Re: [Kimchi-devel] [PATCH v7 0/4] Host device passthrough: Summary

Hi, This patch series is to enable Kimchi to assign hos devices directly to a VM, thus greately improve VM performance. Currently we support assigning PCI device, USB device and SCSI LUN. For example, we can assign an NIC to VM to improve guest network throughput, or passthrough a USB camera to enable the guest OS to record video. Host devices form a tree. We can assign most of the devices in the tree to VM. By assigning a device, all the devices in its sub-tree are also assigned. It might not make sense to assign a USB controller, because the host may be using one of the devices connected to the controller. Instead, Kimchi just presents the "leaf" devices to assign to guest. In recent Linux kernel and KVM, it is able to recognize the IOMMU group of a PCI device. The "leaf" PCI devices in the same IOMMU group should be assigned and dismissed together. The IOMMU group is the actual smallest isolation granularity of the PCI devices. The first patch is to list all host devices information. It's useful on its own to show host devices information. The second patch is to list all eligible host devices to assign, as well as the "affected" devices in the same IOMMU group. The third patch creates a sub-collection "hostdevs" to the VM resource, and deals with assigning and dismissing devices. The fourth patch adds a sub-collection "vm_holders" to the host device resource. It's to list all VMs that are holding the device. I'll update API and unit test once everyone is happy with the interface and logic.

v7: Some minor coding style improvements. v6: Do not passthrough PCI device of class code 0x07. It might contains system device not suitable to assign to guest. v5: Filter ealigible pci devices according to pci class. When assigning a device to VM, check if there are other VMs holding it. Use "kimchi.model.utils.get_vm_config_flag()" to correctly set the device attaching API flag. v4: Add new sub-collection to host device to list the VMs holding the device. v3: Fix a small naming error introduced by rebase. v2: Handle the devices in VM's sub-collection "hostdevs". v1: Handle the devices in VM template. Zhou Zheng Sheng (4): Host device passthrough: List all types of host devices Host device passthrough: List eligible device to passthrough Host device passthrough: Directly assign and dissmis host device from VM Host device passthrough: List VMs that are holding a host device docs/API.md | 11 +- src/kimchi/control/host.py | 16 ++ src/kimchi/control/vm/hostdevs.py | 44 +++++ src/kimchi/featuretests.py | 10 +- src/kimchi/hostdev.py | 311 +++++++++++++++++++++++++++++++ src/kimchi/i18n.py | 9 + src/kimchi/mockmodel.py | 7 +- src/kimchi/model/config.py | 2 + src/kimchi/model/host.py | 32 ++-- src/kimchi/model/libvirtstoragepool.py | 18 +- src/kimchi/model/vmhostdevs.py | 323 +++++++++++++++++++++++++++++++++ src/kimchi/rollbackcontext.py | 3 + src/kimchi/xmlutils.py | 26 ++- tests/test_rest.py | 6 +- tests/test_storagepool.py | 7 +- 15 files changed, 786 insertions(+), 39 deletions(-) create mode 100644 src/kimchi/control/vm/hostdevs.py create mode 100644 src/kimchi/hostdev.py create mode 100644 src/kimchi/model/vmhostdevs.py