doc: update vhost doc
Remove experimental attribute from multiqueue section, add description of QEMU num_queues parameter and expand example. Change-Id: I13d67ece0734aa8c57eeb07eabc34442ca532d47 Signed-off-by: Pawel Wodkowski <pawelx.wodkowski@intel.com> Reviewed-on: https://review.gerrithub.io/386501 Tested-by: SPDK Automated Test System <sys_sgsw@intel.com> Reviewed-by: Dariusz Stojaczyk <dariuszx.stojaczyk@intel.com> Reviewed-by: Paweł Niedźwiecki <pawelx.niedzwiecki@intel.com> Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com> Reviewed-by: Jim Harris <james.r.harris@intel.com>
This commit is contained in:
Pawel Wodkowski
Daniel Verkamp
parent
b1e850cd10
commit
745c0496fe
111
doc/vhost.md
111
doc/vhost.md
@ -1,6 +1,6 @@
|
||||
# vhost {#vhost}
|
||||
|
||||
# vhost Getting Started Guide {#vhost_getting_started}
|
||||
# Getting Started Guide {#vhost_getting_started}
|
||||
|
||||
The Storage Performance Development Kit vhost application is named `vhost`.
|
||||
This application extends SPDK to present virtio storage controllers to QEMU-based
|
||||
@ -108,12 +108,12 @@ pick one core from `ReactorMask` masked by `Cpumask`. `Cpumask` must be a subset
|
||||
|
||||
Userspace vhost-scsi adds the following command line option for QEMU:
|
||||
~~~
|
||||
-device vhost-user-scsi-pci,id=scsi0,chardev=char0
|
||||
-device vhost-user-scsi-pci,id=scsi0,chardev=char0[,num_queues=N]
|
||||
~~~
|
||||
|
||||
Userspace vhost-blk adds the following command line option for QEMU:
|
||||
~~~
|
||||
-device vhost-user-blk-pci,logical_block_size=4096,size=512M,chardev=char0
|
||||
-device vhost-user-blk-pci,logical_block_size=4096,size=512M,chardev=char0[,num_queues=N]
|
||||
~~~
|
||||
|
||||
In order to start qemu with vhost you need to specify following options:
|
||||
@ -140,29 +140,9 @@ A full list of command line arguments to vhost can be obtained by:
|
||||
app/vhost/vhost -h
|
||||
~~~
|
||||
|
||||
|
||||
## Example
|
||||
|
||||
Assume that qemu and spdk are in respectively `qemu` and `spdk` directories.
|
||||
~~~
|
||||
./qemu/build/x86_64-softmmu/qemu-system-x86_64 \
|
||||
-m 1024 \
|
||||
-object memory-backend-file,id=mem,size=1G,mem-path=/dev/hugepages,share=on \
|
||||
-numa node,memdev=mem \
|
||||
-drive file=$PROJECTS/os.qcow2,if=none,id=disk \
|
||||
-device ide-hd,drive=disk,bootindex=0 \
|
||||
-chardev socket,id=char0,path=./spdk/vhost.0 \
|
||||
-device vhost-user-scsi-pci,id=scsi0,chardev=char0 \
|
||||
-chardev socket,id=char1,path=./spdk/vhost.1 \
|
||||
-device vhost-user-blk-pci,logical_block_size=4096,size=512M,chardev=char1 \
|
||||
--enable-kvm
|
||||
~~~
|
||||
|
||||
# Experimental Features {#vhost_experimental}
|
||||
|
||||
## Multi-Queue Block Layer (blk-mq)
|
||||
|
||||
It is possible to use the Linux kernel block multi-queue feature with vhost.
|
||||
For best performance use the Linux kernel block multi-queue feature with vhost.
|
||||
To enable it on Linux, it is required to modify kernel options inside the
|
||||
virtual machine.
|
||||
|
||||
@ -174,7 +154,88 @@ Instructions below for Ubuntu OS:
|
||||
4. Reboot virtual machine
|
||||
|
||||
To achieve better performance, make sure to increase number of cores
|
||||
assigned to the VM.
|
||||
assigned to the VM and add `num_queues` parameter to the QEMU `device`. It should be enough
|
||||
to set `num_queues=4` to saturate physical device. Adding too many queues might lead to SPDK
|
||||
vhost performance degradation if many vhost devices are used because each device will require
|
||||
additional `num_queues` to be polled.
|
||||
|
||||
# Example {#vhost_example}
|
||||
|
||||
Run SPDK vhost with two controllers: Virtio SCSI and Virtio block.
|
||||
|
||||
Virtio SCSI controller with two LUNs:
|
||||
|
||||
- SCSI target 1, LUN 0 backed by Malloc0 bdev
|
||||
- SCSI target 5, LUN 0 backed by Malloc1 bdev
|
||||
|
||||
Virtio block device backed by Malloc2 bdev
|
||||
|
||||
For better performance use 4 VCPU (`-smp 4`) and 4 queues for each controller
|
||||
(`num_queues=4`). Assume that QEMU and SPDK are in respectively `qemu` and `spdk` directories.
