From 038eb472a0d970a17ccf4343ead0666df5c92f9d Mon Sep 17 00:00:00 2001 From: Michal Privoznik Date: Fri, 19 Jan 2018 11:34:54 +0100 Subject: [PATCH] qemu: Expose rx/tx_queue_size in qemu.conf too In 2074ef6cd4a2 and c56cdf259 (and friends) we've added two attributes to virtio NICs: rx_queue_size and tx_queue_size. However, sysadmins might want to set these on per-host basis but don't necessarily have an access to domain XML (e.g. because they are generated by some other app). So let's expose them under qemu.conf (the settings from domain XML still take precedence as they are more specific ones). Signed-off-by: Michal Privoznik Reviewed-by: John Ferlan --- docs/formatdomain.html.in | 14 ++++++-- src/qemu/libvirtd_qemu.aug | 4 +++ src/qemu/qemu.conf | 6 ++++ src/qemu/qemu_command.c | 55 ++++++++++++++++++++++-------- src/qemu/qemu_command.h | 3 +- src/qemu/qemu_conf.c | 4 +++ src/qemu/qemu_conf.h | 3 ++ src/qemu/qemu_hotplug.c | 2 +- src/qemu/test_libvirtd_qemu.aug.in | 2 ++ 9 files changed, 74 insertions(+), 19 deletions(-) diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in index 3ec1173c6f..6707744bda 100644 --- a/docs/formatdomain.html.in +++ b/docs/formatdomain.html.in @@ -5456,7 +5456,12 @@ qemu-kvm -net nic,model=? /dev/null some restrictions on actual value. For instance, latest QEMU (as of 2016-09-01) requires value to be a power of two from [256, 1024] range. - Since 2.3.0 (QEMU and KVM only)

+ Since 2.3.0 (QEMU and KVM only) + Additionally, since 4.1.0 the + value can be set in the qemu.conf file in order + to override the hypervisor default value. Note that XML has + higher precedence because it's more specific. +

In general you should leave this option alone, unless you are very certain you know what you are doing. @@ -5472,7 +5477,12 @@ qemu-kvm -net nic,model=? /dev/null range. In addition to that, this may work only for a subset of interface types, e.g. aforementioned QEMU enables this option only for vhostuser type. - Since 3.7.0 (QEMU and KVM only)

+ Since 3.7.0 (QEMU and KVM only) + Additionally, since 4.1.0 the + value can be set in the qemu.conf file in order + to override the hypervisor default value. Note that XML has + higher precedence because it's more specific. +

In general you should leave this option alone, unless you are very certain you know what you are doing. diff --git a/src/qemu/libvirtd_qemu.aug b/src/qemu/libvirtd_qemu.aug index c19bf3a43a..084290296a 100644 --- a/src/qemu/libvirtd_qemu.aug +++ b/src/qemu/libvirtd_qemu.aug @@ -118,6 +118,9 @@ module Libvirtd_qemu = let vxhs_entry = bool_entry "vxhs_tls" | str_entry "vxhs_tls_x509_cert_dir" + let virtio_entry = int_entry "rx_queue_size" + | int_entry "tx_queue_size" + (* Each entry in the config is one of the following ... *) let entry = default_tls_entry | vnc_entry @@ -137,6 +140,7 @@ module Libvirtd_qemu = | gluster_debug_level_entry | memory_entry | vxhs_entry + | virtio_entry let comment = [ label "#comment" . del /#[ \t]*/ "# " . store /([^ \t\n][^\n]*)?