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2020-10-05block: drop bdrv_prwvVladimir Sementsov-Ogievskiy
Now that we are not maintaining boilerplate code for coroutine wrappers, there is no more sense in keeping the extra indirection layer of bdrv_prwv(). Let's drop it and instead generate pure bdrv_preadv() and bdrv_pwritev(). Currently, bdrv_pwritev() and bdrv_preadv() are returning bytes on success, auto generated functions will instead return zero, as their _co_ prototype. Still, it's simple to make the conversion safe: the only external user of bdrv_pwritev() is test-bdrv-drain, and it is comfortable enough with bdrv_co_pwritev() instead. So prototypes are moved to local block/coroutines.h. Next, the only internal use is bdrv_pread() and bdrv_pwrite(), which are modified to return bytes on success. Of course, it would be great to convert bdrv_pread() and bdrv_pwrite() to return 0 on success. But this requires audit (and probably conversion) of all their users, let's leave it for another day refactoring. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20200924185414.28642-7-vsementsov@virtuozzo.com>
2020-10-05block: generate coroutine-wrapper codeVladimir Sementsov-Ogievskiy
Use code generation implemented in previous commit to generated coroutine wrappers in block.c and block/io.c Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20200924185414.28642-6-vsementsov@virtuozzo.com>
2020-10-05scripts: add block-coroutine-wrapper.pyVladimir Sementsov-Ogievskiy
We have a very frequent pattern of creating a coroutine from a function with several arguments: - create a structure to pack parameters - create _entry function to call original function taking parameters from struct - do different magic to handle completion: set ret to NOT_DONE or EINPROGRESS or use separate bool field - fill the struct and create coroutine from _entry function with this struct as a parameter - do coroutine enter and BDRV_POLL_WHILE loop Let's reduce code duplication by generating coroutine wrappers. This patch adds scripts/block-coroutine-wrapper.py together with some friends, which will generate functions with declared prototypes marked by the 'generated_co_wrapper' specifier. The usage of new code generation is as follows: 1. define the coroutine function somewhere int coroutine_fn bdrv_co_NAME(...) {...} 2. declare in some header file int generated_co_wrapper bdrv_NAME(...); with same list of parameters (generated_co_wrapper is defined in "include/block/block.h"). 3. Make sure the block_gen_c declaration in block/meson.build mentions the file with your marker function. Still, no function is now marked, this work is for the following commit. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200924185414.28642-5-vsementsov@virtuozzo.com> [Added encoding='utf-8' to open() calls as requested by Vladimir. Fixed typo and grammar issues pointed out by Eric Blake. Removed clang-format dependency that caused build test issues. --Stefan] Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-10-05block: declare some coroutine functions in block/coroutines.hVladimir Sementsov-Ogievskiy
We are going to keep coroutine-wrappers code (structure-packing parameters, BDRV_POLL wrapper functions) in separate auto-generated files. So, we'll need a header with declaration of original _co_ functions, for those which are static now. As well, we'll need declarations for wrapper functions. Do these declarations now, as a preparation step. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20200924185414.28642-4-vsementsov@virtuozzo.com>
2020-10-05block/io: refactor coroutine wrappersVladimir Sementsov-Ogievskiy
Most of our coroutine wrappers already follow this convention: We have 'coroutine_fn bdrv_co_<something>(<normal argument list>)' as the core function, and a wrapper 'bdrv_<something>(<same argument list>)' which does parameter packing and calls bdrv_run_co(). The only outsiders are the bdrv_prwv_co and bdrv_common_block_status_above wrappers. Let's refactor them to behave as the others, it simplifies further conversion of coroutine wrappers. This patch adds an indirection layer, but it will be compensated by a further commit, which will drop bdrv_co_prwv together with the is_write logic, to keep the read and write paths separate. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20200924185414.28642-3-vsementsov@virtuozzo.com>
2020-10-05block: return error-code from bdrv_invalidate_cacheVladimir Sementsov-Ogievskiy
This is the only coroutine wrapper from block.c and block/io.c which doesn't return a value, so let's convert it to the common behavior, to simplify moving to generated coroutine wrappers in a further commit. Also, bdrv_invalidate_cache is a void function, returning error only through **errp parameter, which is considered to be bad practice, as it forces callers to define and propagate local_err variable, so conversion is good anyway. This patch leaves the conversion of .bdrv_co_invalidate_cache() driver callbacks and bdrv_invalidate_cache_all() for another day. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20200924185414.28642-2-vsementsov@virtuozzo.com>
2020-10-05block/nvme: Replace magic value by SCALE_MS definitionPhilippe Mathieu-Daudé
