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2024-02-07migration/multifd: Unify multifd and TLS connection pathsFabiano Rosas
During multifd channel creation (multifd_send_new_channel_async) when TLS is enabled, the multifd_channel_connect function is called twice, once to create the TLS handshake thread and another time after the asynchrounous TLS handshake has finished. This creates a slightly confusing call stack where multifd_channel_connect() is called more times than the number of channels. It also splits error handling between the two callers of multifd_channel_connect() causing some code duplication. Lastly, it gets in the way of having a single point to determine whether all channel creation tasks have been initiated. Refactor the code to move the reentrancy one level up at the multifd_new_send_channel_async() level, de-duplicating the error handling and allowing for the next patch to introduce a synchronization point common to all the multifd channel creation, regardless of TLS. Note that the previous code would never fail once p->c had been set. This patch changes this assumption, which affects refcounting, so add comments around object_unref to explain the situation. Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Fabiano Rosas <farosas@suse.de> Link: https://lore.kernel.org/r/20240206215118.6171-6-farosas@suse.de Signed-off-by: Peter Xu <peterx@redhat.com>
2024-02-07migration/multifd: Move multifd_send_setup error handling in to the functionFabiano Rosas
Hide the error handling inside multifd_send_setup to make it cleaner for the next patch to move the function around. Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Fabiano Rosas <farosas@suse.de> Link: https://lore.kernel.org/r/20240206215118.6171-4-farosas@suse.de Signed-off-by: Peter Xu <peterx@redhat.com>
2024-02-07migration/multifd: Remove p->runningFabiano Rosas
We currently only need p->running to avoid calling qemu_thread_join() on a non existent thread if the thread has never been created. However, there are at least two bugs in this logic: 1) On the sending side, p->running is set too early and qemu_thread_create() can be skipped due to an error during TLS handshake, leaving the flag set and leading to a crash when multifd_send_cleanup() calls qemu_thread_join(). 2) During exit, the multifd thread clears the flag while holding the channel lock. The counterpart at multifd_send_cleanup() reads the flag outside of the lock and might free the mutex while the multifd thread still has it locked. Fix the first issue by setting the flag right before creating the thread. Rename it from p->running to p->thread_created to clarify its usage. Fix the second issue by not clearing the flag at the multifd thread exit. We don't have any use for that. Note that these bugs are straight-forward logic issues and not race conditions. There is still a gap for races to affect this code due to multifd_send_cleanup() being allowed to run concurrently with the thread creation loop. This issue is solved in the next patches. Cc: qemu-stable <qemu-stable@nongnu.org> Fixes: 29647140157a ("migration/tls: add support for multifd tls-handshake") Reported-by: Avihai Horon <avihaih@nvidia.com> Reported-by: chenyuhui5@huawei.com Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Fabiano Rosas <farosas@suse.de> Link: https://lore.kernel.org/r/20240206215118.6171-3-farosas@suse.de Signed-off-by: Peter Xu <peterx@redhat.com>
2024-02-07migration/multifd: Join the TLS threadFabiano Rosas
We're currently leaking the resources of the TLS thread by not joining it and also overwriting the p->thread pointer altogether. Fixes: a1af605bd5 ("migration/multifd: fix hangup with TLS-Multifd due to blocking handshake") Cc: qemu-stable <qemu-stable@nongnu.org> Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Fabiano Rosas <farosas@suse.de> Link: https://lore.kernel.org/r/20240206215118.6171-2-farosas@suse.de Signed-off-by: Peter Xu <peterx@redhat.com>
2024-02-06migration/multifd: Optimize sender side to be locklessPeter Xu
