Re: [Xen-devel] [RFC 1/2] xen/mm: Clarify the granularity for each Frame Number

2015-08-12 Thread Jan Beulich
>>> On 12.08.15 at 14:57, wrote: > On 12/08/15 12:58, Jan Beulich wrote: > On 12.08.15 at 13:13, wrote: >>> On 12/08/15 11:33, Jan Beulich wrote: >>> On 12.08.15 at 11:57, wrote: > On 12/08/2015 08:16, Jan Beulich wrote: > On 05.08.15 at 15:18, wrote: >>> When the backen

Re: [Xen-devel] [RFC 1/2] xen/mm: Clarify the granularity for each Frame Number

2015-08-12 Thread Julien Grall
On 12/08/15 12:58, Jan Beulich wrote: On 12.08.15 at 13:13, wrote: >> On 12/08/15 11:33, Jan Beulich wrote: >> On 12.08.15 at 11:57, wrote: On 12/08/2015 08:16, Jan Beulich wrote: On 05.08.15 at 15:18, wrote: >> When the backend is 64K, it will map the foreign 4K at th

Re: [Xen-devel] [RFC 1/2] xen/mm: Clarify the granularity for each Frame Number

2015-08-12 Thread Jan Beulich
>>> On 12.08.15 at 13:13, wrote: > On 12/08/15 11:33, Jan Beulich wrote: > On 12.08.15 at 11:57, wrote: >>> On 12/08/2015 08:16, Jan Beulich wrote: >>> On 05.08.15 at 15:18, wrote: > When the backend is 64K, it will map the foreign 4K at the top of a 64K > page. It's a waste of m

Re: [Xen-devel] [RFC 1/2] xen/mm: Clarify the granularity for each Frame Number

2015-08-12 Thread Julien Grall
On 12/08/15 11:33, Jan Beulich wrote: On 12.08.15 at 11:57, wrote: >> On 12/08/2015 08:16, Jan Beulich wrote: >> On 05.08.15 at 15:18, wrote: On 05/08/15 13:46, Andrew Cooper wrote: > On 05/08/15 13:36, Julien Grall wrote: >> So we need to introduce the concept of in each de

Re: [Xen-devel] [RFC 1/2] xen/mm: Clarify the granularity for each Frame Number

2015-08-12 Thread Jan Beulich
>>> On 12.08.15 at 11:57, wrote: > On 12/08/2015 08:16, Jan Beulich wrote: > On 05.08.15 at 15:18, wrote: >>> On 05/08/15 13:46, Andrew Cooper wrote: On 05/08/15 13:36, Julien Grall wrote: > So we need to introduce the concept of in each definition. This patch > makes clear that

Re: [Xen-devel] [RFC 1/2] xen/mm: Clarify the granularity for each Frame Number

2015-08-12 Thread Julien Grall
Hi Jan, On 12/08/2015 08:16, Jan Beulich wrote: On 05.08.15 at 15:18, wrote: On 05/08/15 13:46, Andrew Cooper wrote: On 05/08/15 13:36, Julien Grall wrote: So we need to introduce the concept of in each definition. This patch makes clear that MFN and GFN is always 4KB and PFN may vary. Is

Re: [Xen-devel] [RFC 1/2] xen/mm: Clarify the granularity for each Frame Number

2015-08-12 Thread Jan Beulich
>>> On 05.08.15 at 15:18, wrote: > On 05/08/15 13:46, Andrew Cooper wrote: >> On 05/08/15 13:36, Julien Grall wrote: >>> So we need to introduce the concept of in each definition. This patch >>> makes clear that MFN and GFN is always 4KB and PFN may vary. >> >> Is (or rather will) a 4K dom0 able

Re: [Xen-devel] [RFC 1/2] xen/mm: Clarify the granularity for each Frame Number

2015-08-05 Thread Julien Grall
Hi, On 05/08/15 13:46, Andrew Cooper wrote: > On 05/08/15 13:36, Julien Grall wrote: >> On 05/08/15 12:40, Andrew Cooper wrote: >>> I think a section about granularity is worthwhile, but probably a >>> separate paragraph. I think it is also worth keeping Xen's idea of >>> memory all at 4K, and in

Re: [Xen-devel] [RFC 1/2] xen/mm: Clarify the granularity for each Frame Number

2015-08-05 Thread Andrew Cooper
On 05/08/15 13:36, Julien Grall wrote: > On 05/08/15 12:40, Andrew Cooper wrote: >> I think a section about granularity is worthwhile, but probably a >> separate paragraph. I think it is also worth keeping Xen's idea of >> memory all at 4K, and in cases where 64K is in use, require appropriate >>

Re: [Xen-devel] [RFC 1/2] xen/mm: Clarify the granularity for each Frame Number

2015-08-05 Thread Julien Grall
On 05/08/15 12:40, Andrew Cooper wrote: > I think a section about granularity is worthwhile, but probably a > separate paragraph. I think it is also worth keeping Xen's idea of > memory all at 4K, and in cases where 64K is in use, require appropriate > alignment in the parameter. Which would conf

Re: [Xen-devel] [RFC 1/2] xen/mm: Clarify the granularity for each Frame Number

2015-08-05 Thread Ian Campbell
On Wed, 2015-08-05 at 12:40 +0100, Andrew Cooper wrote: > > 64K granularity is also similar to 2M/1G superpages in their handling, > the difference being that 64K can't be subdivided if necessary? 64K is actually a separate basic "granule" (to use the ARM term), i.e. alternative to the 4K leaf pa

Re: [Xen-devel] [RFC 1/2] xen/mm: Clarify the granularity for each Frame Number

2015-08-05 Thread Andrew Cooper
On 05/08/15 12:28, Julien Grall wrote: > From: Stefano Stabellini > > ARM64 is able to support 64KB and 4KB page granularities. While the guest > will support both granularities, Xen and hypercall interface will always > be in 4KB. > > Signed-off-by: Stefano Stabellini > Signed-off-by: Julien Gra

[Xen-devel] [RFC 1/2] xen/mm: Clarify the granularity for each Frame Number

2015-08-05 Thread Julien Grall
From: Stefano Stabellini ARM64 is able to support 64KB and 4KB page granularities. While the guest will support both granularities, Xen and hypercall interface will always be in 4KB. Signed-off-by: Stefano Stabellini Signed-off-by: Julien Grall --- Cc: Ian Campbell Cc: Ian Jackson Cc: Jan B