch created mechanically via: spatch --sp-file scripts/coccinelle/qobject.cocci \ --macro-file scripts/cocci-macro-file.h --dir . --in-place then touched up manually to fix a couple of '?:' back to original spacing, as well as avoiding a long line in monitor.c. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20170427215821.19397-7-eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-04-28qcow2: Allow discard of final unaligned clusterEric Blake
As mentioned in commit 0c1bd46, we ignored requests to discard the trailing cluster of an unaligned image. While discard is an advisory operation from the guest standpoint, (and we are therefore free to ignore any request), our qcow2 implementation exploits the fact that a discarded cluster reads back as 0. As long as we discard on cluster boundaries, we are fine; but that means we could observe non-zero data leaked at the tail of an unaligned image. Enhance iotest 66 to cover this case, and fix the implementation to honor a discard request on the final partial cluster. Signed-off-by: Eric Blake <eblake@redhat.com> Message-id: 20170407013709.18440-1-eblake@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-04-28block: Add .bdrv_truncate() error messagesMax Reitz
Add missing error messages for the block driver implementations of .bdrv_truncate(); drop the generic one from block.c's bdrv_truncate(). Since one of these changes touches a mis-indented block in block/file-posix.c, this patch fixes that coding style issue along the way. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20170328205129.15138-5-mreitz@redhat.com Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-04-28block: Add errp to BD.bdrv_truncate()Max Reitz
Add an Error parameter to the block drivers' bdrv_truncate() interface. If a block driver does not set this in case of an error, the generic bdrv_truncate() implementation will do so. Where it is obvious, this patch also makes some block drivers set this value. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20170328205129.15138-4-mreitz@redhat.com Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-04-28block: Add errp to b{lk,drv}_truncate()Max Reitz
For one thing, this allows us to drop the error message generation from qemu-img.c and blockdev.c and instead have it unified in bdrv_truncate(). Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20170328205129.15138-3-mreitz@redhat.com Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-02-28block: Add BDRV_O_RESIZE for blk_new_open()Kevin Wolf
blk_new_open() is a convenience function that processes flags rather than QDict options as a simple way to just open an image file. In order to keep it convenient in the future, it must automatically request the necessary permissions. This can easily be inferred from the flags for read and write, but we need another flag that tells us whether to get the resize permission. We can't just always request it because that means that no block jobs can run on the resulting BlockBackend (which is something that e.g. qemu-img commit wants to do), but we also can't request it never because most of the .bdrv_create() implementations call blk_truncate(). The solution is to introduce another flag that is passed by all users that want to resize the image. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Acked-by: Fam Zheng <famz@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-28block: Add error parameter to blk_insert_bs()Kevin Wolf
Now that blk_insert_bs() requests the BlockBackend permissions for the node it attaches to, it can fail. Instead of aborting, pass the errors to the callers. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28block: Add permissions to blk_new()Kevin Wolf
We want every user to be specific about the permissions it needs, so we'll pass the initial permissions as parameters to blk_new(). A user only needs to call blk_set_perm() if it wants to change the permissions after the fact. The permissions are stored in the BlockBackend and applied whenever a BlockDriverState should be attached in blk_insert_bs(). This does not include actually choosing the right set of permissions everywhere yet. Instead, the usual FIXME comment is added to each place and will be addressed in individual patches. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28block: Request child permissions in format driversKevin Wolf
This makes use of the .bdrv_child_perm() implementation for formats that we just added. All format drivers expose the permissions they actually need nows, so that they can be set accordingly and updated when parents are attached or detached. The only format not included here is raw, which was already converted with the other filter drivers. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Fam Zheng <famz@redhat.com>
2017-02-24block: Attach bs->file only during .bdrv_open()Kevin Wolf
The way that attaching bs->file worked was a bit unusual in that it was the only child that would be attached to a node which is not opened yet. Because of this, the block layer couldn't know yet which permissions the driver would eventually need. This patch moves the point where bs->file is attached to the beginning of the individual .bdrv_open() implementations, so drivers already know what they are going to do with the child. This is also more consistent with how driver-specific children work. For a moment, bdrv_open() gets its own BdrvChild to perform image probing, but instead of directly assigning this BdrvChild to the BDS, it becomes a temporary one and the node name is passed as an option to the drivers, so that they can simply use bdrv_open_child() to create another reference for their own use. This duplicated child for (the not opened yet) bs is not the final state, a follow-up patch will change the image probing code to use a BlockBackend, which is completely independent of bs. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-24block: Pass BdrvChild to bdrv_truncate()Kevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-24qcow2: Use BB for resizing in qcow2_amend_options()Kevin Wolf
