Bug 1762775

Patches proposed upstram

https://lists.gnu.org/archive/html/qemu-devel/2019-10/msg04295.html

Patches merged upstream

https://lists.gnu.org/archive/html/qemu-devel/2019-10/msg07688.html

We'll get this as part of the rebase to QEMU 4.2

Tried to verify this bug as below.


Scenario1 (Regression test with luks)
No new regression bugs. Refer to below link for more details, please.
https://projects.engineering.redhat.com/browse/XKVMEIGHT-1498 


Scenario2 (Performance test)

Steps:
1.Create a data disk over tmpfs.
# mkdir tmp
# mount tmpfs tmp/ -t tmpfs -o size=50G
# qemu-img create -f luks --object secret,id=sec0,data=test -o key-secret=sec0 data.luks 5G
# df -T tmp/data.luks
Filesystem     Type  1K-blocks    Used Available Use% Mounted on
tmpfs          tmpfs  52428800 2620432  49808368   5% /home/test/tmp

2. Boot a guest with this data disk.
# /usr/libexec/qemu-kvm \
    -name 'guest-rhel7.7' \
    -machine q35 \
    -nodefaults \
    -vga qxl \
    -object secret,id=sec0,data=test \
    -device pcie-root-port,port=0x10,chassis=1,id=pci.1,bus=pcie.0,multifunction=on,addr=0x2 \
    -device pcie-root-port,port=0x11,chassis=2,id=pci.2,bus=pcie.0,addr=0x2.0x1 \
    -device pcie-root-port,port=0x12,chassis=3,id=pci.3,bus=pcie.0,addr=0x2.0x2 \
    -device pcie-root-port,port=0x13,chassis=4,id=pci.4,bus=pcie.0,addr=0x2.0x3 \
    -device pcie-root-port,port=0x14,chassis=5,id=pci.5,bus=pcie.0,addr=0x2.0x4 \
    -device pcie-root-port,port=0x15,chassis=6,id=pci.6,bus=pcie.0,addr=0x2.0x5 \
    -device pcie-root-port,port=0x16,chassis=7,id=pci.7,bus=pcie.0,addr=0x2.0x6 \
    -blockdev driver=file,cache.direct=on,cache.no-flush=off,node-name=my_file,filename=rhel820-64-virtio.qcow2 \
    -blockdev driver=qcow2,node-name=my,file=my_file \
    -device virtio-blk-pci,id=virtio_blk_pci0,drive=my,bus=pci.2 \
    -blockdev driver=file,cache.direct=off,cache.no-flush=off,node-name=my_file1,filename=tmp/data.luks \
    -blockdev driver=luks,key-secret=sec0,node-name=my1,file=my_file1 \
    -device virtio-blk-pci,id=virtio_blk_pci1,drive=my1,bus=pci.3 \
    -vnc :0 \
    -m 8192 \
    -smp 4 \
    -netdev tap,id=hostnet0,vhost=on \
    -device virtio-net-pci,netdev=hostnet0,id=net0,mac=52:56:00:00:00:07,bus=pci.4,addr=0x0 \
    -chardev socket,id=qmp_id_qmpmonitor1,path=/home/qmp-sock2,server,nowait \
    -mon chardev=qmp_id_qmpmonitor1,mode=control  \
    -boot order=cdn,once=c,menu=off,strict=off  \
    -enable-kvm \
    -monitor stdio


3. Test the i/o performance via `fio`. 

In ‘qemu-kvm-4.2.0-2.module+el8.2.0+5135+ed3b2489’.

