- Linaro-open-discussions - op-lists.linaro.org

Re: [Linaro-open-discussions] Suggested Agenda / timings for Monday 7 Dec call

by Vincent Guittot

On Tue, 8 Dec 2020 at 18:02, Lorenzo Pieralisi via Linaro-open-discussions <linaro-open-discussions(a)op-lists.linaro.org> wrote: > > On Thu, Dec 03, 2020 at 01:40:55PM +0000, Jonathan Cameron wrote: > > > > Hi All, > > > > The previous thread has gotten rather convoluted, so I'm going to have a go at extracting > > a brief summary of topics and suggesting some straw man timings. > > These are all discussion topics, so name just indicates who I think will do the intro. > > Note I'd suggest we keep fairly tightly to timings and if it looks like a particular > > conversation is going long, we schedule a follow up. > > Hi Jonathan, all, > > thanks for the sync-up yesterday, I have already started following up > on some topics (ACPI CPU hotplug). > > I would like to put forward this topic for the next meeting agenda: > > https://lore.kernel.org/linux-acpi/20201201025944.18260-1-song.bao.hua@hisi… > > I think it is a discussion that would benefit from a conference like > discussion to add to mailing list discussions that already took place. I agree. > > Please let me know if that's feasible. > > Thanks, > Lorenzo > > > VLPI Migration support on Gic V4.1: lushenming (Huawei) - 15 mins > > Topic requested by Lorenzo Pieralisi (ARM) > > In GICv4.1, migration has been supported except for (directly-injected) > > VLPI. And GICv4.1 spec explicitly gives a way to get the VLPI's pending > > state (which was crucially missing in GICv4.0). So we make VLPI migration > > capable on GICv4.1 in this patch set. > > (5 min) Intro to the work, then questions (10 min). > > > > vCPU HP: Salil Mehta (Huawei) 25 mins. > > Lorenzo has questions + it's an expansive topic. > > I would suggest interested people catch up with slides from KVM forum 2020 > > https://kvmforum2020.sched.com/event/eE4m/challenges-in-supporting-virtual-… (video not public yet) > > (5 min) Open questions statement, then move to discussion. > > > > RMR related topics - follow up on last call: Lorenzo Pieralisi (ARM) - 5 mins > > There were outstanding questions around whether PCIe reenumeration could > > cause problems here. > > (Lorenzo, Shameer, there were a few other open questions around this topic, > > do we have any other updates for Monday?) > > > > Generic Initiators: Jonathan Cameron (Huawei) - 5 mins > > Very brief intro to GIs + current status + opening for questions. > > More detail etc in this email. > > https://op-lists.linaro.org/pipermail/linaro-open-discussions/2020-November… > > > > Ideally slides should go to Mike in advance to upload to the collaborate page. > > > > Anything I've missed? > > > > Thanks, > > > > Jonathan > > > -- > Linaro-open-discussions mailing list > https://collaborate.linaro.org/display/LOD/Linaro+Open+Discussions+Home > https://op-lists.linaro.org/mailman/listinfo/linaro-open-discussions

5 years, 3 months

1
0
0 0

Re: [Linaro-open-discussions] QEMU's next v8-A emulation model

by Jerome Forissier

On 12/3/20 10:21 PM, Alex Bennée via Linaro-open-discussions wrote: > > Hi, > > There has been some discussion on the card QEMU-414: > > https://projects.linaro.org/browse/QEMU-414 > > about adding another CPU model to QEMU that is somewhat more advanced > than the current v8.0 offerings but isn't quite the rolling "all the ARM > you can eat" -cpu max. So far the primary interest I'm aware of has come > from people working on the SBSA and BSA reference platforms who want to > have something with a few more features than the base v8.0 spec which we > have covered. Perhaps more related to '-cpu max' than to what you're asking specifically, but what about S-EL2 support? One day or another it could come in handy for OP-TEE testing and debugging for instance. Thanks, -- Jerome

5 years, 3 months

3
2
0 0

SCMI server in TEE

by Vincent Guittot

Hi All, A meeting about the SCMI server is scheduled Wednesday, Dec 9th. Among the topics, we will discuss how to abstract SCP-firmware on different Os and enable multiple event queues in single threaded mode. All details to join the meeting can be found here: https://collaborate.linaro.org/display/SCMI Regards, Vincent

5 years, 3 months

1
0
0 0

Re: [Linaro-open-discussions] Notes on Linaro Open Discussions meeting 4 Nov 2020

