segfault at start with latest qemu-kvm.git

DISCUSSION David S. Ahern 2 participants 7 messages Mar 3, 2010 – Mar 4, 2010 KVM

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David S. Ahern

author

2010-03-03 20:54 UTC #0 lore raw

With latest qemu-kvm.git I am getting a segfault at start:

/tmp/qemu-kvm-test/bin/qemu-system-x86_64 -m 1024 -smp 2 \
-drive file=/images/f12-x86_64.img,if=virtio,cache=none,boot=on

kvm_create_vcpu: Invalid argument
Segmentation fault (core dumped)

git bisect points to:

Bisecting: 0 revisions left to test after this (roughly 0 steps) [52b03dd70261934688cb00768c4b1e404716a337] qemu-kvm: Move kvm_set_boot_cpu_id

$ git show
commit 7811d4e8ec057d25db68f900be1f09a142faca49
Author: Marcelo Tosatti <[email protected]>
Date:   Mon Mar 1 21:36:31 2010 -0300

If I manually back out the patch it will boot fine.

Signature · 1 line

David

Jan Kiszka

2010-03-03 23:09 UTC #1 lore raw

Quoted 16 lines · David S. Ahern

With latest qemu-kvm.git I am getting a segfault at start:
/tmp/qemu-kvm-test/bin/qemu-system-x86_64 -m 1024 -smp 2 \
-drive file=/images/f12-x86_64.img,if=virtio,cache=none,boot=on
kvm_create_vcpu: Invalid argument
Segmentation fault (core dumped)
git bisect points to:
Bisecting: 0 revisions left to test after this (roughly 0 steps) [52b03dd70261934688cb00768c4b1e404716a337] qemu-kvm: Move kvm_set_boot_cpu_id

Quoted 8 lines

$ git show
commit 7811d4e8ec057d25db68f900be1f09a142faca49
Author: Marcelo Tosatti <[email protected]>
Date:   Mon Mar 1 21:36:31 2010 -0300

If I manually back out the patch it will boot fine.

Problem persists after removing the build directory and doing a fresh configure && make? I'm asking before taking the bug (which would be mine, likely) as I recently spent some hours "debugging" a volatile build system issue.

Jan

David S. Ahern

author

2010-03-03 23:11 UTC #2 lore raw

Quoted 26 lines · Jan Kiszka

Quoted 16 lines · David S. Ahern
With latest qemu-kvm.git I am getting a segfault at start:
/tmp/qemu-kvm-test/bin/qemu-system-x86_64 -m 1024 -smp 2 \
-drive file=/images/f12-x86_64.img,if=virtio,cache=none,boot=on
kvm_create_vcpu: Invalid argument
Segmentation fault (core dumped)
git bisect points to:
Bisecting: 0 revisions left to test after this (roughly 0 steps) [52b03dd70261934688cb00768c4b1e404716a337] qemu-kvm: Move kvm_set_boot_cpu_id
Quoted 8 lines
$ git show
commit 7811d4e8ec057d25db68f900be1f09a142faca49
Author: Marcelo Tosatti <[email protected]>
Date:   Mon Mar 1 21:36:31 2010 -0300
If I manually back out the patch it will boot fine.

Quoted 7 lines

Problem persists after removing the build directory and doing a fresh configure && make? I'm asking before taking the bug (which would be mine, likely) as I recently spent some hours "debugging" a volatile build system issue.
Jan

Before sending the email I pulled a fresh clone in a completely different directory (/tmp) to determine if it was something I introduced. I then went back to my usual location, unapplied the patch and it worked fine.

David

Jan Kiszka

2010-03-03 23:20 UTC #3 lore raw

Quoted 34 lines · David S. Ahern

Quoted 30 lines · Jan Kiszka
Quoted 16 lines · David S. Ahern
With latest qemu-kvm.git I am getting a segfault at start:
/tmp/qemu-kvm-test/bin/qemu-system-x86_64 -m 1024 -smp 2 \
-drive file=/images/f12-x86_64.img,if=virtio,cache=none,boot=on
kvm_create_vcpu: Invalid argument
Segmentation fault (core dumped)
git bisect points to:
Bisecting: 0 revisions left to test after this (roughly 0 steps) [52b03dd70261934688cb00768c4b1e404716a337] qemu-kvm: Move kvm_set_boot_cpu_id
Quoted 8 lines
$ git show
commit 7811d4e8ec057d25db68f900be1f09a142faca49
Author: Marcelo Tosatti <[email protected]>
Date:   Mon Mar 1 21:36:31 2010 -0300
If I manually back out the patch it will boot fine.
Problem persists after removing the build directory and doing a fresh configure && make? I'm asking before taking the bug (which would be mine, likely) as I recently spent some hours "debugging" a volatile build system issue.

Quoted 7 lines

Quoted 2 lines
Jan
Before sending the email I pulled a fresh clone in a completely different directory (/tmp) to determine if it was something I introduced. I then went back to my usual location, unapplied the patch and it worked fine.

OK, that reason can be excluded. What's your host kernel kvm version?

(Of course, the issue does not show up here. But virtio currently does not boot for me - independent of my patch.)

