Re: KVM call agenda for 2013-05-28
On Sun, Jun 2, 2013 at 2:43 AM, Michael S. Tsirkin wrote: > On Fri, May 31, 2013 at 01:45:55PM +0200, Laszlo Ersek wrote: >> On 05/31/13 09:09, Jordan Justen wrote: >> >> > Why is updating the ACPI tables in seabios viewed as such a burden? >> > Either qemu does it, or seabios... (And, OVMF too, but I don't think >> > you guys are concerned with that. :) >> >> I am :) >> >> > On the flip side, why is moving the ACPI tables to QEMU such an issue? >> > It seems like Xen and virtualbox both already do this. Why is running >> > iasl not an issue for them? >> >> I think something was mentioned about iasl having problems on BE >> machines? I could be easily wrong but I *guess* qemu's hosts x targets >> (emulate what on what) set is a proper superset of xen's and >> virtualbox's. Presumably if you want to run an x86 guest on a MIPS host, >> and also want to build qemu on the same MIPS (or SPARC) host, you'd have >> to run iasl there too. > > You guys should take a look at the patch series I posted. > > That's solved there by the means of keeping iasl output in qemu git tree. > configure checks for a working iasl and enables/disables > using this pre-processed output accordingly. > Everyone developing ASL code would still need working iasl > but that's already the case today. I'm sorry the I haven't had time to review your series yet. But, from what you saying about it in this thread, it sounds like a good plan. -Jordan -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: KVM call agenda for 2013-05-28
On Thu, May 30, 2013 at 10:34:26PM -0400, Kevin O'Connor wrote: > On Tue, May 28, 2013 at 07:53:09PM -0400, Kevin O'Connor wrote: > > There were discussions on potentially introducing a middle component > > to generate the tables. Coreboot was raised as a possibility, and > > David thought it would be okay to use coreboot for both OVMF and > > SeaBIOS. The possibility was also raised of a "rom" that lives in the > > qemu repo, is run in the guest, and generates the tables (which is > > similar to the hvmloader approach that Xen uses). > > Given the objections to implementing ACPI directly in QEMU, I don't think that's a given, just yet. So far Anthony asked to be shown the kind of project that ACPI generation in QEMU would enable. Since qemu community wasn't directly exposed to the ACPI-related patches it's easy to see how qemu maintainers won't be aware of the churn and maintainance overhead caused by generating them on the guest side. That seems reasonable, so please hang on just a little bit longer until I post acpi hotplug support for pci bridges based on this code. Then we can discuss. -- MST -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: KVM call agenda for 2013-05-28
On Fri, May 31, 2013 at 01:45:55PM +0200, Laszlo Ersek wrote: > On 05/31/13 09:09, Jordan Justen wrote: > > > Why is updating the ACPI tables in seabios viewed as such a burden? > > Either qemu does it, or seabios... (And, OVMF too, but I don't think > > you guys are concerned with that. :) > > I am :) > > > On the flip side, why is moving the ACPI tables to QEMU such an issue? > > It seems like Xen and virtualbox both already do this. Why is running > > iasl not an issue for them? > > I think something was mentioned about iasl having problems on BE > machines? I could be easily wrong but I *guess* qemu's hosts x targets > (emulate what on what) set is a proper superset of xen's and > virtualbox's. Presumably if you want to run an x86 guest on a MIPS host, > and also want to build qemu on the same MIPS (or SPARC) host, you'd have > to run iasl there too. You guys should take a look at the patch series I posted. That's solved there by the means of keeping iasl output in qemu git tree. configure checks for a working iasl and enables/disables using this pre-processed output accordingly. Everyone developing ASL code would still need working iasl but that's already the case today. > > tables :) > > Impossible. :) > > In earnest, I think what we have now is (mostly) correct, just not > extensive / flexible enough. No support for PCI hotplug or CPU hotplug, > none for S3 (although all of these tie into UEFI deeply), no MTRR setup, > no MPTABLE; let alone a non-PIIX chipset. (Well maybe I shouldn't lump > these under the "ACPI umbrella".) > > > but I haven't seen it as much of a burden. (Of course, > > Laszlo has helped out with many of the ACPI changes