by Lorenzo Pieralisi

On Thu, Nov 26, 2020 at 08:47:45AM +0000, Jonathan Cameron wrote: > Hi Mike, > > > > lushenming is happy to present / discuss the topic Lorenzo requested. > > > > https://lore.kernel.org/linux-arm-kernel/ > 20201123065410.1915-1-lushenming(a)huawei.com > > For agenda list please add “VLPI Migration support on Gic V4.1” Thanks ! > Lorenzo also mentioned he had an update on > > “Use of BDF to identify PCI devices in ACPI tables” > > which I’d definitely like to be on the agenda. On this it is rather that I had the IORT specs firmed up so the bus re-enumeration is not a problem anymore. Side note: I noticed that in x86 world RMR the PCI topology is described hierarchically with dev-function pairs starting from the root bus but we don't want to go that way in IORT - I don't necessarily see a reason for that. Let's speak. > Final topic that has been discussed for inclusion is > > “vCPU hotplug” > > Let’s move that up to confirmed topics. Yes. I have a couple of questions on this topic so we can and probably should move it up the agenda because they can take some time. Lorenzo > It’s going to be a full agenda, so I suggest we try to share slides in advance > and we keep > > to a fairly tight schedule! > > > > For those doing slides, I assume best approach is email them to you Mike and > you upload > > them to the collaborate page? Perhaps if people could also let Mike know > expected time > > needed (always a guess) then we can decide to spill some topics to a future > meeting or > > email discussion if necessary. > > > > Thanks, > > > > Jonathan > > > > > > From: Mike Holmes [mailto:mike.holmes@linaro.org] > Sent: 26 November 2020 07:28 > To: Jonathan Cameron <jonathan.cameron(a)huawei.com> > Cc: Lorenzo Pieralisi <lorenzo.pieralisi(a)arm.com>; > linaro-open-discussions(a)op-lists.linaro.org > Subject: Re: [Linaro-open-discussions] Notes on Linaro Open Discussions meeting > 4 Nov 2020 > > > > I see a lot of new subscriptions to the list - welcome. > > Here is the updated meeting slot poll for the week of December 7th to December > 12th > > https://doodle.com/poll/sgy9esiim4rapitz?utm_source=poll&utm_medium=link > > > > Agenda > > https://collaborate.linaro.org/display/LOD/Linaro+Open+Discussions+Home > > > > > > > > On Wed, Nov 25, 2020 at 4:14 PM Jonathan Cameron <Jonathan.Cameron(a)huawei.com> > wrote: > > On Wed, 25 Nov 2020 16:05:51 +0000 > Mike Holmes <mike.holmes(a)linaro.org> wrote: > > > On Wed, Nov 25, 2020 at 4:01 PM Lorenzo Pieralisi via > > Linaro-open-discussions <linaro-open-discussions(a)op-lists.linaro.org> > wrote: > > > > > On Wed, Nov 25, 2020 at 03:22:19PM +0000, Jonathan Cameron wrote: > > > > On Wed, 25 Nov 2020 13:58:38 +0000 > > > > Lorenzo Pieralisi <lorenzo.pieralisi(a)arm.com> wrote: > > > > > > > > > On Wed, Nov 25, 2020 at 12:51:49PM +0000, Jonathan Cameron wrote: > > > > > > > > > > [...] > > > > > > > > > > > > Is December 2nd confirmed as next session ? If possible 3PM > GMT > > > works > > > > > > > better for me; the NUMA topic raised by Jonathan is another > > > interesting > > > > > > > topic for debate. > > > > > > > > > > > > Just to check, which NUMA topic? > > > > > > > > > > > > > https://op-lists.linaro.org/pipermail/linaro-open-discussions/ > 2020-November/000016.html > > > > > > > > > > It would be useful (for me certainly) if you can give an update on > > > > > what's still pending in the items in the discussion above (eg it is > > > > > not clear what the "PCI fix" is) + how it is linked to CXL. > > > > > > > > Sure, that should be a fairly short topic, but I'm happy to try to > fill > > > in the gaps. > > > > @Mike, can you add "Generic initiators - pending items" to the > agenda. > > > > > > > > For the PCI 'fix' it is this one that got applied and then reverted > in > > > 4.20 timeframe > > > > > > > http://patchwork.ozlabs.org/project/linux-pci/patch/ > 20180912152140.3676-2-Jonathan.Cameron(a)huawei.com/ > > > > I've not rebased or tested it recently so I'll check that it still > > > appears to be right > > > > before the call. > > > > > > > > > > > > > > The vCPU hotplug is also worth adding (even though I do not know > what > > > > > was discussed at KVM forum). > > > > > > > > I was just about to email about that one. From our side, all that > is > > > currently > > > > going on around vCPU Hotplug is a rebase. At KVM forum Mark R > kindly > > > offered > > > > to see if he could find out answers to a few open questions. > Perhaps > > > catch > > > > up with Mark, or see if he can make the call? > > > > > > Ok, will catch up with him, it is probably better if I have some time > > > to do it (ie postpone the call for a week). > > > > > > > > Furthermore, I am keen on discussing this: > > > > > > > > > > > > > https://lore.kernel.org/linux-arm-kernel/ > 20201123065410.1915-1-lushenming(a)huawei.com > > > > > > > > > > if the submitters are available, it would help to get some context > in > > > > > relation to upstream discussions. > > > > > > > > I've messaged lushenming so hopefully we can sort out something on > that > > > front. > > > > > > > > Looks like finding a time next week is proving challenging. If that > > > > fails, perhaps we should try for the week after? > > > > > > Yes we can, it would be easier to prepare the topics and find a > suitable > > > day as well, next week it looks like it is challenging. It would also > > > give us some time to extend the invite. > > > > > > Please let me know and apologies to Mike for all these emails to get it > > > organized. > > > > > > > No problem, as soon as it is confirmed we want to try for the following > > week I can set up a poll to pick the day and hour > > Definitely sounds like a better plan. Fingers