51232e2e40
8 Commits
Author | SHA1 | Message | Date | |
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Fiona Ebner
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f1eed34ac7 |
update submodule and patches to QEMU 8.2.2
This version includes both the AioContext lock and the block graph lock, so there might be some deadlocks lurking. It's not possible to disable the block graph lock like was done in QEMU 8.1, because there are no changes like the function bdrv_schedule_unref() that require it. QEMU 9.0 will finally get rid of the AioContext locking. During live-restore with a VirtIO SCSI drive with iothread there is a known racy deadlock related to the AioContext lock. Not new [1], but not sure if more likely now. Should be fixed in QEMU 9.0. The block graph lock comes with annotations that can be checked by clang's TSA. This required changes to the block drivers, i.e. alloc-track, pbs, zeroinit as well as taking the appropriate locks in pve-backup, savevm-async, vma-reader. Local variable shadowing is prohibited via a compiler flag now, required slight adaptation in vma.c. Major changes only affect alloc-track: * It is not possible to call a generated co-wrapper like bdrv_get_info() while holding the block graph lock exclusively [0], which does happen during initialization of alloc-track when the backing hd is set and the refresh_limits driver callback is invoked. The bdrv_get_info() call to get the cluster size is moved to directly after opening the file child in track_open(). The important thing is that at least the request alignment for the write target is used, because then the RMW cycle in bdrv_pwritev will gather enough data from the backing file. Partial cluster allocations in the target are not a fundamental issue, because the driver returns its allocation status based on the bitmap, so any other data that maps to the same cluster will still be copied later by a stream job (or during writes to that cluster). * Replacing the node cannot be done in the track_co_change_backing_file() callback, because it is a coroutine and cannot hold the block graph lock exclusively. So it is moved to the stream job itself with the auto-remove option not having an effect anymore (qemu-server would always set it anyways). In the future, there could either be a special option for the stream job, or maybe the upcoming blockdev-replace QMP command can be used. Replacing the backing child is actually already done in the stream job, so no need to do it in the track_co_change_backing_file() callback. It also cannot be called from a coroutine. Looking at the implementation in the qcow2 driver, it doesn't seem to be intended to change the backing child itself, just update driver-internal state. Other changes: * alloc-track: Error out early when used without auto-remove. Since replacing the node now happens in the stream job, where the option cannot be read from (it's internal to the driver), it will always be treated as 'on'. Makes sure to have users beside qemu-server notice the change (should they even exist). The option can be fully dropped in the future while adding a version guard in qemu-server. * alloc-track: Avoid seemingly superfluous child permission update. Doesn't seem necessary nowadays (maybe after commit "alloc-track: fix deadlock during drop" where the dropping is not rescheduled and delayed anymore or some upstream change). Replacing the block node will already update the permissions of the new node (which was the file child before). Should there really be some issue, instead of having a drop state, this could also be just based off the fact whether there is still a backing child. Dumping the cumulative (shared) permissions for the BDS with a debug print yields the same values after this patch and with QEMU 8.1, namely 3 and 5. * PBS block driver: compile unconditionally. Proxmox VE always needs it and something in the build process changed to make it not enabled by default. Probably would need to move the build option to meson otherwise. * backup: job unreferencing during cleanup needs to happen outside of coroutine, so it was moved to before invoking the clean * mirror: Cherry-pick stable fix to avoid potential deadlock. * savevm-async: migrate_init now can fail, so propagate potential error. * savevm-async: compression counters are not accessible outside migration/ram-compress now, so drop code that prophylactically set it to zero. [0]: https://lore.kernel.org/qemu-devel/220be383-3b0d-4938-b584-69ad214e5d5d@proxmox.com/ [1]: https://lore.kernel.org/qemu-devel/e13b488e-bf13-44f2-acca-e724d14f43fd@proxmox.com/ Signed-off-by: Fiona Ebner <f.ebner@proxmox.com> |
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Fiona Ebner
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10e1093325 |
update submodule and patches to QEMU 8.1.2