When reviewing my attempt to refactor send_prepare(), Fabiano suggested we try out with dropping the mutex in multifd code [1]. I thought about that before but I never tried to change the code. Now maybe it's time to give it a stab. This only optimizes the sender side. The trick here is multifd has a clear provider/consumer model, that the migration main thread publishes requests (either pending_job/pending_sync), while the multifd sender threads are consumers. Here we don't have a lot of complicated data sharing, and the jobs can logically be submitted lockless. Arm the code with atomic weapons. Two things worth mentioning: - For multifd_send_pages(): we can use qatomic_load_acquire() when trying to find a free channel, but that's expensive if we attach one ACQUIRE per channel. Instead, keep the qatomic_read() on reading the pending_job flag as we do already, meanwhile use one smp_mb_acquire() after the loop to guarantee the memory ordering. - For pending_sync: it doesn't have any extra data required since now p->flags are never touched, it should be safe to not use memory barrier. That's different from pending_job. Provide rich comments for all the lockless operations to state how they are paired. With that, we can remove the mutex. [1] https://lore.kernel.org/r/87o7d1jlu5.fsf@suse.de Suggested-by: Fabiano Rosas <farosas@suse.de> Reviewed-by: Fabiano Rosas <farosas@suse.de> Link: https://lore.kernel.org/r/20240202102857.110210-24-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com>
2024-02-05migration/multifd: Fix MultiFDSendParams.packet_num racePeter Xu
As reported correctly by Fabiano [1] (while per Fabiano, it sourced back to Elena's initial report in Oct 2023), MultiFDSendParams.packet_num is buggy to be assigned and stored. Consider two consequent operations of: (1) queue a job into multifd send thread X, then (2) queue another sync request to the same send thread X. Then the MultiFDSendParams.packet_num will be assigned twice, and the first assignment can get lost already. To avoid that, we move the packet_num assignment from p->packet_num into where the thread will fill in the packet. Use atomic operations to protect the field, making sure there's no race. Note that atomic fetch_add() may not be good for scaling purposes, however multifd should be fine as number of threads should normally not go beyond 16 threads. Let's leave that concern for later but fix the issue first. There's also a trick on how to make it always work even on 32 bit hosts for uint64_t packet number. Switching to uintptr_t as of now to simply the case. It will cause packet number to overflow easier on 32 bit, but that shouldn't be a major concern for now as 32 bit systems is not the major audience for any performance concerns like what multifd wants to address. We also need to move multifd_send_state definition upper, so that multifd_send_fill_packet() can reference it. [1] https://lore.kernel.org/r/87o7d1jlu5.fsf@suse.de Reported-by: Elena Ufimtseva <elena.ufimtseva@oracle.com> Reviewed-by: Fabiano Rosas <farosas@suse.de> Link: https://lore.kernel.org/r/20240202102857.110210-23-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com>
2024-02-05migration/multifd: Stick with send/recv on function namesPeter Xu
Most of the multifd code uses send/recv to represent the two sides, but some rare cases use save/load. Since send/recv is the majority, replacing the save/load use cases to use send/recv globally. Now we reach a consensus on the naming. Reviewed-by: Fabiano Rosas <farosas@suse.de> Link: https://lore.kernel.org/r/20240202102857.110210-22-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com>
2024-02-05migration/multifd: Cleanup multifd_load_cleanup()Peter Xu
Use similar logic to cleanup the recv side. Note that multifd_recv_terminate_threads() may need some similar rework like the sender side, but let's leave that for later. Reviewed-by: Fabiano Rosas <farosas@suse.de> Link: https://lore.kernel.org/r/20240202102857.110210-21-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com>
2024-02-05migration/multifd: Cleanup multifd_save_cleanup()Peter Xu
Shrink the function by moving relevant works into helpers: move the thread join()s into multifd_send_terminate_threads(), then create two more helpers to cover channel/state cleanups. Add a TODO entry for the thread terminate process because p->running is still buggy. We need to fix it at some point but not yet covered. Suggested-by: Fabiano Rosas <farosas@suse.de> Reviewed-by: Fabiano Rosas <farosas@suse.de> Link: https://lore.kernel.org/r/20240202102857.110210-20-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com>
2024-02-05migration/multifd: Rewrite multifd_queue_page()Peter Xu
The current multifd_queue_page() is not easy to read and follow. It is not good with a few reasons: - No helper at all to show what exactly does a condition mean; in short, readability is low. - Rely on pages->ramblock being cleared to detect an empty queue. It's slightly an overload of the ramblock pointer, per Fabiano [1], which I also agree. - Contains a self recursion, even if not necessary.. Rewrite this function. We add some comments to make it even clearer on what it does. [1] https://lore.kernel.org/r/87wmrpjzew.fsf@suse.de Reviewed-by: Fabiano Rosas <farosas@suse.de> Link: https://lore.kernel.org/r/20240202102857.110210-19-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com>