|
||||
~~~
|
||||
host: $ cd spdk
|
||||
host: $ cat vhost.conf
|
||||
[Rpc]
|
||||
Enable Yes
|
||||
Listen 127.0.0.1:5261
|
||||
|
||||
[Malloc]
|
||||
NumberOfLuns 3
|
||||
LunSizeInMb 128
|
||||
BlockSize 512
|
||||
|
||||
[VhostScsi0]
|
||||
Name vhost_scsi0_socket
|
||||
Dev 1 Malloc0
|
||||
Dev 5 Malloc1
|
||||
|
||||
[VhostBlk0]
|
||||
Name vhost_blk0_socket
|
||||
Dev Malloc2
|
||||
|
||||
host: $ sudo ./app/vhost/vhost -c vhost.conf -s 1024 -m 1 &
|
||||
[ DPDK EAL parameters: vhost -c 1 -m 1024 --file-prefix=spdk_pid191213 ]
|
||||
EAL: Detected 48 lcore(s)
|
||||
EAL: Probing VFIO support...
|
||||
EAL: VFIO support initialized
|
||||
<< REMOVED CONSOLE LOG >>
|
||||
VHOST_CONFIG: bind to vhost_scsi0_socket
|
||||
vhost.c: 592:spdk_vhost_dev_construct: *NOTICE*: Controller vhost_scsi0_socket: new controller added
|
||||
vhost_scsi.c: 840:spdk_vhost_scsi_dev_add_dev: *NOTICE*: Controller vhost_scsi0_socket: defined device 'Dev 1' using lun 'Malloc0'
|
||||
vhost_scsi.c: 840:spdk_vhost_scsi_dev_add_dev: *NOTICE*: Controller vhost_scsi0_socket: defined device 'Dev 5' using lun 'Malloc1'
|
||||
VHOST_CONFIG: vhost-user server: socket created, fd: 65
|
||||
VHOST_CONFIG: bind to vhost_blk0_socket
|
||||
vhost.c: 592:spdk_vhost_dev_construct: *NOTICE*: Controller vhost_blk0_socket: new controller added
|
||||
vhost_blk.c: 720:spdk_vhost_blk_construct: *NOTICE*: Controller vhost_blk0_socket: using bdev 'Malloc2'
|
||||
|
||||
host: $ cd ..
|
||||
host: $ sudo ./qemu/build/x86_64-softmmu/qemu-system-x86_64 --enable-kvm -m 1024 \
|
||||
-cpu host -smp 4 -nographic \
|
||||
-object memory-backend-file,id=mem,size=1G,mem-path=/dev/hugepages,share=on -numa node,memdev=mem \
|
||||
-drive file=guest_os_image.qcow2,if=none,id=disk \
|
||||
-device ide-hd,drive=disk,bootindex=0 \
|
||||
-chardev socket,id=spdk_vhost_scsi0,path=./spdk/vhost_scsi0_socket \
|
||||
-device vhost-user-scsi-pci,id=scsi0,chardev=spdk_vhost_scsi0,num_queues=4 \
|
||||
-chardev socket,id=spdk_vhost_blk0,path=./spdk/vhost_blk0_socket \
|
||||
-device vhost-user-blk-pci,logical_block_size=512,size=128M,chardev=spdk_vhost_blk0,num_queues=4
|
||||
|
||||
<< LOGIN TO GUEST OS >>
|
||||
guest: ~$ lsblk --output "NAME,KNAME,MODEL,HCTL,SIZE,VENDOR,SUBSYSTEMS"
|
||||
NAME KNAME MODEL HCTL SIZE VENDOR SUBSYSTEMS
|
||||
fd0 fd0 4K block:platform
|
||||
sda sda QEMU HARDDISK 1:0:0:0 80G ATA block:scsi:pci
|
||||
sda1 sda1 80G block:scsi:pci
|
||||
sdb sdb Malloc disk 2:0:1:0 128M INTEL block:scsi:virtio:pci
|
||||
sdc sdc Malloc disk 2:0:5:0 128M INTEL block:scsi:virtio:pci
|
||||
vda vda 128M 0x1af4 block:virtio:pci
|
||||
|
||||
guest: $ sudo poweroff
|
||||
host: $ fg
|
||||
<< CTRL + C >>
|
||||
vhost.c:1006:session_shutdown: *NOTICE*: Exiting
|
||||
~~~
|
||||
|
||||
We can see that `sdb` and `sdc` are SPDK vhost-scsi LUNs, and `vda` is SPDK vhost-blk disk.
|
||||
|
||||
# Known bugs and limitations {#vhost_bugs}
|
||||
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user