[libvirt] [PATCH] qemu : support persistent add/delete network interface

[Wen Congyang]

At 05/18/2011 02:13 PM, KAMEZAWA Hiroyuki Write:
>>From 226239905ec9b01fd0bd0ce050de97d7f0d9e19c Mon Sep 17 00:00:00 2001
> From: KAMEZAWA Hiroyuki <kamezawa.hiroyu at jp.fujitsu.com>
> Date: Wed, 18 May 2011 15:14:28 +0900
> Subject: [PATCH] qemu - support persistent add/delete network interface
> 
> This patch allows to modify interfaces of domain(qemu).
> 
> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu at jp.fujitsu.com>
> 
> * src/conf/domain_conf.c:
> (virDomainNetInsert) : Insert a network device to domain definition.
> (virDomainNetIndexByMac/Ifname) : Returns an index of net device in array.
> (virDomainNetRemoveByMac): Remove a NIC of passed MAC address.
> 
> * src/qemu/qemu_driver.c
> (qemuDomainAttachDeviceConfig): add codes for NIC.
> (qemuDomainDetachDeviceConfig): add codes for NIC.
> ---
>  src/conf/domain_conf.c   |   55 ++++++++++++++++++++++++++++++++++++++++++++++
>  src/conf/domain_conf.h   |    5 ++++
>  src/libvirt_private.syms |    4 +++
>  src/qemu/qemu_driver.c   |   32 ++++++++++++++++++++++++++
>  4 files changed, 96 insertions(+), 0 deletions(-)
> 
> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
> index 498438a..de9abe9 100644
> --- a/src/conf/domain_conf.c
> +++ b/src/conf/domain_conf.c
> @@ -5163,6 +5163,61 @@ int virDomainDiskRemoveByName(virDomainDefPtr def, const char *name)
>      return 0;
>  }
>  
> +int virDomainNetInsert(virDomainDefPtr def, virDomainNetDefPtr net)
> +{
> +    if (VIR_REALLOC_N(def->nets, def->nnets) < 0)

s/def->nnets/def->nnets+1/

> +        return -1;
> +    def->nets[def->nnets]  = net;
> +    def->nnets++;
> +    return 0;
> +}
> +
> +int virDomainNetIndexByMac(virDomainDefPtr def, const unsigned char *mac)
> +{
> +    int i;
> +
> +    for (i = 0; i < def->nnets; i++)
> +        if (!memcmp(def->nets[i]->mac, mac, VIR_MAC_BUFLEN))
> +            return i;
> +    return -1;
> +}
> +
> +int virDomainNetIndexByIfname(virDomainDefPtr def, const char *name)
> +{
> +    int i;
> +
> +    for (i = 0; i < def->nnets; i++)
> +        if (def->nets[i]->ifname && STREQ(def->nets[i]->ifname, name))
> +            return i;
> +    return -1;
> +}
> +
> +static void virDomainNetRemove(virDomainDefPtr def, size_t i)
> +{
> +    if (def->nnets > 1) {
> +        memmove(def->nets + i,
> +                def->nets + i + 1,
> +                sizeof(*def->nets) * (def->nnets - (i + 1)));
> +        def->nnets--;
> +        if (VIR_REALLOC_N(def->nets, def->nnets) < 0) {
> +            /* ignore harmless */
> +        }
> +    } else {
> +        VIR_FREE(def->nets);
> +        def->nnets = 0;
> +    }
> +}
> +
> +int virDomainNetRemoveByMac(virDomainDefPtr def, const unsigned char *mac)
> +{
> +    int i = virDomainNetIndexByMac(def, mac);
> +
> +    if (i < 0)
> +        return -1;
> +    virDomainNetRemove(def, i);
> +    return 0;
> +}
> +
>  
>  int virDomainControllerInsert(virDomainDefPtr def,
>                                virDomainControllerDefPtr controller)
> diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
> index fe42f21..274e22b 100644
> --- a/src/conf/domain_conf.h
> +++ b/src/conf/domain_conf.h
> @@ -1359,6 +1359,11 @@ int virDomainDiskDefAssignAddress(virCapsPtr caps, virDomainDiskDefPtr def);
>  void virDomainDiskRemove(virDomainDefPtr def, size_t i);
>  int virDomainDiskRemoveByName(virDomainDefPtr def, const char *name);
>  
> +int virDomainNetIndexByMac(virDomainDefPtr def, const unsigned char *mac);
> +int virDomainNetIndexByIfname(virDomainDefPtr def, const char *iface);
> +int virDomainNetInsert(virDomainDefPtr def, virDomainNetDefPtr net);
> +int virDomainNetRemoveByMac(virDomainDefPtr def, const unsigned char *mac);
> +
>  int virDomainControllerInsert(virDomainDefPtr def,
>                                virDomainControllerDefPtr controller);
>  void virDomainControllerInsertPreAlloced(virDomainDefPtr def,
> diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
> index 7b6151c..2695c2e 100644
> --- a/src/libvirt_private.syms
> +++ b/src/libvirt_private.syms
> @@ -290,6 +290,10 @@ virDomainLoadAllConfigs;
>  virDomainMemballoonModelTypeFromString;
>  virDomainMemballoonModelTypeToString;
>  virDomainNetDefFree;
> +virDomainNetIndexByIfname;
> +virDomainNetIndexByMac;
> +virDomainNetInsert;
> +virDomainNetRemoveByMac;
>  virDomainNetTypeToString;
>  virDomainObjAssignDef;
>  virDomainObjCopyPersistentDef;
> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
> index fdb3b30..0a547eb 100644
> --- a/src/qemu/qemu_driver.c
> +++ b/src/qemu/qemu_driver.c
> @@ -4245,6 +4245,7 @@ qemuDomainAttachDeviceConfig(virDomainDefPtr vmdef,
>                               virDomainDeviceDefPtr dev)
>  {
>      virDomainDiskDefPtr disk;
> +    virDomainNetDefPtr net;
>  
>      switch (dev->type) {
>      case VIR_DOMAIN_DEVICE_DISK:
> @@ -4267,6 +4268,28 @@ qemuDomainAttachDeviceConfig(virDomainDefPtr vmdef,
>              return -1;
>          break;
>  
> +    case VIR_DOMAIN_DEVICE_NET:
> +        net = dev->data.net;
> +        if (net->ifname && virDomainNetIndexByIfname(vmdef, net->ifname)) {

