Re: [Qemu-devel] [PATCH 00/12] virtio: cleanup ioeventfd start/stop

[Cornelia Huck]

On Wed, 19 Oct 2016 14:17:59 +0200
Cornelia Huck <address@hidden> wrote:

> On Mon, 10 Oct 2016 13:53:28 +0200
> Paolo Bonzini <address@hidden> wrote:
> 
> > This series started as an attempt to always use the dataplane path
> > for virtio-blk and virtio-scsi when ioeventfd is active.  The aim
> > was three-fold:
> > 
> > 1) to add more coverage for dataplane
> > 
> > 2) to remove virtio_add_queue_aio
> > 
> > 3) to simplify the dataplane start/stop code
> > 
> > It achieves the first two objectives, and while it doesn't quite
> > achieve the third it does cleanup the generic ioeventfd code in
> > virtio-bus more than I expected.  In particular, it reduces the set
> > of callbacks that transports must implement, and it removes the ugly
> > case where ioeventfd is started with generic callbacks and then moved
> > to the dataplane callbacks.  It also enables some simplification of the
> > functions that deal with host notifiers, and detects some configuration
> > errors better.
> > 
> > I've tested it with virtio-blk, virtio-scsi and vhost-net.
> 
> Hm. 'make check' on a s390 host faults in check-qtest-aarch64 (your
> branch rebased to current master; master itself is fine). I'll see if I
> can find out more (probably later today).

I've bisected this to patch 4 ("virtio: add start_ioeventfd and
stop_ioeventfd to VirtioDeviceClass").

More details of the failure:
- host is s390x with Fedora 23
- # Configured with: '../configure' '--target-list=s390x-softmmu 
s390x-linux-user aarch64-softmmu' '--enable-kvm' '--enable-vhost-net' 
'--enable-linux-aio'
- dmesg has:
[ 1774.006703] User process fault: interruption code 0010 ilc:3 in 
qemu-system-aarch64[10000000+7b9000]
[ 1774.006720] Failing address: 0000000000000000 TEID: 0000000000000800
[ 1774.006723] Fault in primary space mode while using user ASCE.
[ 1774.006731] AS:00000000373ac1c7 R3:0000000048148007 S:0000000000000020 
[ 1774.006739] CPU: 1 PID: 24183 Comm: qemu-system-aar Not tainted 
4.8.0-20161019.0.eb97ed0.8b99dbe.fc23.s390xdefault #1
[ 1774.006742] Hardware name: IBM              2827 H43              738        
      (LPAR)
[ 1774.006745] task: 000000004ccb8008 task.stack: 00000000355e0000
[ 1774.006748] User PSW : 0705000180000000 0000000010332380
[ 1774.006753]            R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:1 AS:0 CC:0 PM:0 
RI:0 EA:3
[ 1774.006757] User GPRS: 0000000000000003 0000000000000000 0000000000000000 
0000000000000001
[ 1774.006761]            00000000102e1740 0000000000000178 000000001069b2ac 
00000000101f8278
[ 1774.006764]            0000000000000000 0000000047471ee0 0000000000000000 
00000000101f6600
[ 1774.006766]            0000000000000000 000000004795f788 00000000102e14a0 
000003ffe307e988
[ 1774.006774] User Code: 000000001033237a: 07fe                bcr     15,%r14
                          000000001033237c: 0707                bcr     0,%r7
                         #000000001033237e: 0707                bcr     0,%r7
                         >0000000010332380: e32020000004        lg      
%r2,0(%r2)
                          0000000010332386: 07fe                bcr     15,%r14
                          0000000010332388: e31020000004        lg      
%r1,0(%r2)
                          000000001033238e: e32010500090        llgc    
%r2,80(%r1)
                          0000000010332394: 07fe                bcr     15,%r14
[ 1774.006812] Last Breaking-Event-Address:
[ 1774.006816]  [<00000000102e149a>] 0x102e149a

(once for each failure)
- failures are in qom-test for aarch64:
TEST: tests/qom-test... (pid=23997)
  /aarch64/qom/integratorcp:                                           OK
  /aarch64/qom/nuri:                                                   OK
  /aarch64/qom/verdex:                                                 OK
  /aarch64/qom/ast2500-evb:                                            OK
  /aarch64/qom/smdkc210:                                               OK
  /aarch64/qom/collie:                                                 OK
  /aarch64/qom/imx25-pdk:                                              OK
  /aarch64/qom/none:                                                   OK
  /aarch64/qom/spitz:                                                  OK
  /aarch64/qom/realview-pbx-a9:                                        OK
  /aarch64/qom/realview-eb:                                            OK
  /aarch64/qom/versatilepb:                                            OK
  /aarch64/qom/realview-pb-a8:                                         OK
  /aarch64/qom/musicpal:                                               OK
  /aarch64/qom/z2:                                                     OK
  /aarch64/qom/akita:                                                  OK
  /aarch64/qom/virt-2.7:                                               Broken 
pipe
FAIL
GTester: last random seed: R02Saec62eb6f9ebd3e5bfcbf42d0aaf165a
(pid=24053)
  /aarch64/qom/kzm:                                                    OK
  /aarch64/qom/virt-2.8:                                               Broken 
pipe
FAIL
GTester: last random seed: R02S3472a1653451d1812262f7d72624492e
(pid=24063)
  /aarch64/qom/realview-eb-mpcore:                                     OK
  /aarch64/qom/sx1:                                                    OK
  /aarch64/qom/sx1-v1:                                                 OK
  /aarch64/qom/virt-2.6:                                               Broken 
pipe
FAIL
GTester: last random seed: R02Se4b753c5be66c0ef7870bebcca8771f8
(pid=24098)
  /aarch64/qom/cubieboard:                                             OK
  /aarch64/qom/highbank:                                               OK
  /aarch64/qom/raspi2:                                                 OK
  /aarch64/qom/netduino2:                                              OK
  /aarch64/qom/terrier:                                                OK
  /aarch64/qom/n810:                                                   OK
  /aarch64/qom/mainstone:                                              OK
  /aarch64/qom/palmetto-bmc:                                           OK
  /aarch64/qom/sabrelite:                                              OK
  /aarch64/qom/midway:                                                 OK
  /aarch64/qom/cheetah:                                                OK
  /aarch64/qom/tosa:                                                   OK
  /aarch64/qom/borzoi:                                                 OK
  /aarch64/qom/versatileab:                                            OK
  /aarch64/qom/lm3s6965evb:                                            OK
  /aarch64/qom/n800:                                                   OK
  /aarch64/qom/connex:                                                 OK
  /aarch64/qom/xilinx-zynq-a9:                                         OK
  /aarch64/qom/xlnx-ep108:                                             OK
  /aarch64/qom/vexpress-a9:                                            Broken 
pipe
FAIL
GTester: last random seed: R02Sdf4aceaaef3ceb060fd5996ecfd05bbb
(pid=24180)
  /aarch64/qom/vexpress-a15:                                           Broken 
pipe
FAIL
GTester: last random seed: R02Sdf4de27065ea3baf0b2acc109af636b8
(pid=24187)
  /aarch64/qom/xlnx-zcu102:                                            OK
  /aarch64/qom/canon-a1100:                                            OK
  /aarch64/qom/lm3s811evb:                                             OK
FAIL: tests/qom-test

Do these boards maybe have something interesting in common?

No further time to look into this today, sorry.