# fio --filename=/dev/vdb --direct=1 --rw=randrw --bs=4K --name=my_test --iodepth=1 --ioengine=libaio
my_test: (g=0): rw=randrw, bs=(R) 4096B-4096B, (W) 4096B-4096B, (T) 4096B-4096B, ioengine=libaio, iodepth=1
fio-3.7
Starting 1 process
Jobs: 1 (f=1): [m(1)][100.0%][r=27.6MiB/s,w=27.0MiB/s][r=7063,w=6917 IOPS][eta 00m:00s]
my_test: (groupid=0, jobs=1): err= 0: pid=2519: Thu Dec 12 19:15:28 2019
   read: IOPS=7067, BW=27.6MiB/s (28.9MB/s)(2561MiB/92771msec)
    slat (nsec): min=7158, max=72640, avg=8355.29, stdev=881.43
    clat (usec): min=28, max=5768, avg=55.42, stdev=11.76
     lat (usec): min=46, max=5776, avg=64.98, stdev=11.83
    clat percentiles (usec):
     |  1.00th=[   45],  5.00th=[   48], 10.00th=[   52], 20.00th=[   55],
     | 30.00th=[   55], 40.00th=[   56], 50.00th=[   56], 60.00th=[   57],
     | 70.00th=[   57], 80.00th=[   58], 90.00th=[   59], 95.00th=[   60],
     | 99.00th=[   66], 99.50th=[   68], 99.90th=[  102], 99.95th=[  114],
     | 99.99th=[  141]
   bw (  KiB/s): min=25912, max=30848, per=100.00%, avg=28268.81, stdev=803.40, samples=185
   iops        : min= 6478, max= 7712, avg=7067.20, stdev=200.84, samples=185
  write: IOPS=7060, BW=27.6MiB/s (28.9MB/s)(2559MiB/92771msec)
    slat (nsec): min=7419, max=60383, avg=8597.30, stdev=903.69
    clat (usec): min=34, max=16401, avg=58.16, stdev=21.79
     lat (usec): min=51, max=16415, avg=67.97, stdev=21.84
    clat percentiles (usec):
     |  1.00th=[   47],  5.00th=[   50], 10.00th=[   53], 20.00th=[   57],
     | 30.00th=[   58], 40.00th=[   58], 50.00th=[   59], 60.00th=[   60],
     | 70.00th=[   60], 80.00th=[   61], 90.00th=[   63], 95.00th=[   64],
     | 99.00th=[   69], 99.50th=[   72], 99.90th=[  111], 99.95th=[  121],
     | 99.99th=[  139]
   bw (  KiB/s): min=26272, max=30744, per=100.00%, avg=28244.72, stdev=817.28, samples=185
   iops        : min= 6568, max= 7686, avg=7061.17, stdev=204.29, samples=185
  lat (usec)   : 50=7.61%, 100=92.28%, 250=0.11%, 500=0.01%, 750=0.01%
  lat (usec)   : 1000=0.01%
  lat (msec)   : 2=0.01%, 4=0.01%, 10=0.01%, 20=0.01%
  cpu          : usr=10.43%, sys=16.48%, ctx=1310729, majf=0, minf=14
  IO depths    : 1=100.0%, 2=0.0%, 4=0.0%, 8=0.0%, 16=0.0%, 32=0.0%, >=64=0.0%
     submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     issued rwts: total=655676,655044,0,0 short=0,0,0,0 dropped=0,0,0,0
     latency   : target=0, window=0, percentile=100.00%, depth=1

Run status group 0 (all jobs):
   READ: bw=27.6MiB/s (28.9MB/s), 27.6MiB/s-27.6MiB/s (28.9MB/s-28.9MB/s), io=2561MiB (2686MB), run=92771-92771msec
  WRITE: bw=27.6MiB/s (28.9MB/s), 27.6MiB/s-27.6MiB/s (28.9MB/s-28.9MB/s), io=2559MiB (2683MB), run=92771-92771msec

Disk stats (read/write):
  vdb: ios=654841/654182, merge=0/0, ticks=37662/39406, in_queue=43, util=99.91%


