Re: 2.6.27-rc xen pvops regression?

From: Alex Nixon
Date: Sun Aug 31 2008 - 18:12:47 EST


Bernhard Schmidt wrote:
Hello,

I've been a happy user of vanilla 2.6.26 with pvops in my Xen domU for
a couple of months. I wanted to test 2.6.27-rc (-rc3 a couple of weeks
ago, -rc5 just now) to verify another issue and ran into the following
error
Thanks Bernhard - I'm able to reproduce it with your config.

I've had a look, and it seems the register_vcpu_info hypercall is being made twice, failing on the second time. In fact, paravirt_pagetable_setup_{start,done} are both being called twice - once from arch/x86/kernel/setup.c, and then again from arch/x86/mm/init_32.c

I suspect one of them should go, but I'm not familiar enough with this code to suggest which one.

But still with that crudely resolved, the kernel BUGs (see below). Jeremy - any ideas?

- Alex


`xm dmesg':

(XEN) mm.c:2249:d168 Mfn 24384 not pinned

dmesg:

EXT3-fs: mounted filesystem with ordered data mode.
VFS: Mounted root (ext3 filesystem) readonly.
Freeing unused kernel memory: 160k freed
------------[ cut here ]------------
kernel BUG at /local/scratch/hotplug.linux.trees.git/arch/x86/xen/enlighten.c:850!
invalid opcode: 0000 [#1]

Pid: 1, comm: init Tainted: G W (2.6.27-rc5-tip-00672-ge5c5407-dirty #52)
EIP: 0061:[<c0102b04>] EFLAGS: 00010282 CPU: 0
EIP is at pin_pagetable_pfn+0x3f/0x4b
EAX: ffffffea EBX: e242dd74 ECX: 00000001 EDX: 00000000
ESI: 00007ff0 EDI: 00000000 EBP: e242dd8c ESP: e242dd74
DS: 007b ES: 007b FS: 0000 GS: 0000 SS: e021
Process init (pid: 1, ti=e242c000 task=e242a000 task.ti=e242c000)
Stack: 00000004 00024384 00000000 c144e8e0 00022747 00000000 e242dd9c c0102ee8
c02fe5d4 c144e8e0 e242dda4 c0102f23 e242ddbc c0116722 00000000 00000000
00000000 00000000 e242de2c c01467a8 00000000 c1000000 00000000 22747067
Call Trace:
[<c0102ee8>] ? xen_release_ptpage+0x52/0x71
[<c0102f23>] ? xen_release_pte+0xd/0xf
[<c0116722>] ? __pte_free_tlb+0x35/0x4b
[<c01467a8>] ? free_pgd_range+0x377/0x38c
[<c015a4bf>] ? setup_arg_pages+0x1b8/0x22b
[<c017a80f>] ? load_elf_binary+0x3f1/0x10a4
[<c0104ffa>] ? check_events+0x8/0xe
[<c0104f71>] ? xen_restore_fl_direct_end+0x0/0x3
[<c0104937>] ? xen_force_evtchn_callback+0xf/0x14
[<c0104f71>] ? xen_restore_fl_direct_end+0x0/0x3
[<c014298a>] ? page_address+0x85/0xa2
[<c0159c51>] ? put_arg_page+0x8/0xa
[<c0159e27>] ? copy_strings+0x156/0x160
[<c0159ea8>] ? search_binary_handler+0x42/0x10a
[<c015ad64>] ? do_execve+0x129/0x192
[<c0105354>] ? sys_execve+0x29/0x50
[<c0106b1e>] ? syscall_call+0x7/0xb
[<c0109b2f>] ? kernel_execve+0x17/0x1c
[<c0102140>] ? run_init_process+0x17/0x19
[<c01021e3>] ? init_post+0xa1/0xf2
[<c01077df>] ? kernel_thread_helper+0x7/0x10

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/