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/markup_oops.pl | 366 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 366 insertions(+) create mode 100755 scripts/markup_oops.pl (limited to 'scripts/markup_oops.pl') diff --git a/scripts/markup_oops.pl b/scripts/markup_oops.pl new file mode 100755 index 000000000..e476caf52 --- /dev/null +++ b/scripts/markup_oops.pl @@ -0,0 +1,366 @@ +#!/usr/bin/env perl +# SPDX-License-Identifier: GPL-2.0-only + +use File::Basename; +use Math::BigInt; +use Getopt::Long; + +# Copyright 2008, Intel Corporation +# +# This file is part of the Linux kernel +# +# Authors: +# Arjan van de Ven + + +my $cross_compile = ""; +my $vmlinux_name = ""; +my $modulefile = ""; + +# Get options +Getopt::Long::GetOptions( + 'cross-compile|c=s' => \$cross_compile, + 'module|m=s' => \$modulefile, + 'help|h' => \&usage, +) || usage (); +my $vmlinux_name = $ARGV[0]; +if (!defined($vmlinux_name)) { + my $kerver = `uname -r`; + chomp($kerver); + $vmlinux_name = "/lib/modules/$kerver/build/vmlinux"; + print "No vmlinux specified, assuming $vmlinux_name\n"; +} +my $filename = $vmlinux_name; + +# Parse the oops to find the EIP value + +my $target = "0"; +my $function; +my $module = ""; +my $func_offset = 0; +my $vmaoffset = 0; + +my %regs; + + +sub parse_x86_regs +{ + my ($line) = @_; + if ($line =~ /EAX: ([0-9a-f]+) EBX: ([0-9a-f]+) ECX: ([0-9a-f]+) EDX: ([0-9a-f]+)/) { + $regs{"%eax"} = $1; + $regs{"%ebx"} = $2; + $regs{"%ecx"} = $3; + $regs{"%edx"} = $4; + } + if ($line =~ /ESI: ([0-9a-f]+) EDI: ([0-9a-f]+) EBP: ([0-9a-f]+) ESP: ([0-9a-f]+)/) { + $regs{"%esi"} = $1; + $regs{"%edi"} = $2; + $regs{"%esp"} = $4; + } + if ($line =~ /RAX: ([0-9a-f]+) RBX: ([0-9a-f]+) RCX: ([0-9a-f]+)/) { + $regs{"%eax"} = $1; + $regs{"%ebx"} = $2; + $regs{"%ecx"} = $3; + } + if ($line =~ /RDX: ([0-9a-f]+) RSI: ([0-9a-f]+) RDI: ([0-9a-f]+)/) { + $regs{"%edx"} = $1; + $regs{"%esi"} = $2; + $regs{"%edi"} = $3; + } + if ($line =~ /RBP: ([0-9a-f]+) R08: ([0-9a-f]+) R09: ([0-9a-f]+)/) { + $regs{"%r08"} = $2; + $regs{"%r09"} = $3; + } + if ($line =~ /R10: ([0-9a-f]+) R11: ([0-9a-f]+) R12: ([0-9a-f]+)/) { + $regs{"%r10"} = $1; + $regs{"%r11"} = $2; + $regs{"%r12"} = $3; + } + if ($line =~ /R13: ([0-9a-f]+) R14: ([0-9a-f]+) R15: ([0-9a-f]+)/) { + $regs{"%r13"} = $1; + $regs{"%r14"} = $2; + $regs{"%r15"} = $3; + } +} + +sub reg_name +{ + my ($reg) = @_; + $reg =~ s/r(.)x/e\1x/; + $reg =~ s/r(.)i/e\1i/; + $reg =~ s/r(.)p/e\1p/; + return $reg; +} + +sub process_x86_regs +{ + my ($line, $cntr) = @_; + my $str = ""; + if (length($line) < 40) { + return ""; # not an asm istruction + } + + # find the arguments to the instruction + if ($line =~ /([0-9a-zA-Z\,\%\(\)\-\+]+)$/) { + $lastword = $1; + } else { + return ""; + } + + # we need to find the registers that get clobbered, + # since their value is no longer relevant for previous + # instructions in the stream. + + $clobber = $lastword; + # first, remove all memory operands, they're read only + $clobber =~ s/\([a-z0-9\%\,]+\)//g; + # then, remove everything before the comma, thats the read part + $clobber =~ s/.*\,//g; + + # if this is the instruction that faulted, we haven't actually done + # the write yet... nothing is clobbered. + if ($cntr == 0) { + $clobber = ""; + } + + foreach $reg (keys(%regs)) { + my $clobberprime = reg_name($clobber); + my $lastwordprime = reg_name($lastword); + my $val = $regs{$reg}; + if ($val =~ /^[0]+$/) { + $val = "0"; + } else { + $val =~ s/^0*//; + } + + # first check if we're clobbering this register; if we do + # we print it with a =>, and then delete its value + if ($clobber =~ /$reg/ || $clobberprime =~ /$reg/) { + if (length($val) > 0) { + $str = $str . " $reg => $val "; + } + $regs{$reg} = ""; + $val = ""; + } + # now check if we're reading this register + if ($lastword =~ /$reg/ || $lastwordprime =~ /$reg/) { + if (length($val) > 0) { + $str = $str . " $reg = $val "; + } + } + } + return $str; +} + +# parse the oops +while () { + my $line = $_; + if ($line =~ /EIP: 0060:\[\<([a-z0-9]+)\>\]/) { + $target = $1; + } + if ($line =~ /RIP: 0010:\[\<([a-z0-9]+)\>\]/) { + $target = $1; + } + if ($line =~ /EIP is at ([a-zA-Z0-9\_]+)\+0x([0-9a-f]+)\/0x[a-f0-9]/) { + $function = $1; + $func_offset = $2; + } + if ($line =~ /RIP: 0010:\[\<[0-9a-f]+\>\] \[\<[0-9a-f]+\>\] ([a-zA-Z0-9\_]+)\+0x([0-9a-f]+)\/0x[a-f0-9]/) { + $function = $1; + $func_offset = $2; + } + + # check if it's a module + if ($line =~ /EIP is at ([a-zA-Z0-9\_]+)\+(0x[0-9a-f]+)\/0x[a-f0-9]+\W\[([a-zA-Z0-9\_\-]+)\]/) { + $module = $3; + } + if ($line =~ /RIP: 0010:\[\<[0-9a-f]+\>\] \[\<[0-9a-f]+\>\] ([a-zA-Z0-9\_]+)\+(0x[0-9a-f]+)\/0x[a-f0-9]+\W\[([a-zA-Z0-9\_\-]+)\]/) { + $module = $3; + } + parse_x86_regs($line); +} + +my $decodestart = Math::BigInt->from_hex("0x$target") - Math::BigInt->from_hex("0x$func_offset"); +my $decodestop = Math::BigInt->from_hex("0x$target") + 8192; +if ($target eq "0") { + print "No oops found!\n"; + usage(); +} + +# if it's a module, we need to find the .ko file and calculate a load offset +if ($module ne "") { + if ($modulefile eq "") { + $modulefile = `modinfo -F filename $module`; + chomp($modulefile); + } + $filename = $modulefile; + if ($filename eq "") { + print "Module .ko file for $module not found. Aborting\n"; + exit; + } + # ok so we found the module, now we need to calculate the vma offset + open(FILE, $cross_compile."objdump -dS $filename |") || die "Cannot start objdump"; + while () { + if ($_ =~ /^([0-9a-f]+) \<$function\>\:/) { + my $fu = $1; + $vmaoffset = Math::BigInt->from_hex("0x$target") - Math::BigInt->from_hex("0x$fu") - Math::BigInt->from_hex("0x$func_offset"); + } + } + close(FILE); +} + +my $counter = 0; +my $state = 0; +my $center = -1; +my @lines; +my @reglines; + +sub InRange { + my ($address, $target) = @_; + my $ad = "0x".$address; + my $ta = "0x".$target; + my $delta = Math::BigInt->from_hex($ad) - Math::BigInt->from_hex($ta); + + if (($delta > -4096) && ($delta < 4096)) { + return 1; + } + return 0; +} + + + +# first, parse the input into the lines array, but to keep size down, +# we only do this for 4Kb around the sweet spot + +open(FILE, $cross_compile."objdump -dS --adjust-vma=$vmaoffset --start-address=$decodestart --stop-address=$decodestop $filename |") || die "Cannot start objdump"; + +while () { + my $line = $_; + chomp($line); + if ($state == 0) { + if ($line =~ /^([a-f0-9]+)\:/) { + if (InRange($1, $target)) { + $state = 1; + } + } + } + if ($state == 1) { + if ($line =~ /^([a-f0-9][a-f0-9][a-f0-9][a-f0-9][a-f0-9][a-f0-9]+)\:/) { + my $val = $1; + if (!InRange($val, $target)) { + last; + } + if ($val eq $target) { + $center = $counter; + } + } + $lines[$counter] = $line; + + $counter = $counter + 1; + } +} + +close(FILE); + +if ($counter == 0) { + print "No matching code found \n"; + exit; +} + +if ($center == -1) { + print "No matching code found \n"; + exit; +} + +my $start; +my $finish; +my $codelines = 0; +my $binarylines = 0; +# now we go up and down in the array to find how much we want to print + +$start = $center; + +while ($start > 1) { + $start = $start - 1; + my $line = $lines[$start]; + if ($line =~ /^([a-f0-9]+)\:/) { + $binarylines = $binarylines + 1; + } else { + $codelines = $codelines + 1; + } + if ($codelines > 10) { + last; + } + if ($binarylines > 20) { + last; + } +} + + +$finish = $center; +$codelines = 0; +$binarylines = 0; +while ($finish < $counter) { + $finish = $finish + 1; + my $line = $lines[$finish]; + if ($line =~ /^([a-f0-9]+)\:/) { + $binarylines = $binarylines + 1; + } else { + $codelines = $codelines + 1; + } + if ($codelines > 10) { + last; + } + if ($binarylines > 20) { + last; + } +} + + +my $i; + + +# start annotating the registers in the asm. +# this goes from the oopsing point back, so that the annotator +# can track (opportunistically) which registers got written and +# whos value no longer is relevant. + +$i = $center; +while ($i >= $start) { + $reglines[$i] = process_x86_regs($lines[$i], $center - $i); + $i = $i - 1; +} + +$i = $start; +while ($i < $finish) { + my $line; + if ($i == $center) { + $line = "*$lines[$i] "; + } else { + $line = " $lines[$i] "; + } + print $line; + if (defined($reglines[$i]) && length($reglines[$i]) > 0) { + my $c = 60 - length($line); + while ($c > 0) { print " "; $c = $c - 1; }; + print "| $reglines[$i]"; + } + if ($i == $center) { + print "<--- faulting instruction"; + } + print "\n"; + $i = $i +1; +} + +sub usage { + print <