On 05/16/2013 08:49 AM, Michal Privoznik wrote:
> 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 | 113 ++++++++++++++++++++++++--------------------
> src/util/virnetdevtap.h | 2 +
> 5 files changed, 71 insertions(+), 53 deletions(-)
>
> diff --git a/src/network/bridge_driver.c b/src/network/bridge_driver.c
> index 6c6ce6d..ad4ab00 100644
> --- a/src/network/bridge_driver.c
> +++ b/src/network/bridge_driver.c
> @@ -2495,7 +2495,7 @@ 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 67baad3..a053d49 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..62a1ba2 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
"array of file descriptors ..."
> + * @tapfdSize: size of @tapfd
"number of file descriptors in @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;
> - }
> + int fd;
>
> memset(&ifr, 0, sizeof(ifr));
> + for (i = 0; i < tapfdSize; i++) {
> + if ((fd = open("/dev/net/tun", O_RDWR)) < 0) {
> + virReportSystemError(errno, "%s",
> + _("Unable to open /dev/net/tun, is tun module loaded?"));
> + goto cleanup;
> + }
>
> - ifr.ifr_flags = IFF_TAP|IFF_NO_PI;
> + 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)
> + if (ret < 0) {
> VIR_FORCE_CLOSE(fd);
> + while (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
"number of file descriptors in @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)
ACK with comment fixes.
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