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2024-02-05migration/multifd: Move header prepare/fill into send_prepare()Peter Xu1-0/+4
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: Drop MultiFDSendParams.normal[] arrayPeter Xu1-3/+4
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>
2023-07-25migration: spelling fixesMichael Tokarev1-1/+1
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru> Reviewed-by: Fabiano Rosas <farosas@suse.de>
2023-04-24migration: Move parameters functions to option.cJuan Quintela1-0/+1
Signed-off-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
2022-12-15multifd: Create page_size fields into both MultiFD{Recv,Send}ParamsJuan Quintela1-8/+6
We were calling qemu_target_page_size() left and right. Signed-off-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Leonardo Bras <leobras@redhat.com>
2022-07-20multifd: Copy pages before compressing them with zlibIlya Leoshkevich1-8/+30
zlib_send_prepare() compresses pages of a running VM. zlib does not make any thread-safety guarantees with respect to changing deflate() input concurrently with deflate() [1]. One can observe problems due to this with the IBM zEnterprise Data Compression accelerator capable zlib [2]. When the hardware acceleration is enabled, migration/multifd/tcp/plain/zlib test fails intermittently [3] due to sliding window corruption. The accelerator's architecture explicitly discourages concurrent accesses [4]: Page 26-57, "Other Conditions": As observed by this CPU, other CPUs, and channel programs, references to the parameter block, first, second, and third operands may be multiple-access references, accesses to these storage locations are not necessarily block-concurrent, and the sequence of these accesses or references is undefined. Mark Adler pointed out that vanilla zlib performs double fetches under certain circumstances as well [5], therefore we need to copy data before passing it to deflate(). [1] https://zlib.net/manual.html [2] https://github.com/madler/zlib/pull/410 [3] https://lists.nongnu.org/archive/html/qemu-devel/2022-03/msg03988.html [4] http://publibfp.dhe.ibm.com/epubs/pdf/a227832c.pdf [5] https://lists.gnu.org/archive/html/qemu-devel/2022-07/msg00889.html Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Message-Id: <20220705203559.2960949-1-iii@linux.ibm.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-03-21Use g_new() & friends where that makes obvious senseMarkus Armbruster1-2/+2
g_new(T, n) is neater than g_malloc(sizeof(T) * n). It's also safer, for two reasons. One, it catches multiplication overflowing size_t. Two, it returns T * rather than void *, which lets the compiler catch more type errors. This commit only touches allocations with size arguments of the form sizeof(T). Patch created mechanically with: $ spatch --in-place --sp-file scripts/coccinelle/use-g_new-etc.cocci \ --macro-file scripts/cocci-macro-file.h FILES... Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Reviewed-by: Cédric Le Goater <clg@kaod.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Message-Id: <20220315144156.1595462-4-armbru@redhat.com> Reviewed-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
2022-01-28multifd: recv side only needs the RAMBlock host addressJuan Quintela1-1/+1
So we can remove the MultiFDPages. Signed-off-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-01-28multifd: Use normal pages array on the recv sideJuan Quintela1-4/+4
Signed-off-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> --- Rename num_normal_pages to total_normal_pages (peter)
2022-01-28multifd: Use normal pages array on the send sideJuan Quintela1-3/+3
We are only sending normal pages through multifd channels. Later on this series, we are going to also send zero pages. We are going to detect if a page is zero or non zero in the multifd channel thread, not on the main thread. So we receive an array of pages page->offset[N] And we will end with: p->normal[N - zero_pages] p->zero[zero_pages]. In this patch, we just copy all the pages in offset to normal. for (i = 0; i < pages->num; i++) { p->narmal[p->normal_num] = pages->offset[i]; p->normal_num++: } Later in the series this becomes: for (i = 0; i < pages->num; i++) { if (buffer_is_zero(page->offset[i])) { p->zerol[p->zero_num] = pages->offset[i]; p->zero_num++: } else { p->narmal[p->normal_num] = pages->offset[i]; p->normal_num++: } } Signed-off-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> --- Improving comment (dave) Renaming num_normal_pages to total_normal_pages (peter)
2022-01-28multifd: Remove send_write() methodJuan Quintela1-17/+0
Everything use now iov's. Signed-off-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-01-28multifd: Make zlib use iov'sJuan Quintela1-4/+4
Signed-off-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-01-28multifd: Use proper maximum compression valuesJuan Quintela1-2/+2
It happens that there are functions to calculate the worst possible compression size for a packet. Use them. Suggested-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-01-28migration: All this fields are unsignedJuan Quintela1-10/+10
So printing it as %d is wrong. Notice that for the channel id, that is an uint8_t, but I changed it anyways for consistency. Signed-off-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com>
2021-12-15multifd: Make zlib compression method not use iovsJuan Quintela1-8/+9
Signed-off-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2021-12-15multifd: remove used parameter from send_recv_pages() methodJuan Quintela1-5/+4
It is already there as p->pages->num. Signed-off-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2021-12-15multifd: remove used parameter from send_prepare() methodJuan Quintela1-4/+3
It is already there as p->pages->num. Signed-off-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2021-12-15multifd: Add missing documentionJuan Quintela1-0/+2
Signed-off-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2021-12-15multifd: Delete useless operationJuan Quintela1-9/+4
We are dividing by page_size to multiply again in the only use. Once there, improve the comments. Signed-off-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2020-02-28multifd: Add zlib compression multifd supportJuan Quintela1-0/+325
Signed-off-by: Juan Quintela <quintela@redhat.com> Acked-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>