[Kimchi-devel] [PATCH v8 0/4] Host device passthrough: Summary

[Aline Manera]

On 07/21/2014 06:36 AM, Zhou Zheng Sheng wrote:
> 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.

The patch set seems good for me (unless the typo I mentioned)
Go ahead with the API, tests and mockmodel updates.

>
> v8:
>    Change the URI for listing affected passthrough devices, suggested by
>    Aline. Move hostdev.py to src/kimchi/model.py. Still discussing API
>    with the front-end developer. Once the API accepted, The author should
>    add tests for model and mockmodel, and change API.md and API.json
>    accordingly.
> 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             |   7 +
>   src/kimchi/control/vm/hostdevs.py      |  44 +++++
>   src/kimchi/featuretests.py             |  10 +-
>   src/kimchi/i18n.py                     |  10 +
>   src/kimchi/mockmodel.py                |   7 +-
>   src/kimchi/model/config.py             |   2 +
>   src/kimchi/model/host.py               |  38 ++--
>   src/kimchi/model/hostdev.py            | 311 +++++++++++++++++++++++++++++++
>   src/kimchi/model/libvirtstoragepool.py |  18 +-
>   src/kimchi/model/vmhostdevs.py         | 324 +++++++++++++++++++++++++++++++++
>   src/kimchi/rollbackcontext.py          |   3 +
>   src/kimchi/xmlutils.py                 |  26 ++-
>   tests/test_rest.py                     |   6 +-
>   tests/test_storagepool.py              |   7 +-
>   15 files changed, 784 insertions(+), 40 deletions(-)
>   create mode 100644 src/kimchi/control/vm/hostdevs.py
>   create mode 100644 src/kimchi/model/hostdev.py
>   create mode 100644 src/kimchi/model/vmhostdevs.py
>