Use self-explicit SCALE_MS definition instead of magic value (missed in similar commit e4f310fe7f5). Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20200922083821.578519-7-philmd@redhat.com>
2020-10-05block/nvme: Use register definitions from 'block/nvme.h'Philippe Mathieu-Daudé
Use the NVMe register definitions from "block/nvme.h" which ease a bit reviewing the code while matching the datasheet. Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20200922083821.578519-6-philmd@redhat.com>
2020-10-05block/nvme: Drop NVMeRegs structure, directly use NvmeBarPhilippe Mathieu-Daudé
NVMeRegs only contains NvmeBar. Simplify the code by using NvmeBar directly. This triggers a checkpatch.pl error: ERROR: Use of volatile is usually wrong, please add a comment #30: FILE: block/nvme.c:691: + volatile NvmeBar *regs; This is a false positive as in our case we are using I/O registers, so the 'volatile' use is justified. Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20200922083821.578519-5-philmd@redhat.com>
2020-10-05block/nvme: Reduce I/O registers scopePhilippe Mathieu-Daudé
We only access the I/O register in nvme_init(). Remove the reference in BDRVNVMeState and reduce its scope. Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20200922083821.578519-4-philmd@redhat.com>
2020-10-05block/nvme: Map doorbells pages write-onlyPhilippe Mathieu-Daudé
Per the datasheet sections 3.1.13/3.1.14: "The host should not read the doorbell registers." As we don't need read access, map the doorbells with write-only permission. We keep a reference to this mapped address in the BDRVNVMeState structure. Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20200922083821.578519-3-philmd@redhat.com>
2020-10-05util/vfio-helpers: Pass page protections to qemu_vfio_pci_map_bar()Philippe Mathieu-Daudé
Pages are currently mapped READ/WRITE. To be able to use different protections, add a new argument to qemu_vfio_pci_map_bar(). Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20200922083821.578519-2-philmd@redhat.com>
2020-10-02Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into stagingPeter Maydell
Block layer patches: - Add block export infrastructure - iotests improvements - Document the throttle block filter - Misc code cleanups # gpg: Signature made Fri 02 Oct 2020 15:36:53 BST # gpg: using RSA key DC3DEB159A9AF95D3D7456FE7F09B272C88F2FD6 # gpg: issuer "kwolf@redhat.com" # gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" [full] # Primary key fingerprint: DC3D EB15 9A9A F95D 3D74 56FE 7F09 B272 C88F 2FD6 * remotes/kevin/tags/for-upstream: (37 commits) qcow2: Use L1E_SIZE in qcow2_write_l1_entry() qemu-storage-daemon: Fix help line for --export iotests: Test block-export-* QMP interface iotests: Allow supported and unsupported formats at the same time iotests: Introduce qemu_nbd_list_log() iotests: Factor out qemu_tool_pipe_and_status() nbd: Deprecate nbd-server-add/remove nbd: Merge nbd_export_new() and nbd_export_create() block/export: Move writable to BlockExportOptions block/export: Add query-block-exports block/export: Create BlockBackend in blk_exp_add() block/export: Move blk to BlockExport block/export: Add BLOCK_EXPORT_DELETED event block/export: Add block-export-del block/export: Move strong user reference to block_exports block/export: Add 'id' option to block-export-add block/export: Add blk_exp_close_all(_type) block/export: Allocate BlockExport in blk_exp_add() block/export: Add node-name to BlockExportOptions block/export: Move AioContext from NBDExport to BlockExport ... Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-10-02qcow2: Use L1E_SIZE in qcow2_write_l1_entry()Alberto Garcia
We overlooked these in 02b1ecfa100e7ecc2306560cd27a4a2622bfeb04 Signed-off-by: Alberto Garcia <berto@igalia.com> Message-Id: <20200928162333.14998-1-berto@igalia.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02qemu-storage-daemon: Fix help line for --exportKevin Wolf
Commit 5f479a8d renamed the 'device' option of --export into 'node-name', but forgot to update the help in qemu-storage-daemon. Fixes: 5f479a8dc086bfa42c9f94e9ab69962f256e207f Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20200930133909.58820-1-kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02iotests: Test block-export-* QMP interfaceKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20200924152717.287415-32-kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02iotests: Allow supported and unsupported formats at the same timeKevin Wolf
This is useful for specifying 'generic' as supported (which includes only writable image formats), but still excluding some incompatible writable formats. It also removes more lines than it adds. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20200924152717.287415-31-kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02iotests: Introduce qemu_nbd_list_log()Kevin Wolf
Add a function to list the NBD exports offered by an NBD server. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20200924152717.287415-30-kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02iotests: Factor out qemu_tool_pipe_and_status()Kevin Wolf