In ‘qemu-kvm-4.1.0-14.module+el8.1.0+4548+ed1300f4’.
# fio --filename=/dev/vdb --direct=1 --rw=randrw --bs=4K --name=my_test --iodepth=1 --ioengine=libaio
my_test: (g=0): rw=randrw, bs=(R) 4096B-4096B, (W) 4096B-4096B, (T) 4096B-4096B, ioengine=libaio, iodepth=1
fio-3.7
Starting 1 process
Jobs: 1 (f=1): [m(1)][100.0%][r=23.8MiB/s,w=23.0MiB/s][r=6098,w=5898 IOPS][eta 00m:00s]
my_test: (groupid=0, jobs=1): err= 0: pid=2432: Thu Dec 12 19:27:47 2019
   read: IOPS=6143, BW=23.0MiB/s (25.2MB/s)(2561MiB/106732msec)
    slat (usec): min=7, max=1465, avg= 8.51, stdev= 2.52
    clat (usec): min=29, max=8477, avg=66.84, stdev=12.85
     lat (usec): min=61, max=8487, avg=76.57, stdev=13.13
    clat percentiles (usec):
     |  1.00th=[   57],  5.00th=[   61], 10.00th=[   62], 20.00th=[   65],
     | 30.00th=[   66], 40.00th=[   67], 50.00th=[   68], 60.00th=[   69],
     | 70.00th=[   69], 80.00th=[   70], 90.00th=[   71], 95.00th=[   72],
     | 99.00th=[   77], 99.50th=[   80], 99.90th=[  143], 99.95th=[  151],
     | 99.99th=[  176]
   bw (  KiB/s): min=23169, max=26040, per=100.00%, avg=24571.66, stdev=514.37, samples=213
   iops        : min= 5792, max= 6510, avg=6142.89, stdev=128.60, samples=213
  write: IOPS=6137, BW=23.0MiB/s (25.1MB/s)(2559MiB/106732msec)
    slat (usec): min=7, max=946, avg= 8.71, stdev= 1.46
    clat (usec): min=3, max=4664, avg=67.79, stdev= 9.44
     lat (usec): min=62, max=4674, avg=77.71, stdev= 9.57
    clat percentiles (usec):
     |  1.00th=[   58],  5.00th=[   62], 10.00th=[   63], 20.00th=[   66],
     | 30.00th=[   67], 40.00th=[   68], 50.00th=[   69], 60.00th=[   70],
     | 70.00th=[   70], 80.00th=[   71], 90.00th=[   72], 95.00th=[   74],
     | 99.00th=[   78], 99.50th=[   81], 99.90th=[  143], 99.95th=[  153],
     | 99.99th=[  178]
   bw (  KiB/s): min=22912, max=26168, per=100.00%, avg=24549.62, stdev=540.81, samples=213
   iops        : min= 5728, max= 6542, avg=6137.40, stdev=135.21, samples=213
  lat (usec)   : 4=0.01%, 50=0.01%, 100=99.81%, 250=0.18%, 500=0.01%
  lat (usec)   : 750=0.01%, 1000=0.01%
  lat (msec)   : 2=0.01%, 4=0.01%, 10=0.01%
  cpu          : usr=9.04%, sys=14.55%, ctx=1310724, majf=0, minf=14
  IO depths    : 1=100.0%, 2=0.0%, 4=0.0%, 8=0.0%, 16=0.0%, 32=0.0%, >=64=0.0%
     submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     issued rwts: total=655676,655044,0,0 short=0,0,0,0 dropped=0,0,0,0
     latency   : target=0, window=0, percentile=100.00%, depth=1

Run status group 0 (all jobs):
   READ: bw=23.0MiB/s (25.2MB/s), 23.0MiB/s-23.0MiB/s (25.2MB/s-25.2MB/s), io=2561MiB (2686MB), run=106732-106732msec
  WRITE: bw=23.0MiB/s (25.1MB/s), 23.0MiB/s-23.0MiB/s (25.1MB/s-25.1MB/s), io=2559MiB (2683MB), run=106732-106732msec

Disk stats (read/write):
  vdb: ios=655169/654565, merge=0/0, ticks=45097/45662, in_queue=22, util=99.94%

QEMU has been recently split into sub-components and as a one-time operation to avoid breakage of tools, we are setting the QEMU sub-component of this BZ to "General". Please review and change the sub-component if necessary the next time you review this BZ. Thanks

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2020:2017