Commit Graph

26 Commits

Author SHA1 Message Date
Yuan Liu
5ef7e26bdb migration/multifd: solve zero page causing multiple page faults
Implemented recvbitmap tracking of received pages in multifd.

If the zero page appears for the first time in the recvbitmap, this
page is not checked and set.

If the zero page has already appeared in the recvbitmap, there is no
need to check the data but directly set the data to 0, because it is
unlikely that the zero page will be migrated multiple times.

Signed-off-by: Yuan Liu <yuan1.liu@intel.com>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Link: https://lore.kernel.org/r/20240401154110.2028453-2-yuan1.liu@intel.com
[peterx: touch up the comment, as the bitmap is used outside postcopy now]
Signed-off-by: Peter Xu <peterx@redhat.com>
2024-04-23 18:36:01 -04:00
Peter Maydell
e692f9c6a6 * Add missing ERRP_GUARD() statements in functions that need it
* Prefer fast cpu_env() over slower CPU QOM cast macro
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Merge tag 'pull-request-2024-03-12' of https://gitlab.com/thuth/qemu into staging

* Add missing ERRP_GUARD() statements in functions that need it
* Prefer fast cpu_env() over slower CPU QOM cast macro

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# gpg: Good signature from "Thomas Huth <th.huth@gmx.de>" [full]
# gpg:                 aka "Thomas Huth <thuth@redhat.com>" [full]
# gpg:                 aka "Thomas Huth <huth@tuxfamily.org>" [full]
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* tag 'pull-request-2024-03-12' of https://gitlab.com/thuth/qemu: (55 commits)
  user: Prefer fast cpu_env() over slower CPU QOM cast macro
  target/xtensa: Prefer fast cpu_env() over slower CPU QOM cast macro
  target/tricore: Prefer fast cpu_env() over slower CPU QOM cast macro
  target/sparc: Prefer fast cpu_env() over slower CPU QOM cast macro
  target/sh4: Prefer fast cpu_env() over slower CPU QOM cast macro
  target/rx: Prefer fast cpu_env() over slower CPU QOM cast macro
  target/ppc: Prefer fast cpu_env() over slower CPU QOM cast macro
  target/openrisc: Prefer fast cpu_env() over slower CPU QOM cast macro
  target/nios2: Prefer fast cpu_env() over slower CPU QOM cast macro
  target/mips: Prefer fast cpu_env() over slower CPU QOM cast macro
  target/microblaze: Prefer fast cpu_env() over slower CPU QOM cast macro
  target/m68k: Prefer fast cpu_env() over slower CPU QOM cast macro
  target/loongarch: Prefer fast cpu_env() over slower CPU QOM cast macro
  target/i386/hvf: Use CPUState typedef
  target/hexagon: Prefer fast cpu_env() over slower CPU QOM cast macro
  target/cris: Prefer fast cpu_env() over slower CPU QOM cast macro
  target/avr: Prefer fast cpu_env() over slower CPU QOM cast macro
  target/alpha: Prefer fast cpu_env() over slower CPU QOM cast macro
  target: Replace CPU_GET_CLASS(cpu -> obj) in cpu_reset_hold() handler
  bulk: Call in place single use cpu_env()
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2024-03-12 16:55:42 +00:00
Philippe Mathieu-Daudé
ee1004bba6 bulk: Access existing variables initialized to &S->F when available
When a variable is initialized to &struct->field, use it
in place. Rationale: while this makes the code more concise,
this also helps static analyzers.

Mechanical change using the following Coccinelle spatch script:

 @@
 type S, F;
 identifier s, m, v;
 @@
      S *s;
      ...
      F *v = &s->m;
      <+...
 -    &s->m
 +    v
      ...+>

Inspired-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20240129164514.73104-2-philmd@linaro.org>
Acked-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
[thuth: Dropped hunks that need a rebase, and fixed sizeof() in pmu_realize()]
Signed-off-by: Thomas Huth <thuth@redhat.com>
2024-03-12 11:46:16 +01:00
Hao Xiang
303e6f54f9 migration/multifd: Implement zero page transmission on the multifd thread.
1. Add zero_pages field in MultiFDPacket_t.
2. Implements the zero page detection and handling on the multifd
threads for non-compression, zlib and zstd compression backends.
3. Added a new value 'multifd' in ZeroPageDetection enumeration.
4. Adds zero page counters and updates multifd send/receive tracing
format to track the newly added counters.

