Wire up PATCH requests with the virtio-mem device.
All the validation is performed in the device, but the actual operation
is not yet implemented.

Signed-off-by: Riccardo Mancini <[email protected]>

Add entry for the patch API in Swagger and in the docs.

Signed-off-by: Riccardo Mancini <[email protected]>

Test that the new PATCH API behaves as expected.
Also updates expected metrics and fixes memory monitor to account for
hotplugging.

Signed-off-by: Riccardo Mancini <[email protected]>

Parse virtio requests over the queue and always ack them. Following
commits will add the state management inside the device.

Signed-off-by: Riccardo Mancini <[email protected]>

This commit adds block state management and implements the virtio
requests for the virtio-mem device.

Block state is tracked using a BitVec, each bit representing a single
block.

Plug/Unplug requests are validated before being executed to verify the
range is valid (aligned and within range), and that all blocks in range
are unplugged/plugged, as per the virtio spec.

UplugAll is the only request where usable_region_size can be lowered.

This commit is missing the dynamic KVM slot management which will be
added later.

Signed-off-by: Riccardo Mancini <[email protected]>

Adds unit tests using VirtioTestHelper to verify correct functioning of
the new device.

Signed-off-by: Riccardo Mancini <[email protected]>

Add the virtio-mem device metrics to the integ test validation.

Signed-off-by: Riccardo Mancini <[email protected]>

If the handler receives a UFFD remove event, it currently stores the PFN
and will reply with a zero page whenever it receives a pagefault event
for that page.
This works well with 4k pages, but zeropage is not supported on
hugepages. In order to support hugepages, let's just unregister from
UFFD whenever we get a remove event. By doing so, the handler won't
receive a notification for the removed page, and the VM will get a new
zero page from the kernel.

Signed-off-by: Riccardo Mancini <[email protected]>

This moves the logic to measure RSS to framework.utils and adds a logic
to also include huge pages in the measurement.

Furthermore, this also adds caching for the firecracker_pid, as well as
a new property to get the corresponding psutil.Process.

Signed-off-by: Riccardo Mancini <[email protected]>

Move the logic to get the MemAvailable from /proc/meminfo inside the
guest to a new guest_stats module in the test framework. This provides a
new class MeminfoGuest that can be used to retrieve this information
(and more!).

Signed-off-by: Riccardo Mancini <[email protected]>

Add integration tests for the new device:
 - check that the device is detected
 - check that hotplugging and unplugging works
 - check that memory can be used after hotplugging
 - check that memory is freed on hotunplug
 - check different config combinations
 - check different uvm types
 - check that contents are preserved across snapshot-restore

Signed-off-by: Riccardo Mancini <[email protected]>

Since these tests need to be run on an ag=1 host, move them under the
"performance" folder.

Signed-off-by: Riccardo Mancini <[email protected]>

These tests add unit test coverage to the builder.rs and vm.rs files
which where previously untested in the memory hotplug case.

Signed-off-by: Riccardo Mancini <[email protected]>