On Tue, Jun 11, 2013 at 3:52 AM, Pawit Pornkitprasan <p.pa...@gmail.com> wrote: > 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
This looks like a compelling idea, though I am sure not limited to just networking (think GPU passthrough). How are things like live migration affected? Are you making planner changes to deal with the limiting factor of a single PCI-passthrough VM being available per host? What's the level of effort to extend this to work with VMware DirectPath I/O and PCI passthrough on XenServer? --David
