On 11/26/18 6:44 AM, David Gibson wrote: > On Fri, Nov 23, 2018 at 11:28:24AM +0100, Cédric Le Goater wrote: >> On 11/23/18 2:10 AM, David Gibson wrote: >>> On Thu, Nov 22, 2018 at 05:50:07PM +1100, Benjamin Herrenschmidt wrote: >>>> On Thu, 2018-11-22 at 15:44 +1100, David Gibson wrote: >>>>> >>>>> Sorry, didn't think of this in my first reply. >>>>> >>>>> 1) Does the hardware ever actually write back to the EAS? I know it >>>>> does for the END, but it's not clear why it would need to for the >>>>> EAS. If not, we don't need the setter. >>>> >>>> Nope, though the PAPR model will via hcalls >>> >>> Right, bit AIUI the set_eas hook is about abstracting PAPR vs bare >>> metal details. Since the hcall knows it's PAPR it can just update the >>> backing information for the EAS directly, and no need for an >>> abstracted hook. >> >> Indeed, the first versions of the XIVE patchset did not use such hooks, >> but when discussed we said we wanted abstract methods for the router >> to validate the overall XIVE model, which is useful for PowerNV. >> >> We can change again and have the hcalls get/set directly in the EAT >> and ENDT. It would certainly simplify the sPAPR model. > > I think that's the better approach.
ok. let's keep that in mind for : [PATCH v5 11/36] spapr/xive: use the VCPU id as a NVT identifier [PATCH v5 16/36] spapr: add hcalls support for the XIVE exploitation which are using the XiveRouter methods to access the controller EAT and ENDT. I thought that was good practice to validate the model but we can use direct sPAPR table accessors or none at all. I think these prereq patches could be merged now : [PATCH v5 12/36] spapr: initialize VSMT before initializing the IRQ [PATCH v5 13/36] spapr: introduce a spapr_irq_init() routine [PATCH v5 14/36] spapr: modify the irq backend 'init' method This one also : [PATCH v5 21/36] spapr: extend the sPAPR IRQ backend for XICS Thanks, C.
