[pve-devel] [PATCH qemu-server 1/3] pci: choose devices: don't reserve pciids when vm is already running

[Dominik Csapak]

since the only way this could happen is when we're being called
from 'qm showcmd' and there we don't want to reserve or create anything.

In case the vm was not running, we actually reserve the devices, so we
want to call 'cleanup_pci_devices' after to remove those again. This
minimizes the timespan where those devices are not available for real vm
starts.

Signed-off-by: Dominik Csapak <d.csapak at proxmox.com>
---
alternatively we could pass the info through that we're in 'showcmd',
but since that's a relatively long call chain and the involved functions
already have a lot of parameters, i opted for this. I'm not opposed to
another solution, if wanted, though.

 PVE/QemuServer.pm                | 5 +++++
 PVE/QemuServer/PCI.pm            | 9 +++++++--
 test/run_config2command_tests.pl | 5 ++++-
 3 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/PVE/QemuServer.pm b/PVE/QemuServer.pm
index b26da505..b2cbe00e 100644
--- a/PVE/QemuServer.pm
+++ b/PVE/QemuServer.pm
@@ -6129,6 +6129,11 @@ sub vm_commandline {
     my $defaults = load_defaults();
 
     my $cmd = config_to_command($storecfg, $vmid, $conf, $defaults, $forcemachine, $forcecpu);
+    # if the vm is not running, we need to clean up the reserved/created devices
+    if (!PVE::QemuServer::Helpers::vm_running_locally($vmid)) {
+	eval { cleanup_pci_devices($vmid, $conf) };
+	warn $@ if $@;
+    }
 
     return PVE::Tools::cmd2string($cmd);
 }
diff --git a/PVE/QemuServer/PCI.pm b/PVE/QemuServer/PCI.pm
index 1673041b..97eb2165 100644
--- a/PVE/QemuServer/PCI.pm
+++ b/PVE/QemuServer/PCI.pm
@@ -523,6 +523,9 @@ sub parse_hostpci_devices {
 my sub choose_hostpci_devices {
     my ($devices, $vmid) = @_;
 
+    # if the vm is running, we must be in 'showcmd', so don't actually reserve or create anything
+    my $is_running = PVE::QemuServer::Helpers::vm_running_locally($vmid) ? 1 : 0;
+
     my $used = {};
 
     my $add_used_device = sub {
@@ -555,8 +558,10 @@ my sub choose_hostpci_devices {
 	    my $ids = [map { $_->{id} } @$alternative];
 
 	    next if grep { defined($used->{$_}) } @$ids; # already used
-	    eval { reserve_pci_usage($ids, $vmid, 10, undef) };
-	    next if $@;
+	    if (!$is_running) {
+		eval { reserve_pci_usage($ids, $vmid, 10, undef) };
+		next if $@;
+	    }
 
 	    # found one that is not used or reserved
 	    $add_used_device->($alternative);
diff --git a/test/run_config2command_tests.pl b/test/run_config2command_tests.pl
index d48ef562..9b5e87ff 100755
--- a/test/run_config2command_tests.pl
+++ b/test/run_config2command_tests.pl
@@ -196,7 +196,10 @@ $qemu_server_module->mock(
     },
     get_initiator_name => sub {
 	return 'iqn.1993-08.org.debian:01:aabbccddeeff';
-    }
+    },
+    cleanup_pci_devices => {
+	# do nothing
+    },
 );
 
 my $qemu_server_config;
-- 
2.39.2