Re: [PATCH] riscv: Raise an exception if pte reserved bits are not cleared

2023-04-17 Thread Andrea Parri
Hi Alistair, > > @@ -936,6 +936,11 @@ restart: > > return TRANSLATE_FAIL; > > } > > > > +/* PTE reserved bits must be cleared otherwise an exception is > > raised */ > > +if (riscv_cpu_mxl(env) == MXL_RV64 && (pte & PTE_RESERVED)) { > > +return TR

Re: [PATCH] RISC-V: Add support for Ztso

2022-10-13 Thread Andrea Parri
> > AFAICT, Ztso allows the forwarding in question too. Simulations with > > the axiomatic formalization confirm such expectation: > > OK that seems to be what it says in: > https://five-embeddev.com/riscv-isa-manual/latest/ztso.html > 'In both of these memory models, it is the that allows a ha

Re: [PATCH] RISC-V: Add support for Ztso

2022-10-13 Thread Andrea Parri
> > > Is x86's brand of memory ordering strong enough for Ztso? > > > I thought x86 had an optimisation where it was allowed to store forward > > > within the current CPU causing stores not to be quite strictly ordered. [...] > then a bit further down, '8.2.3.5 Intra-Processor Forwarding Is Allow