We have three almost identical functions that call an external process and return its output and return code. Refactor them into small wrappers around a common function. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20200924152717.287415-29-kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02nbd: Deprecate nbd-server-add/removeKevin Wolf
These QMP commands are replaced by block-export-add/del. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20200924152717.287415-28-kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02nbd: Merge nbd_export_new() and nbd_export_create()Kevin Wolf
There is no real reason any more why nbd_export_new() and nbd_export_create() should be separate functions. The latter only performs a few checks before it calls the former. What makes the current state stand out is that it's the only function in BlockExportDriver that is not a static function inside nbd/server.c, but a small wrapper in blockdev-nbd.c that then calls back into nbd/server.c for the real functionality. Move all the checks to nbd/server.c and make the resulting function static to improve readability. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200924152717.287415-27-kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02block/export: Move writable to BlockExportOptionsKevin Wolf
The 'writable' option is a basic option that will probably be applicable to most if not all export types that we will implement. Move it from NBD to the generic BlockExport layer. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200924152717.287415-26-kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02block/export: Add query-block-exportsKevin Wolf
This adds a simple QMP command to query the list of block exports. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200924152717.287415-25-kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02block/export: Create BlockBackend in blk_exp_add()Kevin Wolf
Every export type will need a BlockBackend, so creating it centrally in blk_exp_add() instead of the .create driver callback avoids duplication. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200924152717.287415-24-kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02block/export: Move blk to BlockExportKevin Wolf
Every block export has a BlockBackend representing the disk that is exported. It should live in BlockExport therefore. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200924152717.287415-23-kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02block/export: Add BLOCK_EXPORT_DELETED eventKevin Wolf
Clients may want to know when an export has finally disappeard (block-export-del returns earlier than that in the general case), so add a QAPI event for it. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20200924152717.287415-22-kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02block/export: Add block-export-delKevin Wolf
Implement a new QMP command block-export-del and make nbd-server-remove a wrapper around it. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200924152717.287415-21-kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02block/export: Move strong user reference to block_exportsKevin Wolf
The reference owned by the user/monitor that is created when adding the export and dropped when removing it was tied to the 'exports' list in nbd/server.c. Every block export will have a user reference, so move it to the block export level and tie it to the 'block_exports' list in block/export/export.c instead. This is necessary for introducing a QMP command for removing exports. Note that exports are present in block_exports even after the user has requested shutdown. This is different from NBD's exports where exports are immediately removed on a shutdown request, even if they are still in the process of shutting down. In order to avoid that the user still interacts with an export that is shutting down (and possibly removes it a second time), we need to remember if the user actually still owns it. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200924152717.287415-20-kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02block/export: Add 'id' option to block-export-addKevin Wolf
We'll need an id to identify block exports in monitor commands. This adds one. Note that this is different from the 'name' option in the NBD server, which is the externally visible export name. While block export ids need to be unique in the whole process, export names must be unique only for the same server. Different export types or (potentially in the future) multiple NBD servers can have the same export name externally, but still need different block export ids internally. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200924152717.287415-19-kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02block/export: Add blk_exp_close_all(_type)Kevin Wolf
This adds a function to shut down all block exports, and another one to shut down the block exports of a single type. The latter is used for now when stopping the NBD server. As soon as we implement support for multiple NBD servers, we'll need a per-server list of exports and it will be replaced by a function using that. As a side effect, the BlockExport layer has a list tracking all existing exports now. closed_exports loses its only user and can go away. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200924152717.287415-18-kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02block/export: Allocate BlockExport in blk_exp_add()Kevin Wolf
