Re: [Xen-devel] xen-unstable: commit commit 63753b3e0dc56efb1acf94fa46f3fee7bc59281c leaves HVM guest dangling after shutdown or destroy.

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 30.04.13 at 15:55, Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx> wrote:
> On Wed, Apr 24, 2013 at 10:31:20AM +0100, George Dunlap wrote:
>> On Tue, Apr 23, 2013 at 4:35 PM, Roger Pau Monnà <roger.pau@xxxxxxxxxx> 
>> wrote:
>> > On 20/04/13 20:56, Konrad Rzeszutek Wilk wrote:
>> >>
>> >>
>> >> Sander Eikelenboom <linux@xxxxxxxxxxxxxx> wrote:
>> >>
>> >>> Hi,
>> >>>
>> >>> Commit 63753b3e0dc56efb1acf94fa46f3fee7bc59281c x86: allow
>> >>> VCPUOP_register_vcpu_info to work again on PVHVM guests
>> >>>
>> >>> Leaves HVM guests dangling after shutdown or destroy:
>> >>>
>> >>> xl list gives:
>> >>> (null)                                      16     0     4     --p--d
>> >>>   11.5
>> >>> (null)                                      17     0     1     --ps-d
>> >>>   12.0
>> >>>
>> >>> (first was destroyed, second shutdown)
>> >>>
>> >>> The actual xl and qemu processes are gone, so guest only seem to be
>> >>> still registered in the hypervisor.
>> >>>
>> >>> Another thing this seems to trigger (and that perhaps needs fixing) is
>> >>> that a "xl shutdown --all --wait" doesn't wait anymore.
>> >>> It returns immediately, probably due to the "nullified" name ?
>> >>
>> >> Is this only happening with Linux guests?
>> >
>> > AFAIK this seems to happen with guests that use
>> > VCPUOP_register_vcpu_info (I'm seeing the same on FreeBSD).
>> 
>> Are we leaving a reference to a page dangling around somewhere?
> 
> <nods> That is my thinking. George, if you would not mind - could you add
> this to the list of bugs for Xen 4.3 I am responsible for.

Perhaps you can take this off the list again right away: A brief look
at the code shows that unmap_vcpu_info() is being called only for
PV guests. Patch below/attached (compile tested only).

Jan

x86: call unmap_vcpu_info() regardless of guest type

This fixes a regression from 63753b3e ("x86: allow
VCPUOP_register_vcpu_info to work again on PVHVM guests").

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -2013,7 +2013,11 @@ int domain_relinquish_resources(struct d
 
         /* Drop the in-use references to page-table bases. */
         for_each_vcpu ( d, v )
+        {
             vcpu_destroy_pagetables(v);
+
+            unmap_vcpu_info(v);
+        }
 
         if ( !is_hvm_domain(d) )
         {
@@ -2025,8 +2029,6 @@ int domain_relinquish_resources(struct d
                  * mappings.
                  */
                 destroy_gdt(v);
-
-                unmap_vcpu_info(v);
             }
 
             if ( d->arch.pv_domain.pirq_eoi_map != NULL )

Attachment: x86-unmap-vcpu-info-pvhvm.patch
Description: Text document

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel