Re: [PATCH] paging_enabled and non-HVM guests

[Anthony Liguori <aliguori@us.ibm.com>]

Hollis Blanchard wrote:
> On Tue, 2006-05-09 at 13:31 +0200, Simon Kagstrom wrote:
>   
>> I had a problem with the GDB-server crashing on connections in
>> xen_ptrace.c:map_domain_va(). paging_enabled() should only be checked
>> for HVM guests, and the patch adds a check for that.
>>
>> Signed-off-by: Simon Kagstrom <ska@bth.se>
>>
>> diff -r 4501d60d6add tools/libxc/xc_ptrace.c
>> --- a/tools/libxc/xc_ptrace.c	Tue May  9 09:57:05 2006
>> +++ b/tools/libxc/xc_ptrace.c	Tue May  9 13:26:14 2006
>> @@ -374,7 +374,7 @@
>>      if (fetch_regs(xc_handle, cpu, NULL))
>>          return NULL;
>>  
>> -    if (!paging_enabled(&ctxt[cpu])) { 
>> +    if ( (ctxt[cpu].flags & VGCF_HVM_GUEST) && !paging_enabled(&ctxt[cpu])) { 
>>          static void * v;
>>          unsigned long page;
>>     
>
> I looked at this a couple weeks ago, and I think the real problem is
> that the CR registers are never updated in Xen's vcpu structure, and so
> xc_vcpu_getcontext() doesn't get them either. So Xen should be fixed; we
> shouldn't add workarounds to userland.
>   

I think that the CR registers are never changed during the life of a PV 
domain.  I think all that's needed is for some sane values to be set 
during domain creation and things start working.  I believe Ryan had a 
patch that did this?

Regards,

Anthony Liguori