Jan

David S. Ahern

author

2010-03-03 23:23 UTC #4 lore raw

Quoted 43 lines · Jan Kiszka

Quoted 34 lines · David S. Ahern
Quoted 30 lines · Jan Kiszka
Quoted 16 lines · David S. Ahern
With latest qemu-kvm.git I am getting a segfault at start:
/tmp/qemu-kvm-test/bin/qemu-system-x86_64 -m 1024 -smp 2 \
-drive file=/images/f12-x86_64.img,if=virtio,cache=none,boot=on
kvm_create_vcpu: Invalid argument
Segmentation fault (core dumped)
git bisect points to:
Bisecting: 0 revisions left to test after this (roughly 0 steps) [52b03dd70261934688cb00768c4b1e404716a337] qemu-kvm: Move kvm_set_boot_cpu_id
Quoted 8 lines
$ git show
commit 7811d4e8ec057d25db68f900be1f09a142faca49
Author: Marcelo Tosatti <[email protected]>
Date:   Mon Mar 1 21:36:31 2010 -0300
If I manually back out the patch it will boot fine.
Problem persists after removing the build directory and doing a fresh configure && make? I'm asking before taking the bug (which would be mine, likely) as I recently spent some hours "debugging" a volatile build system issue.
Quoted 7 lines
Quoted 2 lines
Jan
Before sending the email I pulled a fresh clone in a completely different directory (/tmp) to determine if it was something I introduced. I then went back to my usual location, unapplied the patch and it worked fine.

Quoted 7 lines

OK, that reason can be excluded. What's your host kernel kvm version?
(Of course, the issue does not show up here. But virtio currently does not boot for me - independent of my patch.)
Jan

Fedora Core 12,

Linux daahern-lx 2.6.31.12-174.2.22.fc12.x86_64 #1 SMP Fri Feb 19 18:55:03 UTC 2010 x86_64 x86_64 x86_64 GNU/Linux

David

Jan Kiszka

2010-03-03 23:56 UTC #5 lore raw

Quoted 46 lines · David S. Ahern

Quoted 45 lines · Jan Kiszka
Quoted 33 lines · David S. Ahern
Quoted 30 lines · Jan Kiszka
Quoted 16 lines · David S. Ahern
With latest qemu-kvm.git I am getting a segfault at start:
/tmp/qemu-kvm-test/bin/qemu-system-x86_64 -m 1024 -smp 2 \
-drive file=/images/f12-x86_64.img,if=virtio,cache=none,boot=on
kvm_create_vcpu: Invalid argument
Segmentation fault (core dumped)
git bisect points to:
Bisecting: 0 revisions left to test after this (roughly 0 steps) [52b03dd70261934688cb00768c4b1e404716a337] qemu-kvm: Move kvm_set_boot_cpu_id
Quoted 8 lines
$ git show
commit 7811d4e8ec057d25db68f900be1f09a142faca49
Author: Marcelo Tosatti <[email protected]>
Date:   Mon Mar 1 21:36:31 2010 -0300
If I manually back out the patch it will boot fine.
Problem persists after removing the build directory and doing a fresh configure && make? I'm asking before taking the bug (which would be mine, likely) as I recently spent some hours "debugging" a volatile build system issue.
Quoted 6 lines
Quoted 2 lines
Jan
Before sending the email I pulled a fresh clone in a completely different directory (/tmp) to determine if it was something I introduced. I then went back to my usual location, unapplied the patch and it worked fine.
OK, that reason can be excluded. What's your host kernel kvm version?
(Of course, the issue does not show up here. But virtio currently does not boot for me - independent of my patch.)

Quoted 8 lines

Quoted 2 lines
Jan
Fedora Core 12,
Linux daahern-lx 2.6.31.12-174.2.22.fc12.x86_64 #1 SMP Fri Feb 19 18:55:03 UTC 2010 x86_64 x86_64 x86_64 GNU/Linux

Reproduced after switching back to kvm-kmod-2.6.31, will debug.

Thanks,
Jan

Jan Kiszka

2010-03-04 08:28 UTC #6 lore raw

Quoted 48 lines · Jan Kiszka

Quoted 47 lines · David S. Ahern
Quoted 46 lines · Jan Kiszka
Quoted 32 lines · David S. Ahern
Quoted 30 lines · Jan Kiszka
Quoted 16 lines · David S. Ahern
With latest qemu-kvm.git I am getting a segfault at start:
/tmp/qemu-kvm-test/bin/qemu-system-x86_64 -m 1024 -smp 2 \
-drive file=/images/f12-x86_64.img,if=virtio,cache=none,boot=on
kvm_create_vcpu: Invalid argument
Segmentation fault (core dumped)
git bisect points to:
Bisecting: 0 revisions left to test after this (roughly 0 steps) [52b03dd70261934688cb00768c4b1e404716a337] qemu-kvm: Move kvm_set_boot_cpu_id
Quoted 8 lines
$ git show
commit 7811d4e8ec057d25db68f900be1f09a142faca49
Author: Marcelo Tosatti <[email protected]>
Date:   Mon Mar 1 21:36:31 2010 -0300
If I manually back out the patch it will boot fine.
Problem persists after removing the build directory and doing a fresh configure && make? I'm asking before taking the bug (which would be mine, likely) as I recently spent some hours "debugging" a volatile build system issue.
Quoted 6 lines
Quoted 2 lines
Jan
Before sending the email I pulled a fresh clone in a completely different directory (/tmp) to determine if it was something I introduced. I then went back to my usual location, unapplied the patch and it worked fine.
OK, that reason can be excluded. What's your host kernel kvm version?
(Of course, the issue does not show up here. But virtio currently does not boot for me - independent of my patch.)
Jan

Quoted 8 lines

Quoted 5 lines
Fedora Core 12,
Linux daahern-lx 2.6.31.12-174.2.22.fc12.x86_64 #1 SMP Fri Feb 19 18:55:03 UTC 2010 x86_64 x86_64 x86_64 GNU/Linux
Reproduced after switching back to kvm-kmod-2.6.31, will debug.

Subtle memory corruption: qemu_malloc is returning a pointer that happens to become kvm_state twice. I bet my patch just exchanges some of the involved parties and exposes the issue more prominently. Trying to understand malloc's issue now...

Jan