1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
|
other: 0.922
debug: 0.914
semantic: 0.896
performance: 0.889
permissions: 0.887
socket: 0.882
PID: 0.879
graphic: 0.878
device: 0.872
files: 0.868
network: 0.858
vnc: 0.851
boot: 0.851
KVM: 0.821
The guest will be destroyed when hot plug the VF to guest for the second time.
Environment:
------------
Host OS (ia32/ia32e/IA64):ia32e
Guest OS (ia32/ia32e/IA64):ia32e
Guest OS Type (Linux/Windows):linux
kvm.git Commit: 6557bada461afeaa920a189fae2cff7c8fdce39f
qemu.kvm Commit: cd2d5541271f1934345d8ca42f5fafff1744eee7
Host Kernel Version:3.19.0-rc3
Hardware:Haswell_EP,Ivytown_EP
Bug detailed description:
--------------------------
create guest , then hot plug the VF to the guest for the second time, the guest will be destroyed.
note:
1. hot plug the device to guest with vfio, the guest works fine
2.this should be a qemu bug:
kvm + qemu = result
6557bada + cd2d5541 = bad
6557bada + a805ca54 = good
Reproduce steps:
----------------
1. qemu-system-x86_64 -enable-kvm -m 2G -net none -monitor pty rhel6u5.qcow
2. echo "device_add pci-assign,host=03:10.1,id=nic" >/dev/pts/2
3. cat /dev/pts/2 &
4. echo "device_del nic" >/dev/pts/2
5. echo "device_add pci-assign,host=03:10.0,id=nic" >/dev/pts/2
Current result:
----------------
guest will be destroyed when hot plug the vf to guest for the second time.
Expected result:
----------------
guest works fine when hot plug the vf to guest for the second time
Basic root-causing log:
----------------------
[root@vt-hsw2 cathy]# qemu-system-x86_64 -enable-kvm -m 2G -net none -monitor pty rhel6u5.qcow
char device redirected to /dev/pts/2 (label compat_monitor0)
Segmentation fault (core dumped)
some dmesg log:
pci-stub 0000:03:10.1: kvm deassign device
pci-stub 0000:03:10.1: enabling device (0000 -> 0002)
qemu-system-x86[9894]: segfault at 0 ip (null) sp 00007fa73df0cae8 error 14
pci-stub 0000:03:10.1: kvm assign device
the first bad commit is:
commit ec6f25e788ef57ce1e9f734984ef8885172fd9e2
Merge: 007c99f 9ef1473
Author: Peter Maydell <email address hidden>
Date: Tue Feb 3 21:37:16 2015 +0000
Merge remote-tracking branch 'remotes/rth/tags/pull-tg-s390-20150203' into staging
s390 translator bug fixes
# gpg: Signature made Tue 03 Feb 2015 20:39:15 GMT using RSA key ID 4DD0279B
# gpg: Good signature from "Richard Henderson <email address hidden>"
# gpg: aka "Richard Henderson <email address hidden>"
# gpg: aka "Richard Henderson <email address hidden>"
* remotes/rth/tags/pull-tg-s390-20150203:
target-s390x: fix and optimize slb* and slbg* computation of carry/borrow flag
target-s390x: support OC and NC in the EX instruction
disas/s390.c: Remove unused variables
target-s390x: Mark check_privileged() as !CONFIG_USER_ONLY
target-s390: Implement ECAG
target-s390: Implement LURA, LURAG, STURG
target-s390: Fix STURA
target-s390: Fix STIDP
target-s390: Implement EPSW
target-s390: Implement SAM specification exception
Signed-off-by: Peter Maydell <email address hidden>
please ignore comment 1.
the first bad commit:
commit 374f2981d1f10bc4307f250f24b2a7ddb9b14be0
Author: Paolo Bonzini <email address hidden>
Date: Fri May 17 12:37:03 2013 +0200
memory: protect current_map by RCU
Replace the flat_view_mutex with RCU, avoiding futex contention for
dataplane on large systems and many iothreads.
Reviewed-by: Fam Zheng <email address hidden>
Signed-off-by: Paolo Bonzini <email address hidden>
kvm.git + qemu.git:4ff6f8e6_3d30395f
host kernel:4.0.0_rc1
test on Haswell_EP
when hot plug the vf to guest for the second time, the guest works fine.
|