On 6/25/2026 6:41 PM, Alistair Francis wrote: > On Wed, Jun 24, 2026 at 5:18 AM Pierrick Bouvier > <[email protected]> wrote: >> >> On 6/23/2026 12:01 PM, Daniel Henrique Barboza wrote: >>> >>> >>> On 6/23/2026 1:10 PM, Pierrick Bouvier wrote: >>>> On 6/23/2026 4:38 AM, Daniel Henrique Barboza wrote: >>>>> >>>>> >>>>> On 6/23/2026 6:58 AM, Peter Maydell wrote: >>>>>> On Tue, 23 Jun 2026 at 10:49, Daniel Henrique Barboza >>>>>> <[email protected]> wrote: >>>>>>> >>>>>>> >>>>>>> >>>>>>> On 6/22/2026 6:34 PM, Pierrick Bouvier wrote: >>>>>>>> On 6/22/2026 2:23 PM, Philippe Mathieu-Daudé wrote: >>>>>>>>> On 22/6/26 22:52, Pierrick Bouvier wrote: >>>>>>>>>> On 6/22/2026 12:31 PM, Daniel Henrique Barboza wrote: >>>>>>>>>>> Hello, >>>>>>>>>>> >>>>>>>>>>> This series looks scary but it's mostly trivial and mechanical >>>>>>>>>>> work. >>>>>>>>>>> >>>>>>>>>>> It is yet another attempt at fixing --disable-tcg. We have a >>>>>>>>>>> recent >>>>>>>>>>> work sent to the ML [1] and we had Phil's attempt back in 2023 >>>>>>>>>>> [2]. >>>>>>>>>>> Phil's work didn't get merged and it's now too hard to rebase and >>>>>>>>>>> revive, the most recent attempt got misled into the 'what is >>>>>>>>>>> common code >>>>>>>>>>> between TCG and KVM' dungeon. >>>>>>>>> >>>>>>>>> >>>>>>>>>> It seems like series does not apply on top of master, would that be >>>>>>>>>> possible to rebase it? >>>>>>>>> >>>>>>>>> For some reason the RISC-V series are handled distinctly than the >>>>>>>>> rest of QEMU, Alistair queues work on his repository and developers >>>>>>>>> are custome to base their series on top of it (otherwise Alistair >>>>>>>>> can not apply them on his tree and asks for reposts), see the >>>>>>>>> riscv-to-apply.next branch on https://github.com/alistair23/qemu. >>>>>>>> >>>>>>>> Unfortunately, it makes it hard to run any kind of automated testing, >>>>>>>> especially for series like this that target specific configs. >>>>>>> >>>>>>> Don't we have ways of saying in the commit message "these patches >>>>>>> applies >>>>>>> on top of these other patches" and then the tooling would deal with >>>>>>> it? >>>>>>> I remember patchew doing stuff like that with that "Based-on: >>>>>>> <message-id>" >>>>>>> tag. >>>>>> >>>>>> Yes, Based-on: is our convention for marking "this patchset needs some >>>>>> other one to be applied first". But that should be the exception rather >>>>>> than a common case -- if patchsets regularly need to be based on >>>>>> something other than head-of-git, this is I think a sign that >>>>>> maintainers are not sending out pull requests frequently enough. >>>>>> >>>>>> I would prefer it if QEMU didn't develop kernel-style "subsystems >>>>>> have their own particular workflows" fragmentation -- I don't >>>>>> think we're big enough or that sub-parts of QEMU are sufficiently >>>>>> well separated for it to work out well. >>>>> >>>>> I agree that rebasing things on master is better than rebasing it on the >>>>> maintainer's tree. And we could make a better job at informing >>>>> developers that >>>>> submitting a patch for qemu-riscv, vfio or any particular subtree, means >>>>> that >>>>> the patch should be based on a maintainer tree X. >>>>> >>>>> The thing is that sending patches on master only works if master is >>>>> always up >>>>> to date, and that's not feasible with our current style of merging PRs. >>>>> This >>>>> series we're commenting on is an example: it doesn't apply to master >>>>> because >>>>> there are pre-approved RISC-V patches in the maintainer's tree from 2 >>>>> days ago >>>>> (also my patches, I might add) that caused conflicts that I wasn't aware >>>>> that >>>>> would happen. This conflict would have to be dealt with at some point >>>>> by myself >>>>> or the maintainer, and it's not like 2 days is too much time without >>>>> a PR. >>>>> >>>>> We can argue "this is an exception that doesn't happen that often, we >>>>> should >>>>> stick with using master as a base", and to a certain extend that's >>>>> true. But >>>>> then this sort of conflict happens again, then