If the interface already exists, the return value of virDomainNetIndexByIfname()
is great or equal than 0, not a boolean.

I think you mean 'virDomainNetIndexByIfname(vmdef, net->ifname) >= 0'

> +            qemuReportError(VIR_ERR_INVALID_ARG,
> +                            _("iface %s already exists"), net->ifname);
> +            return -1;
> +        }
> +        if (virDomainNetIndexByMac(vmdef, net->mac) >= 0) {
> +            char macbuf[VIR_MAC_STRING_BUFLEN];
> +            virFormatMacAddr(net->mac, macbuf);
> +            qemuReportError(VIR_ERR_INVALID_ARG,
> +                            _("mac %s already exists"), macbuf);
> +            return -1;
> +        }
> +        if (virDomainNetInsert(vmdef, net)) {
> +            virReportOOMError();
> +            return -1;
> +        }
> +        dev->data.net = NULL;
> +        if (qemuDomainAssignPCIAddresses(vmdef) < 0)
> +            return -1;
> +        break;
>      default:
>           qemuReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
>                           _("persistent attach of device is not supported"));
> @@ -4281,6 +4304,7 @@ qemuDomainDetachDeviceConfig(virDomainDefPtr vmdef,
>                               virDomainDeviceDefPtr dev)
>  {
>      virDomainDiskDefPtr disk;
> +    virDomainNetDefPtr net;
>  
>      switch (dev->type) {
>      case VIR_DOMAIN_DEVICE_DISK:
> @@ -4291,6 +4315,14 @@ qemuDomainDetachDeviceConfig(virDomainDefPtr vmdef,
>              return -1;
>          }
>          break;
> +    case VIR_DOMAIN_DEVICE_NET:
> +        net = dev->data.net;
> +        if (virDomainNetRemoveByMac(vmdef, net->mac)) {
> +            qemuReportError(VIR_ERR_INVALID_ARG,
> +                            _("no target device %s"), disk->dst);

If disk->dst is correct, but net->mac is wrong, this error message
may confuse the user.

> +            return -1;
> +        }
> +        break;
>      default:
>          qemuReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
>                          _("persistent detach of device is not supported"));