[libvirt] [PATCH 2/2] Handle hotplug change on VLAN configuration using OVS

[Michal Privoznik]

On 07/17/2017 05:49 PM, Antoine Millet wrote:
> A new function virNetDevOpenvswitchUpdateVlan has been created to instruct
> OVS of the changes. qemuDomainChangeNet has been modified to handle the
> update of the VLAN configuration for a running guest and rely on
> virNetDevOpenvswitchUpdateVlan to do the actual update if needed.
> ---
>  src/libvirt_private.syms        |  1 +
>  src/qemu/qemu_hotplug.c         | 16 +++++++++++++---
>  src/util/virnetdevopenvswitch.c | 41 +++++++++++++++++++++++++++++++++++++++++
>  src/util/virnetdevopenvswitch.h |  4 ++++
>  4 files changed, 59 insertions(+), 3 deletions(-)
> 
> diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
> index 187b12b32..36caf6fbf 100644
> --- a/src/libvirt_private.syms
> +++ b/src/libvirt_private.syms
> @@ -2206,6 +2206,7 @@ virNetDevOpenvswitchInterfaceStats;
>  virNetDevOpenvswitchRemovePort;
>  virNetDevOpenvswitchSetMigrateData;
>  virNetDevOpenvswitchSetTimeout;
> +virNetDevOpenvswitchUpdateVlan;
>  
>  
>  # util/virnetdevtap.h
> diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
> index 4bc49720b..b9ad9e6c8 100644
> --- a/src/qemu/qemu_hotplug.c
> +++ b/src/qemu/qemu_hotplug.c
> @@ -2998,6 +2998,7 @@ qemuDomainChangeNet(virQEMUDriverPtr driver,
>      bool needReplaceDevDef = false;
>      bool needBandwidthSet = false;
>      bool needCoalesceChange = false;
> +    bool needVlanUpdate = false;
>      int ret = -1;
>      int changeidx = -1;
>  
> @@ -3279,12 +3280,15 @@ qemuDomainChangeNet(virQEMUDriverPtr driver,
>                          virDomainNetGetActualDirectDev(newdev)) ||
>          virDomainNetGetActualDirectMode(olddev) != virDomainNetGetActualDirectMode(newdev) ||
>          !virNetDevVPortProfileEqual(virDomainNetGetActualVirtPortProfile(olddev),
> -                                    virDomainNetGetActualVirtPortProfile(newdev)) ||
> -        !virNetDevVlanEqual(virDomainNetGetActualVlan(olddev),
> -                            virDomainNetGetActualVlan(newdev))) {
> +                                    virDomainNetGetActualVirtPortProfile(newdev))) {
>          needReconnect = true;
>      }
>  
> +    if (!virNetDevVlanEqual(virDomainNetGetActualVlan(olddev),
> +                             virDomainNetGetActualVlan(newdev))) {
> +        needVlanUpdate = true;
> +    }
> +
>      if (olddev->linkstate != newdev->linkstate)
>          needLinkStateChange = true;
>  
> @@ -3344,6 +3348,12 @@ qemuDomainChangeNet(virQEMUDriverPtr driver,
>          goto cleanup;
>      }
>  
> +    if (needVlanUpdate) {
> +        if (virNetDevOpenvswitchUpdateVlan(newdev->ifname, &newdev->vlan) < 0)
> +            goto cleanup;
> +        needReplaceDevDef = true;
> +    }
> +
>      if (needReplaceDevDef) {
>          /* the changes above warrant replacing olddev with newdev in
>           * the domain's nets list.
> diff --git a/src/util/virnetdevopenvswitch.c b/src/util/virnetdevopenvswitch.c
> index 89ed0c91c..a12bc3dbc 100644
> --- a/src/util/virnetdevopenvswitch.c
> +++ b/src/util/virnetdevopenvswitch.c
> @@ -459,3 +459,44 @@ virNetDevOpenvswitchGetVhostuserIfname(const char *path,
>      VIR_FREE(ovs_timeout);
>      return ret;
>  }
> +
> +/**
> + * virNetDevOpenvswitchUpdateVlan:
> + * @ifname: the network interface name
> + * @virtVlan: VLAN configuration to be applied
> + *
> + * Update VLAN configuration of an OVS port.
> + *
> + * Returns 0 in case of success or -1 in case of failure.
> + */
> +int virNetDevOpenvswitchUpdateVlan(const char *ifname,
> +                                   virNetDevVlanPtr virtVlan)
> +{
> +    int ret = -1;
> +    virCommandPtr cmd = NULL;
> +
> +    cmd = virCommandNew(OVSVSCTL);
> +    virNetDevOpenvswitchAddTimeout(cmd);
> +    virCommandAddArgList(cmd,
> +                         "--", "--if-exists", "clear", "Port", ifname, "tag",
> +                         "--", "--if-exists", "clear", "Port", ifname, "trunk",
> +                         "--", "--if-exists", "clear", "Port", ifname, "vlan_mode",
> +                         "--", "--if-exists", "set", "Port", ifname, NULL);
> +
> +    if (virNetDevOpenvswitchConstructVlans(cmd, virtVlan) < 0) {
> +        virReportError(VIR_ERR_INTERNAL_ERROR,
> +                       _("Unable to construct vlan configuration for port %s"), ifname);

This rewrites original error reported by
virNetDevOpenvswitchConstructVlans().

> +        goto cleanup;
> +    }
> +
> +    if (virCommandRun(cmd, NULL) < 0) {
> +        virReportError(VIR_ERR_INTERNAL_ERROR,
> +                       _("Unable to set vlan configuration on port %s"), ifname);
> +        goto cleanup;
> +    }
> +
> +    ret = 0;
> + cleanup:
> +    virCommandFree(cmd);
> +    return ret;
> +}

ACK

Michal