Re: [PATCH v2] Call xen_cleanhighmap() with 4MB aligned for page tables mapping
From: Juergen Gross
Date: Wed Sep 27 2017 - 10:33:11 EST
On 27/09/17 15:38, Boris Ostrovsky wrote:
> On 09/27/2017 05:43 AM, Juergen Gross wrote:
>> On 27/09/17 11:41, Zhenzhong Duan wrote:
>>> When bootup a PVM guest with large memory(Ex.240GB), XEN provided initial
>>> mapping overlaps with kernel module virtual space. When mapping in this space
>>> is cleared by xen_cleanhighmap(), in certain case there could be an 2MB mapping
>>> left. This is due to XEN initialize 4MB aligned mapping but xen_cleanhighmap()
>>> finish at 2MB boundary.
>
> Does this mapping need to be 4MB-aligned?
I guess you are questioning the alignment of addr to be 4MB?
In this case you are right: the end of the mapping is 4MB aligned, as
correctly stated in the comment added.
> (I also think this should go to stable trees)
Indeed.
Juergen