hw/9pfs: Use little-endian format for xattr values

With security_model=mapped-xattr, we encode the uid,gid and other file
attributes as extended attributes of the file. We save them under
user.virtfs.* namespace.

Use little-endian encoding for on-disk values. This enables us to export
the same directory from both little-endian and big-endian hosts.

NOTE: This will break big-endian host that have virtFS exports
using security model mapped-xattr. They will have to use external tools
to convert the xattr to little-endian format.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
net: Forbid dealing with packets when VM is not running

For all NICs(except virtio-net) emulated by qemu,
Such as e1000, rtl8139, pcnet and ne2k_pci,
Qemu can still receive packets when VM is not running.

If this happened in *migration's* last PAUSE VM stage, but
before the end of the migration, the new receiving packets will possibly dirty
parts of RAM which has been cached in *iovec*(will be sent asynchronously) and
dirty parts of new RAM which will be missed.
This will lead serious network fault in VM.

To avoid this, we forbid receiving packets in generic net code when
VM is not running.

Bug reproduction steps:
(1) Start a VM which configured at least one NIC
(2) In VM, open several Terminal and do *Ping IP -i 0.1*
(3) Migrate the VM repeatedly between two Hosts
And the *PING* command in VM will very likely fail with message:
'Destination HOST Unreachable', the NIC in VM will stay unavailable unless you
run 'service network restart'

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
hw/9pfs: Don't return type from host in readdir on local 9p filesystem

When using mapped mode in 9pfs, readdir implementation
should not return file type in d_type from the host
readdir, instead, it should use the type stored in
the extended attributes.  Since d_type is optional
and reading ext attrs for every readdir is expensive,
it should be sufficient to just set d_type to DT_UNKNOWN,
so guest will know to look it up separately.

This is a -stable material.

Signed-off-by: Bastian Blank <waldi@debian.org>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
virtio-net: don't run bh on vm stopped

commit 783e7706937fe15523b609b545587a028a2bdd03
    virtio-net: stop/start bh when appropriate

is incomplete: BH might execute within the same main loop iteration but
after vmstop, so in theory, we might trigger an assertion.
I was unable to reproduce this in practice,
but it seems clear enough that the potential is there, so worth fixing.

Cc: qemu-stable@nongnu.org
Reported-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
virtio: don't call device on !vm_running

On vm stop, virtio changes vm_running state
too soon, so callbacks can get envoked with
vm_running = false;

Cc: qemu-stable@nongnu.org
Cc: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
net: invoke callback when purging queue

devices rely on packet callbacks eventually running,
but we violate this rule whenever we purge the queue.
To fix, invoke callbacks on all packets on purge.
Set length to 0, this way callers can detect that
this happened and re-queue if necessary.

Cc: qemu-stable@nongnu.org
Cc: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
net: complete all queued packets on VM stop

This completes all packets, ensuring that callbacks
will not run when VM is stopped.

Cc: qemu-stable@nongnu.org
Cc: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
virtio-net: purge outstanding packets when starting vhost

whenever we start vhost, virtio could have outstanding packets
queued, when they complete later we'll modify the ring
while vhost is processing it.

To prevent this, purge outstanding packets on vhost start.

Cc: qemu-stable@nongnu.org
Cc: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Merge remote-tracking branch 'remotes/stefanha/tags/net-pull-request' into staging

Net patches

# gpg: Signature made Thu 04 Sep 2014 17:32:44 BST using RSA key ID 81AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>"
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>"

* remotes/stefanha/tags/net-pull-request:
  virtio-net: purge outstanding packets when starting vhost
  net: complete all queued packets on VM stop
  net: invoke callback when purging queue
  virtio: don't call device on !vm_running
  virtio-net: don't run bh on vm stopped
  net: Forbid dealing with packets when VM is not running

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Merge remote-tracking branch 'remotes/kvaneesh/for-upstream' into staging

* remotes/kvaneesh/for-upstream:
  hw/9pfs: Don't return type from host in readdir on local 9p filesystem
  hw/9pfs: Use little-endian format for xattr values

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Merge remote-tracking branch 'remotes/afaerber/tags/qom-devices-for-peter' into staging

QOM infrastructure fixes and device conversions

* Cleanups for recursive device unrealization

# gpg: Signature made Thu 04 Sep 2014 18:17:35 BST using RSA key ID 3E7E013F
# gpg: Good signature from "Andreas Färber <afaerber@suse.de>"
# gpg:                 aka "Andreas Färber <afaerber@suse.com>"

* remotes/afaerber/tags/qom-devices-for-peter:
  qdev: Add cleanup logic in device_set_realized() to avoid resource leak
  qdev: Use NULL instead of local_err for qbus_child unrealize
  qdev: Use error_abort instead of using local_err
  memory: Remove object_property_add_child_array()
  qom: Add automatic arrayification to object_property_add()
  machine: Clean up -machine handling
  qom: Make object_child_foreach() safe for objects removal

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>