I must have been blind, of course your testcase in the description is fine. Sorry for even asking.
I'll give it a try if it also works to reflect the improvement on some HW I can access, but if not thanks for offer to test it on your side. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1847948 Title: Improve NVMe guest performance on Bionic QEMU Status in The Ubuntu-power-systems project: Triaged Status in linux package in Ubuntu: Fix Released Status in qemu package in Ubuntu: Fix Released Status in linux source package in Bionic: New Status in qemu source package in Bionic: Triaged Bug description: == 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 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-power-systems/+bug/1847948/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