/ . del /\n/ "\n" ] let empty = [ label "#empty" . eol ] diff --git a/src/qemu/qemu.conf b/src/qemu/qemu.conf index 43dd561cca..62c4265ea9 100644 --- a/src/qemu/qemu.conf +++ b/src/qemu/qemu.conf @@ -775,3 +775,9 @@ # This directory is used for memoryBacking source if configured as file. # NOTE: big files will be stored here #memory_backing_dir = "/var/lib/libvirt/qemu/ram" + +# The following two values set the default RX/TX ring buffer size for virtio +# interfaces. These values are taken unless overridden in domain XML. For more +# info consult docs to corresponding attributes from domain XML. +#rx_queue_size = 1024 +#tx_queue_size = 1024 diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c index 899f0cbbbf..5432700287 100644 --- a/src/qemu/qemu_command.c +++ b/src/qemu/qemu_command.c @@ -3751,7 +3751,8 @@ qemuBuildNicStr(virDomainNetDefPtr net, char * -qemuBuildNicDevStr(virDomainDefPtr def, +qemuBuildNicDevStr(virQEMUDriverConfigPtr cfg, + virDomainDefPtr def, virDomainNetDefPtr net, int vlan, unsigned int bootindex, @@ -3871,21 +3872,41 @@ qemuBuildNicDevStr(virDomainDefPtr def, virBufferAsprintf(&buf, ",mq=on,vectors=%zu", 2 * vhostfdSize + 2); } } - if (usingVirtio && net->driver.virtio.rx_queue_size) { - if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_VIRTIO_NET_RX_QUEUE_SIZE)) { - virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", - _("virtio rx_queue_size option is not supported with this QEMU binary")); - goto error; + if (usingVirtio) { + unsigned int rx_queue_size = net->driver.virtio.rx_queue_size; + + if (rx_queue_size == 0) + rx_queue_size = cfg->rx_queue_size; + + if (rx_queue_size) { + if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_VIRTIO_NET_RX_QUEUE_SIZE)) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", + _("virtio rx_queue_size option is " + "not supported with this QEMU binary")); + goto error; + } + + net->driver.virtio.rx_queue_size = rx_queue_size; + virBufferAsprintf(&buf, ",rx_queue_size=%u", rx_queue_size); } - virBufferAsprintf(&buf, ",rx_queue_size=%u", net->driver.virtio.rx_queue_size); } - if (usingVirtio && net->driver.virtio.tx_queue_size) { - if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_VIRTIO_NET_TX_QUEUE_SIZE)) { - virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", - _("virtio tx_queue_size option is not supported with this QEMU binary")); - goto error; + if (usingVirtio) { + unsigned int tx_queue_size = net->driver.virtio.tx_queue_size; + + if (tx_queue_size == 0) + tx_queue_size = cfg->tx_queue_size; + + if (tx_queue_size) { + if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_VIRTIO_NET_TX_QUEUE_SIZE)) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", + _("virtio tx_queue_size option is " + "not supported with this QEMU binary")); + goto error; + } + + net->driver.virtio.tx_queue_size = tx_queue_size; + virBufferAsprintf(&buf, ",tx_queue_size=%u", tx_queue_size); } - virBufferAsprintf(&buf, ",tx_queue_size=%u", net->driver.virtio.tx_queue_size); } if (usingVirtio && net->mtu) { @@ -8571,7 +8592,7 @@ qemuBuildVhostuserCommandLine(virQEMUDriverPtr driver, virCommandAddArg(cmd, netdev); VIR_FREE(netdev); - if (!(nic = qemuBuildNicDevStr(def, net, -1, bootindex, + if (!