2024-02-05migration/multifd: Change retval of multifd_send_pages()Peter Xu
Using int is an overkill when there're only two options. Change it to a boolean. Reviewed-by: Fabiano Rosas <farosas@suse.de> Link: https://lore.kernel.org/r/20240202102857.110210-18-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com>
2024-02-05migration/multifd: Change retval of multifd_queue_page()Peter Xu
Using int is an overkill when there're only two options. Change it to a boolean. Reviewed-by: Fabiano Rosas <farosas@suse.de> Link: https://lore.kernel.org/r/20240202102857.110210-17-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com>
2024-02-05migration/multifd: Split multifd_send_terminate_threads()Peter Xu
Split multifd_send_terminate_threads() into two functions: - multifd_send_set_error(): used when an error happened on the sender side, set error and quit state only - multifd_send_terminate_threads(): used only by the main thread to kick all multifd send threads out of sleep, for the last recycling. Use multifd_send_set_error() in the three old call sites where only the error will be set. Use multifd_send_terminate_threads() in the last one where the main thread will kick the multifd threads at last in multifd_save_cleanup(). Both helpers will need to set quitting=1. Suggested-by: Fabiano Rosas <farosas@suse.de> Reviewed-by: Fabiano Rosas <farosas@suse.de> Link: https://lore.kernel.org/r/20240202102857.110210-16-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com>
2024-02-05migration/multifd: Forbid spurious wakeupsPeter Xu
Now multifd's logic is designed to have no spurious wakeup. I still remember a talk to Juan and he seems to agree we should drop it now, and if my memory was right it was there because multifd used to hit that when still debugging. Let's drop it and see what can explode; as long as it's not reaching soft-freeze. Reviewed-by: Fabiano Rosas <farosas@suse.de> Link: https://lore.kernel.org/r/20240202102857.110210-15-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com>
2024-02-05migration/multifd: Move header prepare/fill into send_prepare()Peter Xu
This patch redefines the interfacing of ->send_prepare(). It further simplifies multifd_send_thread() especially on zero copy. Now with the new interface, we require the hook to do all the work for preparing the IOVs to send. After it's completed, the IOVs should be ready to be dumped into the specific multifd QIOChannel later. So now the API looks like: p->pages -----------> send_prepare() -------------> IOVs This also prepares for the case where the input can be extended to even not any p->pages. But that's for later. This patch will achieve similar goal of what Fabiano used to propose here: https://lore.kernel.org/r/20240126221943.26628-1-farosas@suse.de However the send() interface may not be necessary. I'm boldly attaching a "Co-developed-by" for Fabiano. Co-developed-by: Fabiano Rosas <farosas@suse.de> Reviewed-by: Fabiano Rosas <farosas@suse.de> Link: https://lore.kernel.org/r/20240202102857.110210-14-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com>
2024-02-05migration/multifd: multifd_send_prepare_header()Peter Xu
Introduce a helper multifd_send_prepare_header() to setup the header packet for multifd sender. It's fine to setup the IOV[0] _before_ send_prepare() because the packet buffer is already ready, even if the content is to be filled in. With this helper, we can already slightly clean up the zero copy path. Note that I explicitly put it into multifd.h, because I want it inlined directly into multifd*.c where necessary later. Reviewed-by: Fabiano Rosas <farosas@suse.de> Link: https://lore.kernel.org/r/20240202102857.110210-13-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com>
2024-02-05migration/multifd: Move trace_multifd_send|recv()Peter Xu
Move them into fill/unfill of packets. With that, we can further cleanup the send/recv thread procedure, and remove one more temp var. Reviewed-by: Fabiano Rosas <farosas@suse.de> Link: https://lore.kernel.org/r/20240202102857.110210-12-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com>
2024-02-05migration/multifd: Move total_normal_pages accountingPeter Xu
Just like the previous patch, move the accounting for total_normal_pages on both src/dst sides into the packet fill/unfill procedures. Reviewed-by: Fabiano Rosas <farosas@suse.de> Link: https://lore.kernel.org/r/20240202102857.110210-11-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com>
2024-02-05migration/multifd: Rename p->num_packets and clean it upPeter Xu
