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2023-02-16virtiofsd: Remove sourceDr. David Alan Gilbert
Now remove all the source. Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2023-02-16virtiofsd: Remove build and docs glueDr. David Alan Gilbert
Remove all the virtiofsd build and docs infrastructure. Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2023-02-02docs: add hotlinks to about preface textAlex Bennée
Make it easier to navigate the documentation. Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Acked-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Message-Id: <20230124180127.1881110-20-alex.bennee@linaro.org>
2022-11-05Fix some typos in documentation and commentsStefan Weil
Most of them were found and fixed using codespell. Signed-off-by: Stefan Weil <sw@weilnetz.de> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Thomas Huth <thuth@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20221030105944.311940-1-sw@weilnetz.de> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2022-09-30qemu-img: Wean documentation and help output off '?' for helpMarkus Armbruster
'?' for help is deprecated since commit c8057f951d "Support 'help' as a synonym for '?' in command line options", v1.2.0. We neglected to update output of qemu-img --help and the manual. Do that now. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20220908130842.641410-1-armbru@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-08-01misc: fix commonly doubled up wordsDaniel P. Berrangé
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> Message-Id: <20220707163720.1421716-5-berrange@redhat.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Thomas Huth <thuth@redhat.com>
2022-07-18Replace 'whitelist' with 'allow'Thomas Huth
Let's use more inclusive language here and avoid terms that are frowned upon nowadays. Message-Id: <20220711095300.60462-1-thuth@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Thomas Huth <thuth@redhat.com>
2022-06-24vduse-blk: Add name optionXie Yongji
Currently we use 'id' option as the name of VDUSE device. It's a bit confusing since we use one value for two different purposes: the ID to identfy the export within QEMU (must be distinct from any other exports in the same QEMU process, but can overlap with names used by other processes), and the VDUSE name to uniquely identify it on the host (must be distinct from other VDUSE devices on the same host, but can overlap with other export types like NBD in the same process). To make it clear, this patch adds a separate 'name' option to specify the VDUSE name for the vduse-blk export instead. Signed-off-by: Xie Yongji <xieyongji@bytedance.com> Message-Id: <20220614051532.92-7-xieyongji@bytedance.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-06-24vduse-blk: Add serial optionXie Yongji
Add a 'serial' option to allow user to specify this value explicitly. And the default value is changed to an empty string as what we did in "hw/block/virtio-blk.c". Signed-off-by: Xie Yongji <xieyongji@bytedance.com> Message-Id: <20220614051532.92-6-xieyongji@bytedance.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-06-24qsd: document vduse-blk exportsStefan Hajnoczi
Document vduse-blk exports in qemu-storage-daemon --help and the qemu-storage-daemon(1) man page. Based-on: <20220523084611.91-1-xieyongji@bytedance.com> Cc: Xie Yongji <xieyongji@bytedance.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20220525121947.859820-1-stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-05-25docs: Correct the default thread-pool-sizeLiu Yiding
Refer to 26ec190964 virtiofsd: Do not use a thread pool by default Signed-off-by: Liu Yiding <liuyd.fnst@fujitsu.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Message-id: 20220413042054.1484640-1-liuyd.fnst@fujitsu.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2022-05-12nbd/server: Allow MULTI_CONN for shared writable exportsEric Blake
According to the NBD spec, a server that advertises NBD_FLAG_CAN_MULTI_CONN promises that multiple client connections will not see any cache inconsistencies: when properly separated by a single flush, actions performed by one client will be visible to another client, regardless of which client did the flush. We always satisfy these conditions in qemu - even when we support multiple clients, ALL clients go through a single point of reference into the block layer, with no local caching. The effect of one client is instantly visible to the next client. Even if our backend were a network device, we argue that any multi-path caching effects that would cause inconsistencies in back-to-back actions not seeing the effect of previous actions would be a bug in that backend, and not the fault of caching in qemu. As such, it is safe to unconditionally advertise CAN_MULTI_CONN for any qemu NBD server situation that supports parallel clients. Note, however, that we don't want to advertise CAN_MULTI_CONN when we know that a second client cannot connect (for historical reasons, qemu-nbd defaults to a single connection