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| author | Sean Christopherson <seanjc@google.com> | 2026-09-23 09:37:21 -0700 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2026-09-26 00:39:55 -0400 |
| commit | 93de2a6a4b91b72607136dd656edf03fb399d27f (patch) | |
| tree | 9220c76eb23cb39a146fac9692ee69afa4aa3135 /Documentation/tools/rtla/rtla-timerlat-hist.rst | |
| download | linux-stable-93de2a6a4b91b72607136dd656edf03fb399d27f.tar.gz linux-stable-93de2a6a4b91b72607136dd656edf03fb399d27f.zip | |
KVM: SEV: Do cache maintenance on the source VM during intra-host migrationgrafted
Manually perform cache maintenance on the source VM during intra-host
migration to ensure no stale data is left in CPU caches after the VM is
destroyed. Because the source VM is "converted" to a non-SEV VM, KVM's
memory reclaim flows won't trigger cache maintenance, e.g. when all guest
memory is reclaimed in response to detaching from the mmu_notifier.
Note, relying on the destination VM to do cache maintenance isn't an option
as KVM doesn't require identical guest memory configurations, i.e. the
source VM may have access to memory that the destination VM does not.
Enforcing equivalent memory configurations is infeasible, as it would
require a *deep* comparison of memslots, e.g. to verify that not only are
the memslot identical, but what the memslots point at is also identical.
Fixes: b56639318bb2 ("KVM: SEV: Add support for SEV intra host migration")
Cc: stable@vger.kernel.org
Reported-by: Stefan Teodorescu <fane@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20260923163721.1584779-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'Documentation/tools/rtla/rtla-timerlat-hist.rst')
| -rw-r--r-- | Documentation/tools/rtla/rtla-timerlat-hist.rst | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/Documentation/tools/rtla/rtla-timerlat-hist.rst b/Documentation/tools/rtla/rtla-timerlat-hist.rst new file mode 100644 index 000000000..dab75677b --- /dev/null +++ b/Documentation/tools/rtla/rtla-timerlat-hist.rst @@ -0,0 +1,113 @@ +.. |tool| replace:: timerlat hist + +===================== +rtla-timerlat-hist +===================== +------------------------------------------------ +Histograms of the operating system timer latency +------------------------------------------------ + +:Manual section: 1 + +SYNOPSIS +======== +**rtla timerlat hist** [*OPTIONS*] ... + +DESCRIPTION +=========== + +.. include:: common_timerlat_description.txt + +The **rtla timerlat hist** displays a histogram of each tracer event +occurrence. This tool uses the periodic information, and the +**osnoise:** tracepoints are enabled when using the **-T** option. + +OPTIONS +======= + +.. include:: common_timerlat_options.txt + +.. include:: common_hist_options.txt + +.. include:: common_options.txt + +.. include:: common_timerlat_aa.txt + +EXAMPLE +======= +In the example below, **rtla timerlat hist** is set to run for *10* minutes, +in the cpus *0-4*, *skipping zero* only lines. Moreover, **rtla timerlat +hist** will change the priority of the *timerlat* threads to run under +*SCHED_DEADLINE* priority, with a *100us* runtime every *1ms* period. The +*1ms* period is also passed to the *timerlat* tracer. Auto-analysis is disabled +to reduce overhead :: + + [root@alien ~]# timerlat hist -d 10m -c 0-4 -P d:100us:1ms -p 1000 --no-aa + # RTLA timerlat histogram + # Time unit is microseconds (us) + # Duration: 0 00:10:00 + Index IRQ-000 Thr-000 IRQ-001 Thr-001 IRQ-002 Thr-002 IRQ-003 Thr-003 IRQ-004 Thr-004 + 0 276489 0 206089 0 466018 0 481102 0 205546 0 + 1 318327 35487 388149 30024 94531 48382 83082 71078 388026 55730 + 2 3282 122584 4019 126527 28231 109012 23311 89309 4568 98739 + 3 940 11815 837 9863 6209 16227 6895 17196 910 9780 + 4 444 17287 424 11574 2097 38443 2169 36736 462 13476 + 5 206 43291 255 25581 1223 101908 1304 101137 236 28913 + 6 132 101501 96 64584 635 213774 757 215471 99 73453 + 7 74 169347 65 124758 350 57466 441 53639 69 148573 + 8 53 85183 31 156751 229 9052 306 9026 39 139907 + 9 22 10387 12 42762 161 2554 225 2689 19 26192 + 10 13 1898 8 5770 114 1247 128 1405 13 3772 + 11 9 560 9 924 71 686 76 765 8 713 + 12 4 256 2 360 50 411 64 474 3 278 + 13 2 167 2 172 43 256 53 350 4 180 + 14 1 88 1 116 15 198 42 223 0 115 + 15 2 63 3 94 11 139 20 150 0 58 + 16 2 37 0 56 5 78 10 102 0 39 + 17 0 18 0 28 4 57 8 80 0 15 + 18 0 8 0 17 2 50 6 56 0 12 + 19 0 9 0 5 0 19 0 48 0 18 + 20 0 4 0 8 0 11 2 27 0 4 + 21 0 2 0 3 1 9 1 18 0 6 + 22 0 1 0 3 1 7 0 3 0 5 + 23 0 2 0 4 0 2 0 7 0 2 + 24 0 2 0 2 1 3 0 3 0 5 + 25 0 0 0 1 0 1 0 1 0 3 + 26 0 1 0 0 0 2 0 2 0 0 + 27 0 0 0 3 0 1 0 0 0 1 + 28 0 0 0 3 0 0 0 1 0 0 + 29 0 0 0 2 0 2 0 1 0 3 + 30 0 1 0 0 0 0 0 0 0 0 + 31 0 1 0 0 0 0 0 2 0 2 + 32 0 0 0 1 0 2 0 0 0 0 + 33 0 0 0 2 0 0 0 0 0 1 + 34 0 0 0 0 0 0 0 0 0 2 + 35 0 1 0 1 0 0 0 0 0 1 + 36 0 1 0 0 0 1 0 1 0 0 + 37 0 0 0 1 0 0 0 0 0 0 + 40 0 0 0 0 0 1 0 1 0 0 + 41 0 0 0 0 0 0 0 0 0 1 + 42 0 0 0 0 0 0 0 0 0 1 + 44 0 0 0 0 0 1 0 0 0 0 + 46 0 0 0 0 0 0 0 1 0 0 + 47 0 0 0 0 0 0 0 0 0 1 + 50 0 0 0 0 0 0 0 0 0 1 + 54 0 0 0 1 0 0 0 0 0 0 + 58 0 0 0 1 0 0 0 0 0 0 + over: 0 0 0 0 0 0 0 0 0 0 + count: 600002 600002 600002 600002 600002 600002 600002 600002 600002 600002 + min: 0 1 0 1 0 1 0 1 0 1 + avg: 0 5 0 5 0 4 0 4 0 5 + max: 16 36 15 58 24 44 21 46 13 50 + +SEE ALSO +======== +**rtla-timerlat**\(1), **rtla-timerlat-top**\(1) + +`Timerlat tracer <https://docs.kernel.org/trace/timerlat-tracer.html>`__ + +AUTHOR +====== +Written by Daniel Bristot de Oliveira <bristot@kernel.org> + +.. include:: common_appendix.txt |