From: Mark McLoughlin <markmc@redhat.com>
To: kvm <kvm@vger.kernel.org>
Subject: 2.6.29-rc3 circular locking dependency detected
Date: Tue, 03 Feb 2009 10:25:26 +0000 [thread overview]
Message-ID: <1233656726.3726.22.camel@blaa> (raw)
Hi,
Just saw this when starting a guest with an assigned device.
Cheers,
Mark.
=======================================================
[ INFO: possible circular locking dependency detected ]
2.6.29-0.74.rc3.git3.fc11.x86_64 #1
-------------------------------------------------------
qemu-kvm/3706 is trying to acquire lock:
(&kvm->lock){--..}, at: [<ffffffffa013a25f>] kvm_emulate_pio+0x1ab/0x1ff [kvm]
but task is already holding lock:
(&kvm->slots_lock){----}, at: [<ffffffffa013c4c0>] kvm_arch_vcpu_ioctl_run+0x49
7/0x73a [kvm]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&kvm->slots_lock){----}:
[<ffffffff8106e9c1>] __lock_acquire+0xaab/0xc41
[<ffffffff8106ebe4>] lock_acquire+0x8d/0xba
[<ffffffff813826ae>] down_read+0x4b/0x7f
[<ffffffffa0137ff2>] kvm_iommu_map_guest+0x62/0xb8 [kvm]
[<ffffffffa01363ea>] kvm_vm_ioctl+0x3f4/0x7f1 [kvm]
[<ffffffff810eac30>] vfs_ioctl+0x2a/0x78
[<ffffffff810eb0e9>] do_vfs_ioctl+0x46b/0x4ab
[<ffffffff810eb17e>] sys_ioctl+0x55/0x77
[<ffffffff810112ba>] system_call_fastpath+0x16/0x1b
[<ffffffffffffffff>] 0xffffffffffffffff
-> #0 (&kvm->lock){--..}:
[<ffffffff8106e862>] __lock_acquire+0x94c/0xc41
[<ffffffff8106ebe4>] lock_acquire+0x8d/0xba
[<ffffffff8138205a>] __mutex_lock_common+0x107/0x39c
[<ffffffff81382398>] mutex_lock_nested+0x35/0x3a
[<ffffffffa013a25f>] kvm_emulate_pio+0x1ab/0x1ff [kvm]
[<ffffffffa015c875>] handle_io+0x6e/0x76 [kvm_intel]
[<ffffffffa015d202>] kvm_handle_exit+0x1ba/0x1db [kvm_intel]
[<ffffffffa013c534>] kvm_arch_vcpu_ioctl_run+0x50b/0x73a [kvm]
[<ffffffffa01344a7>] kvm_vcpu_ioctl+0xfc/0x48b [kvm]
[<ffffffff810eac30>] vfs_ioctl+0x2a/0x78
[<ffffffff810eb0e9>] do_vfs_ioctl+0x46b/0x4ab
[<ffffffff810eb17e>] sys_ioctl+0x55/0x77
[<ffffffff810112ba>] system_call_fastpath+0x16/0x1b
[<ffffffffffffffff>] 0xffffffffffffffff
other info that might help us debug this:
2 locks held by qemu-kvm/3706:
#0: (&vcpu->mutex){--..}, at: [<ffffffffa0136ceb>] vcpu_load+0x15/0x37 [kvm]
#1: (&kvm->slots_lock){----}, at: [<ffffffffa013c4c0>] kvm_arch_vcpu_ioctl_run
+0x497/0x73a [kvm]
stack backtrace:
Pid: 3706, comm: qemu-kvm Not tainted 2.6.29-0.74.rc3.git3.fc11.x86_64 #1
Call Trace:
[<ffffffff8106dc65>] print_circular_bug_tail+0x71/0x7c
[<ffffffff8106e862>] __lock_acquire+0x94c/0xc41
[<ffffffff8106ebe4>] lock_acquire+0x8d/0xba
[<ffffffffa013a25f>] ? kvm_emulate_pio+0x1ab/0x1ff [kvm]
[<ffffffff8138205a>] __mutex_lock_common+0x107/0x39c
[<ffffffffa013a25f>] ? kvm_emulate_pio+0x1ab/0x1ff [kvm]
[<ffffffffa013a25f>] ? kvm_emulate_pio+0x1ab/0x1ff [kvm]
[<ffffffff81382398>] mutex_lock_nested+0x35/0x3a
[<ffffffffa013a25f>] kvm_emulate_pio+0x1ab/0x1ff [kvm]
[<ffffffffa015b695>] ? kvm_register_read+0x26/0x35 [kvm_intel]
[<ffffffffa015c875>] handle_io+0x6e/0x76 [kvm_intel]
[<ffffffffa015d202>] kvm_handle_exit+0x1ba/0x1db [kvm_intel]
[<ffffffffa013c534>] kvm_arch_vcpu_ioctl_run+0x50b/0x73a [kvm]
[<ffffffffa01344a7>] kvm_vcpu_ioctl+0xfc/0x48b [kvm]
[<ffffffff81163618>] ? inode_has_perm+0x6c/0x72
[<ffffffff810eac30>] vfs_ioctl+0x2a/0x78
[<ffffffff810eb0e9>] do_vfs_ioctl+0x46b/0x4ab
[<ffffffff810eb17e>] sys_ioctl+0x55/0x77
[<ffffffff810112ba>] system_call_fastpath+0x16/0x1b
next reply other threads:[~2009-02-03 10:25 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-02-03 10:25 Mark McLoughlin [this message]
2009-02-03 10:47 ` 2.6.29-rc3 circular locking dependency detected Avi Kivity
2009-02-03 16:35 ` Mark McLoughlin
2009-02-05 18:23 ` [PATCH 1/1] kvm: fix circular locking dependency Mark McLoughlin
2009-02-05 18:52 ` Chris Wright
2009-02-06 8:57 ` Mark McLoughlin
2009-02-08 5:28 ` Marcelo Tosatti
2009-02-08 9:43 ` Avi Kivity
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1233656726.3726.22.camel@blaa \
--to=markmc@redhat.com \
--cc=kvm@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.