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>
When a virtio device is paused an event is written to the appropriate
"pause" EventFd for the device. This will be noticed by the the device's
epoll_wait(), an atomic bool checked an if true then the thread is
parked(). When resuming the bool is reset and the thread is unpark()ed.
However the event triggering the pause is still in the EventFd so the
epoll_wait() will continue to return but because the boolean is not set
the thread will not be park()ed but instead we will busy loop around an
event that is not being consumed.
The solution is to drain the "pause" EventFd when the event is first
received and thus the epoll_wait() will only return for the pause event
once. This resolves the infinite epoll_wait() wake-ups.
Fixes: #869
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>
Remove duplicated code across the different devices by handling
the virtio feature pages in VirtioDevice itself rather than
in the backends. This works as no virtio devices use feature
bits beyond 64-bits.
Signed-off-by: Cathy Zhang <cathy.zhang@intel.com>
Based on the new structures previously introduced, the new topology
feature is being fully implemented through this commit. This allows
the description of the devices attached to the virtual IOMMU, which
is why a new function attach_devices() has been introduced. It gives
the virtual IOMMU device the full list of devices which must be attached
to it, letting the device share this information through its virtio
configuration.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
The virtio-iommu device defines a new virtio feature allowing the
topology to be discovered fully through virtio configuration.
By topology, it means describing the devices attached to the virtual
IOMMU. This is currently managed through ACPI with IORT and VIOT table,
but this is another way of describing it.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Now that we unified epoll_thread to potentially be a vector of threads,
it makes sense to make it a plural field.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Although only the block and net virtio devices can actually be multi
threaded (for now), handling them as special cases makes the code more
complex.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Callbacks are not the most Rust idiomatic way of programming. The right
way is to use a Trait to provide multiple implementation of the same
interface.
Additionally, a Trait will allow for multiple functions to be defined
while using callbacks means that a new callback must be introduced for
each new function we want to add.
For these two reasons, the current commit modifies the existing
VirtioInterrupt callback into a Trait of the same name.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
By implementing this virtio feature, we let the virtio-iommu driver call
the device backend so that it can probe each device that gets attached.
Through this probing, the device provides a range of reserved memory
related to MSI. This is mandatory for x86 architecture as we want to
avoid the default MSI range assigned by the virtio-iommu driver if no
range is provided at all. The default range is 0x8000000-0x80FFFFF but
it only makes sense for ARM architectures.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@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>
Due to the amount of code currently duplicated across virtio devices,
the stats for this commit is on the large side but it's mostly more
duplicated code, unfortunately.
Migratable and Snapshotable placeholder implementations are provided as
well, making all virtio devices Migratable.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
In order to speed up the boot time and reduce the amount of mappings,
this patch exposes the virtio-iommu device as supporting both 2M and 4k
page sizes.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
This patch relies on the trait implementation provided for each device
which requires some sort of external update based on a map or unmap.
Whenever a MAP or UNMAP request comes through the virtqueues, it
triggers a call to the external mapping trait with map()/unmap()
functions being invoked.
Those external mappings are meant to be used from VFIO and vhost-user
devices as they need to update their own mappings. In case of VFIO, the
goal is to update the DMAR table in the physical IOMMU, while vhost-user
devices needs to update their internal representation of the virtqueues.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
This patch introduces the first implementation of the virtio-iommu
device. This device emulates an IOMMU for the guest, which allows
special use cases like nesting passed through devices, or even using
IOVAs from the guest.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