crossed people have slightly > more open schedules that week! > > Thanks for sorting this out Mike. > > Jonathan > > > > > > > > > > > Thanks, > > > Lorenzo > > > > > > > Thanks, > > > > > > > > Jonathan > > > > > > > > > > > > > > > > > > Thanks ! > > > > > Lorenzo > > > > > > > > > > > I've lost track of what we are talking about. > > > > > > > > > > > > > Other than that we can slot in the topics that > > > > > > > weren't discussed last time: > > > > > > > > > > > > > > > > > https://collaborate.linaro.org/display/LOD/Linaro+Open+Discussions+Home > > > > > > > > > > > > > > > even though those require a bit of preparation so the sooner > we > > > finalize > > > > > > > the schedule the better. > > > > > > > > > > > > Seems we have clashed with some internal Huawei activities so > some > > > people who > > > > > > would normally be active are snowed under this week. > > > > > > > > > > > > Jonathan > > > > > > > > > > > > > > > > > > > > Please let me know, thanks. > > > > > > > > > > > > > > Lorenzo > > > > > > > > > > > > > > > * DT alignment. Don't want different solutions for each > firmware > > > type. > > > > > > > > * Lorenzo / Sami to check IORT revision E is final. > > > > > > > > > > > > > > > > SVA > > > > > > > > === > > > > > > > > > > > > > > > > Zangfei gave summary: > > > > > > > > - Huawei has devices that are not PCIe but are presented as > > > such. > > > > > > > > - They support stall mode for SVA (spec violation) > > > > > > > > - Resistance from kernel maintainers to maintaining a white > > > list for any quirk. Fine to fix > > > > > > > > it once (JPB), but not to keep doing so. > > > > > > > > - Note that stall mode not yet supported at all (JPB to > send > > > out this cycle). > > > > > > > > - If longer term fix need add can't be done via PCISIG etc > then > > > need to convince > > > > > > > > PCI and SMMU maintainers. Noted that quirk is very > little > > > code. > > > > > > > > > > > > > > > > * Other SVA topics. > > > > > > > > - Mentioned virtual SVA (no actually problems just > expressing > > > interest!) > > > > > > > > - Would need Eric Auger, wasn't on topic list so Eric not > on > > > call. > > > > > > > > > > > > > > > > AI: Nothing planned until after JPB has upstreamed stall > mode. > > > Hard to have discussion before that. > > > > > > > > > > > > > > > > DVFS > > > > > > > > ==== > > > > > > > > > > > > > > > > guohanjun > > > > > > > > > > > > > > > > Solutions exist for > > > > > > > > * CPU DVFS (voltage + frequency scaling) > > > > > > > > * PCIe device power states etc > > > > > > > > > > > > > > > > No standard way of controlling Uncore voltage and frequency > for > > > ACPI based systems. > > > > > > > > > > > > > > > > 3 options: > > > > > > > > 1. MMIO / kernel driver. > > > > > > > > 2. PSCI via trusted firmware and system management > controller. > > > > > > > > 3. ACPI (wrapping up an op region and SCMI) > > > > > > > > > > > > > > > > Clarifications / discussions. > > > > > > > > * Vincent G: Power states, or voltage frequency of interest? > > > > Ans Voltage Freq > > > > > > > > * Considered SCMI? Ans: Works only for DT as SCMI under > ACPI > > > is wrapped up in AML > > > > > > > > so looks like an ACPI interface. > > > > > > > > * Sudeep H: Necessary to trace CPU freq? Yes. > > > > > > > > * Sudeep H: Why not do it in firmware entirely? Ans. Not > just > > > CPU. For example PCI device accessing > > > > > > > > memory may well need the ring bus to be fast. > > > > > > > > * Vincent G: Bandwidth affected? Yes. VG: mobile does this > by > > > specifying a BW requirement (via SCMI.- > > > > > > > > * Sudeep H Observed need to expose it via ACPI spec. (option > 3 > > > above). > > > > > > > > * Sudeep H: Does PCI also need fine-grain control? We might > > > need to add to the spec. > > > > > > > > * Sudeep H: What are the requirements? gaohanjun: Now we > just > > > frequency scaling. > > > > > > > > * Jonathan C: Noted PCI power state is not enough. It's > > > workload dependent. > > > > > > > > * Sudeep H: We need to gather all the info, need to talk in > > > ASWG about DVFS > > > > > > > > * Jonathan C: For now direct control probably makes sense. > > > Whilst it would be nice to have > > > > > > > > a detailed enough system description in a standard way to > > > make general software that is a > > > > > > > > big spec job. > > > > > > > > * Jonathan C: Seems like true standard SW will not happen > any > > > time soon. > > > > > > > > > > > > > > > > AI: RFC to the linux-pm / linux-acpi Rafael and those in > this > > > discussion to ask about > > > > > > > > interest in adding per device DVFS to ACPI spec. > Possibly > > > pursue code first ACPI > > > > > > > > approach. > > > > > > > > > > > > > > > > If I've miss listed or "volunteered" anyone for AIs they > didn't > > > agree to then please > > > > > > > > correct that. > > > > > > > > > > > > > > > > Thanks all for contributions. I for one found it a very > useful > > > call! > > > > > > > > > > > > > > > > Jonathan > > > > > > > > > > > > > > > > > > > > > > > > -- > > > > > > > > Linaro-open-discussions mailing list > > > > > > > > > > > https://collaborate.linaro.org/display/LOD/Linaro+Open+Discussions+Home > > > > > > > > > > > > https://op-lists.linaro.org/mailman/listinfo/linaro-open-discussions > > > > > > > > > > > > > -- > > > Linaro-open-discussions mailing list > > > https://collaborate.linaro.org/display/LOD/Linaro+Open+Discussions+Home > > > https://op-lists.linaro.org/mailman/listinfo/linaro-open-discussions > > > > > > > > > > > > -- > > Mike Holmes | Director, Foundation Technologies, Linaro > > Mike.Holmes(a)linaro.org > > "Work should be fun and collaborative, the rest follows" > > > >

