Re: 2.6.27-rc4 pvops domU on Xen 3.3 Kernel panic

[Jeremy Fitzhardinge <jeremy@goop.org>]

Todd Deshane wrote:
> I'm trying to build a kernel.org domU to run on Xen 3.3
>
> My first attempt produced a kernel panic.
>
> Below is my setup and the panic that occurred during boot right after:
>
> [    0.004000] Initializing cgroup subsys cpuacct
> [    0.008000]
> [    0.008000] CPU 0/0 -> Node 0
> [    0.008000] CPU: Physical Processor ID: 0
> [    0.008000] CPU: Processor Core ID: 0
> [    0.008000] SMP alternatives: switching to UP code
> [    0.020001] Freeing SMP alternatives: 22k freed
>
> The same panic happens for both default vcpus, vcpus=1, and vcpus=2
>
> Any ideas or hints?
>   

Ah, it's a bug which has been since fixed, but it looks like the fix
hasn't made it into mainline.  Patch below.

(Ingo, can you push this to Linus?  It needs to be in mainline.)

    J

commit b56afe1d41653fb07ab1b5af5ccc12001c4dd5a0
Author: Eduardo Habkost <ehabkost@redhat.com>
Date:   Thu Jul 24 12:15:45 2008 -0300

    x86, xen: Use native_pte_flags instead of native_pte_val for .pte_flags
    
    Using native_pte_val triggers the BUG_ON() in the paravirt_ops
    version of pte_flags().
    
    Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
    Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
    Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 06219e6..e2767c2 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1347,7 +1347,7 @@ static const struct pv_mmu_ops xen_mmu_ops __initdata = {
 	.ptep_modify_prot_commit = __ptep_modify_prot_commit,
 
 	.pte_val = xen_pte_val,
-	.pte_flags = native_pte_val,
+	.pte_flags = native_pte_flags,
 	.pgd_val = xen_pgd_val,
 
 	.make_pte = xen_make_pte,