in OVMF, so his > > opinion should be taken into consideration too. :) > > It hasn't been a "burden" in the sense of me not liking the activity; I > actually like fiddling with knobs. It has certainly been extra work to > bring OVMF's ACPI tables closer to SeaBIOS's functionality / flexibility > (and we still lag behind it quite.). > > Due to licensing differences I can't just port code from SeaBIOS to OVMF > (and I never have without explicit permission), so it's been a lot of > back and forth with acpidump / iasl -d in guests (massage OVMF, boot > guest, check guest dmesg / lspci, dump tables, compare, repeat), brain > picking colleagues, the ACPI and PIIX specs and so on. I have a page on > the RH intranet dedicated to this. When something around these parts is > being changed (or looks like it could be changed) in SeaBIOS, or between > qemu and SeaBIOS, I always must be alert and consider reimplementing it > in, or porting it with permission to, OVMF. (Most recent example: > pvpanic device -- currently only in SeaBIOS.) > > It worries me that if I slack off, or am busy with something else, or > simply don't notice, then the gap will widen again. I appreciate > learning a bunch about ACPI, and don't mind the days of work that went > into some of my simple-looking ACPI patches for OVMF, but had the tables > come from a common (programmatic) source, none of this would have been > an issue, and I wouldn't have felt even occasionally that ACPI patches > for OVMF were both duplicate work *and* futile (considering how much > ahead SeaBIOS was). > > I don't mind reimplementing stuff, or porting it with permission, going > forward, but the sophisticated parts in SeaBIOS are a hard nut. For > example I'll never be able to auto-extract offsets from generated AML > and patch the AML using those offsets; the edk2 build tools (a project > separate from edk2) don't support this, and it takes several months to > get a thing as simple as gcc-47 build flags into edk2-buildtools. > > Instead I have to write template ASL, compile it to AML, hexdump the > result, verify it against the AML grammar in the ACPI spec (offsets > aren't obvious, BytePrefix and friends are a joy), define & initialize a > packed struct or array in OVMF, and patch the template AML using fixed > field names or array subscripts. Workable, but dog slow. If the ACPI > payload came from up above, we might be as well provided with a list of > (canonical name, offset, size) triplets, and could perhaps blindly patch > the contents. (Not unlike Michael's linker code for connecting tables > into a hierarchy.) > > AFAIK most recently iasl got built-in support for offset extraction (and > in the process the current SeaBIOS build method was broken...), so that > part might get easier in the future. > > Oh well it's Friday, sorry about this rant! :) I'll happily do what I > can in the current status quo, but frequently, it won't amount to much. > > Thanks, > Laszlo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: KVM call agenda for 2013-05-28
On Fri, May 31, 2013 at 5:01 PM, Laszlo Ersek wrote: > On 05/31/13 23:03, Jordan Justen wrote: > >> Of course, the fact that the current FAT driver is exclusionary for >> free software projects is a point that is not lost on me. I just don't >> agree that the best response to this is a GPL'd FAT driver. > > What would you suggest? Wasn't that a few levels up in this thread? (And properly phased in the form of a question, no less! :) -Jordan -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: KVM call agenda for 2013-05-28
On Fri, May 31, 2013 at 07:58:36AM -0500, Anthony Liguori wrote: > Kevin O'Connor writes: > > Given the objections to implementing ACPI directly in QEMU, one > > possible way forward would be to split the current SeaBIOS rom into > > two roms: "qvmloader" and "seabios". The "qvmloader" would do the > > qemu specific platform init (pci init, smm init, mtrr init, bios > > tables) and then load and run the regular seabios rom. > What about a small change to the SeaBIOS build system to allow ACPI > table generation to be done via a "plugin". Using a runtime plugin (eg, "qplugin") would require a more complex handoff then qvmloader. With qplugin, seabios would need to know what memory qplugin is compiled to run in and make sure it didn't allocate anything there. Similarly, qplugin would need to not stomp on seabios while it runs, and it