On 4/29/19 10:41 AM, Peter Maydell wrote: > On Wed, 3 Apr 2019 at 05:05, Richard Henderson > <richard.hender...@linaro.org> wrote: >> >> Most of the existing users would continue around a loop which >> would fault the tlb entry in via a normal load/store. But for >> SVE we have a true non-faulting case which requires the new >> probing form of tlb_fill. > > So am I right in thinking that this fixes a bug where we > previously would mark a load as faulted if the memory happened > not to be in the TLB, whereas now we will correctly pull in the > TLB entry and do the load ?
Yes. > (Since guest code ought to be handling the "non-first-load > faulted" case by looping round or otherwise arranging to > retry, nothing in practice would have noticed this bug, right?) Yes. The only case with changed behaviour is (expected to be) SVE no-fault, where the loop you mention would have produced different incorrect results. r~