(nic = qemuBuildNicDevStr(cfg, def, net, -1, bootindex, queues, qemuCaps))) { virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("Error generating NIC -device string")); @@ -8608,6 +8629,7 @@ qemuBuildInterfaceCommandLine(virQEMUDriverPtr driver, int **nicindexes, bool chardevStdioLogd) { + virQEMUDriverConfigPtr cfg = NULL; int ret = -1; char *nic = NULL, *host = NULL; int *tapfd = NULL; @@ -8669,6 +8691,8 @@ qemuBuildInterfaceCommandLine(virQEMUDriverPtr driver, return -1; } + cfg = virQEMUDriverGetConfig(driver); + switch (actualType) { case VIR_DOMAIN_NET_TYPE_NETWORK: case VIR_DOMAIN_NET_TYPE_BRIDGE: @@ -8864,7 +8888,7 @@ qemuBuildInterfaceCommandLine(virQEMUDriverPtr driver, virCommandAddArgList(cmd, "-netdev", host, NULL); } if (qemuDomainSupportsNicdev(def, net)) { - if (!(nic = qemuBuildNicDevStr(def, net, vlan, bootindex, + if (!(nic = qemuBuildNicDevStr(cfg, def, net, vlan, bootindex, vhostfdSize, qemuCaps))) goto cleanup; virCommandAddArgList(cmd, "-device", nic, NULL); @@ -8908,6 +8932,7 @@ qemuBuildInterfaceCommandLine(virQEMUDriverPtr driver, VIR_FREE(host); VIR_FREE(tapfdName); VIR_FREE(vhostfdName); + virObjectUnref(cfg); return ret; } diff --git a/src/qemu/qemu_command.h b/src/qemu/qemu_command.h index 31c9da673c..6449883291 100644 --- a/src/qemu/qemu_command.h +++ b/src/qemu/qemu_command.h @@ -90,7 +90,8 @@ char *qemuBuildNicStr(virDomainNetDefPtr net, int vlan); /* Current, best practice */ -char *qemuBuildNicDevStr(virDomainDefPtr def, +char *qemuBuildNicDevStr(virQEMUDriverConfigPtr cfg, + virDomainDefPtr def, virDomainNetDefPtr net, int vlan, unsigned int bootindex, diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c index af503d31cb..2fa96431fa 100644 --- a/src/qemu/qemu_conf.c +++ b/src/qemu/qemu_conf.c @@ -912,6 +912,10 @@ int virQEMUDriverConfigLoadFile(virQEMUDriverConfigPtr cfg, if (virConfGetValueString(conf, "memory_backing_dir", &cfg->memoryBackingDir) < 0) goto cleanup; + if (virConfGetValueUInt(conf, "rx_queue_size", &cfg->rx_queue_size) < 0 || + virConfGetValueUInt(conf, "tx_queue_size", &cfg->tx_queue_size) < 0) + goto cleanup; + ret = 0; cleanup: diff --git a/src/qemu/qemu_conf.h b/src/qemu/qemu_conf.h index a553e30e2e..3f38a76c26 100644 --- a/src/qemu/qemu_conf.h +++ b/src/qemu/qemu_conf.h @@ -206,6 +206,9 @@ struct _virQEMUDriverConfig { bool vxhsTLS; char *vxhsTLSx509certdir; + + unsigned int rx_queue_size; + unsigned int tx_queue_size; }; /* Main driver state */ diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c index 5be3e0659a..a8979db2e8 100644 --- a/src/qemu/qemu_hotplug.c +++ b/src/qemu/qemu_hotplug.c @@ -1120,7 +1120,7 @@ qemuDomainAttachNetDevice(virQEMUDriverPtr driver, for (i = 0; i < vhostfdSize; i++) VIR_FORCE_CLOSE(vhostfd[i]); - if (!(nicstr = qemuBuildNicDevStr(vm->def, net, vlan, 0, + if (!(nicstr = qemuBuildNicDevStr(cfg, vm->def, net, vlan, 0, queueSize, priv->qemuCaps))) goto try_remove; diff --git a/src/qemu/test_libvirtd_qemu.aug.in b/src/qemu/test_libvirtd_qemu.aug.in index 688e5b9fda..4fc4e2f4ec 100644 --- a/src/qemu/test_libvirtd_qemu.aug.in +++ b/src/qemu/test_libvirtd_qemu.aug.in @@ -100,3 +100,5 @@ module Test_libvirtd_qemu = { "1" = "mount" } } { "memory_backing_dir" = "/var/lib/libvirt/qemu/ram" } +{ "rx_queue_size" = "1024" } +{ "tx_queue_size" = "1024" }