This patch series is the first step towards enabling
hardware offloading of the L2 packet switching feature on virtio-net device to
host machine.
We are considering that this hardware offloading enables
the use of high-performance networks in virtual infrastructures,
such as container infrastructures on VMs.
To enable L2 packet switching by SR-IOV VFs, we are considering the following:
- making the guest recognize virtio-net devices as SR-IOV PF devices
(archived with this patch series)
- allowing virtio-net devices to connect SR-IOV VFs to the backend networks,
leaving the L2 packet switching feature to the management layer like libvirt
- This makes hardware offloading of L2 packet switching possible.
For example, when using vDPA devices, it allows the guest
to utilize SR-IOV NIC embedded switch of hosts.
This patch series aims to enable SR-IOV emulation on virtio-net devices.
With this series, the guest can identify the virtio-net device as an SR-IOV PF
device.
The newly added property 'sriov_max_vfs' allows us to enable the SR-IOV feature
on the virtio-net device.
Currently, we are unable to specify the properties of a VF created from the
guest.
The properties are set to their default values.
In the future, we plan to allow users to set the properties.
qemu-system-x86_64 --device virtio-net,sriov_max_vfs=<num>
# when 'sriov_max_vfs' is present, the SR-IOV feature will be automatically
enabled
# <num> means the max number of VF on guest
Example commands to create VFs in virtio-net device from the guest:
guest% readlink -f /sys/class/net/eth1/device
/sys/devices/pci0000:00/0000:00:02.0/0000:01:00.0/virtio1
guest% echo "2" > /sys/devices/pci0000:00/0000:00:02.0/0000:01:00.0/sriov_numvfs
guest% ip link show
eth0: ....
eth1: ....
eth2: .... #virtual VF created
eth3: .... #virtual VF created
Please note that communication between VF and PF/VF is not possible by this
patch series itself.
Yui Washizu (1):
virtio-pci: add SR-IOV capability
hw/pci/msix.c | 8 +++--
hw/pci/pci.c | 4 +++
hw/virtio/virtio-pci.c | 62 ++++++++++++++++++++++++++++++----
include/hw/virtio/virtio-pci.h | 1 +
4 files changed, 66 insertions(+), 9 deletions(-)
--
2.39.3
