CentOS virt - Jul 2013 - Xen kernel fixes

Hi,

I have made the for-centos-v5 branch available on

git://xenbits.xen.org/people/dvrabel/linux.git

This is based on 3.4.54 and includes the following additional fixes
(since the for-centos-v4 branch).

* x86/xen: during early setup, only 1:1 map the ISA region

Fixes a boot failure if tboot is used.

* xen/evtchn: avoid a deadlock when unbinding an event channel

Fixes a potential deadlock by users (e.g., qemu, xenstored) of
/dev/xen/evtchn.

You may also wish to consider enabling
CONFIG_XEN_BALLOON_MEMORY_HOTPLUG.  The kernel bug that was causing
problems is already fixed (by xen/balloon: Subtract from
xen_released_pages the count that is populated) and now that dom0 will
not try to auto-balloon by default, enabling this option should no
longer cause problems in dom0.

This option is required to increase the amount of memory in a guest
using this kernel above the initial amount.

David

On 07/22/2013 10:49 AM, David Vrabel wrote:
> Hi,
>
> I have made the for-centos-v5 branch available on
>
> git://xenbits.xen.org/people/dvrabel/linux.git
>
> This is based on 3.4.54 and includes the following additional fixes
> (since the for-centos-v4 branch).
>
> * x86/xen: during early setup, only 1:1 map the ISA region
>
> Fixes a boot failure if tboot is used.
>
> * xen/evtchn: avoid a deadlock when unbinding an event channel
>
> Fixes a potential deadlock by users (e.g., qemu, xenstored) of
> /dev/xen/evtchn.
>
> You may also wish to consider enabling
> CONFIG_XEN_BALLOON_MEMORY_HOTPLUG.  The kernel bug that was causing
> problems is already fixed (by xen/balloon: Subtract from
> xen_released_pages the count that is populated) and now that dom0 will
> not try to auto-balloon by default, enabling this option should no
> longer cause problems in dom0.
>
> This option is required to increase the amount of memory in a guest
> using this kernel above the initial amount.
>
David,

There are two unset Xen ballon options ... they are:

# CONFIG_XEN_SELFBALLOONING is not set
# CONFIG_XEN_BALLOON_MEMORY_HOTPLUG is not set

I see that you have recommended:

CONFIG_XEN_BALLOON_MEMORY_HOTPLUG=y

what about:

CONFIG_XEN_SELFBALLOONING

(Leave it unset or set it to yes as well)

Thanks,
Johnny Hughes

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On 22/07/13 21:26, Johnny Hughes wrote:
> 
> There are two unset Xen ballon options ... they are:
> 
> # CONFIG_XEN_SELFBALLOONING is not set
> # CONFIG_XEN_BALLOON_MEMORY_HOTPLUG is not set
> 
> I see that you have recommended:
> 
> CONFIG_XEN_BALLOON_MEMORY_HOTPLUG=y
> 
> what about:
> 
> CONFIG_XEN_SELFBALLOONING
> 
> (Leave it unset or set it to yes as well)
Leave XEN_SELFBALLOONING disabled.  It's a feature that will cause the
guest to set its own balloon target which is not a change we want to
make at this stage.

David