would need to coordinate with seabios where to place the final tables. With qvmloader, there is no need to coordinate memory addresses, so it can run anywhere, deploy the tables in their final location, and then launch seabios. > This could be as simple as moving acpi.c and *.dsl into the QEMU build > tree and then having a way to point the SeaBIOS makefiles to our copy of > it. I don't see how that would work. It would complicate the seabios build (as it would require a copy of qemu source to compile), and the resulting seabios binary would be strongly tied to the qemu version it was compiled with and vice-versa. This would break distro seabios rpms. It would also cause great pain when bisecting and would be confusing even during regular compile/debug cycles. Internal seabios calls (eg, memory allocations, pci config accesses) would need to be static interfaces, etc. -Kevin -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: KVM call agenda for 2013-05-28
On 05/31/13 23:03, Jordan Justen wrote: > Of course, the fact that the current FAT driver is exclusionary for > free software projects is a point that is not lost on me. I just don't > agree that the best response to this is a GPL'd FAT driver. What would you suggest? Thank you, Laszlo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: KVM call agenda for 2013-05-28
On Fri, May 31, 2013 at 1:27 PM, Anthony Liguori wrote: > Jordan Justen writes: > >> On Fri, May 31, 2013 at 7:38 AM, Anthony Liguori >> wrote: >>> In terms of creating a FAT module, the most likely source would seem to >>> be the kernel code and since that's GPL, I don't think it's terribly >>> avoidable to end up with a GPL'd uefi implementation. >> >> Why would OpenBSD not be a potential source? >> >> http://www.openbsd.org/cgi-bin/cvsweb/src/sys/msdosfs/ > > If someone is going to do it, that's fine. > > But if me, it's going to be a GPL base. Of potential modules for GPL, this wouldn't be my first choice. For EDK II it would be nice if all the core essential pieces were BSD licensed. This allows more flexibility for those that don't want to use GPL. Of course, the fact that the current FAT driver is exclusionary for free software projects is a point that is not lost on me. I just don't agree that the best response to this is a GPL'd FAT driver. (But, it does seem fair. :) > Actually, enabling GPL > contributions to OVMF is a major motivating factor for me in this whole > discussion. I wouldn't mind figuring out a way to allow GPL components for people that prefer that. EDK II has thus far not proved very welcoming on this front. I think the main repo will remain BSD though. I think that the sub-modules option is the best way to address this. But, I'm not going to bother with creating the sub-module repos if no one is going to use them. (As it was in the past.) -Jordan -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: KVM call agenda for 2013-05-28
Jordan Justen writes: > On Fri, May 31, 2013 at 11:35 AM, Anthony Liguori > wrote: >> As I think more about it, I think forking edk2 is inevitable. We need a >> clean repo that doesn't include the proprietary binaries. I doubt >> upstream edk2 is willing to remove the binaries. > > No, probably not unless a BSD licensed alternative was available. :) > > But, in thinking about what might make sense for EDK II with git, one > option that should be considered is breaking the top-level 'packages' > into separate sub-modules. I had gone so far as to start pushing repos > as sub-modules. > > But, as the effort to convert EDK II to git has stalled (actually > never even thought about leaving the ground), I abandoned that > approach and went back to just mirroring one EDK II. > > I could fairly easily re-enable mirror the sub-set of packages needed > for OVMF. So, in that case, the FatBinPkg sub-module could easily be > dropped from a tree. > >> But this can be quite simple using a combination of git-svn and a >> rewriting script. We did exactly this to pull out the VGABios from >> Bochs and remove the binaries associated with it. It's 100% automated >> and can be kept in sync via a script on qemu.org. > > I would love to mirror the BaseTools as a sub-package without all the > silly windows binaries... What script did you guys use? We did this in git pre-history, now git has a fancy git-filter-branch command that makes it a breeze: http://git-scm.com/book/ch6-4.html Regards, Anthony Liguori > > -Jordan -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: KVM call agenda for 2013-05-28