Bigger notable changes: * Commit 1a30b0f5d7 ("block: .bdrv_open is non-coroutine and unlocked") broke the PVE backup patches, in particular setting up the backup dump block driver, because bdrv_new_open_driver() cannot be called from a coroutine. To fix it, bdrv_co_open() is used instead, and while it's a much more involved function, the result should be essentially the same. The only difference I noticed is that the BDRV_O_ALLOW_RDWR flag is also set in the resulting bds (block driver state), but that shouldn't hurt. Smaller notable changes: * aio_set_fd_handler() dropped its 'is_external' parameter stating that all callers now pass false in 60f782b6b7 ("aio: remove aio_disable_external() API"). The calls in the PVE patches also passed false, so just drop the parameter too. * global_state_store() does not have a return value anymore, so the user in the PVE savevm-async patch was adapted. For context, see c33f1829f8 ("migration: never fail in global_state_store()"). * Renames affecting the PVE savevm-async patch: migrate_use_block() -> migrate_block() and ram_counters -> mig_stats 9d4b1e5f22 ("migration: Move migrate_use_block() to options.c") aff3f6606d ("migration: Rename ram_counters to mig_stats") Signed-off-by: Fiona Ebner <f.ebner@proxmox.com> Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com> |
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Fiona Ebner
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bf251437e9 |
update submodule and patches to QEMU 8.0.0
Many changes were necessary this time around: * QAPI was changed to avoid redundant has_* variables, see commit 44ea9d9be3 ("qapi: Start to elide redundant has_FOO in generated C") for details. This affected many QMP commands added by Proxmox too. * Pending querying for migration got split into two functions, one to estimate, one for exact value, see commit c8df4a7aef ("migration: Split save_live_pending() into state_pending_*") for details. Relevant for savevm-async and PBS dirty bitmap. * Some block (driver) functions got converted to coroutines, so the Proxmox block drivers needed to be adapted. * Alloc track auto-detaching during PBS live restore got broken by AioContext-related changes resulting in a deadlock. The current, hacky method was replaced by a simpler one. Stefan apparently ran into a problem with that when he wrote the driver, but there were improvements in the stream job code since then and I didn't manage to reproduce the issue. It's a separate patch "alloc-track: fix deadlock during drop" for now, you can find the details there. * Async snapshot-related changes: - The pending querying got adapted to the above-mentioned split and a patch is added to optimize it/make it more similar to what upstream code does. - Added initialization of the compression counters (for future-proofing). - It's necessary the hold the BQL (big QEMU lock = iothread mutex) during the setup phase, because block layer functions are used there and not doing so leads to racy, hard-to-debug crashes or hangs. It's necessary to change some upstream code too for this, a version of the patch "migration: for snapshots, hold the BQL during setup callbacks" is intended to be upstreamed. - Need to take the bdrv graph read lock before flushing. * hmp_info_balloon was moved to a different file. * Needed to include a new headers from time to time to still get the correct functions. Signed-off-by: Fiona Ebner <f.ebner@proxmox.com> |
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Fiona Ebner
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d03e1b3ce3 |
update submodule and patches to 7.2.0
User-facing breaking change: The slirp submodule for user networking got removed. It would be necessary to add the --enable-slirp option to the build and/or install the appropriate library to continue building it. Since PVE is not explicitly supporting it, it would require additionally installing the libslirp0 package on all installations and there is *very* little mention on the community forum when searching for "slirp" or "netdev user", the plan is to only enable it again if there is some real demand for it. Notable changes: * The big change for this release is the rework of job locking, using a job mutex and introducing _locked() variants of job API functions moving away from call-side AioContext locking. See (in the qemu submodule) commit 6f592e5aca ("job.c: enable job lock/unlock and remove Aiocontext locks") and previous commits for context. Changes required for the backup patches: * Use WITH_JOB_LOCK_GUARD() and call the _locked() variant of job API functions where appropriate (many are only availalbe as a _locked() variant). * Remove acquiring/releasing AioContext around functions taking the job mutex lock internally. The patch introducing sequential transaction support for jobs needs to temporarily unlock the job mutex to call job_start() when starting the next job in the transaction. * The zeroinit block driver now marks its child as primary. The documentation in include/block/block-common.h states: > Filter node has exactly one FILTERED|PRIMARY child, and may have > other children which must not have these bits Without this, an assert will trigger when copying to a zeroinit target with qemu-img convert, because bdrv_child_cb_attach() expects any non-PRIMARY child to be not FILTERED: > qemu-img convert -n -p -f raw -O raw input.raw zeroinit:output.raw > qemu-img: ../block.c:1476: bdrv_child_cb_attach: Assertion > `!(child->role & BDRV_CHILD_FILTERED)' failed. Signed-off-by: Fiona Ebner <f.ebner@proxmox.com> |
