Re: [Xen-devel] [PATCH v2 for-4.10] x86/mm: Make PV linear pagetables optional

2017-10-19 Thread Julien Grall
Hi George, On 18/10/17 11:51, George Dunlap wrote: Allowing pagetables to point to other pagetables of the same level (often called 'linear pagetables') has been included in Xen since its inception; but recently it has been the source of a number of subtle reference-counting bugs. It is not

Re: [Xen-devel] [PATCH v2 for-4.10] x86/mm: Make PV linear pagetables optional

2017-10-18 Thread Jan Beulich
>>> On 18.10.17 at 15:49, wrote: > On 10/18/2017 02:41 PM, Jan Beulich wrote: > On 18.10.17 at 12:51, wrote: >>> @@ -2334,6 +2368,9 @@ static int _put_page_type(struct page_info *page, >>> bool preemptible, >>>

Re: [Xen-devel] [PATCH v2 for-4.10] x86/mm: Make PV linear pagetables optional

2017-10-18 Thread George Dunlap
On 10/18/2017 02:41 PM, Jan Beulich wrote: On 18.10.17 at 12:51, wrote: >> --- a/xen/arch/x86/Kconfig >> +++ b/xen/arch/x86/Kconfig >> @@ -37,6 +37,26 @@ source "arch/Kconfig" >> config PV >> def_bool y >> >> +config PV_LINEAR_PT >> + bool "Support for

Re: [Xen-devel] [PATCH v2 for-4.10] x86/mm: Make PV linear pagetables optional

2017-10-18 Thread Jan Beulich
>>> On 18.10.17 at 12:51, wrote: > --- a/xen/arch/x86/Kconfig > +++ b/xen/arch/x86/Kconfig > @@ -37,6 +37,26 @@ source "arch/Kconfig" > config PV > def_bool y > > +config PV_LINEAR_PT > + bool "Support for PV linear pagetables" > + depends on PV > +

Re: [Xen-devel] [PATCH v2 for-4.10] x86/mm: Make PV linear pagetables optional

2017-10-18 Thread Wei Liu
On Wed, Oct 18, 2017 at 11:51:59AM +0100, George Dunlap wrote: > Allowing pagetables to point to other pagetables of the same level > (often called 'linear pagetables') has been included in Xen since its > inception; but recently it has been the source of a number of subtle > reference-counting

[Xen-devel] [PATCH v2 for-4.10] x86/mm: Make PV linear pagetables optional

2017-10-18 Thread George Dunlap
Allowing pagetables to point to other pagetables of the same level (often called 'linear pagetables') has been included in Xen since its inception; but recently it has been the source of a number of subtle reference-counting bugs. It is not used by Linux or MiniOS; but it used used by NetBSD and