Re: [Xen-devel] [PATCH v6] x86/p2m: use large pages for MMIO mappings

2016-02-02 Thread Andrew Cooper
On 02/02/16 13:24, Jan Beulich wrote: On 01.02.16 at 16:00, wrote: >> On 01/02/16 09:14, Jan Beulich wrote: >>> --- a/xen/arch/x86/mm/p2m.c >>> +++ b/xen/arch/x86/mm/p2m.c >>> @@ -899,48 +899,64 @@ void p2m_change_type_range(struct domain >>> p2m_unlock(p2m);

Re: [Xen-devel] [PATCH v6] x86/p2m: use large pages for MMIO mappings

2016-02-02 Thread Jan Beulich
>>> On 02.02.16 at 15:33, wrote: > On 02/02/16 13:24, Jan Beulich wrote: > On 01.02.16 at 16:00, wrote: >>> On 01/02/16 09:14, Jan Beulich wrote: --- a/xen/arch/x86/mm/p2m.c +++ b/xen/arch/x86/mm/p2m.c @@ -899,48 +899,64 @@

Re: [Xen-devel] [PATCH v6] x86/p2m: use large pages for MMIO mappings

2016-02-02 Thread Jan Beulich
>>> On 01.02.16 at 16:00, wrote: > On 01/02/16 09:14, Jan Beulich wrote: >> --- a/xen/arch/x86/mm/p2m.c >> +++ b/xen/arch/x86/mm/p2m.c >> @@ -899,48 +899,64 @@ void p2m_change_type_range(struct domain >> p2m_unlock(p2m); >> } >> >> -/* Returns: 0 for success,

[Xen-devel] [PATCH v6] x86/p2m: use large pages for MMIO mappings

2016-02-01 Thread Jan Beulich
When mapping large BARs (e.g. the frame buffer of a graphics card) the overhead of establishing such mappings using only 4k pages has, particularly after the XSA-125 fix, become unacceptable. Alter the XEN_DOMCTL_memory_mapping semantics once again, so that there's no longer a fixed amount of

Re: [Xen-devel] [PATCH v6] x86/p2m: use large pages for MMIO mappings

2016-02-01 Thread Andrew Cooper
On 01/02/16 09:14, Jan Beulich wrote: > --- a/xen/arch/x86/mm/p2m.c > +++ b/xen/arch/x86/mm/p2m.c > @@ -899,48 +899,64 @@ void p2m_change_type_range(struct domain > p2m_unlock(p2m); > } > > -/* Returns: 0 for success, -errno for failure */ > +/* > + * Returns: > + *0 for