[libvirt] [PATCH] conf: Remove the actual hostdev when removing a network

[Cole Robinson]

On 09/03/2013 11:29 AM, Peter Krempa wrote:
> Commit 50348e6edfa reused the code to remove the hostdev portion of a
> network definition on multiple places but forgot to take into account
> that sometimes the "actual" network is passed and in some cases the
> parent of that.
> 
> This patch uses the virDomainNetGetActualHostdev() helper to acquire the
> correct pointer all the time while removing the hostdev portion from the
> list.
> ---
>  src/conf/domain_conf.c | 14 +++++++-------
>  1 file changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
> index e412f28..cef4cf9 100644
> --- a/src/conf/domain_conf.c
> +++ b/src/conf/domain_conf.c
> @@ -10002,14 +10002,14 @@ void
>  virDomainNetRemoveHostdev(virDomainDefPtr def,
>                            virDomainNetDefPtr net)
>  {
> -    if (net->type == VIR_DOMAIN_NET_TYPE_HOSTDEV) {
> -        /* hostdev net devices are normally also be in the hostdevs
> -         * array, but might have already been removed by the time we
> -         * get here.
> -         */
> -        virDomainHostdevDefPtr hostdev = &net->data.hostdev.def;
> -        size_t i;
> +    /* hostdev net devices are normally also be in the hostdevs
> +     * array, but might have already been removed by the time we
> +     * get here.
> +     */
> +    virDomainHostdevDefPtr hostdev = virDomainNetGetActualHostdev(net);
> +    size_t i;
> 
> +    if (hostdev) {
>          for (i = 0; i < def->nhostdevs; i++) {
>              if (def->hostdevs[i] == hostdev) {
>                  virDomainHostdevRemove(def, i);
> 

This causes a crash for me on failed guest startup. XML attached, guest is
legitimately failing because libvirt doesn't know about the CPU model it
specifies. Reverting this patch fixes the crash. Snipped backtrace:

#0  virDomainNetGetActualHostdev (iface=iface at entry=0x7fffd41d7930)
    at conf/domain_conf.c:17879
#1  0x00007ffff7562f10 in virDomainNetRemoveHostdev (
    def=def at entry=0x7fffd41c7400, net=net at entry=0x7fffd41d7930)
    at conf/domain_conf.c:10009
#2  0x00007fffddda5d65 in qemuProcessStop (driver=driver at entry=0x7fffd409f0c0,
    vm=vm at entry=0x7fffd41c7ea0, reason=reason at entry=VIR_DOMAIN_SHUTOFF_FAILED,
    flags=flags at entry=2) at qemu/qemu_process.c:4270
#3  0x00007fffddda7e01 in qemuProcessStart (conn=conn at entry=0x7fffd0000a80,
    driver=driver at entry=0x7fffd409f0c0, vm=vm at entry=0x7fffd41c7ea0,
    migrateFrom=migrateFrom at entry=0x0, stdin_fd=stdin_fd at entry=-1,
    stdin_path=stdin_path at entry=0x0, snapshot=snapshot at entry=0x0,
    vmop=vmop at entry=VIR_NETDEV_VPORT_PROFILE_OP_CREATE, flags=<optimized out>,
    flags at entry=1) at qemu/qemu_process.c:4051

- Cole

-------------- next part --------------
<domain type='qemu'>
  <name>f19-arm-virtio</name>
  <uuid>aaf2c9da-aab2-3244-be96-9a23b85f6b07</uuid>
  <description>f19 arm guest w/ virtio config</description>
  <memory unit='KiB'>1048576</memory>
  <currentMemory unit='KiB'>1048576</currentMemory>
  <vcpu placement='static'>1</vcpu>
  <os>
    <type arch='armv7l' machine='vexpress-a9'>hvm</type>
    <kernel>/mnt/data/devel/images/f19-arm.kernel</kernel>
    <initrd>/mnt/data/devel/images/f19-arm.initrd</initrd>
    <cmdline>console=ttyAMA0 rw root=/dev/vda3</cmdline>
    <dtb>/mnt/data/devel/images/f19-arm.dtb</dtb>
    <boot dev='hd'/>
  </os>
  <features>
    <acpi/>
    <apic/>
    <pae/>
  </features>
  <cpu mode='custom' match='exact'>
    <model fallback='allow'>cortex-a15</model>
  </cpu>
  <clock offset='utc'/>
  <on_poweroff>destroy</on_poweroff>
  <on_reboot>restart</on_reboot>
  <on_crash>restart</on_crash>
  <devices>
    <emulator>/bin/qemu-system-arm</emulator>
    <disk type='file' device='disk'>
      <driver name='qemu' type='raw'/>
      <source file='/mnt/data/devel/images/f19-arm.raw'/>
      <target dev='vda' bus='virtio'/>
      <address type='virtio-mmio'/>
    </disk>
    <interface type='network'>
      <mac address='52:54:00:92:86:86'/>
      <source network='default'/>
      <model type='virtio'/>
      <address type='virtio-mmio'/>
    </interface>
    <serial type='pty'>
      <target port='0'/>
    </serial>
    <console type='pty'>
      <target type='serial' port='0'/>
    </console>
  </devices>
</domain>