This field, no matter whether on src or dest, is only used for debugging purpose. They can even be removed already, unless it still more or less provide some accounting on "how many packets are sent/recved for this thread". The other more important one is called packet_num, which is embeded in the multifd packet headers (MultiFDPacket_t). So let's keep them for now, but make them much easier to understand, by doing below: - Rename both of them to packets_sent / packets_recved, the old name (num_packets) are waaay too confusing when we already have MultiFDPacket_t.packets_num. - Avoid worrying on the "initial packet": we know we will send it, that's good enough. The accounting won't matter a great deal to start with 0 or with 1. - Move them to where we send/recv the packets. They're: - multifd_send_fill_packet() for senders. - multifd_recv_unfill_packet() for receivers. Reviewed-by: Fabiano Rosas <farosas@suse.de> Link: https://lore.kernel.org/r/20240202102857.110210-10-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com>
2024-02-05migration/multifd: Drop pages->num check in sender threadPeter Xu
Now with a split SYNC handler, we always have pages->num set for pending_job==true. Assert it instead. Reviewed-by: Fabiano Rosas <farosas@suse.de> Link: https://lore.kernel.org/r/20240202102857.110210-9-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com>
2024-02-05migration/multifd: Simplify locking in sender threadPeter Xu
The sender thread will yield the p->mutex before IO starts, trying to not block the requester thread. This may be unnecessary lock optimizations, because the requester can already read pending_job safely even without the lock, because the requester is currently the only one who can assign a task. Drop that lock complication on both sides: (1) in the sender thread, always take the mutex until job done (2) in the requester thread, check pending_job clear lockless Reviewed-by: Fabiano Rosas <farosas@suse.de> Link: https://lore.kernel.org/r/20240202102857.110210-8-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com>
2024-02-05migration/multifd: Separate SYNC request with normal jobsPeter Xu
Multifd provide a threaded model for processing jobs. On sender side, there can be two kinds of job: (1) a list of pages to send, or (2) a sync request. The sync request is a very special kind of job. It never contains a page array, but only a multifd packet telling the dest side to synchronize with sent pages. Before this patch, both requests use the pending_job field, no matter what the request is, it will boost pending_job, while multifd sender thread will decrement it after it finishes one job. However this should be racy, because SYNC is special in that it needs to set p->flags with MULTIFD_FLAG_SYNC, showing that this is a sync request. Consider a sequence of operations where: - migration thread enqueue a job to send some pages, pending_job++ (0->1) - [...before the selected multifd sender thread wakes up...] - migration thread enqueue another job to sync, pending_job++ (1->2), setup p->flags=MULTIFD_FLAG_SYNC - multifd sender thread wakes up, found pending_job==2 - send the 1st packet with MULTIFD_FLAG_SYNC and list of pages - send the 2nd packet with flags==0 and no pages This is not expected, because MULTIFD_FLAG_SYNC should hopefully be done after all the pages are received. Meanwhile, the 2nd packet will be completely useless, which contains zero information. I didn't verify above, but I think this issue is still benign in that at least on the recv side we always receive pages before handling MULTIFD_FLAG_SYNC. However that's not always guaranteed and just tricky. One other reason I want to separate it is using p->flags to communicate between the two threads is also not clearly defined, it's very hard to read and understand why accessing p->flags is always safe; see the current impl of multifd_send_thread() where we tried to cache only p->flags. It doesn't need to be that complicated. This patch introduces pending_sync, a separate flag just to show that the requester needs a sync. Alongside, we remove the tricky caching of p->flags now because after this patch p->flags should only be used by multifd sender thread now, which will be crystal clear. So it is always thread safe to access p->flags. With that, we can also safely convert the pending_job into a boolean, because we don't support >1 pending jobs anyway. Always use atomic ops to access both flags to make sure no cache effect. When at it, drop the initial setting of "pending_job = 0" because it's always allocated using g_new0(). Reviewed-by: Fabiano Rosas <farosas@suse.de> Link: https://lore.kernel.org/r/20240202102857.110210-7-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com>
2024-02-05migration/multifd: Drop MultiFDSendParams.normal[] arrayPeter Xu