5 years, 3 months

1
0
0 0

linaro open discussion : Kernel topics Ageda

by Mike Holmes

Confirmed topics - Lorenzo - IORT - Reserve memory regions (RMR) and the RMR flags to free up IOVA. - Jonathon - Generic initiators - pending items - lushenming - VLPI Migration support on Gic V4.1 https://lore.kernel.org/linux-arm-kernel/20201123065410.1915-1-lushenming@h… - Jonathon - Use of BDF to identify PCI devices in ACPI tables - Jonathon - vCPU hotplug https://collaborate.linaro.org/display/LOD/2020-12-07+Meeting+Meeting+notes <https://collaborate.linaro.org/display/LOD/2020-12-07+Meeting+Meeting+notes> ------------------------------------------------------ Topic: linaro-open-discussion meeting Time: Dec 7, 2020 02:00 PM London Join Zoom Meeting https://linaro-org.zoom.us/j/4417312160 Meeting ID: 441 731 2160 One tap mobile +16465588656,,4417312160# US (New York) +16699009128,,4417312160# US (San Jose) Dial by your location +1 646 558 8656 US (New York) +1 669 900 9128 US (San Jose) +1 253 215 8782 US (Tacoma) +1 301 715 8592 US (Washington D.C) +1 312 626 6799 US (Chicago) +1 346 248 7799 US (Houston) 877 853 5247 US Toll-free 888 788 0099 US Toll-free Meeting ID: 441 731 2160 Find your local number: https://linaro-org.zoom.us/u/aUcYpPkSC -- Mike Holmes | Director, Foundation Technologies, Linaro Mike.Holmes(a)linaro.org <mike.holmes(a)linaro.org> "Work should be fun and collaborative, the rest follows"

5 years, 3 months

1
0
0 0

Re: [Linaro-open-discussions] Notes on Linaro Open Discussions meeting 4 Nov 2020