Signed-off-by: Hao Xiang <hao.xiang@bytedance.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Link: https://lore.kernel.org/r/20240311180015.3359271-5-hao.xiang@linux.dev
Signed-off-by: Peter Xu <peterx@redhat.com>
2024-03-11 16:57:09 -04:00
Fabiano Rosas
9db1912513 migration/multifd: Decouple recv method from pages
Next patches will abstract the type of data being received by the
channels, so do some cleanup now to remove references to pages and
dependency on 'normal_num'.

Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Link: https://lore.kernel.org/r/20240229153017.2221-14-farosas@suse.de
Signed-off-by: Peter Xu <peterx@redhat.com>
2024-03-01 15:42:04 +08:00
Fabiano Rosas
402dd7ac1c migration/multifd: Rename MultiFDSend|RecvParams::data to compress_data
Use a more specific name for the compression data so we can use the
generic for the multifd core code.

Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Link: https://lore.kernel.org/r/20240229153017.2221-13-farosas@suse.de
Signed-off-by: Peter Xu <peterx@redhat.com>
2024-03-01 15:42:04 +08:00
Peter Xu
25a1f87875 migration/multifd: Move header prepare/fill into send_prepare()
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>
2024-02-05 14:42:10 +08:00
Peter Xu
efd8c5439d migration/multifd: Drop MultiFDSendParams.normal[] array
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>
2024-02-05 14:42:10 +08:00
Michael Tokarev
d8b71d96b3 migration: spelling fixes
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
2023-07-25 17:13:20 +03:00
Juan Quintela
1dfc4b9e19 migration: Move parameters functions to option.c
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
2023-04-24 15:01:46 +02:00
Juan Quintela
ddec20f858 multifd: Create page_size fields into both MultiFD{Recv,Send}Params
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>
2022-12-15 10:30:37 +01:00
Ilya Leoshkevich
007e179ef0 multifd: Copy pages before compressing them with zlib
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>
2022-07-20 12:15:08 +01:00
Markus Armbruster
b21e238037 Use g_new() & friends where that makes obvious sense
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>
2022-03-21 15:44:44 +01:00
Juan Quintela
faf60935df multifd: recv side only needs the RAMBlock host address
So we can remove the MultiFDPages.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-01-28 15:38:23 +01:00
Juan Quintela
cf2d4aa8a2 multifd: Use normal pages array on the recv side
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)
2022-01-28 15:38:23 +01:00
Juan Quintela
815956f039 multifd: Use normal pages array on the send side
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)
2022-01-28 15:38:23 +01:00
Juan Quintela
468fcb5dd0 multifd: Remove send_write() method
Everything use now iov's.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-01-28 15:38:23 +01:00
Juan Quintela
48a4a44c1c multifd: Make zlib use iov's
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-01-28 15:38:23 +01:00
Juan Quintela
fc6705229c multifd: Use proper maximum compression values
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>
2022-01-28 15:38:23 +01:00
Juan Quintela
04e1140494 migration: All this fields are unsigned
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>
2022-01-28 15:38:22 +01:00
Juan Quintela
a5ed229488 multifd: Make zlib compression method not use iovs
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2021-12-15 10:38:34 +01:00
Juan Quintela
40a4bfe9d3 multifd: remove used parameter from send_recv_pages() method
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>
2021-12-15 10:31:42 +01:00
Juan Quintela
02fb81043e multifd: remove used parameter from send_prepare() method
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>
2021-12-15 10:31:42 +01:00
Juan Quintela
18ede636bc multifd: Add missing documention
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2021-12-15 10:31:42 +01:00
Juan Quintela
47a1782461 multifd: Delete useless operation
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>
2021-12-15 10:31:42 +01:00
Juan Quintela
7ec2c2b3c1 multifd: Add zlib compression multifd support
Signed-off-by: Juan Quintela <quintela@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2020-02-28 09:24:43 +01:00