This array is redundant when p->pages exists. Now we extended the life of p->pages to the whole period where pending_job is set, it should be safe to always use p->pages->offset[] rather than p->normal[]. Drop the array. Alongside, the normal_num is also redundant, which is the same to p->pages->num. This doesn't apply to recv side, because there's no extra buffering on recv side, so p->normal[] array is still needed. Reviewed-by: Fabiano Rosas <farosas@suse.de> Link: https://lore.kernel.org/r/20240202102857.110210-6-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com>
2024-02-05migration/multifd: Postpone reset of MultiFDPages_tPeter Xu
Now we reset MultiFDPages_t object in the multifd sender thread in the middle of the sending job. That's not necessary, because the "*pages" struct will not be reused anyway until pending_job is cleared. Move that to the end after the job is completed, provide a helper to reset a "*pages" object. Use that same helper when free the object too. This prepares us to keep using p->pages in the follow up patches, where we may drop p->normal[]. Reviewed-by: Fabiano Rosas <farosas@suse.de> Link: https://lore.kernel.org/r/20240202102857.110210-5-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com>
2024-02-05migration/multifd: Drop MultiFDSendParams.quit, cleanup error pathsPeter Xu
Multifd send side has two fields to indicate error quits: - MultiFDSendParams.quit - &multifd_send_state->exiting Merge them into the global one. The replacement is done by changing all p->quit checks into the global var check. The global check doesn't need any lock. A few more things done on top of this altogether: - multifd_send_terminate_threads() Moving the xchg() of &multifd_send_state->exiting upper, so as to cover the tracepoint, migrate_set_error() and migrate_set_state(). - multifd_send_sync_main() In the 2nd loop, add one more check over the global var to make sure we don't keep the looping if QEMU already decided to quit. - multifd_tls_outgoing_handshake() Use multifd_send_terminate_threads() to set the error state. That has a benefit of updating MigrationState.error to that error too, so we can persist that 1st error we hit in that specific channel. - multifd_new_send_channel_async() Take similar approach like above, drop the migrate_set_error() because multifd_send_terminate_threads() already covers that. Unwrap the helper multifd_new_send_channel_cleanup() along the way; not really needed. Reviewed-by: Fabiano Rosas <farosas@suse.de> Link: https://lore.kernel.org/r/20240202102857.110210-4-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com>
2024-02-05migration/multifd: multifd_send_kick_main()Peter Xu
When a multifd sender thread hit errors, it always needs to kick the main thread by kicking all the semaphores that it can be waiting upon. Provide a helper for it and deduplicate the code. Reviewed-by: Fabiano Rosas <farosas@suse.de> Link: https://lore.kernel.org/r/20240202102857.110210-3-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com>
2024-02-05migration/multifd: Drop stale comment for multifd zero copyPeter Xu
We've already done that with multifd_flush_after_each_section, for multifd in general. Drop the stale "TODO-like" comment. Reviewed-by: Fabiano Rosas <farosas@suse.de> Link: https://lore.kernel.org/r/20240202102857.110210-2-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com>
2024-01-16migration/multifd: Change multifd_pages_init argumentFabiano Rosas
The 'size' argument is actually the number of pages that fit in a multifd packet. Change it to uint32_t and rename. Signed-off-by: Fabiano Rosas <farosas@suse.de> Reviewed-by: Peter Xu <peterx@redhat.com> Link: https://lore.kernel.org/r/20240104142144.9680-4-farosas@suse.de Signed-off-by: Peter Xu <peterx@redhat.com>
2024-01-16migration/multifd: Remove QEMUFile from where it is not neededFabiano Rosas
Signed-off-by: Fabiano Rosas <farosas@suse.de> Reviewed-by: Peter Xu <peterx@redhat.com> Link: https://lore.kernel.org/r/20240104142144.9680-3-farosas@suse.de Signed-off-by: Peter Xu <peterx@redhat.com>
2024-01-16migration/multifd: Remove MultiFDPages_t::packet_numFabiano Rosas
This was introduced by commit 34c55a94b1 ("migration: Create multipage support") and never used. Signed-off-by: Fabiano Rosas <farosas@suse.de> Reviewed-by: Peter Xu <peterx@redhat.com> Link: https://lore.kernel.org/r/20240104142144.9680-2-farosas@suse.de Signed-off-by: Peter Xu <peterx@redhat.com>
2024-01-04migration/multifd: Remove unnecessary usage of local ErrorAvihai Horon
According to Error API, usage of ERRP_GUARD() or a local Error instead of errp is needed if errp is passed to void functions, where it is later dereferenced to see if an error occurred. There are several places in multifd.c that use local Error although it is not needed. Change these places to use errp directly. Signed-off-by: Avihai Horon <avihaih@nvidia.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Link: https://lore.kernel.org/r/20231231093016.14204-12-avihaih@nvidia.com Signed-off-by: Peter Xu <peterx@redhat.com>
