Public bug reported:

== Comment: #0 - Murilo Opsfelder Araujo  - 2019-10-11 14:16:14 ==

---Problem Description---
Back-port the following patches to Bionic QEMU to improve NVMe guest 
performance by more than 200%:

?vfio-pci: Allow mmap of MSIX BAR?
https://git.qemu.org/?p=qemu.git;a=commit;h=ae0215b2bb56a9d5321a185dde133bfdd306a4c0

?ppc/spapr, vfio: Turn off MSIX emulation for VFIO devices?
https://git.qemu.org/?p=qemu.git;a=commit;h=fcad0d2121976df4b422b4007a5eb7fcaac01134
 
---uname output---
na
 
---Additional Hardware Info---
0030:01:00.0 Non-Volatile memory controller: Samsung Electronics Co Ltd NVMe 
SSD Controller 172Xa/172Xb (rev 01) 

 
Machine Type = AC922 
 
---Debugger---
A debugger is not configured
 
---Steps to Reproduce---
 Install or setup a guest image and boot it.

Once guest is running, passthrough the NVMe disk to the guest using the
XML:

host$ cat nvme-disk.xml
<hostdev mode='subsystem' type='pci' managed='no'>
   <driver name='vfio'/>
    <source>
        <address domain='0x0030' bus='0x01' slot='0x00' function='0x0'/>
    </source>
</hostdev>

host$ virsh attach-device <domain> nvme-disk.xml --live

On the guest, run fio benchmarks:

guest$ fio --direct=1 --rw=randrw --refill_buffers --norandommap
--randrepeat=0 --ioengine=libaio --bs=4k --rwmixread=100 --iodepth=16
--runtime=60 --name=job1 --filename=/dev/nvme0n1 --numjobs=4

Results are similar with numjobs=4 and numjobs=64, respectively:

   READ: bw=385MiB/s (404MB/s), 78.0MiB/s-115MiB/s (81.8MB/s-120MB/s), 
io=11.3GiB (12.1GB), run=30001-30001msec
   READ: bw=382MiB/s (400MB/s), 2684KiB/s-12.6MiB/s (2749kB/s-13.2MB/s), 
io=11.2GiB (12.0GB), run=30001-30009msec

With the two patches applied, performance improved significantly for
numjobs=4 and numjobs=64 cases, respectively:

   READ: bw=1191MiB/s (1249MB/s), 285MiB/s-309MiB/s (299MB/s-324MB/s), 
io=34.9GiB (37.5GB), run=30001-30001msec
   READ: bw=4273MiB/s (4481MB/s), 49.7MiB/s-113MiB/s (52.1MB/s-119MB/s), 
io=125GiB (134GB), run=30001-30005msec

 
Userspace tool common name: qemu 

Userspace rpm: qemu 
 
The userspace tool has the following bit modes: 64-bit 

Userspace tool obtained from project website:  na

** Affects: qemu (Ubuntu)
     Importance: Undecided
     Assignee: Ubuntu on IBM Power Systems Bug Triage (ubuntu-power-triage)
         Status: New


** Tags: architecture-ppc64le bugnameltc-181875 severity-medium 
targetmilestone-inin18045

** Tags added: architecture-ppc64le bugnameltc-181875 severity-medium
targetmilestone-inin18045

** Changed in: ubuntu
     Assignee: (unassigned) => Ubuntu on IBM Power Systems Bug Triage 
(ubuntu-power-triage)

** Package changed: ubuntu => qemu (Ubuntu)

-- 
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/1847948

Title:
  Improve NVMe guest performance on Bionic QEMU

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/qemu/+bug/1847948/+subscriptions

-- 
ubuntu-bugs mailing list
ubuntu-bugs@lists.ubuntu.com
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs

Reply via email to