From 0c03a3903536ef222d3f78f825e749c9fe12c835 Mon Sep 17 00:00:00 2001 From: Alexandre Derumier Date: Sun, 13 Nov 2022 15:37:35 +0100 Subject: [PATCH] fix #4296: virtio-net: enable packed queues for qemu 7.1 virtio 1.1 have improve virtio multiqueue performance, with a new implementation called "packed queues". https://www.redhat.com/en/blog/packed-virtqueue-how-reduce-overhead-virtio https://archive.fosdem.org/2018/schedule/event/virtio/attachments/slides/2167/export/events/attachments/virtio/slides/2167/fosdem_virtio1_1.pdf This patch enable it by default for qemu 7.1 This don't break old guests with old virtio 1.0 drivers, as virtio device/devices are forward/backward compatible. Signed-off-by: Alexandre Derumier --- PVE/QemuServer.pm | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/PVE/QemuServer.pm b/PVE/QemuServer.pm index 303a5dd1..033d5491 100644 --- a/PVE/QemuServer.pm +++ b/PVE/QemuServer.pm @@ -1748,7 +1748,7 @@ sub print_pbs_blockdev { } sub print_netdevice_full { - my ($vmid, $conf, $net, $netid, $bridges, $use_old_bios_files, $arch, $machine_type) = @_; + my ($vmid, $conf, $net, $netid, $bridges, $use_old_bios_files, $arch, $machine_type, $machine_version) = @_; my $device = $net->{model}; if ($net->{model} eq 'virtio') { @@ -1762,6 +1762,9 @@ sub print_netdevice_full { # and out of each queue plus one config interrupt and control vector queue my $vectors = $net->{queues} * 2 + 2; $tmpstr .= ",vectors=$vectors,mq=on"; + if (min_version($machine_version, 7, 1)) { + $tmpstr .= ",packed=on"; + } } $tmpstr .= ",bootindex=$net->{bootindex}" if $net->{bootindex} ; @@ -4048,7 +4051,7 @@ sub config_to_command { push @$devices, '-netdev', $netdevfull; my $netdevicefull = print_netdevice_full( - $vmid, $conf, $d, $netname, $bridges, $use_old_bios_files, $arch, $machine_type); + $vmid, $conf, $d, $netname, $bridges, $use_old_bios_files, $arch, $machine_type, $machine_version); push @$devices, '-device', $netdevicefull; } @@ -4280,11 +4283,12 @@ sub vm_deviceplug { return if !qemu_netdevadd($vmid, $conf, $arch, $device, $deviceid); my $machine_type = PVE::QemuServer::Machine::qemu_machine_pxe($vmid, $conf); + my $machine_version = PVE::QemuServer::Machine::extract_version($machine_type); my $use_old_bios_files = undef; ($use_old_bios_files, $machine_type) = qemu_use_old_bios_files($machine_type); my $netdevicefull = print_netdevice_full( - $vmid, $conf, $device, $deviceid, undef, $use_old_bios_files, $arch, $machine_type); + $vmid, $conf, $device, $deviceid, undef, $use_old_bios_files, $arch, $machine_type, $machine_version); qemu_deviceadd($vmid, $netdevicefull); eval { qemu_deviceaddverify($vmid, $deviceid);