Jordan Justen writes: > On Fri, May 31, 2013 at 7:38 AM, Anthony Liguori > wrote: >> In terms of creating a FAT module, the most likely source would seem to >> be the kernel code and since that's GPL, I don't think it's terribly >> avoidable to end up with a GPL'd uefi implementation. > > Why would OpenBSD not be a potential source? > > http://www.openbsd.org/cgi-bin/cvsweb/src/sys/msdosfs/ If someone is going to do it, that's fine. But if me, it's going to be a GPL base. Actually, enabling GPL contributions to OVMF is a major motivating factor for me in this whole discussion. Regards, Anthony Liguori > > We have a half-done ext2 fs from GSoC2011 that started with OpenBSD. > > https://github.com/the-ridikulus-rat/Tianocore_Ext2Pkg > >> If that's inevitable, then we're wasting effort by rewriting stuff under >> a BSD license. >> >> Regards, >> >> Anthony Liguori -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: KVM call agenda for 2013-05-28
On Fri, May 31, 2013 at 11:35 AM, Anthony Liguori wrote: > As I think more about it, I think forking edk2 is inevitable. We need a > clean repo that doesn't include the proprietary binaries. I doubt > upstream edk2 is willing to remove the binaries. No, probably not unless a BSD licensed alternative was available. :) But, in thinking about what might make sense for EDK II with git, one option that should be considered is breaking the top-level 'packages' into separate sub-modules. I had gone so far as to start pushing repos as sub-modules. But, as the effort to convert EDK II to git has stalled (actually never even thought about leaving the ground), I abandoned that approach and went back to just mirroring one EDK II. I could fairly easily re-enable mirror the sub-set of packages needed for OVMF. So, in that case, the FatBinPkg sub-module could easily be dropped from a tree. > But this can be quite simple using a combination of git-svn and a > rewriting script. We did exactly this to pull out the VGABios from > Bochs and remove the binaries associated with it. It's 100% automated > and can be kept in sync via a script on qemu.org. I would love to mirror the BaseTools as a sub-package without all the silly windows binaries... What script did you guys use? -Jordan -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: KVM call agenda for 2013-05-28
On Fri, May 31, 2013 at 7:38 AM, Anthony Liguori wrote: > In terms of creating a FAT module, the most likely source would seem to > be the kernel code and since that's GPL, I don't think it's terribly > avoidable to end up with a GPL'd uefi implementation. Why would OpenBSD not be a potential source? http://www.openbsd.org/cgi-bin/cvsweb/src/sys/msdosfs/ We have a half-done ext2 fs from GSoC2011 that started with OpenBSD. https://github.com/the-ridikulus-rat/Tianocore_Ext2Pkg > If that's inevitable, then we're wasting effort by rewriting stuff under > a BSD license. > > Regards, > > Anthony Liguori -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: KVM call agenda for 2013-05-28
Paolo Bonzini writes: > Il 31/05/2013 19:06, Anthony Liguori ha scritto: >> David Woodhouse writes: >> >>> On Fri, 2013-05-31 at 10:43 -0500, Anthony Liguori wrote: It's even more fundamental. OVMF as a whole (at least in it's usable form) is not Open Source. >>> >>> The FAT module is required to make EDK2 usable, and yes, that's not Open >>> Source. So in a sense you're right. >>> >>> But we're talking here about *replacing* the FAT module with something >>> that *is* open source. And the FAT module isn't a fundamental part of >>> EDK2; it's just an optional module that happens to be bundled with the >>> repository. >> >> So *if* we replace the FAT module *and* that replacement was GPL, would >> there be any objects to having more GPL modules for things like virtio, >> ACPI, etc? >> >> And would that be doable in the context of OVMF or would another project >> need to exist for this purpose? > > I don't think it would be doable in TianoCore. I think it would end up > either in distros, or in QEMU. As I think more about it, I think forking edk2 is inevitable. We need a clean repo that doesn't include the proprietary binaries. I doubt upstream edk2 is willing to remove the binaries. But this can be quite simple using a combination of git-svn and a rewriting script. We did exactly