while nbd-server-add and QMP commands default to unlimited connections; but we already have existing means to let either style of NBD server creation alter those defaults). This is visible by no longer advertising MULTI_CONN for 'qemu-nbd -r' without -e, as in the iotest nbd-qemu-allocation. The harder part of this patch is setting up an iotest to demonstrate behavior of multiple NBD clients to a single server. It might be possible with parallel qemu-io processes, but I found it easier to do in python with the help of libnbd, and help from Nir and Vladimir in writing the test. Signed-off-by: Eric Blake <eblake@redhat.com> Suggested-by: Nir Soffer <nsoffer@redhat.com> Suggested-by: Vladimir Sementsov-Ogievskiy <v.sementsov-og@mail.ru> Message-Id: <20220512004924.417153-3-eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-05-04qemu-img: properly list formats which have consistency check implementedDenis V. Lunev
Simple grep for the .bdrv_co_check callback presence gives the following list of block drivers * QED * VDI * VHDX * VMDK * Parallels which have this callback. The presense of the callback means that consistency check is supported. The patch updates documentation accordingly. Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Kevin Wolf <kwolf@redhat.com> CC: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220407083932.531965-1-den@openvz.org> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-04-21virtiofsd: Add docs/helper for killpriv_v2/no_killpriv_v2 optionLiu Yiding
virtiofsd has introduced killpriv_v2/no_killpriv_v2 for a while. Add description of it to docs/helper. Signed-off-by: Liu Yiding <liuyd.fnst@fujitsu.com> Message-Id: <20220421095151.2231099-1-liuyd.fnst@fujitsu.com> [Small documentation fixes: s/as client supports/as the client supports/ and s/. /. /. --Stefan] Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2022-03-21docs: Consistent typography for options of qemu-nbdEric Blake
Prefer the :option:`--name` form when cross-referencing other options from the qemu-nbd documentation. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20220314203818.3681277-2-eblake@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
2022-03-07qemu-nbd: add --tls-hostname option for TLS certificate validationDaniel P. Berrangé
When using the --list option, qemu-nbd acts as an NBD client rather than a server. As such when using TLS, it has a need to validate the server certificate. This adds a --tls-hostname option which can be used to override the default hostname used for certificate validation. Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> Message-Id: <20220304193610.3293146-5-berrange@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2022-03-04qsd: Add --daemonizeHanna Reitz
To implement this, we reuse the existing daemonizing functions from the system emulator, which mainly do the following: - Fork off a child process, and set up a pipe between parent and child - The parent process waits until the child sends a status byte over the pipe (0 means that the child was set up successfully; anything else (including errors or EOF) means that the child was not set up successfully), and then exits with an appropriate exit status - The child process enters a new session (forking off again), changes the umask, and will ignore terminal signals from then on - Once set-up is complete, the child will chdir to /, redirect all standard I/O streams to /dev/null, and tell the parent that set-up has been completed successfully In contrast to qemu-nbd's --fork implementation, during the set up phase, error messages are not piped through the parent process. qemu-nbd mainly does this to detect errors, though (while os_daemonize() has the child explicitly signal success after set up); because we do not redirect stderr after forking, error messages continue to appear on whatever the parent's stderr was (until set up is complete). Signed-off-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220303164814.284974-4-hreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-02-17virtiofsd: Add an option to enable/disable security labelVivek Goyal
Provide an option "-o security_label/no_security_label" to enable/disable security label functionality. By default these are turned off. If enabled, server will indicate to client that it is capable of handling one security label during file creation. Typically this is expected to be a SELinux label. File server will set this label on the file. It will try to set it atomically wherever possible. But its not possible in all the cases. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Message-Id: <20220208204813.682906-11-vgoyal@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-02-01qemu-img: Unify [-b [-F]] documentationHanna Reitz
