Re: [libvirt] [PATCH v2 06/12] util: Learn virNetDevTapCreate multiqueue network

Currently, the function knows how to open a TAP device for a single time. However, in case of multiqueue network we need to open it multiple times. Moreover, when doing TUNSETIFF ioctl, the IFF_MULTI_QUEUE flag shall be requested. This commit changes a behaviour slightly as well. Till now it was possible to pass NULL as an @fd address by which caller didn't care about returned FD. While this was used only in UML driver, the appropriate UML code snippets has been changed as well. --- src/network/bridge_driver.c | 2 +- src/qemu/qemu_command.c | 2 +- src/uml/uml_conf.c | 5 +- src/util/virnetdevtap.c | 115 ++++++++++++++++++++++++-------------------- src/util/virnetdevtap.h | 2 + 5 files changed, 72 insertions(+), 54 deletions(-) diff --git a/src/network/bridge_driver.c b/src/network/bridge_driver.c index 99c1316..f81e925 100644 --- a/src/network/bridge_driver.c +++ b/src/network/bridge_driver.c @@ -2444,7 +2444,7 @@ networkStartNetworkVirtual(struct network_driver *driver, /* Keep tun fd open and interface up to allow for IPv6 DAD to happen */ if (virNetDevTapCreateInBridgePort(network->def->bridge, &macTapIfName, &network->def->mac, - NULL, &tapfd, NULL, NULL, + NULL, &tapfd, 1, NULL, NULL, VIR_NETDEV_TAP_CREATE_USE_MAC_FOR_BRIDGE | VIR_NETDEV_TAP_CREATE_IFUP | VIR_NETDEV_TAP_CREATE_PERSIST) < 0) { diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c index ec061d1..e4bb2b7 100644 --- a/src/qemu/qemu_command.c +++ b/src/qemu/qemu_command.c @@ -355,7 +355,7 @@ qemuNetworkIfaceConnect(virDomainDefPtr def, if (cfg->privileged) err = virNetDevTapCreateInBridgePort(brname, &net->ifname, &net->mac, - def->uuid, &tapfd, + def->uuid, &tapfd, 1, virDomainNetGetActualVirtPortProfile(net), virDomainNetGetActualVlan(net), tap_create_flags); diff --git a/src/uml/uml_conf.c b/src/uml/uml_conf.c index 52b705c..3fda7e4 100644 --- a/src/uml/uml_conf.c +++ b/src/uml/uml_conf.c @@ -109,6 +109,7 @@ umlConnectTapDevice(virConnectPtr conn, const char *bridge) { bool template_ifname = false; + int tapfd; if (!net->ifname || STRPREFIX(net->ifname, VIR_NET_GENERATED_PREFIX) || @@ -121,7 +122,7 @@ umlConnectTapDevice(virConnectPtr conn, } if (virNetDevTapCreateInBridgePort(bridge, &net->ifname, &net->mac, - vm->uuid, NULL, + vm->uuid, &tapfd, 1, virDomainNetGetActualVirtPortProfile(net), virDomainNetGetActualVlan(net), VIR_NETDEV_TAP_CREATE_IFUP | @@ -139,9 +140,11 @@ umlConnectTapDevice(virConnectPtr conn, } } + VIR_FORCE_CLOSE(tapfd); return 0; error: + VIR_FORCE_CLOSE(tapfd); return -1; } diff --git a/src/util/virnetdevtap.c b/src/util/virnetdevtap.c index 75599db..ee839e3 100644 --- a/src/util/virnetdevtap.c +++ b/src/util/virnetdevtap.c @@ -140,7 +140,8 @@ virNetDevProbeVnetHdr(int tapfd) /** * virNetDevTapCreate: * @ifname: the interface name - * @tapfd: file descriptor return value for the new tap device + * @tapfds: file descriptor return value for the new tap device + * @tapfdSize: size of @tapfd * @flags: OR of virNetDevTapCreateFlags. Only one flag is recognized: * * VIR_NETDEV_TAP_CREATE_VNET_HDR @@ -148,76 +149,85 @@ virNetDevProbeVnetHdr(int tapfd) * VIR_NETDEV_TAP_CREATE_PERSIST * - The device will persist after the file descriptor is closed * - * Creates a tap interface. - * If the @tapfd parameter is supplied, the open tap device file descriptor - * will be returned, otherwise the TAP device will be closed. The caller must - * use virNetDevTapDelete to remove a persistent TAP device when it is no - * longer needed. + * Creates a tap interface. The caller must use virNetDevTapDelete to + * remove a persistent TAP device when it is no longer needed. In case + * @tapfdSize is greater than one, multiqueue extension is requested + * from kernel. * * Returns 0 in case of success or -1 on failure. */ int virNetDevTapCreate(char **ifname, int *tapfd, + int tapfdSize, unsigned int flags) { - int fd; + int i; struct ifreq ifr; int ret = -1; - if ((fd = open("/dev/net/tun", O_RDWR)) < 0) { - virReportSystemError(errno, "%s", - _("Unable to open /dev/net/tun, is tun module loaded?")); - return -1; - } - memset(&ifr, 0, sizeof(ifr)); + for (i = 0; i < tapfdSize; i++) { + int fd; - ifr.ifr_flags = IFF_TAP|IFF_NO_PI; + if ((fd = open("/dev/net/tun", O_RDWR)) < 0) { + virReportSystemError(errno, "%s", + _("Unable to open /dev/net/tun, is tun module loaded?")); + goto cleanup; + }

