Implement server-side support for switch-host client migration. Client
side support is present already in the tree.
Setting the migration information is done using the existing
spice_server_migrate_info() function. A new
spice_server_migrate_switch() function has been added which triggers
sending out the switch-host message.
Seamless migration functions are left there for now.
spice_server_migrate_start() has been chamnged to just fail
unconditionally though as seamless migration is broken anyway.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
We should pass up errors instead of aborting. Do that at least
for bind() failures which actually happen in real live due to the
tcp port being busy.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
We erronously ignored data from guest on the serial channel if no client is
connected. This leads to an assert when the guest writes a second time, since
there is still data unconsumed by us (the host).
Fix by reading data anyway, and discarding it after parsing (and reading) whole
messages from the guest.
Net affect is that any messages the agent sends while no client is connected
get discarded, but only full messages are discarded.
This fixes an abort if booting a winxp guest with vdagent without a connected
client.
We are keeping track of tokens for sending agent data to the client, but
the client send an initial value of ~0, and never gives us new send tokens
so this is all rather useless -> remove it.
Note that it is kept in the migration data struct for compatibility reasons.
read_from_vdi_port(), called from vdagent_char_device_wakeup() may
fail to consume all data because no buffers are available in the
read_bufs ring. When this happens we would fail to ever read more data
from the agent on the guest as the port is throttled and stays throttled
until we've consumed all data from the current buffer.
This patch re-enables the call to read_from_vdi_port() from
vdi_read_buf_release(), so that we will try the read again when space
becomes available in the read_bufs ring.
Together with another nasty hack in the linux guest virtio_console
driver, where it waits for a write to be acked by the host before
continuing with the next one, this can lead to a linux guest
getting stuck / hang (until the write is read by the spice-server
which never happens becaus of the above issues).
Note that even with this patch, the guest will still gets stuck due to
a bug in watch_update_mask in spice-core in qemu, which causes writing
to the client to never resume once it blocked. A patch for this has been
submitted to qemu.
read_from_vdi_port() MUST always be called in a while loop until it returns 0.
This is needed because it can cause new data available events and its
recursion protection causes those to get lost. Calling it until it returns 0
ensures that all data has been consumed.
Example scenario where we can fail to read the available data otherwise:
- server/reds.c: vdagent_char_device_wakeup get called
by hw/spice-vmc.c because data has arrived from the guest,
- hw/spice-vmc.c: vmc_read get calls
- If the vmc_read call depletes the current buffer it calls
virtio_serial_throttle_port(&svc->port, false)
- This causes vmc_have_data to get called, which if in the
mean time another buffer has arrived causes
vdagent_char_device_wakeup to gets called again
(so recursively)
- vdagent_char_device_wakeup is protected against recursive
calling and ignores the second call (a nasty hack)
- if no other data arrives, the arrived data will not get read
This patch adds a channel event callback to the spice core interface.
This new callback will be called for three events:
(1) A new connection has been established.
(2) The channel is ready (i.e. authentication is done,
link message verification passed all tests, channel
is ready to use).
(3) Channel was disconnected.
Qemu will use this to send notifications to the management app.
When upgrading a cluster of machines you typically do this by
upgrading a set of machines at a time, making the new machines run
the new software version, but in a fashion compatible with the old
versions (in terms of e.g. migration). Then when all machines are
upgrades, any new features in the new version can be enabled.
This API allows qemu to limit the set of features that spice uses to
those compatible with an older version, in order to do an upgrade like
this. Right now it doesn't really do much, since we don't keep compat
with 0.4.0 atm (although that may be added later).
There is no guarantee that any future version of spice support
being compatible with any previous version. However, we will always
support compatibility with the previous major version so that clusters
can be upgraded step by step.
This used to be a callback for the vdi_port "data ready" interrupt,
which did indicate either data ready to read or data ready to write, but
this is no longer the case now that virtio-serial is used.
This seemingly simple fix prevents a race that needs to be fixed with
another patch, see freedesktop bz #29903
The vdi_port_write_timer_started flag was not being reset, which prevented
another vdi_port_write_timer_start from actually starting the timer. Fix
is to change order of lines. This happens in the callback of the timer, so
no chance of double timer set.
Remove all uses of @end in the marshaller, instead just using
the C struct array-at-end-of-struct. To make this work we also remove
all use of @end for switches (making them C unions).
We drop the zero member of the notify message so that we can avoid this
use of @end for a primitive in the marshaller (plus its useless to send
over the wire).
We change the offsets and stuff in the migration messages to real pointers.
This is required because we don't want to free messages that just
refer to the unparsed message (like SpiceMsgData).
Also, in the future we might need it for more complex demarshalling.