this to pull out the VGABios from Bochs and remove the binaries associated with it. It's 100% automated and can be kept in sync via a script on qemu.org. > A separate question is whether OVMF makes more sense as part of > TianoCore or rather as part of QEMU. I'm not sure if qemu.git is the right location, but we can certainly host an ovmf.git on qemu.git that embeds the scrubbed version of edk2.git. Of course, this would enable us to add GPL code (including a FAT module) to ovmf.git without any impact on upstream edk2. > With 75% of the free hypervisors > now reunited under the same source repository, the balance is > tilting... :-) Regards, Anthony Liguori > > Paolo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: KVM call agenda for 2013-05-28
Il 31/05/2013 19:06, Anthony Liguori ha scritto: > David Woodhouse writes: > >> On Fri, 2013-05-31 at 10:43 -0500, Anthony Liguori wrote: >>> It's even more fundamental. OVMF as a whole (at least in it's usable >>> form) is not Open Source. >> >> The FAT module is required to make EDK2 usable, and yes, that's not Open >> Source. So in a sense you're right. >> >> But we're talking here about *replacing* the FAT module with something >> that *is* open source. And the FAT module isn't a fundamental part of >> EDK2; it's just an optional module that happens to be bundled with the >> repository. > > So *if* we replace the FAT module *and* that replacement was GPL, would > there be any objects to having more GPL modules for things like virtio, > ACPI, etc? > > And would that be doable in the context of OVMF or would another project > need to exist for this purpose? I don't think it would be doable in TianoCore. I think it would end up either in distros, or in QEMU. A separate question is whether OVMF makes more sense as part of TianoCore or rather as part of QEMU. With 75% of the free hypervisors now reunited under the same source repository, the balance is tilting... Paolo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: KVM call agenda for 2013-05-28
Laszlo Ersek writes: > On 05/31/13 16:38, Anthony Liguori wrote: > >> It's either Open Source or it's not. It's currently not. > > I disagree with this binary representation of Open Source or Not. If it > weren't (mostly) Open Source, how could we fork (most of) it as you're > suggesting (from the soapbox :))? > >> I have a hard >> time sympathesizing with trying to work with a proprietary upstream. > > My experience has been positive. > > First of all, whether UEFI is a good thing or not is controversial. I > won't try to address that. > > However UEFI is here to stay, machines are being shipped with it, Linux > and other OSen try to support it. Developing (or running) an OS in > combination with a specific firmware is sometimes easier / more economic > in a virtual environment, hence there should be support for qemu + UEFI. > It is this mindset that I operate in. (Oh, I also forgot to mention that > this task has been assigned to me by my superiors as well :)) > > Jordan, the OvmfPkg maintainer is responsive and progressive in the true > FLOSS manner (*), which was a nice surprise for a project whose coding > standards for example are made 100% after Windows source code, and whose > mailing list is mostly subscribed to by proprietary vendors. Really when > it comes to OvmfPkg patches the process follows the "normal" FLOSS > development model. > > (*) Jordan, I hope this will prompt you to merge VirtioNetDxe v4 real > soon now :) (Removing seabios from the CC as we've moved far away from seabios as a topic) Just so no one gets the wrong idea, the OVMF team is now a victim of their own success. I had hoped that no one would do the work necessary to get us to the point where we had to seriously think about UEFI support but that's where we are now :-) > Thus far we've been talking copyright rather than patents, but there's > also this: > > http://en.wikipedia.org/wiki/FAT_filesystem#Challenge > http://en.wikipedia.org/wiki/FAT_filesystem#Patent_infringement_lawsuits > > It almost doesn't matter who prevails in such a lawsuit; the > *possibility* of such a lawsuit gives people cold feet. Blame the > USPTO. Just to say it once so I don't have to ever say it again. I'm not going to discuss anything relating to patents and FAT publicly. Everyone should consult with their respective lawyers on such issues. Copyright is straight forward. Patents are not. Regards, Anthony Liguori > > Laszlo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: KVM call agenda for 2013-05-28
