Convert policy calculation

Convert policy calculation to use shift operators and OR operation
instead of binary numbers and addition.

Signed-off-by: Philipp Giersfeld <philipp.giersfeld@canarybit.eu>
Reviewed-by: Fiona Ebner <f.ebner@proxmox.com>
Tested-by: Markus Frank <m.frank@proxmox.com>
Reviewed-by: Markus Frank <m.frank@proxmox.com>
This commit is contained in:
Philipp Giersfeld 2025-03-31 15:59:29 +02:00 committed by Thomas Lamprecht
parent b2aa996f43
commit d8594cf594

View File

@ -846,12 +846,12 @@ sub get_amd_sev_object {
# guest policy bit calculation as described here:
# https://documentation.suse.com/sles/15-SP5/html/SLES-amd-sev/article-amd-sev.html#table-guestpolicy
my $policy = 0b0000;
$policy += 0b0001 if $amd_sev_conf->{'no-debug'};
$policy += 0b0010 if $amd_sev_conf->{'no-key-sharing'};
$policy += 0b0100 if $amd_sev_conf->{type} eq 'es';
my $policy = 0;
$policy |= 1 << 0 if $amd_sev_conf->{'no-debug'};
$policy |= 1 << 1 if $amd_sev_conf->{'no-key-sharing'};
$policy |= 1 << 2 if $amd_sev_conf->{type} eq 'es';
# disable migration with bit 3 nosend to prevent amd-sev-migration-attack
$policy += 0b1000;
$policy |= 1 << 3;
$sev_mem_object .= ',policy='.sprintf("%#x", $policy);
$sev_mem_object .= ',kernel-hashes=on' if ($amd_sev_conf->{'kernel-hashes'});