Kernel Oops with kvm 66 running WinXP

Michal Ludvig
2008-04-26T12:12:26Z

Hi,

I've experienced a kernel Oops on 2.6.24 with kvm 66 on AMD in 64bit
mode while starting up WinXP:

kvm: emulating exchange as write
Unable to handle kernel NULL pointer dereference at 0000000000000000 RIP:
[<ffffffff883a7a5a>] :kvm:x86_emulate_insn+0x3fa/0x4240
PGD 7658d067 PUD 242a6067 PMD 0
Oops: 0002 [1] SMP
CPU 0
Modules linked in: bridge llc reiserfs tun kvm_amd kvm nfs nfsd lockd
nfs_acl auth_rpcgss sunrpc exportfs w83627ehf hwmon_vid autofs4
snd_pcm_oss snd_mixer_oss snd_seq snd_seq_device iptable_filter
ip_tables ip6table_filter ip6_tables x_tables af_packet ipv6 fuse ext2
loop snd_hda_intel snd_pcm snd_timer k8temp i2c_nforce2 i2c_core hwmon
sr_mod button cdrom snd soundcore snd_page_alloc forcedeth sg floppy
linear sd_mod ehci_hcd ohci_hcd usbcore dm_snapshot edd dm_mod fan
sata_nv pata_amd libata scsi_mod thermal processor
Pid: 3139, comm: qemu-system-x86 Not tainted 2.6.24-mludvig #1
RIP: 0010:[<ffffffff883a7a5a>] [<ffffffff883a7a5a>]
:kvm:x86_emulate_insn+0x3fa/0x4240
RSP: 0018:ffff8100609fdc18 EFLAGS: 00010246
RAX: 000000008001003b RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8100609fe000
RBP: ffff8100609ff320 R08: ffff8100609ff3c0 R09: 0000000000000006
R10: 0000000000000002 R11: 0000000000000000 R12: ffff8100609ff368
R13: ffff8100609ff3c0 R14: ffffffff883be600 R15: 0000000001971353
FS: 0000000040804950(0063) GS:ffffffff8053e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 0000000000000000 CR3: 000000006bb74000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process qemu-system-x86 (pid: 3139, threadinfo ffff8100609fc000, task
ffff8100794d5680)
Stack: 00000000609fdc74 0000000012187318 000000000ea5f068 ffff8100609ff3c0
ffff8100609fdc94 ffffffff8839c9e0 0000000000000000 ffff8100609fe000
ffff8100609ff320 0000000000000000 0000000000000000 0000000000000000
Call Trace:
[<ffffffff8839c9e0>] :kvm:kvm_get_cs_db_l_bits+0x20/0x40
[<ffffffff8839dd2f>] :kvm:emulate_instruction+0x1bf/0x340
[<ffffffff883c1a22>] :kvm_amd:emulate_on_interception+0x12/0x60
[<ffffffff883a11d9>] :kvm:kvm_arch_vcpu_ioctl_run+0x169/0x6d0
[<ffffffff8839c14c>] :kvm:kvm_vcpu_ioctl+0x41c/0x440
[<ffffffff802305f3>] __wake_up+0x43/0x70
[<ffffffff803374c1>] __up_read+0x21/0xb0
[<ffffffff802586ec>] futex_wake+0xcc/0xf0
[<ffffffff80259559>] do_futex+0x129/0xbb0
[<ffffffff8022e7bd>] __dequeue_entity+0x3d/0x50
[<ffffffff8839b925>] :kvm:kvm_vm_ioctl+0x85/0x200
[<ffffffff802ab10f>] do_ioctl+0x2f/0xa0
[<ffffffff802ab3a0>] vfs_ioctl+0x220/0x2d0
[<ffffffff802ab4e1>] sys_ioctl+0x91/0xb0
[<ffffffff8020bcae>] system_call+0x7e/0x83

Code: 66 89 02 e9 ee fc ff ff 48 8b 95 88 00 00 00 48 8b 45 78 88
RIP [<ffffffff883a7a5a>] :kvm:x86_emulate_insn+0x3fa/0x4240
RSP <ffff8100609fdc18>
CR2: 0000000000000000
---[ end trace d358bab3f035112e ]---

The host is still alive but the XP guest is locked up in a boot screen.

Michal