by Lorenzo Pieralisi

On Fri, Nov 27, 2020 at 02:50:28PM +0000, Mike Holmes via Linaro-open-discussions wrote: > Ok the doodle poll appears to favour Monday, December 2nd at 2 pm GMT, I > will set up a call for then Monday Dec 7th right ? Thank you very much. Lorenzo > > *Poll "Linaro open discussion meeting time"* > > > > > > > > > https://doodle.com/poll/sgy9esiim4rapitz > > > > > > > > > > > > > > > > > > > > December 2020 > > Mon 7 Tue 8 Wed 9 Thu 10 > > 14:00 – 15:00 15:00 – 16:00 16:00 – 17:00 17:00 – 18:00 17:00 – 18:00 15:00 > – 16:00 16:00 – 17:00 17:00 – 18:00 13:00 – 14:00 > Loic (ST) OK OK > OK > OK OK > > Lorenzo Pieralisi OK OK OK OK OK (OK) (OK) > OK > Jonathan Cameron (Huawei) OK OK OK OK OK OK OK OK OK > Shenming Lu OK OK (OK) (OK) (OK) OK (OK) (OK) OK > Count 4:0:0 4:0:0 2:1:1 3:1:0 2:1:1 3:1:0 2:2:0 1:1:2 3:0:1 > > On Thu, Nov 26, 2020 at 9:01 AM Mike Holmes via Linaro-open-discussions < > linaro-open-discussions(a)op-lists.linaro.org> wrote: > > > Will do. > > > > On Thu, Nov 26, 2020 at 8:58 AM Jonathan Cameron < > > jonathan.cameron(a)huawei.com> wrote: > > > > > Sorry all. Accidental HTML email and also seems list has very tight > > > constraints on size. > > > > > > @Mike can we get those relaxed somewhat as we might sometimes end up with > > > patches > > > going via this list. > > > > > > From: Jonathan Cameron > > > Sent: 26 November 2020 08:47 > > > To: 'Mike Holmes' <mike.holmes(a)linaro.org> > > > Cc: Lorenzo Pieralisi <lorenzo.pieralisi(a)arm.com>; > > > linaro-open-discussions(a)op-lists.linaro.org; lushenming < > > > lushenming(a)huawei.com> > > > Subject: RE: [Linaro-open-discussions] Notes on Linaro Open Discussions > > > meeting 4 Nov 2020 > > > > > > Hi Mike, > > > > > > lushenming is happy to present / discuss the topic Lorenzo requested. > > > > > > > > > > > https://lore.kernel.org/linux-arm-kernel/20201123065410.1915-1-lushenming@h… > > > > > > For agenda list please add “VLPI Migration support on Gic V4.1” > > > > > > Lorenzo also mentioned he had an update on > > > “Use of BDF to identify PCI devices in ACPI tables” > > > which I’d definitely like to be on the agenda. > > > > > > Final topic that has been discussed for inclusion is > > > “vCPU hotplug” > > > Let’s move that up to confirmed topics. > > > > > > It’s going to be a full agenda, so I suggest we try to share slides in > > > advance and we keep > > > to a fairly tight schedule! > > > > > > For those doing slides, I assume best approach is email them to you Mike > > > and you upload > > > them to the collaborate page? Perhaps if people could also let Mike know > > > expected time > > > needed (always a guess) then we can decide to spill some topics to a > > > future meeting or > > > email discussion if necessary. > > > > > > Thanks, > > > > > > Jonathan > > > > > > > > > From: Mike Holmes [mailto:mike.holmes@linaro.org] > > > Sent: 26 November 2020 07:28 > > > To: Jonathan Cameron <jonathan.cameron(a)huawei.com> > > > Cc: Lorenzo Pieralisi <lorenzo.pieralisi(a)arm.com>; > > > linaro-open-discussions(a)op-lists.linaro.org > > > Subject: Re: [Linaro-open-discussions] Notes on Linaro Open Discussions > > > meeting 4 Nov 2020 > > > > > > I see a lot of new subscriptions to the list - welcome. > > > Here is the updated meeting slot poll for the week of December 7th to > > > December 12th > > > https://doodle.com/poll/sgy9esiim4rapitz?utm_source=poll&utm_medium=link > > > > > > Agenda > > > https://collaborate.linaro.org/display/LOD/Linaro+Open+Discussions+Home > > > > > > > > > > > > > > > > > > > -- > > Mike Holmes | Director, Foundation Technologies, Linaro > > Mike.Holmes(a)linaro.org <mike.holmes(a)linaro.org> > > "Work should be fun and collaborative, the rest follows" > > -- > > Linaro-open-discussions mailing list > > https://collaborate.linaro.org/display/LOD/Linaro+Open+Discussions+Home > > https://op-lists.linaro.org/mailman/listinfo/linaro-open-discussions > > > > > -- > Mike Holmes | Director, Foundation Technologies, Linaro > Mike.Holmes(a)linaro.org <mike.holmes(a)linaro.org> > "Work should be fun and collaborative, the rest follows" > -- > Linaro-open-discussions mailing list > https://collaborate.linaro.org/display/LOD/Linaro+Open+Discussions+Home > https://op-lists.linaro.org/mailman/listinfo/linaro-open-discussions

5 years, 3 months

2
1
0 0

Re: [Linaro-open-discussions] Notes on Linaro Open Discussions meeting 4 Nov 2020

by Mike Holmes

Ok the doodle poll appears to favour Monday, December 2nd at 2 pm GMT, I will set up a call for then *Poll "Linaro open discussion meeting time"* https://doodle.com/poll/sgy9esiim4rapitz December 2020 Mon 7 Tue 8 Wed 9 Thu 10 14:00 – 15:00 15:00 – 16:00 16:00 – 17:00 17:00 – 18:00 17:00 – 18:00 15:00 – 16:00 16:00 – 17:00 17:00 – 18:00 13:00 – 14:00 Loic (ST) OK OK OK OK OK Lorenzo Pieralisi OK OK OK OK OK (OK) (OK) OK Jonathan Cameron (Huawei) OK OK OK OK OK OK OK OK OK Shenming Lu OK OK (OK) (OK) (OK) OK (OK) (OK) OK Count 4:0:0 4:0:0 2:1:1 3:1:0 2:1:1 3:1:0 2:2:0 1:1:2 3:0:1 On Thu, Nov 26, 2020 at 9:01 AM Mike Holmes via Linaro-open-discussions < linaro-open-discussions(a)op-lists.linaro.org> wrote: > Will do. > > On Thu, Nov 26, 2020 at 8:58 AM Jonathan Cameron < > jonathan.cameron(a)huawei.com> wrote: > > > Sorry all. Accidental HTML email and also seems list has very tight > > constraints on size. > > > > @Mike can we get those relaxed somewhat as we might sometimes end up with > > patches > > going via this list. > > > > From: Jonathan Cameron > > Sent: 26 November 2020 08:47 > > To: 'Mike Holmes' <mike.holmes(a)linaro.org> > > Cc: Lorenzo Pieralisi <lorenzo.pieralisi(a)arm.com>; > > linaro-open-discussions(a)op-lists.linaro.org; lushenming < > > lushenming(a)huawei.com> > > Subject: RE: [Linaro-open-discussions] Notes on Linaro Open Discussions > > meeting 4 Nov 2020 > > > > Hi Mike, > > > > lushenming is happy to present / discuss the topic Lorenzo requested. > > > > > > > https://lore.kernel.org/linux-arm-kernel/20201123065410.1915-1-lushenming@h… > > > > For agenda list please add “VLPI Migration support on Gic V4.1” > > > > Lorenzo also mentioned he had an update on > > “Use of BDF to identify PCI devices in ACPI tables” > > which I’d definitely like to be on the agenda. > > > > Final topic that has been discussed for inclusion is > > “vCPU hotplug” > > Let’s move that up to confirmed topics. > > > > It’s going to be a full agenda, so I suggest we try to share slides in > > advance and we keep > > to a fairly tight schedule! > > > > For those doing slides, I assume best approach is email them to you Mike > > and you upload > > them to the collaborate page? Perhaps if people could also let Mike know > > expected time > > needed (always a guess) then we can decide to spill some topics to a > > future meeting or > > email discussion if necessary. > > > > Thanks, > > > > Jonathan > > > > > > From: Mike Holmes [mailto:mike.holmes@linaro.org] > > Sent: 26 November 2020 07:28 > > To: Jonathan Cameron <jonathan.cameron(a)huawei.com> > > Cc: Lorenzo Pieralisi <lorenzo.pieralisi(a)arm.com>; > > linaro-open-discussions(a)op-lists.linaro.org > > Subject: Re: [Linaro-open-discussions] Notes on Linaro Open Discussions > > meeting 4 Nov 2020 > > > > I see a lot of new subscriptions to the list - welcome. > > Here is the updated meeting slot poll for the week of December 7th to > > December 12th > > https://doodle.com/poll/sgy9esiim4rapitz?utm_source=poll&utm_medium=link > > > > Agenda > > https://collaborate.linaro.org/display/LOD/Linaro+Open+Discussions+Home > > > > > > > > > > > > -- > Mike Holmes | Director, Foundation Technologies, Linaro > Mike.Holmes(a)linaro.org <mike.holmes(a)linaro.org> > "Work should be fun and collaborative, the rest follows" > -- > Linaro-open-discussions mailing list > https://collaborate.linaro.org/display/LOD/Linaro+Open+Discussions+Home > https://op-lists.linaro.org/mailman/listinfo/linaro-open-discussions > -- Mike Holmes | Director, Foundation Technologies, Linaro Mike.Holmes(a)linaro.org <mike.holmes(a)linaro.org> "Work should be fun and collaborative, the rest follows"

