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

2017-10-18 Thread Jan Beulich
>>> On 18.10.17 at 12:22, wrote: > On 10/18/2017 10:39 AM, Jan Beulich wrote: > On 17.10.17 at 19:10, wrote: >>> @@ -2330,8 +2360,8 @@ static int _put_page_type(struct page_info *page, >>> bool preemptible, >>> * necessary anymore for a dying domain. >>> *

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

2017-10-18 Thread George Dunlap
On 10/18/2017 10:39 AM, Jan Beulich wrote: On 17.10.17 at 19:10, wrote: >> --- a/docs/misc/xen-command-line.markdown >> +++ b/docs/misc/xen-command-line.markdown >> @@ -1422,6 +1422,22 @@ The following resources are available: >> CDP, one COS will corespond two CBMs other than one with C

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

2017-10-18 Thread Jan Beulich
>>> On 18.10.17 at 11:52, wrote: > On 10/18/2017 10:39 AM, Jan Beulich wrote: > On 17.10.17 at 19:10, wrote: >>> --- a/xen/arch/x86/Kconfig >>> +++ b/xen/arch/x86/Kconfig >>> @@ -97,6 +97,27 @@ config TBOOT >>> Technology (TXT) >>> >>> If unsure, say Y. >>> + >>> +config PV_LINE

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

2017-10-18 Thread George Dunlap
On 10/18/2017 10:39 AM, Jan Beulich wrote: On 17.10.17 at 19:10, wrote: >> --- a/docs/misc/xen-command-line.markdown >> +++ b/docs/misc/xen-command-line.markdown >> @@ -1422,6 +1422,22 @@ The following resources are available: >> CDP, one COS will corespond two CBMs other than one with C

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

2017-10-18 Thread Jan Beulich
>>> On 17.10.17 at 19:10, wrote: > --- a/docs/misc/xen-command-line.markdown > +++ b/docs/misc/xen-command-line.markdown > @@ -1422,6 +1422,22 @@ The following resources are available: > CDP, one COS will corespond two CBMs other than one with CAT, due to the > sum of CBMs is fixed, that

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

2017-10-18 Thread George Dunlap
On 10/17/2017 07:05 PM, Andrew Cooper wrote: > On 17/10/17 18:10, 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 subt

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

2017-10-17 Thread Andrew Cooper
On 17/10/17 18:10, 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 used b

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

2017-10-17 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 N

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

2017-10-17 Thread George Dunlap
On 10/17/2017 06:10 PM, 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