again, then again, it >>>>> comes to >>>>> a point where it's easier to tell developers to use the maintainer's >>>>> tree instead >>>>> of master. >>>>> >>>>> Maybe I'm downplaying the problem because I've been sending stuff based >>>>> on the >>>>> maintainer's tree since forever and got used to it. IMO, unless we >>>>> decide to be >>>>> like libvirt and create the "committer" role to allow trustworthy devs >>>>> to push >>>>> stuff to master after acks, making it more feasible to expect master to >>>>> be up to >>>>> date, I'm afraid we're closer to a kernel-style workflow. For better or >>>>> worse. >>>>> >>>>> >>>>> Thanks, >>>>> Daniel >>>>> >>>>> >>>>>> >>>>>> thanks >>>>>> -- PMM >>>>> >>>> >>>> In this very specific case, where base patches are needed, maybe it >>>> would be better to make the required commits appear in this series, and >>>> mention in cover letter that patches 1-N are just coming from another >>>> series and are already reviewed/approved. IMHO it doesn't hurt, and >>>> reviewers are free to skip commits already reviewed. >>> >>> That's fair enough but I wonder if that won't scare people away with >>> even bigger series :D in this case here I would need to either send all >>> the queued patches, making the series go to 40+, or I would need to triage >>> which patches from the queue creates a conflict with this work and send >>> only those. >>> >>> Now, as for qemu-ci ... How farfetched it is to make it read a specific >>> tag >>> in the cover-letter, e.g. "branch-id", that can point to a gitlab/github >>> repo with the patches, and use that code base instead of applying the >>> patches to the master branch? Then for the next version of this work >>> I could do >>> >>> "branch-id: https://gitlab.com/danielhb/qemu/-/tree/riscv_disabletcg_v2"; >>> >> >> Based-on: is a QEMU specific tag, that is only understood by patchew, >> and no other tool to my knowledge. >> b4 has base_commit, which allows to give a specific base, but not a >> specific repository. I'm not aware of any b4 tag that allows to mention >> a base series. It makes sense, series are not branches, and stacking >> them comes with a lot of problems. >> >> So it seems like email workflow is quite limited in this regard, and the >> only way to deal with it properly is to wait for base patches to be >> merged, or include them in the series. >> >> From another perspective, the same problem would exist if we would use a >> forge like GitHub or GitLab. It's not possible to stack PR on top of >> others, and only solution is to wait, or duplicate patches. IMHO, it's a >> sane default, as it forces correct ordering instead of allowing chaotic >> development. >> >>> and the tool would still work. If there's no "branch-id" then it assumes >>> that the patches are to be applied on master. >>> >>> >>> And yeah, in an ideal world the problem goes away if we just do more PRs >>> and >>> strive to keep 'master' updated. I'm just thinking out loud about possible >>> alternatives until we reach that point. > > When you sent v2 of this series it had been one week since the last > RISC-V PR. Are we really aiming for more than one PR a week? > >>> >>> >>> Cheers, >>> Daniel >>> >>>> >>>> Or, a solution I'm not fond of but I ended up adopting most of the time, >>>> just wait for required patches to be merged on master before posting the >>>> series, and work on something else meanwhile. > > I do feel that a few people do that, just not Daniel :) >
Waiting works well if you know the wait period is deterministic. "Ok, I missed this train, let me catch the one next week". Unfortunately, it varies per maintainer, and some are even stochastic processes on their own. I can't blame people who submit and are not maintainer to feel frustration with this, it's a real issue. > Alistair > >>>> >>>> Ideally, yes, it would be better if maintainers could send PR more >>>> frequently to avoid creating those intermediate staging trees. The >>>> faster we merge, the less conflicts we'll have. >>>> >>>> Regards, >>>> Pierrick >>> >> >>
