From 93de2a6a4b91b72607136dd656edf03fb399d27f Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Wed, 23 Sep 2026 09:37:21 -0700 Subject: KVM: SEV: Do cache maintenance on the source VM during intra-host migration 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 Signed-off-by: Sean Christopherson Message-ID: <20260923163721.1584779-3-seanjc@google.com> Signed-off-by: Paolo Bonzini --- scripts/bootgraph.pl | 224 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 224 insertions(+) create mode 100755 scripts/bootgraph.pl (limited to 'scripts/bootgraph.pl') diff --git a/scripts/bootgraph.pl b/scripts/bootgraph.pl new file mode 100755 index 000000000..79c903292 --- /dev/null +++ b/scripts/bootgraph.pl @@ -0,0 +1,224 @@ +#!/usr/bin/env perl +# SPDX-License-Identifier: GPL-2.0-only + +# Copyright 2008, Intel Corporation +# +# This file is part of the Linux kernel +# +# Authors: +# Arjan van de Ven + + +# +# This script turns a dmesg output into a SVG graphic that shows which +# functions take how much time. You can view SVG graphics with various +# programs, including Inkscape, The Gimp and Firefox. +# +# +# For this script to work, the kernel needs to be compiled with the +# CONFIG_PRINTK_TIME configuration option enabled, and with +# "initcall_debug" passed on the kernel command line. +# +# usage: +# dmesg | perl scripts/bootgraph.pl > output.svg +# + +use strict; +use Getopt::Long; +my $header = 0; + +sub help { + my $text = << "EOM"; +Usage: +1) dmesg | perl scripts/bootgraph.pl [OPTION] > output.svg +2) perl scripts/bootgraph.pl -h + +Options: + -header Insert kernel version and date +EOM + my $std=shift; + if ($std == 1) { + print STDERR $text; + } else { + print $text; + } + exit; +} + +GetOptions( + 'h|help' =>\&help, + 'header' =>\$header +); + +my %start; +my %end; +my %type; +my $done = 0; +my $maxtime = 0; +my $firsttime = 99999; +my $count = 0; +my %pids; +my %pidctr; + +my $headerstep = 20; +my $xheader = 15; +my $yheader = 25; +my $cyheader = 0; + +while (<>) { + my $line = $_; + if ($line =~ /([0-9\.]+)\] calling ([a-zA-Z0-9\_\.]+)\+/) { + my $func = $2; + if ($done == 0) { + $start{$func} = $1; + $type{$func} = 0; + if ($1 < $firsttime) { + $firsttime = $1; + } + } + if ($line =~ /\@ ([0-9]+)/) { + $pids{$func} = $1; + } + $count = $count + 1; + } + + if ($line =~ /([0-9\.]+)\] async_waiting @ ([0-9]+)/) { + my $pid = $2; + my $func; + if (!defined($pidctr{$pid})) { + $func = "wait_" . $pid . "_1"; + $pidctr{$pid} = 1; + } else { + $pidctr{$pid} = $pidctr{$pid} + 1; + $func = "wait_" . $pid . "_" . $pidctr{$pid}; + } + if ($done == 0) { + $start{$func} = $1; + $type{$func} = 1; + if ($1 < $firsttime) { + $firsttime = $1; + } + } + $pids{$func} = $pid; + $count = $count + 1; + } + + if ($line =~ /([0-9\.]+)\] initcall ([a-zA-Z0-9\_\.]+)\+.*returned/) { + if ($done == 0) { + $end{$2} = $1; + $maxtime = $1; + } + } + + if ($line =~ /([0-9\.]