Hi Paolo, Looks like it will take more time for KVM RISC-V to be merged under arch/riscv. Let's go ahead with your suggestion of having KVM RISC-V under drivers/staging so that development is not blocked. I will send-out v18 series which will add KVM RISC-V under the staging directory. Should we target Linux-5.14 ? Regards, Anup On Tue, Apr 27, 2021 at 11:13 AM Paul Walmsley <paul.walmsley@xxxxxxxxxx> wrote: > > On Fri, 9 Apr 2021, Palmer Dabbelt wrote: > > > On Wed, 31 Mar 2021 02:21:58 PDT (-0700), pbonzini@xxxxxxxxxx wrote: > > > > > Palmer, are you okay with merging RISC-V KVM? Or should we place it in > > > drivers/staging/riscv/kvm? > > > > I'm certainly ready to drop my objections to merging the code based on > > it targeting a draft extension, but at a bare minimum I want to get a > > new policy in place that everyone can agree to for merging code. I've > > tried to draft up a new policy a handful of times this week, but I'm not > > really quite sure how to go about this: ultimately trying to build > > stable interfaces around an unstable ISA is just a losing battle. I've > > got a bunch of stuff going on right now, but I'll try to find some time > > to actually sit down and finish one. > > > > I know it might seem odd to complain about how slowly things are going > > and then throw up another roadblock, but I really do think this is a > > very important thing to get right. I'm just not sure how we're going to > > get anywhere with RISC-V without someone providing stability, so I want > > to make sure that whatever we do here can be done reliably. If we don't > > I'm worried the vendors are just going to go off and do their own > > software stacks, which will make getting everyone back on the same page > > very difficult. > > I sympathize with Paolo, Anup, and others also. Especially Anup, who has > been updating and carrying the hypervisor patches for a long time now. > And also Greentime, who has been carrying the V extension patches. The > RISC-V hypervisor specification, like several other RISC-V draft > specifications, is taking longer to transition to the officially "frozen" > stage than almost anyone in the RISC-V community would like. > > Since we share this frustration, the next questions are: > > - What are the root causes of the problem? > > - What's the right forum to address the root causes? > > To me, the root causes of the problems described in this thread aren't > with the arch/riscv kernel maintenance guidelines, but rather with the > RISC-V specification process itself. And the right forum to address > issues with the RISC-V specification process is with RISC-V International > itself: the mailing lists, the participants, and the board of directors. > Part of the challenge -- not simply with RISC-V, but with the Linux kernel > or any other community -- is to ensure that incentives (and disincentives) > are aligned with the appropriately responsible parts of the community. > And when it comes to specification development, the right focus to align > those incentives and disincentives is on RISC-V International. > > The arch/riscv patch acceptance guidelines are simply intended to ensure > that the definition of what is and isn't RISC-V remains clear and > unambiguous. Even though the guidelines can result in short-term pain, > the intention is to promote long-term stability and sustainable > maintainability - particularly since the specifications get baked into > hardware. We've observed that attempting to chase draft specifications > can cause significant churn: for example, the history of the RISC-V vector > specification illustrates how a draft extension can undergo major, > unexpected revisions throughout its journey towards ratification. One of > our responsibilities as kernel developers is to minimize that churn - not > simply for our own sanity, or for the usability of RISC-V, but to ensure > that we remain members in good standing of the broader kernel community. > Those of us who were around for the ARM32 and ARM SoC kernel accelerando > absorbed strong lessons in maintainability, and I doubt anyone here is > interested in re-learning those the hard way. > > RVI states that the association is open to community participation. The > organizations that have joined RVI, I believe, have a strong stake in the > health of the RISC-V ecosystem, just as the folks have here in this > discussion. If the goal really is to get quality specifications out the > door faster, then let's focus the energy towards building consensus > towards improving the process at RISC-V International. If that's > possible, the benefits won't only accrue to Linux developers, but to the > entire RISC-V hardware and software development community at large. If > nothing else, it will be an interesting test of whether RISC-V > International can take action to address these concerns and balance them > with those of other stakeholders in the process. > > > - Paul
