Steven,
Looks like commit 198d208df (x86: Keep thread_info on thread stack in
x86_32) broke Xen's 32-bit PV guests.
I poked a little at it and it seems that at least the ifdef in
xen_cpu_up() needs to be adjusted to set up kernel_stack --- that allows
CPUs to get going. This is not enough though (not particularly
surprisingly) and we die a little later with #GPF in xen_iret.
-boris
On 04/03/2014 11:23 PM, Boris Ostrovsky wrote:
> Steven,
>
> Looks like commit 198d208df (x86: Keep thread_info on thread stack in
> x86_32) broke Xen's 32-bit PV guests.
>
> I poked a little at it and it seems that at least the ifdef in
> xen_cpu_up() needs to be adjusted to set up kernel_stack --- that
> allows CPUs to get going. This is not enough though (not particularly
> surprisingly) and we die a little later with #GPF in xen_iret.
I should have probably included some output.
...
[ 1.277533] Freeing unused kernel memory: 780K (c18fe000 - c19c1000)
[ 1.280041] Write protecting the kernel text: 6120k
[ 1.281477] Write protecting the kernel read-only data: 2472k
[ 1.282177] NX-protecting the kernel data: 4120k
[ 1.304957] general protection fault: 0000 [#1] SMP
[ 1.305866] Modules linked in:
[ 1.305866] CPU: 0 PID: 1 Comm: init Not tainted 3.14.0-32b #29
[ 1.305866] task: eb880000 ti: eb84c000 task.ti: eb84c000
[ 1.305866] EIP: e019:[<c100901f>] EFLAGS: 00010046 CPU: 0
[ 1.305866] EIP is at xen_iret+0xb/0x29
[ 1.305866] EAX: 00000000 EBX: 00000000 ECX: 00000000 EDX: 00000000
[ 1.305866] ESI: 00000000 EDI: 00000000 EBP: 00000000 ESP: eb84dfe0
[ 1.305866] DS: 007b ES: 007b FS: 0000 GS: 0000 SS: e021
[ 1.305866] CR0: 8005003b CR2: bf8e0fe0 CR3: 2ac52000 CR4: 00040660
[ 1.305866] Stack:
[ 1.305866] 00000000 b760d020 00000073 00000200 bf8e0fe0 0000007b
c2c2c2c2 c2c2c2c2
[ 1.305866] Call Trace:
[ 1.305866] Code: a1 d8 9f 9b c1 2d ec 1f 00 00 36 8b 40 10 36 8b 04
85 e0 74 8f c1 36 8b 80 c0 90 9b c1 eb 2a 90 f7 44 24 08 00 00 02 80 75
3d 50 <64> a1 d8 9f 9b c1 2d ec 1f 00 00 36 8b 40 10 36 8b 04 85 e0 74
[ 1.305866] EIP: [<c100901f>] xen_iret+0xb/0x29 SS:ESP e021:eb84dfe0
[ 1.305866] ---[ end trace e4f42ac1798ac467 ]---
[ 1.369739] Kernel panic - not syncing: Attempted to kill init!
exitcode=0x0000000b