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

[Aline Manera]

On 07/28/2014 06:38 AM, Zhou Zheng Sheng wrote:
> Hi,
>
> Yu Xin and me tested the patches on a PC with RHEL6.4 installed. We
> turned on vt-d in BIOS, enabled intel_iommu=on in kernel command line.
>
> After setting this, I verified the IOMMU is enabled.
>    dmesg | grep -e DMAR -e IOMMU | grep -e "DRHD base" -e "enabled"
>
> Unfortunately qemu failed to assign PCI devices. The Qemu log was vague.
> I googled and tried some solutions but none worked. It might be the
> problem of the machine itself or the maturity of this feature in kernel
> 2.6 and qemu-kvm 0.12.
>
> I also find the libvirt version on RHEL6 is a bit old, it does not
> provide the necessary device information, so we have to write extra code
> to fetch it. Moreover, the iommu group sysfs is added in Kenel 3.5, so
> RHEL6 does not have it.
>
> It seems we need more time and work to support RHEL6, so I suggest that,
> for the first release of this feature, we support the latest Fedora,
> then in next releases we improve the support for RHEL6.

What about RHEL7, openSUSE 13.1 and Ubuntu 14.04?

> on 2014/07/28 11:01, Zhou Zheng Sheng wrote:
>> Hi,
>>
>> I rebased the patches and send you the drafts for you to test and
>> develop. I'll add doc and unit tests, then send a formal v9 patch to
>> list today.
>>
>> on 2014/07/25 16:39, Yu Xin Huo wrote:
>>> Apply failed.
>>>
>>>
>>> On 7/21/2014 5:36 PM, 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.
>>>>
>>>> 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
>>>>
>>>
>>>
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>>
>