numam-spdk/test/vhost/test_plan.md

SPDK vhost Test Plan

Current Tests

Integrity tests

vhost self test

• compiles SPDK and Qemu
• launches SPDK Vhost
• starts VM with 1 NVMe device attached to it
• issues controller "reset" command using sg3_utils on guest system
• performs data integrity check using dd to write and read data from the device
• runs on 3 host systems (Ubuntu 16.04, Centos 7.3 and Fedora 25) and 1 guest system (Ubuntu 16.04)
• runs against vhost scsi and vhost blk

FIO Integrity tests

• NVMe device is split into 4 LUNs, each is attached to separate vhost controller
• FIO uses job configuration with randwrite mode to verify if random pattern was written to and read from correctly on each LUN
• runs on Fedora 25 and Ubuntu 16.04 guest systems
• runs against vhost scsi and vhost blk

Lvol tests

• starts vhost with at least 1 NVMe device
• starts 1 VM or multiple VMs
• lvol store is constructed on each NVMe device
• on each lvol store 1 lvol bdev will be constructed for each running VM
• Logical volume block device is used as backend instead of using NVMe device backend directly
• after set up, data integrity check will be performed by FIO randwrite operation with verify flag enabled
• optionally nested lvols can be tested with use of appropriate flag; On each base lvol store additional lvol bdev will be created which will serve as a base for nested lvol stores. On each of the nested lvol stores there will be 1 lvol bdev created for each VM running. Nested lvol bdevs will be used along with base lvol bdevs for data integrity check.
• runs against vhost scsi and vhost blk

Filesystem integrity

• runs SPDK with 1 VM with 1 NVMe device attached.
• creates a partition table and filesystem on passed device, and mounts it
• 1GB test file is created on mounted file system and FIO randrw traffic (with enabled verification) is run
• Tested file systems: ext4, brtfs, ntfs, xfs
• runs against vhost scsi and vhost blk

Windows HCK SCSI Compliance Test 2.0.

• Runs SPDK with 1 VM with Windows Server 2012 R2 operating system
• 4 devices are passed into the VM: NVMe, Split NVMe, Malloc and Split Malloc
• On each device Windows HCK SCSI Compliance Test 2.0 is run

MultiOS test

• start 3 VMs with guest systems: Ubuntu 16.04, Fedora 25 and Windows Server 2012 R2
• 3 physical NVMe devices are split into 9 LUNs
• each guest uses 3 LUNs from 3 different physical NVMe devices
• Linux guests run FIO integrity jobs to verify read/write operations, while Windows HCK SCSI Compliance Test 2.0 is running on Windows guest

vhost hot-remove tests

• removing NVMe device (unbind from driver) which is already claimed by controller in vhost
• hotremove tests performed with and without I/O traffic to device
• I/O traffic, if present in test, has verification enabled
• checks that vhost and/or VMs do not crash
• checks that other devices are unaffected by hot-remove of a NVMe device
• performed against vhost blk and vhost scsi

vhost scsi hot-attach and hot-detach tests

• adding and removing devices via RPC to a controller which is already in use by a VM
• I/O traffic generated with FIO read/write operations, verification enabled
• checks that vhost and/or VMs do not crash
• checks that other devices in the same controller are unaffected by hot-attach and hot-detach operations

virtio initiator tests

• virtio user mode: connect to vhost-scsi controller sockets directly on host
• virtio pci mode: connect to virtual pci devices on guest virtual machine
• 6 concurrent jobs are run simultaneously on 7 devices, each with 8 virtqueues

kernel virtio-scsi-pci device

• test support for kernel vhost-scsi device
• create 1GB ramdisk using targetcli
• create target and add ramdisk to it using targetcli
• add created device to virtio pci tests

emulated virtio-scsi-pci device

• test support for QEMU emulated virtio-scsi-pci device
• add emulated virtio device "Virtio0" to virtio pci tests

Test configuration

• SPDK vhost application is used for testing
• FIO using spdk fio_plugin: rw, randrw, randwrite, write with verification enabled.
• trim sequential and trim random then write on trimmed areas with verification enabled only on unmap supporting devices
• FIO job configuration: iodepth=128, block size=4k, runtime=10s
• all test cases run jobs in parallel on multiple bdevs
• 8 queues per device

vhost configuration

• scsi controller with 4 NVMe splits
• 2 block controllers, each with 1 NVMe split
• scsi controller with malloc with 512 block size
• scsi controller with malloc with 4096 block size

Test case 1

• virtio user on host
• perform FIO rw, randwrite, randrw, write, parallel jobs on all devices

Test case 2

• virtio user on host
• perform FIO trim, randtrim, rw, randwrite, randrw, write, - parallel jobs then write on trimmed areas on unmap supporting devices

Test case 3

• virtio pci on vm
• same config as in TC#1

Test case 4

• virtio pci on vm
• same config as in TC#2

Live migration

Live migration feature allows to move running virtual machines between SPDK vhost instances. Following tests include scenarios with SPDK vhost instances running on both the same physical server and between remote servers. Additional configuration of utilities like SSHFS share, NIC IP address adjustment, etc., might be necessary.

Test case 1 - single vhost migration

• Start SPDK Vhost application.
  • Construct a single Malloc bdev.
  • Construct two SCSI controllers and add previously created Malloc bdev to it.
• Start first VM (VM_1) and connect to Vhost_1 controller. Verify if attached disk is visible in the system.
• Start second VM (VM_2) but with "-incoming" option enabled, connect to. Connect to Vhost_2 controller. Use the same VM image as VM_1.
• On VM_1 start FIO write job with verification enabled to connected Malloc bdev.
• Start VM migration from VM_1 to VM_2 while FIO is still running on VM_1.
• Once migration is complete check the result using Qemu monitor. Migration info on VM_1 should return "Migration status: completed".
• VM_2 should be up and running after migration. Via SSH log in and check FIO job result - exit code should be 0 and there should be no data verification errors.
• Cleanup:
  • Shutdown both VMs.
  • Gracefully shutdown Vhost instance.

