55. VF One-shot Rx Interrupt Tests¶

One-shot Rx interrupt feature will split rx interrupt handling from other interrupts like LSC interrupt. It implemented one handling mechanism to eliminate non-deterministic DPDK polling thread wakeup latency.

VFIO’ multiple interrupt vectors support mechanism to enable multiple event fds serving per Rx queue interrupt handling. UIO has limited interrupt support, specifically it only support a single interrupt vector, which is not suitable for enabling multi queues Rx/Tx interrupt.

55.1. Prerequisites¶

Each of the 10Gb Ethernet* ports of the DUT is directly connected in full-duplex to a different port of the peer traffic generator.

Assume PF port PCI addresses are 0000:04:00.0 and 0000:04:00.1, their Interfaces name are p786p1 and p786p2. Assume generated VF PCI address will be 0000:04:10.0, 0000:04:10.1.

Iommu pass through feature has been enabled in kernel:

intel_iommu=on iommu=pt

Support igb_uio and vfio driver, if used vfio, kernel need 3.6+ and enable vt-d in bios. When used vfio, requested to insmod two drivers vfio and vfio-pci.

55.2. Test Case1: VF interrupt pmd in VM with uio¶

Create one VF per Port in host and add these two VFs into VM:

usertools/dpdk-devbind.py --force --bind=vfio-pci 0000:04:00.0 0000:04:00.1
     echo 1 >/sys/bus/pci/devices/0000\:04\:00.0/max_vfs
     echo 1 >/sys/bus/pci/devices/0000\:04\:00.1/max_vfs
     usertools/dpdk-devbind.py --force --bind=pci-stub 0000:04:10.0 0000:04:10.1

Start VM and start l3fwd-power with one queue per port in VM:

l3fwd-power -c 7 -n 4 -- -p 0x3 -P --config="(0,0,1),(1,0,2)"

Send one packet to VF0 and VF1, check that thread on core1 and core2 waked up:

L3FWD_POWER: lcore 1 is waked up from rx interrupt on port1,rxq0
L3FWD_POWER: lcore 2 is waked up from rx interrupt on port1,rxq0

Check the packet has been normally forwarded.

After the packet forwarded, thread on core1 and core 2 will return to sleep:

L3FWD_POWER: lcore 1 sleeps until interrupt on port0,rxq0 triggers
L3FWD_POWER: lcore 2 sleeps until interrupt on port0,rxq0 triggers

Send packet flows to VF0 and VF1, check that thread on core1 and core2 will keep up awake.

55.3. Test Case2: VF interrupt pmd in Host with uio¶

Create one VF per Port in host and make sure PF interface up uses kernel driver to create vf:

echo 1 >/sys/bus/pci/devices/0000\:04\:00.1/sriov_numvf
echo 1 >/sys/bus/pci/devices/0000\:04\:00.1/sriov_numvf

Bind VF device to igb_uio:

./usertools/dpdk-devbind.py --bind=igb_uio 0000:04:10.0 0000:04:10.1

Start host and start l3fwd-power with one queue per port in host:

l3fwd-power -c 7 -n 4 -- -p 0x3 -P --config="(0,0,1),(1,0,2)"

Send one packet to VF0 and VF1, check that thread on core1 and core2 waked up:

L3FWD_POWER: lcore 1 is waked up from rx interrupt on port1,rxq0
L3FWD_POWER: lcore 2 is waked up from rx interrupt on port1,rxq0

Check the packet has been normally forwarded.

After the packet forwarded, thread on core1 and core 2 will return to sleep:

L3FWD_POWER: lcore 1 sleeps until interrupt on port0,rxq0 triggers
L3FWD_POWER: lcore 2 sleeps until interrupt on port0,rxq0 triggers

Send packet flows to VF0 and VF1, check that thread on core1 and core2 will keep up awake.

55.4. Test Case3: VF interrupt pmd in Host with vfio¶

Create one VF per Port in host and make sure PF interface up uses kernel driver to create vf:

echo 1 >/sys/bus/pci/devices/0000\:04\:00.1/sriov_numvf
echo 1 >/sys/bus/pci/devices/0000\:04\:00.1/sriov_numvf

Bind VF device to host igb_uio:

./usertools/dpdk-devbind.py --bind=vfio-pci 0000:04:10.0 0000:04:10.1

Start VM and start l3fwd-power with two queues per port in VM:

l3fwd-power -c 1f -n 4 -- -p 0x3 -P \
   --config="(0,0,1),(0,1,2)(1,0,3),(1,1,4)"

Send packets with increased dest IP to Port0 and Port1, check that thread on core1,core2,core3,core4 waked up:

L3FWD_POWER: lcore 1 is waked up from rx interrupt on port1,rxq0
L3FWD_POWER: lcore 2 is waked up from rx interrupt on port1,rxq1
L3FWD_POWER: lcore 3 is waked up from rx interrupt on port1,rxq0
L3FWD_POWER: lcore 4 is waked up from rx interrupt on port1,rxq1

Check the packet has been normally forwarded.

After the packet forwarded, thread on core1,core2,core3,core4 will return to sleep:

L3FWD_POWER: lcore 1 sleeps until interrupt on port0,rxq0 triggers
L3FWD_POWER: lcore 2 sleeps until interrupt on port0,rxq1 triggers
L3FWD_POWER: lcore 3 sleeps until interrupt on port1,rxq0 triggers
L3FWD_POWER: lcore 4 sleeps until interrupt on port1,rxq1 triggers

Send packet flows to Port0 and Port1, check that thread on core1,core2,core3, core4 will keep up awake.