David Woodhouse writes: > On Fri, 2013-05-31 at 10:43 -0500, Anthony Liguori wrote: >> It's even more fundamental. OVMF as a whole (at least in it's usable >> form) is not Open Source. > > The FAT module is required to make EDK2 usable, and yes, that's not Open > Source. So in a sense you're right. > > But we're talking here about *replacing* the FAT module with something > that *is* open source. And the FAT module isn't a fundamental part of > EDK2; it's just an optional module that happens to be bundled with the > repository. So *if* we replace the FAT module *and* that replacement was GPL, would there be any objects to having more GPL modules for things like virtio, ACPI, etc? And would that be doable in the context of OVMF or would another project need to exist for this purpose? > So I think you're massively overstating the issue. OVMF/EDK2 *is* Open > Source, and replacing the FAT module really isn't that hard. > > We can only bury our heads in the sand and ship qemu with > non-EFI-capable firmware for so long... Which is why I think we need to solve the real problem here. > I *know* there's more work to be done. We have SeaBIOS-as-CSM, Jordan > has mostly sorted out the NV variable storage, and now the FAT issue is > coming up to the top of the pile. But we aren't far from the point where > we can realistically say that we want the Open Source OVMF to be the > default firmware shipped with qemu. Yes, that's why I'm raising this now. We all knew that we'd have to talk about this eventually. Regards, Anthony Liguori > > -- > dwmw2 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: KVM call agenda for 2013-05-28
On 05/31/13 18:33, David Woodhouse wrote: > On Fri, 2013-05-31 at 10:43 -0500, Anthony Liguori wrote: >> It's even more fundamental. OVMF as a whole (at least in it's usable >> form) is not Open Source. > > The FAT module is required to make EDK2 usable, and yes, that's not Open > Source. So in a sense you're right. > > But we're talking here about *replacing* the FAT module with something > that *is* open source. And the FAT module isn't a fundamental part of > EDK2; it's just an optional module that happens to be bundled with the > repository. Yes. *Some* FAT module is a hard requirement. > So I think you're massively overstating the issue. OVMF/EDK2 *is* Open > Source, Agreed, > and replacing the FAT module really isn't that hard. technically it's not hard; for a seasoned file system developer (which I'm not, of course), even possibly missing UEFI bits, it should be children's play actually, considering the high quality of UEFI documentation and the responsiveness of edk2-devel. Considering US legal climate however, it appears *extremely* hard to replace the FAT module, in my unwashed personal opinion. Laszlo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: KVM call agenda for 2013-05-28
On 05/31/13 17:43, Anthony Liguori wrote: > David Woodhouse writes: > >> On Fri, 2013-05-31 at 08:04 -0500, Anthony Liguori wrote: >>> >>> >>> >>> Fork OVMF, drop the fat module, and just add GPL code. It's an easily >>> solvable problem. >> >> Heh. Actually it doesn't need to be a fork. It's modular, and the FAT >> driver is just a single module. Which is actually included in *binary* >> form in the EDK2 repository, I believe, and its source code is >> elsewhere. >> >> We could happily make a GPL¹ or LGPL implementation of a FAT module and >> build our OVMF with that instead, and we wouldn't need to fork OVMF at >> all. > > So can't we have GPL virtio modules too? I don't think there's any > problem there except for the FAT module. I share your assessment. > I would propose more of a virtual fork. It could consist of a git repo with > the GPL modules + a submodule for edk2. Ideally, there would be no need > to actually fork edk2. Indeed. edk2 is extremely modular. But in order to get a useful firmware image ultimately, you need a FAT driver. > My assumption is that edk2 won't take GPL code. Correct, see eg. OvmfPkg/Contributions.txt. Laszlo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: KVM call agenda for 2013-05-28