5 years, 3 months

1
0
0 0

Re: [Linaro-open-discussions] Notes on Linaro Open Discussions meeting 4 Nov 2020

by Mike Holmes

On Wed, Nov 25, 2020 at 4:01 PM Lorenzo Pieralisi via Linaro-open-discussions <linaro-open-discussions(a)op-lists.linaro.org> wrote: > On Wed, Nov 25, 2020 at 03:22:19PM +0000, Jonathan Cameron wrote: > > On Wed, 25 Nov 2020 13:58:38 +0000 > > Lorenzo Pieralisi <lorenzo.pieralisi(a)arm.com> wrote: > > > > > On Wed, Nov 25, 2020 at 12:51:49PM +0000, Jonathan Cameron wrote: > > > > > > [...] > > > > > > > > Is December 2nd confirmed as next session ? If possible 3PM GMT > works > > > > > better for me; the NUMA topic raised by Jonathan is another > interesting > > > > > topic for debate. > > > > > > > > Just to check, which NUMA topic? > > > > > > > https://op-lists.linaro.org/pipermail/linaro-open-discussions/2020-November… > > > > > > It would be useful (for me certainly) if you can give an update on > > > what's still pending in the items in the discussion above (eg it is > > > not clear what the "PCI fix" is) + how it is linked to CXL. > > > > Sure, that should be a fairly short topic, but I'm happy to try to fill > in the gaps. > > @Mike, can you add "Generic initiators - pending items" to the agenda. > > > > For the PCI 'fix' it is this one that got applied and then reverted in > 4.20 timeframe > > > http://patchwork.ozlabs.org/project/linux-pci/patch/20180912152140.3676-2-J… > > I've not rebased or tested it recently so I'll check that it still > appears to be right > > before the call. > > > > > > > > The vCPU hotplug is also worth adding (even though I do not know what > > > was discussed at KVM forum). > > > > I was just about to email about that one. From our side, all that is > currently > > going on around vCPU Hotplug is a rebase. At KVM forum Mark R kindly > offered > > to see if he could find out answers to a few open questions. Perhaps > catch > > up with Mark, or see if he can make the call? > > Ok, will catch up with him, it is probably better if I have some time > to do it (ie postpone the call for a week). > > > > Furthermore, I am keen on discussing this: > > > > > > > https://lore.kernel.org/linux-arm-kernel/20201123065410.1915-1-lushenming@h… > > > > > > if the submitters are available, it would help to get some context in > > > relation to upstream discussions. > > > > I've messaged lushenming so hopefully we can sort out something on that > front. > > > > Looks like finding a time next week is proving challenging. If that > > fails, perhaps we should try for the week after? > > Yes we can, it would be easier to prepare the topics and find a suitable > day as well, next week it looks like it is challenging. It would also > give us some time to extend the invite. > > Please let me know and apologies to Mike for all these emails to get it > organized. > No problem, as soon as it is confirmed we want to try for the following week I can set up a poll to pick the day and hour > > Thanks, > Lorenzo > > > Thanks, > > > > Jonathan > > > > > > > > > > Thanks ! > > > Lorenzo > > > > > > > I've lost track of what we are talking about. > > > > > > > > > Other than that we can slot in the topics that > > > > > weren't discussed last time: > > > > > > > > > > > https://collaborate.linaro.org/display/LOD/Linaro+Open+Discussions+Home > > > > > > > > > > even though those require a bit of preparation so the sooner we > finalize > > > > > the schedule the better. > > > > > > > > Seems we have clashed with some internal Huawei activities so some > people who > > > > would normally be active are snowed under this week. > > > > > > > > Jonathan > > > > > > > > > > > > > > Please let me know, thanks. > > > > > > > > > > Lorenzo > > > > > > > > > > > * DT alignment. Don't want different solutions for each firmware > type. > > > > > > * Lorenzo / Sami to check IORT revision E is final. > > > > > > > > > > > > SVA > > > > > > === > > > > > > > > > > > > Zangfei gave summary: > > > > > > - Huawei has devices that are not PCIe but are presented as > such. > > > > > > - They support stall mode for SVA (spec violation) > > > > > > - Resistance from kernel maintainers to maintaining a white > list for any quirk. Fine to fix > > > > > > it once (JPB), but not to keep doing so. > > > > > > - Note that stall mode not yet supported at all (JPB to send > out this cycle). > > > > > > - If longer term fix need add can't be done via PCISIG etc then > need to convince > > > > > > PCI and SMMU maintainers. Noted that quirk is very little > code. > > > > > > > > > > > > * Other SVA topics. > > > > > > - Mentioned virtual SVA (no actually problems just expressing > interest!) > > > > > > - Would need Eric Auger, wasn't on topic list so Eric not on > call. > > > > > > > > > > > > AI: Nothing planned until after JPB has upstreamed stall mode. > Hard to have discussion before that. > > > > > > > > > > > > DVFS > > > > > > ==== > > > > > > > > > > > > guohanjun > > > > > > > > > > > > Solutions exist for > > > > > > * CPU DVFS (voltage + frequency scaling) > > > > > > * PCIe device power states etc > > > > > > > > > > > > No standard way of controlling Uncore voltage and frequency for > ACPI based systems. > > > > > > > > > > > > 3 options: > > > > > > 1. MMIO / kernel driver. > > > > > > 2. PSCI via trusted firmware and system management controller. > > > > > > 3. ACPI (wrapping up an op region and SCMI) > > > > > > > > > > > > Clarifications / discussions. > > > > > > * Vincent G: Power states, or voltage frequency of interest? > Ans Voltage Freq > > > > > > * Considered SCMI? Ans: Works only for DT as SCMI under ACPI > is wrapped up in AML > > > > > > so looks like an ACPI interface. > > > > > > * Sudeep H: Necessary to trace CPU freq? Yes. > > > > > > * Sudeep H: Why not do it in firmware entirely? Ans. Not just > CPU. For example PCI device accessing > > > > > > memory may well need the ring bus to be fast. > > > > > > * Vincent G: Bandwidth affected? Yes. VG: mobile does this by > specifying a BW requirement (via SCMI.- > > > > > > * Sudeep H Observed need to expose it via ACPI spec. (option 3 > above). > > > > > > * Sudeep H: Does PCI also need fine-grain control? We might > need to add to the spec. > > > > > > * Sudeep H: What are the requirements? gaohanjun: Now we just > frequency scaling. > > > > > > * Jonathan C: Noted PCI power state is not enough. It's > workload dependent. > > > > > > * Sudeep H: We need to gather all the info, need to talk in > ASWG about DVFS > > > > > > * Jonathan C: For now direct control probably makes sense. > Whilst it would be nice to have > > > > > > a detailed enough system description in a standard way to > make general software that is a > > > > > > big spec job. > > > > > > * Jonathan C: Seems like true standard SW will not happen any > time soon. > > > > > > > > > > > > AI: RFC to the linux-pm / linux-acpi Rafael and those in this > discussion to ask about > > > > > > interest in adding per device DVFS to ACPI spec. Possibly > pursue code first ACPI > > > > > > approach. > > > > > > > > > > > > If I've miss listed or "volunteered" anyone for AIs they didn't > agree to then please > > > > > > correct that. > > > > > > > > > > > > Thanks all for contributions. I for one found it a very useful > call! > > > > > > > > > > > > Jonathan > > > > > > > > > > > > > > > > > > -- > > > > > > Linaro-open-discussions mailing list > > > > > > > https://collaborate.linaro.org/display/LOD/Linaro+Open+Discussions+Home > > > > > > > https://op-lists.linaro.org/mailman/listinfo/linaro-open-discussions > > > > > > > -- > Linaro-open-discussions mailing list > https://collaborate.linaro.org/display/LOD/Linaro+Open+Discussions+Home > https://op-lists.linaro.org/mailman/listinfo/linaro-open-discussions > -- Mike Holmes | Director, Foundation Technologies, Linaro Mike.Holmes(a)linaro.org <mike.holmes(a)linaro.org> "Work should be fun and collaborative, the rest follows"