2024-01-04migration/multifd: Fix leaking of Error in TLS error flowAvihai Horon
If there is an error in multifd TLS handshake task, multifd_tls_outgoing_handshake() retrieves the error with qio_task_propagate_error() but never frees it. Fix it by freeing the obtained Error. In addition, the error is not reported at all, so report it with migrate_set_error(). Fixes: 29647140157a ("migration/tls: add support for multifd tls-handshake") Signed-off-by: Avihai Horon <avihaih@nvidia.com> Reviewed-by: Fabiano Rosas <farosas@suse.de> Link: https://lore.kernel.org/r/20231231093016.14204-8-avihaih@nvidia.com Signed-off-by: Peter Xu <peterx@redhat.com>
2024-01-04migration/multifd: Simplify multifd_channel_connect() if else statementAvihai Horon
The else branch in multifd_channel_connect() is redundant because when the if branch is taken the function returns. Simplify the code by removing the else branch. Signed-off-by: Avihai Horon <avihaih@nvidia.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Link: https://lore.kernel.org/r/20231231093016.14204-7-avihaih@nvidia.com Signed-off-by: Peter Xu <peterx@redhat.com>
2024-01-04migration/multifd: Fix error message in multifd_recv_initial_packet()Avihai Horon
In multifd_recv_initial_packet(), if MultiFDInit_t->id is greater than the configured number of multifd channels, an irrelevant error message about multifd version is printed. Change the error message to a relevant one about the channel id. Signed-off-by: Avihai Horon <avihaih@nvidia.com> Reviewed-by: Fabiano Rosas <farosas@suse.de> Link: https://lore.kernel.org/r/20231231093016.14204-6-avihaih@nvidia.com Signed-off-by: Peter Xu <peterx@redhat.com>
2023-11-30migration/multifd: Stop setting p->ioc before connectingFabiano Rosas
This is being shadowed but the assignments at multifd_channel_connect() and multifd_tls_channel_connect() . Signed-off-by: Fabiano Rosas <farosas@suse.de> Message-ID: <20231110200241.20679-2-farosas@suse.de> Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-10-31migration: Remove transferred atomic counterJuan Quintela
After last commit, it is a write only variable. Reviewed-by: Fabiano Rosas <farosas@suse.de> Signed-off-by: Juan Quintela <quintela@redhat.com> Message-ID: <20231025091117.6342-12-quintela@redhat.com>
2023-10-20migration/multifd: Stop checking p->quit in multifd_send_threadFabiano Rosas
We don't need to check p->quit in the multifd_send_thread() because it is shadowed by the 'exiting' flag. Ever since that flag was added p->quit became obsolete as a way to stop the thread. Since p->quit is set at multifd_send_terminate_threads() under the p->mutex lock, the thread will only see it once it loops, so 'exiting' will always be seen first. Note that setting p->quit at multifd_send_terminate_threads() still makes sense because we need a way to inform multifd_send_pages() that the channel has stopped. Signed-off-by: Fabiano Rosas <farosas@suse.de> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com> Message-ID: <20231012140651.13122-3-farosas@suse.de>
2023-10-17migration/multifd: Clarify Error usage in multifd_channel_connectFabiano Rosas
The function is currently called from two sites, one always gives it a NULL Error and the other always gives it a non-NULL Error. In the non-NULL case, all it does it trace the error and return. One of the callers already have tracing, add a tracepoint to the other and stop passing the error into the function. Cc: Markus Armbruster <armbru@redhat.com> Signed-off-by: Fabiano Rosas <farosas@suse.de> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com> Message-ID: <20231012134343.23757-4-farosas@suse.de>
2023-10-17migration/multifd: Unify multifd_send_thread error pathsFabiano Rosas
The preferred usage of the Error type is to always set both the return code and the error when a failure happens. As all code called from the send thread follows this pattern, we'll always have the return code and the error set at the same time. Aside from the convention, in this piece of code this must be the case, otherwise the if (ret != 0) would be exiting the thread without calling multifd_send_terminate_threads() which is incorrect. Unify both paths to make it clear that both are taken when there's an error. Signed-off-by: Fabiano Rosas <farosas@suse.de> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com> Message-ID: <20231012134343.23757-3-farosas@suse.de>
2023-10-17migration/multifd: Remove direct "socket" referencesFabiano Rosas