In order to able to convert bdrv_truncate() to take a BdrvChild and later to correctly check the resize permission here, we need to use a BlockBackend for resizing the image. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-12qcow2: Optimize the refcount-block overlap checkAlberto Garcia
The metadata overlap checks introduced in a40f1c2add help detect corruption in the qcow2 image by verifying that data writes don't overlap with existing metadata sections. The 'refcount-block' check in particular iterates over the refcount table in order to get the addresses of all refcount blocks and check that none of them overlap with the region where we want to write. The problem with the refcount table is that since it always occupies complete clusters its size is usually very big. With the default values of cluster_size=64KB and refcount_bits=16 this table holds 8192 entries, each one of them enough to map 2GB worth of host clusters. So unless we're using images with several TB of allocated data this table is going to be mostly empty, and iterating over it is a waste of CPU. If the storage backend is fast enough this can have an effect on I/O performance. This patch keeps the index of the last used (i.e. non-zero) entry in the refcount table and updates it every time the table changes. The refcount-block overlap check then uses that index instead of reading the whole table. In my tests with a 4GB qcow2 file stored in RAM this doubles the amount of write IOPS. Signed-off-by: Alberto Garcia <berto@igalia.com> Message-id: 20170201123828.4815-1-berto@igalia.com Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-12-06qcow2: Don't strand clusters near 2G intervals during commitEric Blake
The qcow2_make_empty() function is reached during 'qemu-img commit', in order to clear out ALL clusters of an image. However, if the image cannot use the fast code path (true if the image is format 0.10, or if the image contains a snapshot), the cluster size is larger than 512, and the image is larger than 2G in size, then our choice of sector_step causes problems. Since it is not cluster aligned, but qcow2_discard_clusters() silently ignores an unaligned head or tail, we are leaving clusters allocated. Enhance the testsuite to expose the flaw, and patch the problem by ensuring our step size is aligned. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-11-25qcow2: Allow 'cache-clean-interval' in Linux onlyAlberto Garcia
The cache-clean-interval option of qcow2 only works on Linux. However we allow setting it in other systems regardless of whether it works or not. In those systems this option is not simply a no-op: it actually invalidates perfectly valid cache tables for no good reason without freeing their memory. This patch forbids using that option in non-Linux systems. Signed-off-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-11-22block: Return -ENOTSUP rather than assert on unaligned discardsEric Blake
Right now, the block layer rounds discard requests, so that individual drivers are able to assert that discard requests will never be unaligned. But there are some ISCSI devices that track and coalesce multiple unaligned requests, turning it into an actual discard if the requests eventually cover an entire page, which implies that it is better to always pass discard requests as low down the stack as possible. In isolation, this patch has no semantic effect, since the block layer currently never passes an unaligned request through. But the block layer already has code that silently ignores drivers that return -ENOTSUP for a discard request that cannot be honored (as well as drivers that return 0 even when nothing was done). But the next patch will update the block layer to fragment discard requests, so that clients are guaranteed that they are either dealing with an unaligned head or tail, or an aligned core, making it similar to the block layer semantics of write zero fragmentation. CC: qemu-stable@nongnu.org Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-11-22qcow2: Inform block layer about discard boundariesEric Blake
At the qcow2 layer, discard is only possible on a per-cluster basis; at the moment, qcow2 silently rounds any unaligned requests to this granularity. However, an upcoming patch will fix a regression in the block layer ignoring too much of an unaligned discard request, by changing the block layer to break up a discard request at alignment boundaries; for that to work, the block layer must know about our limits. However, we can't go one step further by changing qcow2_discard_clusters() to assert that requests are always aligned, since that helper function is reached on paths outside of the block layer. CC: qemu-stable@nongnu.org Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-10-24qcow2: Support BDRV_REQ_MAY_UNMAPFam Zheng
Handling this is similar to what is done to the L2 entry in the case of compressed clusters. Signed-off-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-10-19crypto: extend mode as a parameter in qcrypto_cipher_supports()Gonglei
It can't guarantee all cipher modes are supported if one cipher algorithm is supported by a backend. Let's extend qcrypto_cipher_supports() to take both the algorithm and mode as parameters. Signed-off-by: Gonglei <arei.gonglei@huawei.com> Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-09-13qcow2: avoid memcpy(dst, NULL, len)Stefan Hajnoczi
Section "7.1.4 Use of library functions" in the C99 standard says: If an argument to a function has an invalid value (such as [...] a null pointer [...]) [...] the behavior is undefined. Additionally the "searching and sorting" functions are specified as requiring valid pointer values as described in 7.1.4. This patch fixes the following sanitizer errors: block/qcow2.c:1807:41: runtime error: null pointer passed as argument 2, which is declared to never be null block/qcow2-cluster.c:86:26: runtime error: null pointer passed as argument 2, which is declared to never be null Reported-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-id: 1473758138-19260-1-git-send-email-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-09-05qcow2: fix iovec size at qcow2_co_pwritev_compressedPavel Butsykin