+)\] async_continuing @ ([0-9]+)/) { + my $pid = $2; + my $func = "wait_" . $pid . "_" . $pidctr{$pid}; + $end{$func} = $1; + $maxtime = $1; + } + if ($line =~ /Write protecting the/) { + $done = 1; + } + if ($line =~ /Freeing unused kernel memory/) { + $done = 1; + } +} + +if ($count == 0) { + print STDERR < \n"; +print "\n"; + + +if ($header) { + my $version = `uname -a`; + my $date = `date`; + print "Kernel version: $version\n"; + $cyheader = $yheader+$headerstep; + print "Date: $date\n"; +} + +my @styles; + +$styles[0] = "fill:rgb(0,0,255);fill-opacity:0.5;stroke-width:1;stroke:rgb(0,0,0)"; +$styles[1] = "fill:rgb(0,255,0);fill-opacity:0.5;stroke-width:1;stroke:rgb(0,0,0)"; +$styles[2] = "fill:rgb(255,0,20);fill-opacity:0.5;stroke-width:1;stroke:rgb(0,0,0)"; +$styles[3] = "fill:rgb(255,255,20);fill-opacity:0.5;stroke-width:1;stroke:rgb(0,0,0)"; +$styles[4] = "fill:rgb(255,0,255);fill-opacity:0.5;stroke-width:1;stroke:rgb(0,0,0)"; +$styles[5] = "fill:rgb(0,255,255);fill-opacity:0.5;stroke-width:1;stroke:rgb(0,0,0)"; +$styles[6] = "fill:rgb(0,128,255);fill-opacity:0.5;stroke-width:1;stroke:rgb(0,0,0)"; +$styles[7] = "fill:rgb(0,255,128);fill-opacity:0.5;stroke-width:1;stroke:rgb(0,0,0)"; +$styles[8] = "fill:rgb(255,0,128);fill-opacity:0.5;stroke-width:1;stroke:rgb(0,0,0)"; +$styles[9] = "fill:rgb(255,255,128);fill-opacity:0.5;stroke-width:1;stroke:rgb(0,0,0)"; +$styles[10] = "fill:rgb(255,128,255);fill-opacity:0.5;stroke-width:1;stroke:rgb(0,0,0)"; +$styles[11] = "fill:rgb(128,255,255);fill-opacity:0.5;stroke-width:1;stroke:rgb(0,0,0)"; + +my $style_wait = "fill:rgb(128,128,128);fill-opacity:0.5;stroke-width:0;stroke:rgb(0,0,0)"; + +my $mult = 1950.0 / ($maxtime - $firsttime); +my $threshold2 = ($maxtime - $firsttime) / 120.0; +my $threshold = $threshold2/10; +my $stylecounter = 0; +my %rows; +my $rowscount = 1; +my @initcalls = sort { $start{$a} <=> $start{$b} } keys(%start); + +foreach my $key (@initcalls) { + my $duration = $end{$key} - $start{$key}; + + if ($duration >= $threshold) { + my ($s, $s2, $s3, $e, $w, $y, $y2, $style); + my $pid = $pids{$key}; + + if (!defined($rows{$pid})) { + $rows{$pid} = $rowscount; + $rowscount = $rowscount + 1; + } + $s = ($start{$key} - $firsttime) * $mult; + $s2 = $s + 6; + $s3 = $s + 1; + $e = ($end{$key} - $firsttime) * $mult; + $w = $e - $s; + + $y = $rows{$pid} * 150; + $y2 = $y + 4; + + $style = $styles[$stylecounter]; + $stylecounter = $stylecounter + 1; + if ($stylecounter > 11) { + $stylecounter = 0; + }; + + if ($type{$key} == 1) { + $y = $y + 15; + print "\n"; + } else { + print "\n"; + if ($duration >= $threshold2) { + print "$key\n"; + } else { + print "$key\n"; + } + } + } +} + + +# print the time line on top +my $time = $firsttime; +my $step = ($maxtime - $firsttime) / 15; +while ($time < $maxtime) { + my $s3 = ($time - $firsttime) * $mult; + my $tm = int($time * 100) / 100.0; + print "$tm\n"; + $time = $time + $step; +} + +print "\n"; -- cgit v1.3.1