Instead of letting the driver allocate and return the BlockExport object, allocate it already in blk_exp_add() and pass it. This allows us to initialise the generic part before calling into the driver so that the driver can just use these values instead of having to parse the options a second time. For symmetry, move freeing the BlockExport to blk_exp_unref(). Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200924152717.287415-17-kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02block/export: Add node-name to BlockExportOptionsKevin Wolf
Every block export needs a block node to export, so add a 'node-name' option to BlockExportOptions and remove the replaced option 'device' from BlockExportOptionsNbd. To maintain compatibility in nbd-server-add, BlockExportOptionsNbd needs to be wrapped by a new type NbdServerAddOptions that adds 'device' back because nbd-server-add doesn't use the BlockExportOptions base type at all (so even without changing it to a 'node-name' option in block-export-add, this compatibility code would be necessary). Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200924152717.287415-16-kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02block/export: Move AioContext from NBDExport to BlockExportKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200924152717.287415-15-kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02block/export: Move refcount from NBDExport to BlockExportKevin Wolf
Having a refcount makes sense for all types of block exports. It is also a prerequisite for keeping a list of all exports at the BlockExport level. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200924152717.287415-14-kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02nbd/server: Simplify export shutdownKevin Wolf
Closing export is somewhat convoluted because nbd_export_close() and nbd_export_put() call each other and the ways they actually end up being nested is not necessarily obvious. However, it is not really necessary to call nbd_export_close() from nbd_export_put() when putting the last reference because it only does three things: 1. Close all clients. We're going to refcount 0 and all clients hold a reference, so we know there is no active client any more. 2. Close the user reference (represented by exp->name being non-NULL). The same argument applies: If the export were still named, we would still have a reference. 3. Freeing exp->description. This is really cleanup work to be done when the export is finally freed. There is no reason to already clear it while clients are still in the process of shutting down. So after moving the cleanup of exp->description, the code can be simplified so that only nbd_export_close() calls nbd_export_put(), but never the other way around. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200924152717.287415-13-kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02qemu-nbd: Use blk_exp_add() to create the exportKevin Wolf
With this change, NBD exports are now only created through the BlockExport interface. This allows us finally to move things from the NBD layer to the BlockExport layer if they make sense for other export types, too. blk_exp_add() returns only a weak reference, so the explicit nbd_export_put() goes away. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200924152717.287415-12-kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02nbd: Remove NBDExport.close callbackKevin Wolf
The export close callback is unused by the built-in NBD server. qemu-nbd uses it only during shutdown to wait for the unrefed export to actually go away. It can just use nbd_export_close_all() instead and do without the callback. This removes the close callback from nbd_export_new() and makes both callers of it more similar. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200924152717.287415-11-kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02nbd: Add writethrough to block-export-addKevin Wolf
qemu-nbd allows use of writethrough cache modes, which mean that write requests made through NBD will cause a flush before they complete. Expose the same functionality in block-export-add. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200924152717.287415-10-kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02nbd: Add max-connections to nbd-server-startKevin Wolf
This is a QMP equivalent of qemu-nbd's --shared option, limiting the maximum number of clients that can attach at the same time. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200924152717.287415-9-kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02block/export: Remove magic from block-export-addKevin Wolf