Test case 2 - single server migration

• Detect RDMA NICs; At least 1 RDMA NIC is needed to run the test. If there is no physical NIC available then emulated Soft Roce NIC will be used instead.
• Create /tmp/share directory and put a test VM image in there.
• Start SPDK NVMeOF Target application.
  • Construct a single NVMe bdev from available bound NVMe drives.
  • Create NVMeoF subsystem with NVMe bdev as single namespace.
• Start first SDPK Vhost application instance (later referred to as "Vhost_1").
  • Use different shared memory ID and CPU mask than NVMeOF Target.
  • Construct a NVMe bdev by connecting to NVMeOF Target (using trtype: rdma).
  • Construct a single SCSI controller and add NVMe bdev to it.
• Start first VM (VM_1) and connect to Vhost_1 controller. Verify if attached disk is visible in the system.
• Start second SDPK Vhost application instance (later referred to as "Vhost_2").
  • Use different shared memory ID and CPU mask than previous SPDK instances.
  • Construct a NVMe bdev by connecting to NVMeOF Target. Connect to the same subsystem as Vhost_1, multiconnection is allowed.
  • Construct a single SCSI controller and add NVMe bdev to it.
• Start second VM (VM_2) but with "-incoming" option enabled.
• Check states of both VMs using Qemu monitor utility. VM_1 should be in running state. VM_2 should be in paused (inmigrate) state.
• Run FIO I/O traffic with verification enabled on to attached NVME on VM_1.
• While FIO is running issue a command for VM_1 to migrate.
• When the migrate call returns check the states of VMs again. VM_1 should be in paused (postmigrate) state. "info migrate" should report "Migration status: completed". VM_2 should be in running state.
• Verify that FIO task completed successfully on VM_2 after migrating. There should be no I/O failures, no verification failures, etc.
• Cleanup:
  • Shutdown both VMs.
  • Gracefully shutdown Vhost instances and NVMEoF Target instance.
  • Remove /tmp/share directory and it's contents.
  • Clean RDMA NIC / Soft RoCE configuration.

Test case 3 - remote server migration

• Detect RDMA NICs on physical hosts. At least 1 RDMA NIC per host is needed to run the test.
• On Host 1 create /tmp/share directory and put a test VM image in there.
• On Host 2 create /tmp/share directory. Using SSHFS mount /tmp/share from Host 1 so that the same VM image can be used on both hosts.
• Start SPDK NVMeOF Target application on Host 1.
  • Construct a single NVMe bdev from available bound NVMe drives.
  • Create NVMeoF subsystem with NVMe bdev as single namespace.
• Start first SDPK Vhost application instance on Host 1(later referred to as "Vhost_1").
  • Use different shared memory ID and CPU mask than NVMeOF Target.
  • Construct a NVMe bdev by connecting to NVMeOF Target (using trtype: rdma).
  • Construct a single SCSI controller and add NVMe bdev to it.
• Start first VM (VM_1) and connect to Vhost_1 controller. Verify if attached disk is visible in the system.
• Start second SDPK Vhost application instance on Host 2(later referred to as "Vhost_2").
  • Construct a NVMe bdev by connecting to NVMeOF Target. Connect to the same subsystem as Vhost_1, multiconnection is allowed.
  • Construct a single SCSI controller and add NVMe bdev to it.
• Start second VM (VM_2) but with "-incoming" option enabled.
• Check states of both VMs using Qemu monitor utility. VM_1 should be in running state. VM_2 should be in paused (inmigrate) state.
• Run FIO I/O traffic with verification enabled on to attached NVME on VM_1.
• While FIO is running issue a command for VM_1 to migrate.
• When the migrate call returns check the states of VMs again. VM_1 should be in paused (postmigrate) state. "info migrate" should report "Migration status: completed". VM_2 should be in running state.
• Verify that FIO task completed successfully on VM_2 after migrating. There should be no I/O failures, no verification failures, etc.
• Cleanup:
  • Shutdown both VMs.
  • Gracefully shutdown Vhost instances and NVMEoF Target instance.
  • Remove /tmp/share directory and it's contents.
  • Clean RDMA NIC configuration.

Performance tests

Tests verifying the performance and efficiency of the module.

FIO Performance 6 NVMes

• SPDK and created controllers run on 2 CPU cores.
• Each NVMe drive is split into 2 Split NVMe bdevs, which gives a total of 12 in test setup.
• 12 vhost controllers are created, one for each Split NVMe bdev. All controllers use the same CPU mask as used for running Vhost instance.
• 12 virtual machines are run as guest systems (with Ubuntu 16.04.2); Each VM connects to a single corresponding vhost controller. Per VM configuration is: 2 pass-through host CPU's, 1 GB RAM, 2 IO controller queues.
• NVMe drives are pre-conditioned before the test starts. Pre-conditioning is done by writing over whole disk sequentially at least 2 times.
• FIO configurations used for tests:
  • IO depths: 1, 8, 128
  • Blocksize: 4k
  • RW modes: read, randread, write, randwrite, rw, randrw
  • Write modes are additionally run with 15 minute ramp-up time to allow better measurements. Randwrite mode uses longer ramp-up preconditioning of 90 minutes per run.
• Each FIO job result is compared with baseline results to allow detecting performance drops.

Future tests and improvements

Stress tests

• Add stability and stress tests (long duration tests, long looped start/stop tests, etc.) to test pool