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Fiona Ebner
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5b15e2ecaf |
update submodule and patches to 7.1.0
Notable changes: * The only big change is the switch to using a custom QIOChannel for savevm-async, because the previously used QEMUFileOps was dropped. Changes to the current implementation: * Switch to vector based methods as required for an IO channel. For short reads the passed-in IO vector is stuffed with zeroes at the end, just to be sure. * For reading: The documentation in include/io/channel.h states that at least one byte should be read, so also error out when whe are at the very end instead of returning 0. * For reading: Fix off-by-one error when request goes beyond end. The wrong code piece was: if ((pos + size) > maxlen) { size = maxlen - pos - 1; } Previously, the last byte would not be read. It's actually possible to get a snapshot .raw file that has content all the way up the final 512 byte (= BDRV_SECTOR_SIZE) boundary without any trailing zero bytes (I wrote a script to do it). Luckily, it didn't cause a real issue, because qemu_loadvm_state() is not interested in the final (i.e. QEMU_VM_VMDESCRIPTION) section. The buffer for reading it is simply freed up afterwards and the function will assume that it read the whole section, even if that's not the case. * For writing: Make use of the generated blk_pwritev() wrapper instead of manually wrapping the coroutine to simplify and save a few lines. * Adapt to changed interfaces for blk_{pread,pwrite}: * a9262f551e ("block: Change blk_{pread,pwrite}() param order") * 3b35d4542c ("block: Add a 'flags' param to blk_pread()") * bf5b16fa40 ("block: Make blk_{pread,pwrite}() return 0 on success") Those changes especially affected the qemu-img dd patches, because the context also changed, but also some of our block drivers used the functions. * Drop qemu-common.h include: it got renamed after essentially everything was moved to other headers. The only remaining user I could find for things dropped from the header between 7.0 and 7.1 was qemu_get_vm_name() in the iscsi-initiatorname patch, but it already includes the header to which the function was moved. Signed-off-by: Fiona Ebner <f.ebner@proxmox.com> |
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Thomas Lamprecht
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4fd0fa7fb3 |
re-export patches in normalized form
iow. using: git format-patch --zero-commit --no-signature --no-numbered --diff-algorithm=myers ... Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com> |
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Fabian Ebner
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4567474e95 |
update submodule and patches to 6.2.0
Notable changes: * bdrv_co_p{discard,readv,writev,write_zeroes} function signatures changed, to using int64_t for offsets/bytes and some still had int rather than BrdvRequestFlags for the flags. * job_cancel_sync now has a force parameter. Commit messages in 73895f3838cd7fdaf185cf1dbc47be58844a966f 4cfb3f05627ad82af473e7f7ae113c3884cd04e3 sound like using force=true makes more sense. * Added 3 patches coming in via qemu-stable tag, most important one is to work around a librbd issue. * Added another 3 patches from qemu-devel to fix issue leading to crash when live migrating with iothread. * cluster_size calculation helper changed (see patch pve/0026). * QAPI's if conditionals now use 'CONFIG_FOO' rather than 'defined(CONFIG_FOO)' Signed-off-by: Fabian Ebner <f.ebner@proxmox.com> |
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Wolfgang Bumiller
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277d33454f |
drop patch force-disabling smm
This drops debian/patches/pve/0005-PVE-Config-smm_available-false.patch (and renumbers the remaining patches) From what I could gather, this patch was originally added due to issues with old kernels. Now we have users which seem to run into issues *with* the patch. All this does is toggle an option, and it's available via a qemu CLI option anyway, so if dropping this patch causes issues for some people we can just add an option to qemu-server & UI control smm explicitly. Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com> Cc: Alexandre Derumier <aderumier@odiso.com> Tested-by: Stefan Reiter <s.reiter@proxmox.com> |