qemu-img convert documents the backing file and backing format options as follows: [-B backing_file [-F backing_fmt]] whereas qemu-img create has this: [-b backing_file] [-F backing_fmt] That is, for convert, we document that -F cannot be given without -B, while for create, way say that they are independent. Indeed, it is technically possible to give -F without -b, because it is left to the block driver to decide whether this is an error or not, so sometimes it is: $ qemu-img create -f qed -F qed test.qed 64M Formatting 'test.qed', fmt=qed size=67108864 backing_fmt=qed [...] And sometimes it is not: $ qemu-img create -f qcow2 -F qcow2 test.qcow2 64M Formatting 'test.qcow2', fmt=qcow2 cluster_size=65536 [...] qemu-img: test.qcow2: Backing format cannot be used without backing file Generally, it does not make much sense, though, and users should only give -F with -b, so document it that way, as we have already done for qemu-img convert (commit 1899bf47375ad40555dcdff12ba49b4b8b82df38). Reported-by: Tingting Mao <timao@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220131135908.32393-1-hreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-02-01qsd: Document fuse's allow-other optionHanna Reitz
We did not add documentation to the storage daemon's man page for fuse's allow-other option when it was introduced, so do that now. Fixes: 8fc54f9428b9763f800 ("export/fuse: Add allow-other option") Signed-off-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220131103124.20325-1-hreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-01-14docs: Correct 'vhost-user-blk' spellingPhilippe Mathieu-Daudé
Reported-by: Eric Blake <eblake@redhat.com> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Message-Id: <20220107105420.395011-2-f4bug@amsat.org> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-01-05docs/tools/qemu-trace-stap.rst: Do not hard-code the QEMU binary nameThomas Huth
In downstream, we want to use a different name for the QEMU binary, and some people might also use the docs for non-x86 binaries, that's why we already created the |qemu_system| placeholder in the past. Use it now in the stap trace doc, too. Message-Id: <20220104103319.179870-1-thuth@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Thomas Huth <thuth@redhat.com>
2021-11-22docs: Render binary names as monospaced textPhilippe Mathieu-Daudé
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-Id: <20211118192744.64325-1-philmd@redhat.com> Reviewed-by: Darren Kenny <darren.kenny@oracle.com> Signed-off-by: Thomas Huth <thuth@redhat.com>
2021-11-22docs: Drop deprecated 'props' from object-addRao, Lei
In commit 5024340745 "qapi/qom: Drop deprecated 'props' from object-add" (v6.0.0), we also should update documents. Signed-off-by: Lei Rao <lei.rao@intel.com> Message-Id: <1637567387-28250-1-git-send-email-lei.rao@intel.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Thomas Huth <thuth@redhat.com>
2021-11-02qemu-img: Consistent docs for convert -FEric Blake
Use consistent capitalization, and fix a missed line (we duplicate the qemu-img synopses in too many places). Fixes: 1899bf4737 (qemu-img: Add -F shorthand to convert) Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20210921142812.2631605-1-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-10-25virtiofsd: xattr mapping add a new type "unsupported"Vivek Goyal
Right now for xattr remapping, we support types of "prefix", "ok" or "bad". Type "bad" returns -EPERM on setxattr and hides xattr in listxattr. For getxattr, mapping code returns -EPERM but getxattr code converts it to -ENODATA. I need a new semantics where if an xattr is unsupported, then getxattr()/setxattr() return -ENOTSUP and listxattr() should hide the xattr. This is needed to simulate that security.selinux is not supported by virtiofs filesystem and in that case client falls back to some default label specified by policy. So add a new type "unsupported" which returns -ENOTSUP on getxattr() and setxattr() and hides xattrs in listxattr(). For example, one can use following mapping rule to not support security.selinux xattr and allow others. "-o xattrmap=/unsupported/all/security.selinux/security.selinux//ok/all///" Suggested-by: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Message-Id: <YUt9qbmgAfCFfg5t@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2021-09-29qemu-nbd: Change default cache mode to writebackNir Soffer
Both qemu and qemu-img use writeback cache mode by default, which is already documented in qemu(1). qemu-nbd uses writethrough cache mode by default, and the default cache mode is not documented. According to the qemu-nbd(8): --cache=CACHE The cache mode to be used with the file. See the documentation of the emulator's -drive cache=... option for allowed values. qemu(1) says: The default mode is cache=writeback. So users have no reason to assume that qemu-nbd is using writethough cache mode. The only hint is the painfully slow writing when using the defaults. Looking in git history, it seems that qemu used writethrough in the past to support broken guests that did not flush data properly, or could not flush due to limitations in qemu. But qemu-nbd clients can use NBD_CMD_FLUSH to flush data, so using writethrough does not help anyone. Change the default cache mode to writback, and document the default