On 05/31/13 16:38, Anthony Liguori wrote: > It's either Open Source or it's not. It's currently not. I disagree with this binary representation of Open Source or Not. If it weren't (mostly) Open Source, how could we fork (most of) it as you're suggesting (from the soapbox :))? > I have a hard > time sympathesizing with trying to work with a proprietary upstream. My experience has been positive. First of all, whether UEFI is a good thing or not is controversial. I won't try to address that. However UEFI is here to stay, machines are being shipped with it, Linux and other OSen try to support it. Developing (or running) an OS in combination with a specific firmware is sometimes easier / more economic in a virtual environment, hence there should be support for qemu + UEFI. It is this mindset that I operate in. (Oh, I also forgot to mention that this task has been assigned to me by my superiors as well :)) Jordan, the OvmfPkg maintainer is responsive and progressive in the true FLOSS manner (*), which was a nice surprise for a project whose coding standards for example are made 100% after Windows source code, and whose mailing list is mostly subscribed to by proprietary vendors. Really when it comes to OvmfPkg patches the process follows the "normal" FLOSS development model. (*) Jordan, I hope this will prompt you to merge VirtioNetDxe v4 real soon now :) I personally think the 2-clause BSDL for 99% of the project was a very sane and practical one from Intel et al. FatPkg is a sad exception. One might even consider it a bad accident: http://thread.gmane.org/gmane.comp.bios.tianocore.devel/1861/focus=1878 I have no idea how that selection process went down, but I assume if FLOSS people had been screaming very loud at that time and had offered a *simple* (which ext2 is not, I gather), wide-spread and unencumbered filesystem, things would be different today. > In terms of creating a FAT module, the most likely source would seem to > be the kernel code and since that's GPL, I don't think it's terribly > avoidable to end up with a GPL'd uefi implementation. > > If that's inevitable, then we're wasting effort by rewriting stuff under > a BSD license. Please ask your employer if they'd be willing to put their name on an original, clean-room, GPL-licensed implementation of FAT32 for UEFI. Thus far we've been talking copyright rather than patents, but there's also this: http://en.wikipedia.org/wiki/FAT_filesystem#Challenge http://en.wikipedia.org/wiki/FAT_filesystem#Patent_infringement_lawsuits It almost doesn't matter who prevails in such a lawsuit; the *possibility* of such a lawsuit gives people cold feet. Blame the USPTO. Laszlo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: KVM call agenda for 2013-05-28
On Fri, 2013-05-31 at 10:43 -0500, Anthony Liguori wrote: > It's even more fundamental. OVMF as a whole (at least in it's usable > form) is not Open Source. The FAT module is required to make EDK2 usable, and yes, that's not Open Source. So in a sense you're right. But we're talking here about *replacing* the FAT module with something that *is* open source. And the FAT module isn't a fundamental part of EDK2; it's just an optional module that happens to be bundled with the repository. So I think you're massively overstating the issue. OVMF/EDK2 *is* Open Source, and replacing the FAT module really isn't that hard. We can only bury our heads in the sand and ship qemu with non-EFI-capable firmware for so long... I *know* there's more work to be done. We have SeaBIOS-as-CSM, Jordan has mostly sorted out the NV variable storage, and now the FAT issue is coming up to the top of the pile. But we aren't far from the point where we can realistically say that we want the Open Source OVMF to be the default firmware shipped with qemu. -- dwmw2 smime.p7s Description: S/MIME cryptographic signature
Re: KVM call agenda for 2013-05-28
David Woodhouse writes: > On Fri, 2013-05-31 at 08:04 -0500, Anthony Liguori wrote: >> >> >> >> Fork OVMF, drop the fat module, and just add GPL code. It's an easily >> solvable problem. > > Heh. Actually it doesn't need to be a fork. It's modular, and the FAT > driver is just a single module. Which is actually included in *binary* > form in the EDK2 repository, I believe, and its source code is > elsewhere. > > We could happily make a GPL¹ or LGPL implementation of a FAT module and > build our OVMF with that instead, and we wouldn't need to fork OVMF at > all. So can't we have GPL virtio modules too? I don't think there's any problem there except for the FAT module. I would propose more of a virtual fork. It could consist of a git repo with