[pve-devel] [PATCH qemu-server 2/3] pci: add helpers to (un)reserve pciids for a vm
Dominik Csapak
d.csapak at proxmox.com
Tue Oct 5 15:11:59 CEST 2021
saves a list of pciid <-> vmid mappings in /var/run
that we can check when we start a vm
Signed-off-by: Dominik Csapak <d.csapak at proxmox.com>
---
PVE/QemuServer/PCI.pm | 89 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 89 insertions(+)
diff --git a/PVE/QemuServer/PCI.pm b/PVE/QemuServer/PCI.pm
index 5608207..0626b76 100644
--- a/PVE/QemuServer/PCI.pm
+++ b/PVE/QemuServer/PCI.pm
@@ -5,6 +5,7 @@ use strict;
use PVE::JSONSchema;
use PVE::SysFSTools;
+use PVE::Tools;
use base 'Exporter';
@@ -461,4 +462,92 @@ sub print_hostpci_devices {
return ($kvm_off, $gpu_passthrough, $legacy_igd);
}
+my $PCIID_RESERVATION_FILE = "/var/run/pve-reserved-pciids";
+my $PCIID_RESERVATION_LCK = "/var/lock/pve-reserved-pciids.lck";
+
+my $parse_pci_reservation = sub {
+ my $pciids = {};
+
+ if (my $fh = IO::File->new ($PCIID_RESERVATION_FILE, "r")) {
+ while (my $line = <$fh>) {
+ if ($line =~ m/^($PCIRE)\s(\d+)\s(\d+)$/) {
+ $pciids->{$1} = {
+ timestamp => $2,
+ vmid => $3,
+ };
+ }
+ }
+ }
+
+ return $pciids;
+};
+
+my $write_pci_reservation = sub {
+ my ($pciids) = @_;
+
+ my $data = "";
+ foreach my $p (keys %$pciids) {
+ $data .= "$p $pciids->{$p}->{timestamp} $pciids->{$p}->{vmid}\n";
+ }
+
+ PVE::Tools::file_set_contents($PCIID_RESERVATION_FILE, $data);
+};
+
+sub remove_pci_reservation {
+ my ($id) = @_;
+
+ my $code = sub {
+ my $pciids = $parse_pci_reservation->();
+
+ delete $pciids->{$id};
+
+ $write_pci_reservation->($pciids);
+ };
+
+ PVE::Tools::lock_file($PCIID_RESERVATION_LCK, 10, $code);
+ die $@ if $@;
+
+ return;
+}
+
+sub reserve_pci_usage {
+ my ($id, $vmid) = @_;
+
+ my $code = sub {
+
+ # have a 60 second grace period, since we reserve before
+ # we actually start the vm
+ my $graceperiod = 60;
+ my $ctime = time();
+
+ my $pciids = $parse_pci_reservation->();
+
+ if (my $pciid = $pciids->{$id}) {
+ if ($pciid->{vmid} == $vmid) {
+ return; # already reserved
+ }
+
+ if (($pciid->{timestamp} + $graceperiod > $ctime) ||
+ PVE::QemuServer::Helpers::vm_running_locally($vmid))
+ {
+ die "PCI device '$id' already in use\n";
+ }
+ }
+
+ $pciids->{$id} = {
+ timestamp => $ctime,
+ vmid => $vmid,
+ };
+
+ $write_pci_reservation->($pciids);
+
+ return;
+ };
+
+ PVE::Tools::lock_file($PCIID_RESERVATION_LCK, 10, $code);
+ die $@ if $@;
+
+ return;
+}
+
1;
--
2.30.2
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