and available values properly in the online help and manual. With this change converting image via qemu-nbd is 3.5 times faster. $ qemu-img create dst.img 50g $ qemu-nbd -t -f raw -k /tmp/nbd.sock dst.img Before this change: $ hyperfine -r3 "./qemu-img convert -p -f raw -O raw -T none -W fedora34.img nbd+unix:///?socket=/tmp/nbd.sock" Benchmark #1: ./qemu-img convert -p -f raw -O raw -T none -W fedora34.img nbd+unix:///?socket=/tmp/nbd.sock Time (mean ± σ): 83.639 s ± 5.970 s [User: 2.733 s, System: 6.112 s] Range (min … max): 76.749 s … 87.245 s 3 runs After this change: $ hyperfine -r3 "./qemu-img convert -p -f raw -O raw -T none -W fedora34.img nbd+unix:///?socket=/tmp/nbd.sock" Benchmark #1: ./qemu-img convert -p -f raw -O raw -T none -W fedora34.img nbd+unix:///?socket=/tmp/nbd.sock Time (mean ± σ): 23.522 s ± 0.433 s [User: 2.083 s, System: 5.475 s] Range (min … max): 23.234 s … 24.019 s 3 runs Users can avoid the issue by using --cache=writeback[1] but the defaults should give good performance for the common use case. [1] https://bugzilla.redhat.com/1990656 Signed-off-by: Nir Soffer <nsoffer@redhat.com> Message-Id: <20210813205519.50518-1-nsoffer@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> CC: qemu-stable@nongnu.org Signed-off-by: Eric Blake <eblake@redhat.com>
2021-09-15qemu-img: Add -F shorthand to convertEric Blake
Although we have long supported 'qemu-img convert -o backing_file=foo,backing_fmt=bar', the fact that we have a shortcut -B for backing_file but none for backing_fmt has made it more likely that users accidentally run into: qemu-img: warning: Deprecated use of backing file without explicit backing format when using -B instead of -o. For similarity with other qemu-img commands, such as create and compare, add '-F $fmt' as the shorthand for '-o backing_fmt=$fmt'. Update iotest 122 for coverage of both spellings. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20210913131735.1948339-1-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-09-13docs: standardize directory index to --- with overlinePaolo Bonzini
Use a standard heading format for the index.rst file in a directory. Using overlines makes it clear that individual documents can use e.g. === for chapter titles and --- for section titles, as suggested in the Linux kernel guidelines[1]. They could do it anyway, because documents included in a toctree are parsed separately and therefore are not tied to the same conventions for headings. However, keeping some consistency is useful since sometimes files are included from multiple places. [1] https://www.kernel.org/doc/html/latest/doc-guide/sphinx.html Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-13docs: standardize book titles to === with overlinePaolo Bonzini
Documents within a Sphinx manual are separate files and therefore can use different conventions for headings. However, keeping some consistency is useful so that included files are easy to get right. This patch uses a standard heading format for book titles, so that it is obvious when a file sits at the top level toctree of a book or man page. The heading is irrelevant for man pages, but keep it consistent as well. Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-08-02docs/tools/virtiofsd.rst: Delete stray backtickPeter Maydell
The documentation of the posix_acl option has a stray backtick at the end of the text (which is rendered literally into the HTML). Delete it. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Message-id: 20210726142338.31872-11-peter.maydell@linaro.org
2021-07-21qemu-img: Add --skip-broken-bitmaps for 'convert --bitmaps'Eric Blake
The point of 'qemu-img convert --bitmaps' is to be a convenience for actions that are already possible through a string of smaller 'qemu-img bitmap' sub-commands. One situation not accounted for already is that if a source image contains an inconsistent bitmap (for example, because a qemu process died abruptly before flushing bitmap state), the user MUST delete those inconsistent bitmaps before anything else useful can be done with the image. We don't want to delete inconsistent bitmaps by default: although a corrupt bitmap is only a loss of optimization rather than a corruption of user-visible data, it is still nice to require the user to opt in to the fact that they are aware of the loss of the bitmap. Still, requiring the user to check 'qemu-img info' to see whether bitmaps are consistent, then use 'qemu-img bitmap --remove' to remove offenders, all before using 'qemu-img convert', is a lot more work than just adding a knob 'qemu-img convert --bitmaps --skip-broken-bitmaps' which opts in to skipping the broken bitmaps. After testing the new option, also demonstrate the way to manually fix things (either deleting bad bitmaps, or re-creating them as empty) so that it is possible to convert without the option. Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1946084 Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20210709153951.2801666-4-eblake@redhat.com> [eblake: warning message tweak, test enhancements] Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2021-07-18docs: Remove "Contents:" lines from top-level subsectionsPeter Maydell