We're about to enable support for other transports in multifd, so remove direct references to sockets. Signed-off-by: Fabiano Rosas <farosas@suse.de> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com> Message-ID: <20231012134343.23757-2-farosas@suse.de>
2023-10-17multifd: reset next_packet_len after sending pagesElena Ufimtseva
Sometimes multifd sends just sync packet with no pages (normal_num is 0). In this case the old value is being preserved and being accounted for while only packet_len is being transferred. Reset it to 0 after sending and accounting for. Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com> Reviewed-by: Fabiano Rosas <farosas@suse.de> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com> Message-ID: <20231011184358.97349-5-elena.ufimtseva@oracle.com>
2023-10-17multifd: fix counters in multifd_send_threadElena Ufimtseva
Previous commit cbec7eb76879d419e7dbf531ee2506ec0722e825 "migration/multifd: Compute transferred bytes correctly" removed accounting for packet_len in non-rdma case, but the next_packet_size only accounts for pages, not for the header packet (normal_pages * PAGE_SIZE) that is being sent as iov[0]. The packet_len part should be added to account for the size of MultiFDPacket and the array of the offsets. Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com> Reviewed-by: Fabiano Rosas <farosas@suse.de> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com> Message-ID: <20231011184358.97349-4-elena.ufimtseva@oracle.com>
2023-07-26migration/multifd: Rename threadinfo.c functionsFabiano Rosas
We're about to add more functions to this file so make it use the same coding style as the rest of the code. Signed-off-by: Fabiano Rosas <farosas@suse.de> Reviewed-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Reviewed-by: Peter Xu <peterx@redhat.com> Message-Id: <20230607161306.31425-2-farosas@suse.de> Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-07-25migration: spelling fixesMichael Tokarev
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru> Reviewed-by: Fabiano Rosas <farosas@suse.de>
2023-06-05bulk: Remove pointless QOM castsPhilippe Mathieu-Daudé
Mechanical change running Coccinelle spatch with content generated from the qom-cast-macro-clean-cocci-gen.py added in the previous commit. Suggested-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> Message-Id: <20230601093452.38972-3-philmd@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Thomas Huth <thuth@redhat.com>
2023-05-18migration/multifd: Compute transferred bytes correctlyJuan Quintela
In the past, we had to put the in the main thread all the operations related with sizes due to qemu_file not beeing thread safe. As now all counters are atomic, we can update the counters just after the do the write. As an aditional bonus, we are able to use the right value for the compression methods. Right now we were assuming that there were no compression at all. Signed-off-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com> Message-Id: <20230515195709.63843-17-quintela@redhat.com>
2023-05-18migration: We don't need the field rate_limit_used anymoreJuan Quintela
Since previous commit, we calculate how much data we have send with migration_transferred_bytes() so no need to maintain this counter and remember to always update it. Signed-off-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Cédric Le Goater <clg@kaod.org> Message-Id: <20230515195709.63843-10-quintela@redhat.com>
2023-05-18migration: Move rate_limit_max and rate_limit_used to migration_statsJuan Quintela
These way we can make them atomic and use this functions from any place. I also moved all functions that use rate_limit to migration-stats. Functions got renamed, they are not qemu_file anymore. qemu_file_rate_limit -> migration_rate_exceeded qemu_file_set_rate_limit -> migration_rate_set qemu_file_get_rate_limit -> migration_rate_get qemu_file_reset_rate_limit -> migration_rate_reset qemu_file_acct_rate_limit -> migration_rate_account. Reviewed-by: Harsh Prateek Bora <harshpb@linux.ibm.com> Signed-off-by: Juan Quintela <quintela@redhat.com> Message-Id: <20230515195709.63843-6-quintela@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-05-10multifd: Add the ramblock to MultiFDRecvParamsLukas Straub
This will be used in the next commits to add colo support to multifd. Signed-off-by: Lukas Straub <lukasstraub2@web.de> Reviewed-by: Juan Quintela <quintela@redhat.com> Message-Id: <88135197411df1a71d7832962b39abf60faf0021.1683572883.git.lukasstraub2@web.de> Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-05-03migration: Drop unused parameter for migration_tls_client_create()Juan Quintela
It is not needed since we moved the accessor for tls properties to options.c. Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Signed-off-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>