+ + memset(&ifr, 0, sizeof(ifr)); + + ifr.ifr_flags = IFF_TAP | IFF_NO_PI; + /* If tapfdSize is greater than one, request multiqueue */ + if (tapfdSize > 1) + ifr.ifr_flags |= IFF_MULTI_QUEUE; # ifdef IFF_VNET_HDR - if ((flags & VIR_NETDEV_TAP_CREATE_VNET_HDR) && - virNetDevProbeVnetHdr(fd)) - ifr.ifr_flags |= IFF_VNET_HDR; + if ((flags & VIR_NETDEV_TAP_CREATE_VNET_HDR) && + virNetDevProbeVnetHdr(fd)) + ifr.ifr_flags |= IFF_VNET_HDR; # endif - if (virStrcpyStatic(ifr.ifr_name, *ifname) == NULL) { - virReportSystemError(ERANGE, - _("Network interface name '%s' is too long"), - *ifname); - goto cleanup; + if (virStrcpyStatic(ifr.ifr_name, *ifname) == NULL) { + virReportSystemError(ERANGE, + _("Network interface name '%s' is too long"), + *ifname); + goto cleanup; - } + } - if (ioctl(fd, TUNSETIFF, &ifr) < 0) { - virReportSystemError(errno, - _("Unable to create tap device %s"), - NULLSTR(*ifname)); - goto cleanup; - } + if (ioctl(fd, TUNSETIFF, &ifr) < 0) { + virReportSystemError(errno, + _("Unable to create tap device %s"), + NULLSTR(*ifname)); + goto cleanup; + } - if ((flags & VIR_NETDEV_TAP_CREATE_PERSIST) && - (errno = ioctl(fd, TUNSETPERSIST, 1))) { - virReportSystemError(errno, - _("Unable to set tap device %s to persistent"), - NULLSTR(*ifname)); - goto cleanup; - } + if (i == 0) { + /* In case we are looping more than once, set other + * TAPs to have the same name */ + VIR_FREE(*ifname); + if (ifr.ifr_name && VIR_STRDUP(*ifname, ifr.ifr_name) < 0) + goto cleanup; + } - VIR_FREE(*ifname); - if (!(*ifname = strdup(ifr.ifr_name))) { - virReportOOMError(); - goto cleanup; + if ((flags & VIR_NETDEV_TAP_CREATE_PERSIST) && + (errno = ioctl(fd, TUNSETPERSIST, 1))) { + virReportSystemError(errno, + _("Unable to set tap device %s to persistent"), + NULLSTR(*ifname)); + goto cleanup; + } + tapfd[i] = fd; } - if (tapfd) - *tapfd = fd; - else - VIR_FORCE_CLOSE(fd); ret = 0; cleanup: - if (ret < 0) - VIR_FORCE_CLOSE(fd); + if (ret < 0) { + for (i = 0; i < tapfdSize; i++) + VIR_FORCE_CLOSE(tapfd[i]); + }

return ret; } @@ -266,6 +276,7 @@ cleanup: #else /* ! TUNSETIFF */ int virNetDevTapCreate(char **ifname ATTRIBUTE_UNUSED, int *tapfd ATTRIBUTE_UNUSED, + int tapfdSize ATTRIBUTE_UNUSED, unsigned int flags ATTRIBUTE_UNUSED) { virReportSystemError(ENOSYS, "%s", @@ -286,7 +297,8 @@ int virNetDevTapDelete(const char *ifname ATTRIBUTE_UNUSED) * @brname: the bridge name * @ifname: the interface name (or name template) * @macaddr: desired MAC address - * @tapfd: file descriptor return value for the new tap device + * @tapfd: array of file descriptor return value for the new tap device + * @tapfdSize: size of @tapfd * @virtPortProfile: bridge/port specific configuration * @flags: OR of virNetDevTapCreateFlags: @@ -314,6 +326,7 @@ int virNetDevTapCreateInBridgePort(const char *brname, const virMacAddrPtr macaddr, const unsigned char *vmuuid, int *tapfd, + int tapfdSize, virNetDevVPortProfilePtr virtPortProfile, virNetDevVlanPtr virtVlan, unsigned int flags) @@ -321,7 +334,7 @@ int virNetDevTapCreateInBridgePort(const char *brname, virMacAddr tapmac; char macaddrstr[VIR_MAC_STRING_BUFLEN]; - if (virNetDevTapCreate(ifname, tapfd, flags) < 0) + if (virNetDevTapCreate(ifname, tapfd, tapfdSize, flags) < 0) return -1; /* We need to set the interface MAC before adding it @@ -372,9 +385,9 @@ int virNetDevTapCreateInBridgePort(const char *brname, return 0; - error: - if (tapfd) - VIR_FORCE_CLOSE(*tapfd); +error: + while (tapfdSize) + VIR_FORCE_CLOSE(tapfd[--tapfdSize]); return -1; } diff --git a/src/util/virnetdevtap.h b/src/util/virnetdevtap.h index 6bfc80c..cb6c284 100644 --- a/src/util/virnetdevtap.h +++ b/src/util/virnetdevtap.h @@ -29,6 +29,7 @@ int virNetDevTapCreate(char **ifname, int *tapfd, + int tapfdSize, unsigned int flags) ATTRIBUTE_NONNULL(1) ATTRIBUTE_RETURN_CHECK; @@ -55,6 +56,7 @@ int virNetDevTapCreateInBridgePort(const char *brname, const virMacAddrPtr macaddr, const unsigned char *vmuuid, int *tapfd, + int tapfdSize, virNetDevVPortProfilePtr virtPortProfile, virNetDevVlanPtr virtVlan, unsigned int flags)