Since the top-level subsections aren't self-contained manuals any more, the "Contents:" lines at the top of each of their index pages look a bit odd; remove them. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Acked-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Message-id: 20210705095547.15790-4-peter.maydell@linaro.org
2021-07-18docs: Stop calling the top level subsections of our manual 'manuals'Peter Maydell
We merged our previous multiple-manual setup into a single Sphinx manual, but we left some text in the various index.rst lines that still calls the top level subsections separate 'manuals'. Update them to talk about "this section of the manual" instead, and remove now-obsolete comments about how the index.rst files are the "top level page for the 'foo' manual". Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Acked-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Message-id: 20210705095547.15790-3-peter.maydell@linaro.org
2021-07-12qemu-img: Reword 'qemu-img map --output=json' docsEric Blake
Reword the paragraphs to list the JSON key first, rather than in the middle of prose. Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20210707184125.2551140-1-eblake@redhat.com> Reviewed-by: Nir Soffer <nsoffer@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2021-07-12qemu-img: Make unallocated part of backing chain obvious in mapEric Blake
The recently-added NBD context qemu:allocation-depth is able to distinguish between locally-present data (even when that data is sparse) [shown as depth 1 over NBD], and data that could not be found anywhere in the backing chain [shown as depth 0]; and the libnbd project was recently patched to give the human-readable name "absent" to an allocation-depth of 0. But qemu-img map --output=json predates that addition, and has the unfortunate behavior that all portions of the backing chain that resolve without finding a hit in any backing layer report the same depth as the final backing layer. This makes it harder to reconstruct a qcow2 backing chain using just 'qemu-img map' output, especially when using "backing":null to artificially limit a backing chain, because it is impossible to distinguish between a QCOW2_CLUSTER_UNALLOCATED (which defers to a [missing] backing file) and a QCOW2_CLUSTER_ZERO_PLAIN cluster (which would override any backing file), since both types of clusters otherwise show as "data":false,"zero":true" (but note that we can distinguish a QCOW2_CLUSTER_ZERO_ALLOCATED, which would also have an "offset": listing). The task of reconstructing a qcow2 chain was made harder in commit 0da9856851 (nbd: server: Report holes for raw images), because prior to that point, it was possible to abuse NBD's block status command to see which portions of a qcow2 file resulted in BDRV_BLOCK_ALLOCATED (showing up as NBD_STATE_ZERO in isolation) vs. missing from the chain (showing up as NBD_STATE_ZERO|NBD_STATE_HOLE); but now qemu reports more accurate sparseness information over NBD. An obvious solution is to make 'qemu-img map --output=json' add an additional "present":false designation to any cluster lacking an allocation anywhere in the chain, without any change to the "depth" parameter to avoid breaking existing clients. The iotests have several examples where this distinction demonstrates the additional accuracy. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20210701190655.2131223-3-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> [eblake: fix more iotest fallout] Signed-off-by: Eric Blake <eblake@redhat.com>
2021-07-05virtiofsd: Add an option to enable/disable posix aclsVivek Goyal
fuse has an option FUSE_POSIX_ACL which needs to be opted in by fuse server to enable posix acls. As of now we are not opting in for this, so posix acls are disabled on virtiofs by default. Add virtiofsd option "-o posix_acl/no_posix_acl" to let users enable/disable posix acl support. By default it is disabled as of now due to performance concerns with cache=none. Currently even if file server has not opted in for FUSE_POSIX_ACL, user can still query acl and set acl, and system.posix_acl_access and system.posix_acl_default xattrs show up listxattr response. Miklos said this is confusing. So he said lets block and filter system.posix_acl_access and system.posix_acl_default xattrs in getxattr/setxattr/listxattr if user has explicitly disabled posix acls using -o no_posix_acl. As of now continuing to keeping the existing behavior if user did not specify any option to disable acl support due to concerns about backward compatibility. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Message-Id: <20210622150852.1507204-8-vgoyal@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2021-07-05docs: describe the security considerations with virtiofsd xattr mappingDaniel P. Berrangé