nbd-server-add tries to be convenient and adds two questionable features that we don't want to share in block-export-add, even for NBD exports: 1. When requesting a writable export of a read-only device, the export is silently downgraded to read-only. This should be an error in the context of block-export-add. 2. When using a BlockBackend name, unplugging the device from the guest will automatically stop the NBD server, too. This may sometimes be what you want, but it could also be very surprising. Let's keep things explicit with block-export-add. If the user wants to stop the export, they should tell us so. Move these things into the nbd-server-add QMP command handler so that they apply only there. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200924152717.287415-8-kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02qemu-nbd: Use raw block driver for --offsetKevin Wolf
Instead of implementing qemu-nbd --offset in the NBD code, just put a raw block node with the requested offset on top of the user image and rely on that doing the job. This does not only simplify the nbd_export_new() interface and bring it closer to the set of options that the nbd-server-add QMP command offers, but in fact it also eliminates a potential source for bugs in the NBD code which previously had to add the offset manually in all relevant places. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200924152717.287415-7-kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02qemu-storage-daemon: Use qmp_block_export_add()Kevin Wolf
No reason to duplicate the functionality locally, we can now just reuse the QMP command block-export-add for --export. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200924152717.287415-6-kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02block/export: Add BlockExport infrastructure and block-export-addKevin Wolf
We want to have a common set of commands for all types of block exports. Currently, this is only NBD, but we're going to add more types. This patch adds the basic BlockExport and BlockExportDriver structs and a QMP command block-export-add that creates a new export based on the given BlockExportOptions. qmp_nbd_server_add() becomes a wrapper around qmp_block_export_add(). Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200924152717.287415-5-kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02qapi: Rename BlockExport to BlockExportOptionsKevin Wolf
The name BlockExport will be used for the struct containing the runtime state of block exports, so change the name of export creation options. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200924152717.287415-4-kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02qapi: Create block-export moduleKevin Wolf
Move all block export related types and commands from block-core to the new QAPI module block-export. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200924152717.287415-3-kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02nbd: Remove unused nbd_export_get_blockdev()Kevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200924152717.287415-2-kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02qemu-io-cmds: Simplify help_onelineDr. David Alan Gilbert
help_oneline is declared and starts as: static void help_oneline(const char *cmd, const cmdinfo_t *ct) { if (cmd) { printf("%s ", cmd); } else { printf("%s ", ct->name); if (ct->altname) { printf("(or %s) ", ct->altname); } } However, there are only two routes to help_oneline being called: help_f -> help_all -> help_oneline(ct->name, ct) help_f -> help_onecmd(argv[1], ct) In the first case, 'cmd' and 'ct->name' are the same thing, so it's impossible for the if (cmd) to be false and then validly print ct->name - this is upsetting gcc ( https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96739 ) In the second case, cmd is argv[1] and we know we've got argv[1] so again (cmd) is non-NULL. Simplify help_oneline by just printing cmd. (Also strengthen argc check just to be pedantic) Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Message-Id: <20200824102914.105619-1-dgilbert@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02docs: Document the throttle block filterAlberto Garcia
This filter was added back in 2017 for QEMU 2.11 but it was never properly documented, so let's explain how it works and add a couple of examples. Signed-off-by: Alberto Garcia <berto@igalia.com> Message-Id: <20200921173016.27935-1-berto@igalia.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02tests/check-block: Do not run the iotests with old versions of bashThomas Huth
macOS is shipped with a very old version of the bash (3.2), which is currently not suitable for running the iotests anymore (e.g. it is missing support for "readarray" which is used in the file tests/qemu-iotests/common.filter). Add a check to skip the iotests in this case - if someone still wants to run the iotests on macOS, they can install a newer version from homebrew, for example. Signed-off-by: Thomas Huth <thuth@redhat.com> Message-Id: <20200918153514.330705-1-thuth@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02block/sheepdog: Replace magic val by NANOSECONDS_PER_SECOND definitionPhilippe Mathieu-Daudé
Use self-explicit NANOSECONDS_PER_SECOND definition instead of magic value. Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-Id: <20200921110145.520944-1-philmd@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>