[pve-devel] [PATCH qemu-server v4 2/4] Convert policy calculation
Philipp Giersfeld
philipp.giersfeld at canarybit.eu
Tue Mar 11 16:04:54 CET 2025
Convert policy calculation to use shift operators and OR operation
instead of binary numbers and addition.
Signed-off-by: Philipp Giersfeld <philipp.giersfeld at canarybit.eu>
Reviewed-by: Daniel Kral <d.kral at proxmox.com>
Reviewed-by: Fiona Ebner <f.ebner at proxmox.com>
Tested-by: Markus Frank <m.frank at proxmox.com>
---
changes since v3: https://lists.proxmox.com/pipermail/pve-devel/2025-February/068578.html
* Fix typo in commit description
PVE/QemuServer/CPUConfig.pm | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/PVE/QemuServer/CPUConfig.pm b/PVE/QemuServer/CPUConfig.pm
index e65d8c26..ad0be16e 100644
--- a/PVE/QemuServer/CPUConfig.pm
+++ b/PVE/QemuServer/CPUConfig.pm
@@ -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'});
--
2.39.5
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