Different guest xattr prefixes have distinct access control rules applied by the guest. When remapping a guest xattr care must be taken that the remapping does not allow the a guest user to bypass guest kernel access control rules. For example if 'trusted.*' which requires CAP_SYS_ADMIN is remapped to 'user.virtiofs.trusted.*', an unprivileged guest user which can write to 'user.*' can bypass the CAP_SYS_ADMIN control. Thus the target of any remapping must be explicitly blocked from read/writes by the guest, to prevent access control bypass. The examples shown in the virtiofsd man page already do the right thing and ensure safety, but the security implications of getting this wrong were not made explicit. This could lead to host admins and apps unwittingly creating insecure configurations. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> Message-Id: <20210611120427.49736-1-berrange@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2021-06-21docs/tools/virtiofsd: Fix bad rst syntaxThomas Huth
For literal blocks, there has to be an empty line after the two colons, and the block itself should be indented. Signed-off-by: Thomas Huth <thuth@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20210607180015.924571-1-thuth@redhat.com> Signed-off-by: Thomas Huth <thuth@redhat.com>
2021-06-21docs/tools/virtiofsd.rst: Do not hard-code the QEMU binary nameThomas Huth
In downstream, we want to use a different name for the QEMU binary, and some people might also use the docs for non-x86 binaries, that's why we already created the |qemu_system| placeholder in the past. Use it now in the virtiofsd doc, too. Signed-off-by: Thomas Huth <thuth@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Message-Id: <20210607174250.920226-1-thuth@redhat.com> Signed-off-by: Thomas Huth <thuth@redhat.com>
2021-05-17Merge remote-tracking branch 'remotes/maxreitz/tags/pull-block-2021-05-14' ↵Peter Maydell
into staging Block patches: - drop block/io write notifiers - qemu-iotests enhancements to make debugging easier - rbd parsing fix - HMP qemu-io fix (for iothreads) - mirror job cancel relaxation (do not cancel in-flight requests when a READY mirror job is canceled with force=false) - document qcow2's data_file and data_file_raw features - fix iotest 297 for pylint 2.8 - block/copy-on-read refactoring # gpg: Signature made Fri 14 May 2021 17:43:40 BST # gpg: using RSA key 91BEB60A30DB3E8857D11829F407DB0061D5CF40 # gpg: issuer "mreitz@redhat.com" # gpg: Good signature from "Max Reitz <mreitz@redhat.com>" [full] # Primary key fingerprint: 91BE B60A 30DB 3E88 57D1 1829 F407 DB00 61D5 CF40 * remotes/maxreitz/tags/pull-block-2021-05-14: write-threshold: deal with includes test-write-threshold: drop extra TestStruct structure test-write-threshold: drop extra tests block/write-threshold: drop extra APIs test-write-threshold: rewrite test_threshold_(not_)trigger tests block: drop write notifiers block/write-threshold: don't use write notifiers qemu-iotests: fix pylint 2.8 consider-using-with error block/copy-on-read: use bdrv_drop_filter() and drop s->active Document qemu-img options data_file and data_file_raw qemu-iotests: fix case of SOCK_DIR already in the environment qemu-iotests: let "check" spawn an arbitrary test command qemu-iotests: move command line and environment handling from TestRunner to TestEnv qemu-iotests: allow passing unittest.main arguments to the test scripts qemu-iotests: do not buffer the test output mirror: stop cancelling in-flight requests on non-force cancel in READY monitor: hmp_qemu_io: acquire aio contex, fix crash block/rbd: Add an escape-aware strchr helper iotests/231: Update expected deprecation message Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2021-05-14Document qemu-img options data_file and data_file_rawConnor Kuehl
The contents of this patch were initially developed and posted by Han Han[1], however, it appears the original patch was not applied. Since then, the relevant documentation has been moved and adapted to a new format. I've taken most of the original wording and tweaked it according to some of the feedback from the original patch submission. I've also adapted it to restructured text, which is the format the documentation currently uses. [1] https://lists.nongnu.org/archive/html/qemu-block/2019-10/msg01253.html Fixes: https://bugzilla.redhat.com/1763105 Signed-off-by: Han Han <hhan@redhat.com> Suggested-by: Max Reitz <mreitz@redhat.com> [ Max: provided description of data_file_raw behavior ] Signed-off-by: Connor Kuehl <ckuehl@redhat.com> Message-Id: <20210505195512.391128-1-ckuehl@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2021-05-14sphinx: adopt kernel readthedoc themeMarc-André Lureau
The default "alabaster" sphinx theme has a couple shortcomings: - the navbar moves along the page - the search bar is not always at the same place - it lacks some contrast and colours The "rtd" theme from readthedocs.org is a popular third party theme used notably by the kernel, with a custom style sheet. I like it better, perhaps others do too. It also simplifies the "Edit on Gitlab" links. Tweak a bit the custom theme to match qemu.org style, use the QEMU logo, and favicon etc. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Tested-by: Bin Meng <bmeng.cn@gmail.com> Message-Id: <20210323115328.4146052-1-marcandre.lureau@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com>
