Re: [libvirt] [PATCH] qemuBuildNicDevStr: Add mq=on for multiqueue networking

If user requested multiqueue networking, beside multiple /dev/tap and /dev/vhost-net openings, we forgot to pass mq=on onto the -device virtio-net-pci command line. This is advised at: http://www.linux-kvm.org/page/Multiqueue#Enable_MQ_feature --- Notes: Maybe worth backporting to maintainer branches too. The MQ was introduced in the 1.0.6 release. src/qemu/qemu_command.c | 7 ++++++- src/qemu/qemu_command.h | 1 + src/qemu/qemu_hotplug.c | 4 +++- 3 files changed, 10 insertions(+), 2 deletions(-) diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c index f151173..d73872a 100644 --- a/src/qemu/qemu_command.c +++ b/src/qemu/qemu_command.c @@ -4730,6 +4730,7 @@ qemuBuildNicDevStr(virDomainDefPtr def, virDomainNetDefPtr net, int vlan, int bootindex, + bool multiqueue, virQEMUCapsPtr qemuCaps) { virBuffer buf = VIR_BUFFER_INITIALIZER; @@ -4782,6 +4783,8 @@ qemuBuildNicDevStr(virDomainDefPtr def, virDomainVirtioEventIdxTypeToString(net->driver.virtio.event_idx)); } } + if (usingVirtio && multiqueue) + virBufferAddLit(&buf, ",mq=on"); if (vlan == -1) virBufferAsprintf(&buf, ",netdev=host%s", net->info.alias); else @@ -7275,7 +7278,9 @@ qemuBuildInterfaceCommandLine(virCommandPtr cmd, virCommandAddArgList(cmd, "-netdev", host, NULL); } if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_DEVICE)) { - if (!(nic = qemuBuildNicDevStr(def, net, vlan, bootindex, qemuCaps))) + bool multiqueue = tapfdSize > 1 || vhostfdSize > 1; + if (!(nic = qemuBuildNicDevStr(def, net, vlan, bootindex,

+ multiqueue, qemuCaps))) goto cleanup; virCommandAddArgList(cmd, "-device", nic, NULL); } else { diff --git a/src/qemu/qemu_command.h b/src/qemu/qemu_command.h index 5c5c025..a9854a3 100644 --- a/src/qemu/qemu_command.h +++ b/src/qemu/qemu_command.h @@ -102,6 +102,7 @@ char * qemuBuildNicDevStr(virDomainDefPtr def, virDomainNetDefPtr net, int vlan, int bootindex, + bool multiqueue, virQEMUCapsPtr qemuCaps); char *qemuDeviceDriveHostAlias(virDomainDiskDefPtr disk, diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c index 478f331..b49073b 100644 --- a/src/qemu/qemu_hotplug.c +++ b/src/qemu/qemu_hotplug.c @@ -859,7 +859,9 @@ int qemuDomainAttachNetDevice(virConnectPtr conn, } if (virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_DEVICE)) { - if (!(nicstr = qemuBuildNicDevStr(vm->def, net, vlan, 0, priv->qemuCaps))) + bool multiqueue = tapfdSize > 1 || vhostfdSize > 1; + if (!(nicstr = qemuBuildNicDevStr(vm->def, net, vlan, 0,

+ multiqueue, priv->qemuCaps))) goto try_remove; } else { if (!(nicstr = qemuBuildNicStr(net, NULL, vlan)))