The same way we added a helper for creating userspace memory mappings
from the MemoryManager, this patch adds a new helper to remove some
previously added mappings.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Now that the restore path uses RestoreConfig structure, we add a new
parameter called "prefault" to it. This will give the user the ability
to populate the pages corresponding to the mapped regions backed by the
snapshotted memory files.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
When CoW can be used, the VM restoration time is reduced, but the pages
are not populated. This can lead to some slowness from the guest when
accessing these pages.
Depending on the use case, we might prefer a slower boot time for better
performances from guest runtime. The way to achieve this is to prefault
the pages in this case, using the MAP_POPULATE flag along with CoW.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
This patch extends the previous behavior on the restore codepath.
Instead of copying the memory regions content from the snapshot files
into the new memory regions, the VMM will use the snapshot region files
as the backing files behind each mapped region. This is done in order to
reduce the time for the VM to be restored.
When the source VM has been initially started with a backing file, this
means it has been mapped with the MAP_SHARED flag. For this case, we
cannot use the CoW trick to speed up the VM restore path and we simply
fallback onto the copy of the memory regions content.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Whenever a MemoryManager is restored from a snapshot, the memory regions
associated with it might need to directly back the mapped memory for
increased performances. If that's the case, a list of external regions
is provided and the MemoryManager should simply ignore what's coming
from the MemoryConfig.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Now that we can choose specific mmap flags for the guest RAM, we create
a new parameter "copy_on_write" meaning that the memory mappings backed
by a file should be performed with MAP_PRIVATE instead of MAP_SHARED.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
In order to anticipate the need for special mmap flags when memory
mapping the guest RAM, we need to switch from from_file() wrapper to
build() wrapper.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
The MemoryManager is somehow a special case, as its restore() function
was not implemented as part of the Snapshottable trait. Instead, and
because restoring memory regions rely both on vm.json and every memory
region snapshot file, the memory manager is restored at creation time.
This makes the restore path slightly different from CpuManager, Vcpu,
DeviceManager and Vm, but achieve the correct restoration of the
MemoryManager along with its memory regions filled with the correct
content.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
By aggregating snapshots from the CpuManager, the MemoryManager and the
DeviceManager, Vm implements the snapshot() function from the
Snapshottable trait.
And by restoring snapshots from the CpuManager, the MemoryManager and
the DeviceManager, Vm implements the restore() function from the
Snapshottable trait.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Yi Sun <yi.y.sun@linux.intel.com>
This implements the send() function of the Transportable trait, so that
the guest memory regions can be saved into one file per region.
This will need to be extended for live migration, as it will require
other transport methods and the recv() function will need to be
implemented too.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
In order to snapshot the content of the guest RAM, the MemoryManager
must implement the Snapshottable trait.
Signed-off-by: Yi Sun <yi.y.sun@linux.intel.com>
A Snapshottable component can snapshot itself and
provide a MigrationSnapshot payload as a result.
A MigrationSnapshot payload is a map of component IDs to a list of
migration sections (MigrationSection). As component can be made of
several Migratable sub-components (e.g. the DeviceManager and its
device objects), a migration snapshot can be made of multiple snapshot
itself.
A snapshot is a list of migration sections, each section being a
component state snapshot. Having multiple sections allows for easier and
backward compatible migration payload extensions.
Once created, a migratable component snapshot may be transported and this
is what the Transportable trait defines, through 2 methods: send and recv.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Yi Sun <yi.y.sun@linux.intel.com>
Whenever the memory is resized, it's important to retrieve the new
region to pass it down to the device manager, this way it can decide
what to do with it.
Also, there's no need to use a boolean as we can instead use an Option
to carry the information about the region. In case of virtio-mem, there
will be no region since the whole memory has been reserved up front by
the VMM at boot. This means only the ACPI hotplug will return a region
and is the only method that requires the memory to be updated from the
device manager.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
This commit adds new option hotplug_method to memory config.
It can set the hotplug method to "acpi" or "virtio-mem".
Signed-off-by: Hui Zhu <teawater@antfin.com>
Use this boolean to turn on the KVM_MEM_READONLY flag to indicate that
this memory mapping should not be writable by the VM.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Relying on the latest vm-memory version, including the freshly
introduced structure GuestMemoryAtomic, this patch replaces every
occurrence of Arc<ArcSwap<GuestMemoryMmap> with
GuestMemoryAtomic<GuestMemoryMmap>.
The point is to rely on the common RCU-like implementation from
vm-memory so that we don't have to do it from Cloud-Hypervisor.
Fixes#735
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Rather than have the MemoryManager device sit on the I/O bus allocate
space for MMIO and add it to the MMIO bus.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
The build is run against "--all-features", "pci,acpi", "pci" and "mmio"
separately. The clippy validation must be run against the same set of
features in order to validate the code is correct.
Because of these new checks, this commit includes multiple fixes
related to the errors generated when manually running the checks.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
After refactoring a common function is used to setup these slots and
that function takes care of allocating a new slot so it is not necessary
to reserve the initial region slots.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Generate and expose the DSDT table entries required to support memory
hotplug. The AML methods call into the MemoryManager via I/O ports
exposed as fields.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Expose the details of hotplug RAM slots via an I/O port. This will be
consumed by the ACPI DSDT tables to report the hotplug memory details to
the guest.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Add a "resize()" method on MemoryManager which will create a new memory
allocation based on the difference between the desired RAM amount and
the amount already in use. After allocating the added RAM using the same
backing method as the boot RAM store the details in a vector and update
the KVM map and create a new GuestMemoryMmap and replace all the users.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
This specifies how much address space should be reserved for hotplugging
of RAM. This space is reserved by adding move the start of the device
area by the desired amount.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Make the GuestMemoryMmap from a Vec<Arc<GuestRegionMmap>> by using this
method we can persist a set of regions in the MemoryManager and then
extend this set with a newly created region. Ultimately that will allow
the hotplug of memory.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
This allows us to change the memory map that is being used by the
devices via an atomic swap (by replacing the map with another one). The
ArcSwap provides the mechanism for atomically swapping from to another
whilst still giving good read performace. It is inside an Arc so that we
can use a single ArcSwap for all users.
Not covered by this change is replacing the GuestMemoryMmap itself.
This change also removes some vertical whitespace from use blocks in the
files that this commit also changed. Vertical whitespace was being used
inconsistently and broke rustfmt's behaviour of ordering the imports as
it would only do it within the block.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
This function will be useful for other parts of the VMM that also
estabilish their own mappings.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
This removes the need to handle a mutable integer and also centralises
the allocation of these slot numbers.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
The memory manager is responsible for setting up the guest memory and in
the long term will also handle addition of guest memory.
In this commit move code for creating the backing memory and populating
the allocator into the new implementation trying to make as minimal
changes to other code as possible.
Follow on commits will further reduce some of the duplicated code.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
