Add a live migration section to the VFIO documentation covering the
requirements beyond snapshot and restore, the dirty tracking behavior,
the destination file descriptor substitution with an example, and the
failure recovery behavior. Link it from the live migration and
snapshot sections.
Signed-off-by: Saravanan D <saravanand@crusoe.ai>
Add a Snapshot and Restore section to docs/vfio.md covering the
migration v2 requirements (Linux 5.18 kernel, variant VFIO
driver such as mlx5_vfio_pci) and the restore sequence for
devices that advertise migration v2.
The behavior description covers the full restore sequence. It
documents the RUNNING to RESUMING single transition (the kernel
walks the intermediate STOP arc), the post load PCI_COMMAND push
to the device, and the MSI or MSI-X eventfd rearm that the
kernel state does not carry. Behavior matches QEMU
vfio_pci_load_config().
It notes one limitation, the snapshot format stores the opaque
device blob as base64 inside the snapshot JSON, which may benefit
from a binary transport path for very large state.
docs/snapshot_restore.md replaces its VFIO out of scope
limitation with a short section that points to docs/vfio.md for
the requirements and behavior.
Signed-off-by: Saravanan D <saravanand@crusoe.ai>
Explain how operators can exclude selected VFIO BARs from mmap
when they know their workloads do not require MMIO access to those
regions.
Documenting the option separately keeps the new device argument
discoverable and calls out the valid BAR index range.
Signed-off-by: Damian Barabonkov <dbctl@pm.me>
Assisted-by: OpenCode:gpt-5.5
When using multiple PCI segments, the 32-bit and 64-bit mmio
aperture is split equally between each segment. Add an option
to configure the 'weight'. For example, a PCI segment with a
`mmio32_aperture_weight` of 2 will be allocated twice as much
32-bit mmio space as a normal PCI segment.
Signed-off-by: Thomas Barrett <tbarrett@crusoeenergy.com>
Fixing a few inconsistencies and extending the document to tackle
multiple devices use case, as well as having multiple devices under the
same IOMMU group.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
With recent kernels, it is now expected to use "bind" control from the
sysfs in order to bind a specific device to the vfio-pci driver.
The use of "new_id" is still required but it is only needed once per
device type. Let's say you want to bind two virtio-net devices, you will
need to add the device_id:vendor_id pair through "new_id", while you
will be required to use "bind" for each device.
Fixes#2545
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Since INTx is now supported for VFIO PCI devices, there is no more
limitations regarding VFIO, which means the documentation must be
updated accordingly.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Because of the behavior of the NVIDIA proprietary driver, we can't
expect NVIDIA cards with only MSI support to be functioning correctly
after they've been passed through with Cloud-Hypervisor.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Now that our CI has transitioned from ClearLinux to Ubuntu images
exclusively, let's update the documentation to refer to Ubuntu images
instead of ClearLinux's ones.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Having the virtual IOMMU created with --iommu is one thing, but we also
need a way to decide if a VFIO device should be attached to the virtual
IOMMU or not. That's why we introduce an extra option "iommu" with the
value "on" or "off". By default, the device is not attached, which means
"iommu=off".
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Having the virtual IOMMU created with --iommu is one thing, but we also
need a way to decide if a virtio-blk device should be attached to this
virtual IOMMU or not. That's why we introduce an extra option "iommu"
with the value "on" or "off". By default, the device is not attached,
which means "iommu=off".
One side effect of this new option is that we had to introduce a new
option for the disk path, simply called "path=".
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
