Re: [Xen-devel] xen/arm: On chip memory mappings

2015-05-20 Thread Edgar E. Iglesias
On Wed, May 20, 2015 at 03:12:24PM +0100, Julien Grall wrote: > On 20/05/15 14:40, Edgar E. Iglesias wrote: > > Thanks for the pointers, > > > > I agree that fundamental differences like these beteween v7 and v8 wouldn't > > be good. > > I didn't find any fundamental differences for device memory

Re: [Xen-devel] xen/arm: On chip memory mappings

2015-05-20 Thread Julien Grall
On 20/05/15 14:40, Edgar E. Iglesias wrote: > Thanks for the pointers, > > I agree that fundamental differences like these beteween v7 and v8 wouldn't > be good. I didn't find any fundamental differences for device memory behavior in the spec. > Possible unpredictable behaviour is worrysome... >

Re: [Xen-devel] xen/arm: On chip memory mappings

2015-05-20 Thread Edgar E. Iglesias
On Tue, May 19, 2015 at 10:23:05AM +0100, Julien Grall wrote: > > > On 19/05/2015 10:09, Ian Campbell wrote: > >On Tue, 2015-05-19 at 15:16 +1000, Edgar E. Iglesias wrote: > >>Hi, > > Hi, > > >>The rules for combining the memory attributes from S1 and S2 translations > >>suggest that mapping th

Re: [Xen-devel] xen/arm: On chip memory mappings

2015-05-19 Thread Julien Grall
On 19/05/2015 10:09, Ian Campbell wrote: On Tue, 2015-05-19 at 15:16 +1000, Edgar E. Iglesias wrote: Hi, Hi, The rules for combining the memory attributes from S1 and S2 translations suggest that mapping things at S2 with Normal memory Inner/Outer WB cacheable would give the guest/S1 flexi

Re: [Xen-devel] xen/arm: On chip memory mappings

2015-05-19 Thread Ian Campbell
On Tue, 2015-05-19 at 15:16 +1000, Edgar E. Iglesias wrote: > Hi, > > I'd like to support the assignment of on chip RAMs to guests, starting with > dom0. > > The mmio-sram compatible device kinda works already but the 2nd stage MMU > mapping is done with DEVICE memory attributes. This doesn't wo

[Xen-devel] xen/arm: On chip memory mappings

2015-05-18 Thread Edgar E. Iglesias
Hi, I'd like to support the assignment of on chip RAMs to guests, starting with dom0. The mmio-sram compatible device kinda works already but the 2nd stage MMU mapping is done with DEVICE memory attributes. This doesn't work well for SRAMs for several reasons (e.g performance, alignment checks e