Hi, I am implementing PCI-Passthrough to use with CloudStack for use with high-performance networking (10 Gigabit Ethernet/Infiniband).
The current design is to attach a PCI ID (from lspci) to a compute offering. (Not a network offering since from CloudStack’s point of view, the pass through device has nothing to do with network and may as well be used for other things.) A host tag can be used to limit deployment to machines with the required PCI device. Then, when starting the virtual machine, the PCI ID is passed into VirtualMachineTO to the agent (currently using KVM) and the agent creates a corresponding <hostdev> ( http://libvirt.org/guide/html/Application_Development_Guide-Device_Config-PCI_Pass.html) tag and then libvirt will handle the rest. For allocation, the current idea is to use CloudStack’s capacity system (at the same place where allocation of CPU and RAM is determined) to limit 1 PCI-Passthrough VM per physical host. The current design has many limitations such as: - One physical host can only have 1 VM with PCI-Passthrough, even if many PCI-cards with equivalent functions are available - The PCI ID is fixed inside the compute offering, so all machines have to be homogeneous and have the same PCI ID for the device. The initial implementation is working. Any suggestions and comments are welcomed. Thank you, Pawit
