This patch introduces keep alive messages support for P2P migration
and it adds two new configuration entries namely 'keepalive_interval'
'keepalive_count' to control it. Behavior of these entries is the
same as qemu driver thus the description is copied from there
with just a few simplifications.
Signed-off-by: NJoao Martins <joao.m.martins@oracle.com>

Introduce support for VIR_MIGRATE_PEER2PEER in libvirt migration.
Most of the changes occur at the source and no modifications at
the receiver.

In P2P mode there is only the Perform phase so we must handle the
connection with the destination and actually perform the
migration. libxlDomainPerformP2P implements the connection to the
destination and libxlDoMigrateP2P implements the actual migration
logic with virConnectPtr. In this function we take care of doing
all phases of migration in the destination similar to
virDomainMigrateVersion3Full. We appropriately save the last
error reported in each of the phases to provide proper reporting.
We don't yet support VIR_MIGRATE_TUNNELED and we always use V3
with extensible params, thus it also makes the implementation
simpler.

It is worth noting that the receiver didn't have any changes, and
since it's still the v3 sequence thus it is possible to migrate
from a P2P to non-P2P host.
Signed-off-by: NJoao Martins <joao.m.martins@oracle.com>

The virStringListLength function does not ever modify the passed
string list. It merely counts the items in it. Make sure that we
reflect this bit in the function header.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

(crobinso: fix up spacing and squash in sheepdog bit suggested
 by Andrea)

Older gcc fails to see that the variable is set iff @hasPriority
== true in which case the former is set a value. Initialize the
value while declaring it to make the compiler shut up.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

It does exactly the same thing as virStringListLength() and it's used in
one place only.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

My commit e11aa749 messed up the parameter order.

Reported by John Ferlan.

Remove the extra spaces, do not align them on '='.

The return type of strlen is 'size_t', which is unsigned and therefore
never less than zero.

Use STREQ to make the check obvious.

We free the key right after calling the API.

Reuse a single variable to remove the typo.

Instead of open-coding it.

Error out if the allocation failed.

Two VIR_STRDUP calls are redundant - just steal the string
converted by VBOX_UTF16_TO_UTF8.

Report an error when the third one fails.

Remove the need to track what type of graphics were present
by temporary variables.

Allocate it as soon as we know we will need it.

Add it to def->ngraphics if it's allocated, removing the need
to use the addDesktop and totalPresent variables to track this.

Separate allocation of the def->graphics array from the allocation
and initialization of its first element.

Note that the only possible values of totalPresent at this point
are 0 or 1, because it equals to guiPresent + sdlPresent.

VIR_ALLOC* already reported an error.

When FRONTEND/Type is not any of "sdl", "gui", "vrdp", we add a DESKTOP.
Use a bool to track this, instead of checking that both
totalPresent ("sdl" or "gui" present) and vrdpPresent are zero.

VRDxEnabled is initialized to false. Put the if (VRDxEnabled)
on the top level to reduce nesting.

Use STREQ_NULLABLE instead of deep nesting.

Error out on allocation failures instead of creating an incomplete
definition.

Fixes a possible crash when def->nvideos is 1, but def->videos is NULL.

For the actions ADD and OLD, split out creating the new lease object,
as well as getting the environment variables that do not affect
the parsing of command line arguments.

Since majority of the steps is shared, the function can be reused to
simplify code.

Similarly to previous path doing this same for vCPUs this also fixes the
a similar bug (which is not tracked).

Rather than iterating 3 times for various settings this function
aggregates all the code into single place. One of the other advantages
is that it can then be reused for properly setting IOThread info on
hotplug.

Since majority of the steps is shared, the function can be reused to
simplify code.

Additionally this resolves
https://bugzilla.redhat.com/show_bug.cgi?id=1244128 since the cpu
bandwidth limiting with cgroups would not be set on the hotplug path.

Additionally the code now sets the thread affinity and honors autoCpuset
as in the regular startup code path.

Rather than iterating 3 times for various settings this function
aggregates all the code into single place. One of the other advantages
is that it can then be reused for properly setting vCPU info on hotplug.

With this approach autoCpuset is also used when setting the process
affinity rather than just via cgroups.

Commit 8cd1d546 consolidates both daemon and remote driver typed param
serialization functions. The consolidation now enforces client to use
VIR_TYPED_PARAM_STRING_OKAY flag to properly serialize string parameters, which
server has used for quite some time now. And this caused an issue, since the
commit had not adjusted client remote calls appropriately, thus causing a
failure in blkiotune, numatune and migration APIs (as per Xen CI tests). This
patch adjusts both remote_driver.c and gendispatch.pl to properly address this
issue.

http://lists.xenproject.org/archives/html/xen-devel/2016-02/msg01012.htmlSigned-off-by: NJoao Martins <joao.m.martins@oracle.com>
Signed-off-by: NErik Skultety <eskultet@redhat.com>

In the commit 7938b533 we've changed the function signature,
however forgot to update stump that's used on systems without
CGroups causing a build failure.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Similarly to previous commit change the way how iothread scheduler info
is stored and clean up a lot of unnecessary code.

Due to bad design the vcpu sched element is orthogonal to the way how
the data belongs to the corresponding objects. Now that vcpus are a
struct that allow to store other info too, let's convert the data to the
sane structure.

The helpers for the conversion are made universal so that they can be
reused for iothreads too.

This patch also resolves https://bugzilla.redhat.com/show_bug.cgi?id=1235180
since with the correct storage approach you can't have dangling data.

virDomainDefFormatInternal is growing rather large. Extract the cputune
formatter into a separate function.

Now that the pinning info is stored elsewhere we can delete all the
obsolete code.

Now with the new struct the data can be stored in a much saner place.

This step can be omitted, so that drivers can decide what to do when the
user requests to use default vcpu pinning.

Now that qemuDomainDetectVcpuPids is able to refresh the vCPU pid
information it can be reused in the hotplug and hotunplug code paths
rather than open-coding a very similar algorithm.

A slight algorithm change is necessary for unplug since the vCPU needs
to be marked offline prior to calling the thread detector function and
eventually rolled back if something fails.

Some callers will need to behave differently when the detection failed
and when the VM crashed during the redetection. Return -2 if it crashed.

Pass a bitmap of enabled guest vCPUs to virCgroupGetPercpuStats so that
non-continuous vCPU topologies can be used.

Move the logic from virDomainDiskDefDstDuplicates into
virDomainDiskDefCheckDuplicateInfo so that we don't have to loop
multiple times through the array of disks. Since the original function
was called in qemuBuildDriveDevStr, it was actually called for every
single disk which was quite wasteful.

Additionally the target uniqueness check needed to be duplicated in
the disk hotplug case, since the disk was inserted into the domain
definition after the device string was formatted and thus
virDomainDiskDefDstDuplicates didn't do anything in that case.

When starting a qemu process there are certain checks done to ensure
that the configuration makes sense. Extract them into a separate
function so that they can be reused in the test code.

Retrieval of the driver capabilities as well as emulator capabilities
does not require the complete qemuProcessStop to be executed on
failure.

We do the check on VM start, but the user could still hotplug a disk
with a conflicting serial or WWN. Reuse the checker function to fix the
issue.