Based on the newly added Vdpa device along with the new vdpa parameter,
this patch enables the support for vDPA devices.
It's important to note this the only virtio device for which we provide
an ExternalDmaMapping instance. This will allow for the right DMA ranges
to be mapped/unmapped.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Introduce a new --vdpa parameter associated with a VdpaConfig for the
future creation of a Vdpa device.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
vDPA is a kernel framework introduced fairly recently in order to handle
devices complying with virtio specification on their datapath, while the
control path is vendor specific. For the datapath, that means the
virtqueues are handled through DMA directly between the hardware and the
guest, while the control path goes through the vDPA framework,
eventually exposed through a vhost-vdpa device.
vDPA, like VFIO, aims at achieving baremetal performance for devices
that are passed into a VM. But unlike VFIO, it provides a simpler/better
framework for achieving migration. Because the DMA accesses between the
device and the guest are going through virtio queues, migration can be
achieved way more easily, and doesn't require each device driver to
implement the migration support. In the VFIO case, each vendor is
expected to provide an implementation of the VFIO migration framework,
which makes things harder as it must be done for each and every device.
So to summarize the point is to support migration for hardware devices
through which we can achieve baremetal performances.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Update the content of the documentation to clarify how the cache option
from virtiofsd has an impact on the host page cache, while the dax
option for the filesystem in the guest has an impact on the guest page
cache.
The document is also updated to not have lines exceeding 80 characters.
Fixes#3826
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Document the reason why someone might need to use the balloon device and
detail the different parameters associated with it.
Fixes#3807
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
This will significantly reduce the size of the DSDT and the effort
required to parse them if there is no requirement to support
hotplug/unplug.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
If the CpuManager is dynamic it devices CPUs can be
hotplugged/unplugged.
Since TDX does not support CPU hotplug this is currently the only
determinator as to whether the CpuManager is dynamic.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Since the code has been adapted to support VIRTIO_F_EVENT_IDX we use
Queue::needs_notification() to determine whether to signal the guest so
it is no longer necessary to check if there are any used descriptors. If
the feature is not negotiated then Queue::needs_notification() will
return true triggering an interrupt of the guest. Theoretically this
could be a spurious interrupt of the guest if there were no used used
descriptors but this is unlikely as we only generate used descriptors
for the control queue as a result of an interrupt of the VMM by the
guest.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
This indicates if anything has been added to the available queue since
it was last iterated through. If it returns true then it is necessary to
iterate through the queue again otherwise it is appropriate to break out
from the loop.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
vmm.ping/vm.info will hang for PUT method, vm.create/vmm.shutdonw hang for GET method.
Because these four APIs do not write the response body when the HTTP method does not match.
Signed-off-by: LiHui <andrewli@kubesphere.io>
In case the virtio device which requires DMA mapping is placed behind a
virtual IOMMU, we shouldn't map/unmap any region manually. Instead, we
provide the DMA handler to the virtio-iommu device so that it can
trigger the proper mappings.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
If a virtio device is associated with a DMA handler, the DMA mapping and
unmapping is performed from the device manager through the handler.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Given that some virtio device might need some DMA handling, we provide a
way to store this through the VirtioPciDevice layer, so that it can be
accessed when the PCI device is removed.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
In anticipation for handling potential DMA mapping/unmapping operations for a
virtio device, we extend the MetaVirtioDevice with an additional field
that holds an optional DMA handler.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
The tuple of information related to each virtio device is too big, and
it's better to factorize it through a dedicated structure.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
