Re: [libvirt] [PATCH 2/2] Modify generic ethernet interface so it will work when sVirt is enabled with qemu

Update code to create generic ethernet interfaces using the new utility library tunctl making changes to create the TAP device in libvirt and pass it to qemu as a file descriptor.

--- diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c index ee4b52b..181f56c 100644 --- a/src/qemu/qemu_command.c +++ b/src/qemu/qemu_command.c @@ -396,6 +396,51 @@ qemuOpenVhostNet(virDomainDefPtr def, } +int qemuEthernetIfaceCreate(virDomainDefPtr def, + virDomainNetDefPtr net, + virBitmapPtr qemuCaps) +{ + int tapfd; + int err; + int vnet_hdr = 0; + unsigned char tapmac[VIR_MAC_BUFLEN]; + + if (qemuCapsGet(qemuCaps, QEMU_CAPS_VNET_HDR)&& + net->model&& STREQ(net->model, "virtio")) + vnet_hdr = 1; + + if (!net->ifname || + STRPREFIX(net->ifname, "vnet") || + strchr(net->ifname, '%')) { + VIR_FREE(net->ifname); + if (!(net->ifname = strdup("vnet%d"))) { + virReportOOMError(); + return -1; + } + } + + err = createTap(&net->ifname, vnet_hdr,&tapfd); + virDomainAuditNetDevice(def, net, "/dev/net/tun", tapfd>= 0); + if (tapfd< 0 || err) + return -1; + + memcpy(tapmac, net->mac, VIR_MAC_BUFLEN); + /* Discourage bridge from using TAP dev MAC */ + tapmac[0] = 0xFE; + err = tapSetInterfaceMac(net->ifname, tapmac); + + if (err) + return -1;

+ + err = tapSetInterfaceUp(net->ifname, 1); + + if (err) + return -1; + + return tapfd; +} + + static int qemuDomainDeviceAliasIndex(virDomainDeviceInfoPtr info, const char *prefix) @@ -4064,6 +4112,18 @@ qemuBuildCommandLine(virConnectPtr conn, if (snprintf(tapfd_name, sizeof(tapfd_name), "%d", tapfd)>= sizeof(tapfd_name)) goto no_memory; + } else if (actualType == VIR_DOMAIN_NET_TYPE_ETHERNET&& + !net->data.ethernet.script) { + int tapfd = qemuEthernetIfaceCreate(def, net, qemuCaps); + if (tapfd< 0) + goto error; + + last_good_net = i; + virCommandTransferFD(cmd, tapfd);