2021-04-01docs: simplify each section titleMarc-André Lureau
Now that we merged into one doc, it makes the nav looks nicer. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <20210323074704.4078381-1-marcandre.lureau@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com>
2021-03-29qsd: Document FUSE exportsMax Reitz
Implementing FUSE exports required no changes to the storage daemon, so we forgot to document them there. Considering that both NBD and vhost-user-blk exports are documented in its man page (and NBD exports in its --help text), we should probably do the same for FUSE. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20210217115844.62661-1-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2021-03-19qemu-img: Use user_creatable_process_cmdline() for --objectKevin Wolf
This switches qemu-img from a QemuOpts-based parser for --object to user_creatable_process_cmdline() which uses a keyval parser and enforces the QAPI schema. Apart from being a cleanup, this makes non-scalar properties accessible. As a side effect, fix wrong exit codes in the object parsing error path of 'qemu-img compare'. This was broken in commit 334c43e2c3 because &error_fatal exits with an exit code of 1, while it should have been 2. Document that exit code 0 is also returned when just requested help was printed instead of comparing images. This is preexisting behaviour that isn't changed by this patch, though another instance of it is added with '--object help'. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Peter Krempa <pkrempa@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2021-03-08docs: qsd: Explain --export nbd,name=... defaultKevin Wolf
The 'name' option for NBD exports is optional. Add a note that the default for the option is the node name (people could otherwise expect that it's the empty string like for qemu-nbd). Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20210305094856.18964-1-kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-03-08docs: replace insecure /tmp examples in qsd docsStefan Hajnoczi
World-writeable directories have security issues. Avoid showing them in the documentation since someone might accidentally use them in situations where they are insecure. There tend to be 3 security problems: 1. Denial of service. An adversary may be able to create the file beforehand, consume all space/inodes, etc to sabotage us. 2. Impersonation. An adversary may be able to create a listen socket and accept incoming connections that were meant for us. 3. Unauthenticated client access. An adversary may be able to connect to us if we did not set the uid/gid and permissions correctly. These can be prevented or mitigated with private /tmp, carefully setting the umask, etc but that requires special action and does not apply to all situations. Just avoid using /tmp in examples. Reported-by: Richard W.M. Jones <rjones@redhat.com> Reported-by: Daniel P. Berrangé <berrange@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20210301172728.135331-3-stefanha@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Reviewed-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-03-08docs: show how to spawn qemu-storage-daemon with fd passingStefan Hajnoczi
The QMP monitor, NBD server, and vhost-user-blk export all support file descriptor passing. This is a useful technique because it allows the parent process to spawn and wait for qemu-storage-daemon without busy waiting, which may delay startup due to arbitrary sleep() calls. This Python example is inspired by the test case written for libnbd by Richard W.M. Jones <rjones@redhat.com>: https://gitlab.com/nbdkit/libnbd/-/commit/89113f484effb0e6c322314ba75c1cbe07a04543 Thanks to Daniel P. Berrangé <berrange@redhat.com> for suggestions on how to get this working. Now let's document it! Reported-by: Richard W.M. Jones <rjones@redhat.com> Cc: Kevin Wolf <kwolf@redhat.com> Cc: Daniel P. Berrangé <berrange@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20210301172728.135331-2-stefanha@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Reviewed-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-03-08qemu-storage-daemon: add --pidfile optionStefan Hajnoczi
Daemons often have a --pidfile option where the pid is written to a file so that scripts can stop the daemon by sending a signal. The pid file also acts as a lock to prevent multiple instances of the daemon from launching for a given pid file. QEMU, qemu-nbd, qemu-ga, virtiofsd, and qemu-pr-helper all support the --pidfile option. Add it to qemu-storage-daemon too. Reported-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20210302142746.170535-1-stefanha@redhat.com> Reviewed-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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