[libvirt] [PATCH 6/6] qemu: Enable multiqueue for macvtaps

[Laine Stump]

On 12/04/2015 07:31 AM, Michal Privoznik wrote:
> https://bugzilla.redhat.com/show_bug.cgi?id=1240439
>
> Ta-da! Now that we know how to open a macvtap device multiple
> times, we can finally enable the multiqueue feature. Everything
> else is already prepared (e.g. command line generation) from the
> previous iteration where the feature was implemented for
> TUN/TAP devices.
>
> Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
> ---

ACK.

>   src/qemu/qemu_command.c | 41 ++++++++++++++++++++++++++---------------
>   src/qemu/qemu_command.h |  2 ++
>   src/qemu/qemu_hotplug.c | 16 +++++++++-------
>   3 files changed, 37 insertions(+), 22 deletions(-)
>
> diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
> index d1ef4ab..821204e 100644
> --- a/src/qemu/qemu_command.c
> +++ b/src/qemu/qemu_command.c
> @@ -212,17 +212,21 @@ qemuVirCommandGetDevSet(virCommandPtr cmd, int fd)
>    * @def: the definition of the VM (needed by 802.1Qbh and audit)
>    * @driver: pointer to the driver instance
>    * @net: pointer to the VM's interface description with direct device type
> + * @tapfd: array of file descriptor return value for the new device
> + * @tapfdSize: number of file descriptors in @tapfd
>    * @vmop: VM operation type
>    *
> - * Returns a filedescriptor on success or -1 in case of error.
> + * Returns 0 on success or -1 in case of error.
>    */
>   int
>   qemuPhysIfaceConnect(virDomainDefPtr def,
>                        virQEMUDriverPtr driver,
>                        virDomainNetDefPtr net,
> +                     int *tapfd,
> +                     size_t tapfdSize,
>                        virNetDevVPortProfileOp vmop)
>   {
> -    int rc;
> +    int ret = -1;
>       char *res_ifname = NULL;
>       virQEMUDriverConfigPtr cfg = virQEMUDriverGetConfig(driver);
>       unsigned int macvlan_create_flags = VIR_NETDEV_MACVLAN_CREATE_WITH_TAP;
> @@ -238,18 +242,18 @@ qemuPhysIfaceConnect(virDomainDefPtr def,
>                                                  virDomainNetGetActualVirtPortProfile(net),
>                                                  &res_ifname,
>                                                  vmop, cfg->stateDir,
> -                                               &rc, 1,
> +                                               tapfd, tapfdSize,
>                                                  macvlan_create_flags) < 0)
> -        return -1;
> +        goto cleanup;
>   
> -    if (rc >= 0) {
> -        virDomainAuditNetDevice(def, net, res_ifname, true);
> -        VIR_FREE(net->ifname);
> -        net->ifname = res_ifname;
> -    }
> +    virDomainAuditNetDevice(def, net, res_ifname, true);
> +    VIR_FREE(net->ifname);
> +    net->ifname = res_ifname;
> +    ret = 0;
>   
> + cleanup:
>       virObjectUnref(cfg);
> -    return rc;
> +    return ret;
>   }
>   
>   
> @@ -8746,7 +8750,8 @@ qemuBuildInterfaceCommandLine(virCommandPtr cmd,
>       /* Currently nothing besides TAP devices supports multiqueue. */
>       if (net->driver.virtio.queues > 0 &&
>           !(actualType == VIR_DOMAIN_NET_TYPE_NETWORK ||
> -          actualType == VIR_DOMAIN_NET_TYPE_BRIDGE)) {
> +          actualType == VIR_DOMAIN_NET_TYPE_BRIDGE ||
> +          actualType == VIR_DOMAIN_NET_TYPE_DIRECT)) {
>           virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
>                          _("Multiqueue network is not supported for: %s"),
>                          virDomainNetTypeToString(actualType));
> @@ -8791,11 +8796,17 @@ qemuBuildInterfaceCommandLine(virCommandPtr cmd,
>                                       tapfd, &tapfdSize) < 0)
>               goto cleanup;
>       } else if (actualType == VIR_DOMAIN_NET_TYPE_DIRECT) {
> -        if (VIR_ALLOC(tapfd) < 0 || VIR_ALLOC(tapfdName) < 0)
> +        tapfdSize = net->driver.virtio.queues;
> +        if (!tapfdSize)
> +            tapfdSize = 1;
> +
> +        if (VIR_ALLOC_N(tapfd, tapfdSize) < 0 ||
> +            VIR_ALLOC_N(tapfdName, tapfdSize) < 0)
>               goto cleanup;
> -        tapfdSize = 1;
> -        tapfd[0] = qemuPhysIfaceConnect(def, driver, net, vmop);
> -        if (tapfd[0] < 0)
> +
> +        memset(tapfd, -1, tapfdSize * sizeof(tapfd[0]));
> +
> +        if (qemuPhysIfaceConnect(def, driver, net, tapfd, tapfdSize, vmop) < 0)
>               goto cleanup;
>       }
>   
> diff --git a/src/qemu/qemu_command.h b/src/qemu/qemu_command.h
> index bebdd27..f0d6900 100644
> --- a/src/qemu/qemu_command.h
> +++ b/src/qemu/qemu_command.h
> @@ -232,6 +232,8 @@ int qemuNetworkIfaceConnect(virDomainDefPtr def,
>   int qemuPhysIfaceConnect(virDomainDefPtr def,
>                            virQEMUDriverPtr driver,
>                            virDomainNetDefPtr net,
> +                         int *tapfd,
> +                         size_t tapfdSize,
>                            virNetDevVPortProfileOp vmop);
>   
>   int qemuOpenVhostNet(virDomainDefPtr def,
> diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
> index 8804d3d..1a3b278 100644
> --- a/src/qemu/qemu_hotplug.c
> +++ b/src/qemu/qemu_hotplug.c
> @@ -947,15 +947,17 @@ int qemuDomainAttachNetDevice(virConnectPtr conn,
>           if (qemuOpenVhostNet(vm->def, net, priv->qemuCaps, vhostfd, &vhostfdSize) < 0)
>               goto cleanup;
>       } else if (actualType == VIR_DOMAIN_NET_TYPE_DIRECT) {
> -        tapfdSize = vhostfdSize = 1;
> -        if (VIR_ALLOC(tapfd) < 0)
> +        tapfdSize = vhostfdSize = net->driver.virtio.queues;
> +        if (!tapfdSize)
> +            tapfdSize = vhostfdSize = 1;
> +        if (VIR_ALLOC_N(tapfd, tapfdSize) < 0)
>               goto cleanup;
> -        *tapfd = -1;
> -        if (VIR_ALLOC(vhostfd) < 0)
> +        memset(tapfd, -1, sizeof(*tapfd) * tapfdSize);
> +        if (VIR_ALLOC_N(vhostfd, vhostfdSize) < 0)
>               goto cleanup;
> -        *vhostfd = -1;
> -        if ((tapfd[0] = qemuPhysIfaceConnect(vm->def, driver, net,
> -                                             VIR_NETDEV_VPORT_PROFILE_OP_CREATE)) < 0)
> +        memset(vhostfd, -1, sizeof(*vhostfd) * vhostfdSize);
> +        if (qemuPhysIfaceConnect(vm->def, driver, net, tapfd, tapfdSize,
> +                                 VIR_NETDEV_VPORT_PROFILE_OP_CREATE) < 0)
>               goto cleanup;
>           iface_connected = true;
>           if (qemuOpenVhostNet(vm->def, net, priv->qemuCaps, vhostfd, &vhostfdSize) < 0)