5 years, 3 months

3
4
0 0

Re: [Linaro-open-discussions] Notes on Linaro Open Discussions meeting 4 Nov 2020

by Mike Holmes

On Thu, Nov 26, 2020 at 8:47 AM Jonathan Cameron < jonathan.cameron(a)huawei.com> wrote: > Hi Mike, > > > > lushenming is happy to present / discuss the topic Lorenzo requested. > > > > > https://lore.kernel.org/linux-arm-kernel/20201123065410.1915-1-lushenming@h… > > > For agenda list please add “VLPI Migration support on Gic V4.1” > > > > Lorenzo also mentioned he had an update on > > “Use of BDF to identify PCI devices in ACPI tables” > > which I’d definitely like to be on the agenda. > > > > Final topic that has been discussed for inclusion is > > “vCPU hotplug” > > Let’s move that up to confirmed topics. > > > > It’s going to be a full agenda, so I suggest we try to share slides in > advance and we keep > > to a fairly tight schedule! > > > > For those doing slides, I assume best approach is email them to you Mike > and you upload > > them to the collaborate page? Perhaps if people could also let Mike know > expected time > > needed (always a guess) then we can decide to spill some topics to a > future meeting or > > email discussion if necessary. > Perfect, I will add the topics and slides > > > Thanks, > > > > Jonathan > > > > > > *From:* Mike Holmes [mailto:mike.holmes@linaro.org] > *Sent:* 26 November 2020 07:28 > *To:* Jonathan Cameron <jonathan.cameron(a)huawei.com> > *Cc:* Lorenzo Pieralisi <lorenzo.pieralisi(a)arm.com>; > linaro-open-discussions(a)op-lists.linaro.org > *Subject:* Re: [Linaro-open-discussions] Notes on Linaro Open Discussions > meeting 4 Nov 2020 > > > > I see a lot of new subscriptions to the list - welcome. > > Here is the updated meeting slot poll for the week of December 7th to > December 12th > > https://doodle.com/poll/sgy9esiim4rapitz?utm_source=poll&utm_medium=link > > > > Agenda > > https://collaborate.linaro.org/display/LOD/Linaro+Open+Discussions+Home > > > > > > > > On Wed, Nov 25, 2020 at 4:14 PM Jonathan Cameron < > Jonathan.Cameron(a)huawei.com> wrote: > > On Wed, 25 Nov 2020 16:05:51 +0000 > Mike Holmes <mike.holmes(a)linaro.org> wrote: > > > On Wed, Nov 25, 2020 at 4:01 PM Lorenzo Pieralisi via > > Linaro-open-discussions <linaro-open-discussions(a)op-lists.linaro.org> > wrote: > > > > > On Wed, Nov 25, 2020 at 03:22:19PM +0000, Jonathan Cameron wrote: > > > > On Wed, 25 Nov 2020 13:58:38 +0000 > > > > Lorenzo Pieralisi <lorenzo.pieralisi(a)arm.com> wrote: > > > > > > > > > On Wed, Nov 25, 2020 at 12:51:49PM +0000, Jonathan Cameron wrote: > > > > > > > > > > [...] > > > > > > > > > > > > Is December 2nd confirmed as next session ? If possible 3PM > GMT > > > works > > > > > > > better for me; the NUMA topic raised by Jonathan is another > > > interesting > > > > > > > topic for debate. > > > > > > > > > > > > Just to check, which NUMA topic? > > > > > > > > > > > > > > https://op-lists.linaro.org/pipermail/linaro-open-discussions/2020-November… > > > > > > > > > > > It would be useful (for me certainly) if you can give an update on > > > > > what's still pending in the items in the discussion above (eg it is > > > > > not clear what the "PCI fix" is) + how it is linked to CXL. > > > > > > > > Sure, that should be a fairly short topic, but I'm happy to try to > fill > > > in the gaps. > > > > @Mike, can you add "Generic initiators - pending items" to the > agenda. > > > > > > > > For the PCI 'fix' it is this one that got applied and then reverted > in > > > 4.20 timeframe > > > > > > > > http://patchwork.ozlabs.org/project/linux-pci/patch/20180912152140.3676-2-J… > > > > > I've not rebased or tested it recently so I'll check that it still > > > appears to be right > > > > before the call. > > > > > > > > > > > > > > The vCPU hotplug is also worth adding (even though I do not know > what > > > > > was discussed at KVM forum). > > > > > > > > I was just about to email about that one. From our side, all that > is > > > currently > > > > going on around vCPU Hotplug is a rebase. At KVM forum Mark R > kindly > > > offered > > > > to see if he could find out answers to a few open questions. > Perhaps > > > catch > > > > up with Mark, or see if he can make the call? > > > > > > Ok, will catch up with him, it is probably better if I have some time > > > to do it (ie postpone the call for a week). > > > > > > > > Furthermore, I am keen on discussing this: > > > > > > > > > > > > > > https://lore.kernel.org/linux-arm-kernel/20201123065410.1915-1-lushenming@h… > > > > > > > > > > > if the submitters are available, it would help to get some context > in > > > > > relation to upstream discussions. > > > > > > > > I've messaged lushenming so hopefully we can sort out something on > that > > > front. > > > > > > > > Looks like finding a time next week is proving challenging. If that > > > > fails, perhaps we should try for the week after? > > > > > > Yes we can, it would be easier to prepare the topics and find a > suitable > > > day as well, next week it looks like it is challenging. It would also > > > give us some time to extend the invite. > > > > > > Please let me know and apologies to Mike for all these emails to get it > > > organized. > > > > > > > No problem, as soon as it is confirmed we want to try for the following > > week I can set up a poll to pick the day and hour > > Definitely sounds like a better plan. Fingers crossed people have slightly > more open schedules that week! > > Thanks for sorting this out Mike. > > Jonathan > > > > > > > > > > > Thanks, > > > Lorenzo > > > > > > > Thanks, > > > > > > > > Jonathan > > > > > > > > > > > > > > > > > > Thanks ! > > > > > Lorenzo > > > > > > > > > > > I've lost track of what we are talking about. > > > > > > > > > > > > > Other than that we can slot in the topics that > > > > > > > weren't discussed last time: > > > > > > > > > > > > > > > > > > https://collaborate.linaro.org/display/LOD/Linaro+Open+Discussions+Home > > > > > > > > > > > > > > even though those require a bit of preparation so the sooner > we > > > finalize > > > > > > > the schedule the better. > > > > > > > > > > > > Seems we have clashed with some internal Huawei activities so > some > > > people who > > > > > > would normally be active are snowed under this week. > > > > > > > > > > > > Jonathan > > > > > > > > > > > > > > > > > > > > Please let me know, thanks. > > > > > > > > > > > > > > Lorenzo > > > > > > > > > > > > > > > * DT alignment. Don't want different solutions for each > firmware > > > type. > > > > > > > > * Lorenzo / Sami to check IORT revision E is final. > > > > > > > > > > > > > > > > SVA > > > > > > > > === > > > > > > > > > > > > > > > > Zangfei gave summary: > > > > > > > > - Huawei has devices that are not PCIe but are presented > as > > > such. > > > > > > > > - They support stall mode for SVA (spec violation) > > > > > > > > - Resistance from kernel maintainers to maintaining a > white > > > list for any quirk. Fine to fix > > > > > > > > it once (JPB), but not to keep doing so. > > > > > > > > - Note that stall mode not yet supported at all (JPB to > send > > > out this cycle). > > > > > > > > - If longer term fix need add can't be done via PCISIG etc > then > > > need to convince > > > > > > > > PCI and SMMU maintainers. Noted that quirk is very > little > > > code. > > > > > > > > > > > > > > > > * Other SVA topics. > > > > > > > > - Mentioned virtual SVA (no actually problems just > expressing > > > interest!) > > > > > > > > - Would need Eric Auger, wasn't on topic list so Eric not > on > > > call. > > > > > > > > > > > > > > > > AI: Nothing planned until after JPB has upstreamed stall > mode. > > > Hard to have discussion before that. > > > > > > > > > > > > > > > > DVFS > > > > > > > > ==== > > > > > > > > > > > > > > > > guohanjun > > > > > > > > > > > > > > > > Solutions exist for > > > > > > > > * CPU DVFS (voltage + frequency scaling) > > > > > > > > * PCIe device power states etc > > > > > > > > > > > > > > > > No standard way of controlling Uncore voltage and frequency > for > > > ACPI based systems. > > > > > > > > > > > > > > > > 3 options: > > > > > > > > 1. MMIO / kernel driver. > > > > > > > > 2. PSCI via trusted firmware and system management > controller. > > > > > > > > 3. ACPI (wrapping up an op region and SCMI) > > > > > > > > > > > > > > > > Clarifications / discussions. > > > > > > > > * Vincent G: Power states, or voltage frequency of > interest? > > > Ans Voltage Freq > > > > > > > > * Considered SCMI? Ans: Works only for DT as SCMI under > ACPI > > > is wrapped up in AML > > > > > > > > so looks like an ACPI interface. > > > > > > > > * Sudeep H: Necessary to trace CPU freq? Yes. > > > > > > > > * Sudeep H: Why not do it in firmware entirely? Ans. Not > just > > > CPU. For example PCI device accessing > > > > > > > > memory may well need the ring bus to be fast. > > > > > > > > * Vincent G: Bandwidth affected? Yes. VG: mobile does this > by > > > specifying a BW requirement (via SCMI.- > > > > > > > > * Sudeep H Observed need to expose it via ACPI spec. > (option 3 > > > above). > > > > > > > > * Sudeep H: Does PCI also need fine-grain control? We > might > > > need to add to the spec. > > > > > > > > * Sudeep H: What are the requirements? gaohanjun: Now we > just > > > frequency scaling. > > > > > > > > * Jonathan C: Noted PCI power state is not enough. It's > > > workload dependent. > > > > > > > > * Sudeep H: We need to gather all the info, need to talk > in > > > ASWG about DVFS > > > > > > > > * Jonathan C: For now direct control probably makes > sense. > > > Whilst it would be nice to have > > > > > > > > a detailed enough system description in a standard way > to > > > make general software that is a > > > > > > > > big spec job. > > > > > > > > * Jonathan C: Seems like true standard SW will not happen > any > > > time soon. > > > > > > > > > > > > > > > > AI: RFC to the linux-pm / linux-acpi Rafael and those in > this > > > discussion to ask about > > > > > > > > interest in adding per device DVFS to ACPI spec. > Possibly > > > pursue code first ACPI > > > > > > > > approach. > > > > > > > > > > > > > > > > If I've miss listed or "volunteered" anyone for AIs they > didn't > > > agree to then please > > > > > > > > correct that. > > > > > > > > > > > > > > > > Thanks all for contributions. I for one found it a very > useful > > > call! > > > > > > > > > > > > > > > > Jonathan > > > > > > > > > > > > > > > > > > > > > > > > -- > > > > > > > > Linaro-open-discussions mailing list > > > > > > > > > > > > https://collaborate.linaro.org/display/LOD/Linaro+Open+Discussions+Home > > > > > > > > > > > https://op-lists.linaro.org/mailman/listinfo/linaro-open-discussions > > > > > > > > > > > > > -- > > > Linaro-open-discussions mailing list > > > > https://collaborate.linaro.org/display/LOD/Linaro+Open+Discussions+Home > > > https://op-lists.linaro.org/mailman/listinfo/linaro-open-discussions > > > > > > > > > > > > -- > > *Mike Holmes* | Director, Foundation Technologies, Linaro > > Mike.Holmes(a)linaro.org <mike.holmes(a)linaro.org> > > "Work should be fun and collaborative, the rest follows" > > > -- Mike Holmes | Director, Foundation Technologies, Linaro Mike.Holmes(a)linaro.org <mike.holmes(a)linaro.org> "Work should be fun and collaborative, the rest follows"