Use bytes as the size would be more exact than s->cluster_size. Although qemu_iovec_to_buf() will not allow to go beyond the qiov. Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-09-05qcow2: cleanup qcow2_co_pwritev_compressed to avoid the recursionPavel Butsykin
Now that the function uses a vector instead of a buffer, there is no need to use recursive code. Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Jeff Cody <jcody@redhat.com> CC: Markus Armbruster <armbru@redhat.com> CC: Eric Blake <eblake@redhat.com> CC: John Snow <jsnow@redhat.com> CC: Stefan Hajnoczi <stefanha@redhat.com> CC: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-09-05qcow2: add qcow2_co_pwritev_compressedPavel Butsykin
Added implementation of the qcow2_co_pwritev_compressed function that will allow us to safely use compressed writes for the qcow2 from running VMs. Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Jeff Cody <jcody@redhat.com> CC: Markus Armbruster <armbru@redhat.com> CC: Eric Blake <eblake@redhat.com> CC: John Snow <jsnow@redhat.com> CC: Stefan Hajnoczi <stefanha@redhat.com> CC: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-26qcow2: do not allocate extra memoryVladimir Sementsov-Ogievskiy
There are no needs to allocate more than one cluster, as we set avail_out for deflate to one cluster. Zlib docs (http://www.zlib.net/manual.html) says: "deflate compresses as much data as possible, and stops when the input buffer becomes empty or the output buffer becomes full." So, deflate will not write more than avail_out to output buffer. If there is not enough space in output buffer for compressed data (it may be larger than input data) deflate just returns Z_OK. (if all data is compressed and written to output buffer deflate returns Z_STREAM_END). Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 1468515565-81313-1-git-send-email-vsementsov@virtuozzo.com Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-07-20qcow2: Switch .bdrv_co_discard() to byte-basedEric Blake
Another step towards killing off sector-based block APIs. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 1468624988-423-15-git-send-email-eblake@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-13coroutine: move entry argument to qemu_coroutine_createPaolo Bonzini
In practice the entry argument is always known at creation time, and it is confusing that sometimes qemu_coroutine_enter is used with a non-NULL argument to re-enter a coroutine (this happens in block/sheepdog.c and tests/test-coroutine.c). So pass the opaque value at creation time, for consistency with e.g. aio_bh_new. Mostly done with the following semantic patch: @ entry1 @ expression entry, arg, co; @@ - co = qemu_coroutine_create(entry); + co = qemu_coroutine_create(entry, arg); ... - qemu_coroutine_enter(co, arg); + qemu_coroutine_enter(co); @ entry2 @ expression entry, arg; identifier co; @@ - Coroutine *co = qemu_coroutine_create(entry); + Coroutine *co = qemu_coroutine_create(entry, arg); ... - qemu_coroutine_enter(co, arg); + qemu_coroutine_enter(co); @ entry3 @ expression entry, arg; @@ - qemu_coroutine_enter(qemu_coroutine_create(entry), arg); + qemu_coroutine_enter(qemu_coroutine_create(entry, arg)); @ reentry @ expression co; @@ - qemu_coroutine_enter(co, NULL); + qemu_coroutine_enter(co); except for the aforementioned few places where the semantic patch stumbled (as expected) and for test_co_queue, which would otherwise produce an uninitialized variable warning. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-05block/qcow2: Don't use cpu_to_*w()Peter Maydell
Don't use the cpu_to_*w() functions, which we are trying to deprecate. Instead either just use cpu_to_*() to do the byteswap, or use st*_be_p() if we need to do the store somewhere other than to a variable that's already the correct type. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-id: 1466093177-17890-1-git-send-email-peter.maydell@linaro.org Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-07-05block: Convert bdrv_co_preadv/pwritev to BdrvChildKevin Wolf
This is the final patch for converting the common I/O path to take a BdrvChild parameter instead of BlockDriverState. The completion of this conversion means that all users that perform I/O on an image need to actually hold a reference (in the form of BdrvChild, possible as part of a BlockBackend) to that image. This also protects against inconsistent use of BlockBackend vs. BlockDriverState functions because direct use of a BlockDriverState isn't possible any more and blk->root is private for block-backends.c. In addition, we can now distinguish different users in the I/O path, and the future op blockers work is going to add assertions based on permissions stored in BdrvChild. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-05block: Convert bdrv_pwrite_zeroes() to BdrvChildKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-05block: Convert bdrv_pwrite(v/_sync) to BdrvChildKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-05block: Convert bdrv_pread(v) to BdrvChildKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-05block: Convert bdrv_write() to BdrvChildKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-05block: Use bool as appropriate for BDS membersEric Blake
Using int for values that are only used as booleans is confusing. While at it, rearrange a couple of members so that all the bools are contiguous. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-05block: Move request_alignment into BlockLimitEric Blake
It makes more sense to have ALL block size limit constraints in the same struct. Improve the documentation while at it. Simplify a couple of conditionals, now that we have audited and documented that request_alignment is always non-zero. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-05qcow2: Set request_alignment during .bdrv_refresh_limits()Eric Blake
We want to eventually stick request_alignment alongside other BlockLimits, but first, we must ensure it is populated at the same time as all other limits, rather than being a special case that is set only when a block is first opened. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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