Re: [PATCH] DOM0_GETDOMAININFO hypercall support for DOMID_SELF

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

Cihula, Joseph wrote:

>The attached (and following) patch allows a privileged domain to use the
>DOM0_GETDOMAININFO dom0_op (and by extension, userspace apps to use
>xc_domain_getinfo()) to query about themselves by specifying the domid
>as DOMID_SELF.
>
>Most importantly, this allows the domain to determine its own domid.
>  
>
If you want to find out your domid (you'll have to be very careful wrt 
save/restore/migrate btw) what you can do today is:

1) Copy libxenctrl.so.3.0.0, libxenstore.so, and xenstore-read into your 
guest.
2) xenstore-read domid

This will work in any type of domain.  You can also just use libxenstore 
directly (just make sure to use xs_domain_open()).
Regards,

Anthony Liguori

>Signed-off-by: joseph.cihula@intel.com
>
>diff -r 6ee4c16bfdec xen/common/dom0_ops.c
>--- a/xen/common/dom0_ops.c     Fri Dec 16 17:58:21 2005
>+++ b/xen/common/dom0_ops.c     Fri Dec 16 18:40:39 2005
>@@ -358,12 +358,17 @@
>     case DOM0_GETDOMAININFO:
>     {
>         struct domain *d;
>+        domid_t dom;
>+
>+        dom = op->u.getdomaininfo.domain;
>+        if ( dom == DOMID_SELF )
>+            dom = current->domain->domain_id;
>
>         read_lock(&domlist_lock);
>
>         for_each_domain ( d )
>         {
>-            if ( d->domain_id >= op->u.getdomaininfo.domain )
>+            if ( d->domain_id >= dom )
>                 break;
>         }
>
>  
>
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>
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