5 years, 3 months

1
0
0 0

Re: [Linaro-open-discussions] Notes on Linaro Open Discussions meeting 4 Nov 2020

by Lorenzo Pieralisi

On Thu, Nov 05, 2020 at 12:36:21PM +0000, Jonathan Cameron via Linaro-open-discussions wrote: > > Hi all, > > This is a fusion of Mike's notes and my own. Please add anything I missed! > People may well be misidentified (sorry about that). Was very good active discussion. > Thanks to all involved and Mike in particular for organizing it and taking live notes. > > General request > > - Slides for all topics next time to introduce topics as not everyone on call will have necessary > background (and those that do might need reminding!) > Hanjun is sending Mike his slides (uncore DVFS) to add to the collaborate page. > > IORT - Reserve memory regions (RMR) > =================================== > > * Shameer gave summary > - IORT Revision E (https://developer.arm.com/documentation/den0049/latest/) introduced new node type. > - A way to describe memory regions that should have unity mapping in the SMMU. > - Use case is a PCIe RAID card that has FW that uses a pool of host memory (hidden from OS). > > * Status > - Patches out for ACPICA > - Question raised by ACPICA reviewers on whether spec is final > - Spec appears final (Lorenzo to check) but may be minor unrelated fix in doc to come (Sami). > - Patches out for kernel on relevant lists. > - Mail from Steven Price (Arm) - (Sami Mujawar who was on the call also involved) interested for EFI > framebuffer use case. > > * Open questions > - Equivalent from AMD has flag to indicate that unity mapping only needed until driver has taken over > (end of kernel boot assumed). Avoids and issue of holes in address space for VMs. > - Huawei not raising this as a requirement, but Lorenzo observed interesting and deserves discussion. > - Kexec interaction needs discussions. Steve looking at this an will bring to list. > - Lorenzo brought up issue of IORT spec using PCI BDF (stream ID?) which may be reenumerated. > - Noted x86 doesn't do this but ARM traditionally does. > - There is a DSM that tells the kernel not to reenumerate the PCI bus which ACPI obeys. > - Jonathan suggestion was potentially opportunity to cache original stream ID before doing the > reenumeration in kernel. > - Lorenzo observed we may need a universal solution for all OSes on this. > Lorenzo took AI to go away and think about it before next call. > - Stalling issues on patch? Probably only Kexec though should be careful around possible future > regressions on the BDF issue (not a blocker) > - Related DT story. Huawei server team not interested as no DT support and can't test. > Lorenzo suggested looping in Thierry Reding and reference a patch set > (probably https://lore.kernel.org/linux-iommu/20200904130000.691933-1-thierry.reding@…) > Huawei more than happy to have others add the DT support :) > > AI summary: > * Kexec discussion - on list. > * Use of BDF discussion - revisit here next time. I have an update on this topic and the RMR flags to free up IOVA. Is December 2nd confirmed as next session ? If possible 3PM GMT works better for me; the NUMA topic raised by Jonathan is another interesting topic for debate. Other than that we can slot in the topics that weren't discussed last time: https://collaborate.linaro.org/display/LOD/Linaro+Open+Discussions+Home even though those require a bit of preparation so the sooner we finalize the schedule the better. Please let me know, thanks. Lorenzo > * DT alignment. Don't want different solutions for each firmware type. > * Lorenzo / Sami to check IORT revision E is final. > > SVA > === > > Zangfei gave summary: > - Huawei has devices that are not PCIe but are presented as such. > - They support stall mode for SVA (spec violation) > - Resistance from kernel maintainers to maintaining a white list for any quirk. Fine to fix > it once (JPB), but not to keep doing so. > - Note that stall mode not yet supported at all (JPB to send out this cycle). > - If longer term fix need add can't be done via PCISIG etc then need to convince > PCI and SMMU maintainers. Noted that quirk is very little code. > > * Other SVA topics. > - Mentioned virtual SVA (no actually problems just expressing interest!) > - Would need Eric Auger, wasn't on topic list so Eric not on call. > > AI: Nothing planned until after JPB has upstreamed stall mode. Hard to have discussion before that. > > DVFS > ==== > > guohanjun > > Solutions exist for > * CPU DVFS (voltage + frequency scaling) > * PCIe device power states etc > > No standard way of controlling Uncore voltage and frequency for ACPI based systems. > > 3 options: > 1. MMIO / kernel driver. > 2. PSCI via trusted firmware and system management controller. > 3. ACPI (wrapping up an op region and SCMI) > > Clarifications / discussions. > * Vincent G: Power states, or voltage frequency of interest? Ans Voltage Freq > * Considered SCMI? Ans: Works only for DT as SCMI under ACPI is wrapped up in AML > so looks like an ACPI interface. > * Sudeep H: Necessary to trace CPU freq? Yes. > * Sudeep H: Why not do it in firmware entirely? Ans. Not just CPU. For example PCI device accessing > memory may well need the ring bus to be fast. > * Vincent G: Bandwidth affected? Yes. VG: mobile does this by specifying a BW requirement (via SCMI.- > * Sudeep H Observed need to expose it via ACPI spec. (option 3 above). > * Sudeep H: Does PCI also need fine-grain control? We might need to add to the spec. > * Sudeep H: What are the requirements? gaohanjun: Now we just frequency scaling. > * Jonathan C: Noted PCI power state is not enough. It's workload dependent. > * Sudeep H: We need to gather all the info, need to talk in ASWG about DVFS > * Jonathan C: For now direct control probably makes sense. Whilst it would be nice to have > a detailed enough system description in a standard way to make general software that is a > big spec job. > * Jonathan C: Seems like true standard SW will not happen any time soon. > > AI: RFC to the linux-pm / linux-acpi Rafael and those in this discussion to ask about > interest in adding per device DVFS to ACPI spec. Possibly pursue code first ACPI > approach. > > If I've miss listed or "volunteered" anyone for AIs they didn't agree to then please > correct that. > > Thanks all for contributions. I for one found it a very useful call! > > Jonathan > > > -- > Linaro-open-discussions mailing list > https://collaborate.linaro.org/display/LOD/Linaro+Open+Discussions+Home > https://op-lists.linaro.org/mailman/listinfo/linaro-open-discussions

5 years, 3 months

2
4
0 0

2026

2025

2024

2023

2022

2021

2020

Linaro-open-discussions