the GPL modules + a submodule for edk2. Ideally, there would be no need to actually fork edk2. My assumption is that edk2 won't take GPL code. But does ovmf really need to live in the edk2 tree? If we're going to get serious about supporting OVMF, it we need something that isn't proprietary. > -- > dwmw2 > > ¹ If it's GPL, of course, then we mustn't include any *other* binary > blobs in our OVMF build. But the whole point in this conversation is > that we don't *want* to do that. So that's fine. It's even more fundamental. OVMF as a whole (at least in it's usable form) is not Open Source. Without even tackling the issue of GPL code sharing, that is a fundamental problem that needs to be solved if we're going to serious about making changes to QEMU to support it. I think solving the general problem will also enable GPL code sharing though. Regards, Anthony Liguori -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: KVM call agenda for 2013-05-28
Laszlo Ersek writes: > On 05/31/13 15:04, Anthony Liguori wrote: >> Laszlo Ersek writes: >> >>> On 05/31/13 09:09, Jordan Justen wrote: >>> >>> Due to licensing differences I can't just port code from SeaBIOS to >>> OVMF >> >> > > :) > >> Fork OVMF, drop the fat module, and just add GPL code. It's an easily >> solvable problem. > > It's not optimal for the "upstream first" principle; OVMF is not Open Source so "upstream first" doesn't apply. At least, the FAT module is not Open Source. Bullet 8 from the Open Source Definition[1] "8. License Must Not Be Specific to a Product The rights attached to the program must not depend on the program's being part of a particular software distribution. If the program is extracted from that distribution and used or distributed within the terms of the program's license, all parties to whom the program is redistributed should have the same rights as those that are granted in conjunction with the original software distribution." License from OVMF FAT module[2]: "Additional terms: In addition to the forgoing, redistribution and use of the code is conditioned upon the FAT 32 File System Driver and all derivative works thereof being used for and designed only to read and/or write to a file system that is directly managed by: Intel’s Extensible Firmware Initiative (EFI) Specification v. 1.0 and later and/or the Unified Extensible Firmware Interface (UEFI) Forum’s UEFI Specifications v.2.0 and later (together the “UEFI Specifications”); only as necessary to emulate an implementation of the UEFI Specifications; and to create firmware, applications, utilities and/or drivers." [1] http://opensource.org/osd-annotated [2] http://sourceforge.net/apps/mediawiki/tianocore/index.php?title=Edk2-fat-driver AFAIK, for the systems that we'd actually want to use OVMF for, a FAT module is a hard requirement. > we'd have to > backport upstream edk2 patches forever (there's a whole lot of edk2 > modules outside of direct OvmfPkg that get built into OVMF.fd -- OvmfPkg > "only" customizes / cherry-picks the full edk2 tree for virtual > machines), or to periodically rebase an ever-increasing set of patches. > > Independently, we need *some* FAT driver (otherwise you can't even boot > most installer media), which is where the already discussed worries lie. > Whatever solves this aspect is independent of forking all of edk2. It's either Open Source or it's not. It's currently not. I have a hard time sympathesizing with trying to work with a proprietary upstream. >> Rewriting BSD implementations of everything is silly. Every other >> vendor that uses TianoCore has a proprietary fork. > > Correct, but they (presumably) keep rebasing their ever accumulating > stuff at least on the periodically refreshed "stable edk2 subset" > (UDK2010, which BTW doesn't include OvmfPkg). This must be horrible for > them, but in exchange they get to remain proprietary (which may benefit > them commercially). > >> Maintaining a GPL >> fork seems just as reasonable. > > Perhaps; diverging from "upstream first" would hurt for certain. Well I'm suggesting creating a real upstream (that is actually Open Source). Then I'm all for upstream first. In terms of creating a FAT module, the most likely source would seem to be the kernel code and since that's GPL, I don't think it's terribly avoidable to end up with a GPL'd uefi implementation. If that's inevitable, then we're wasting effort by rewriting stuff under a BSD license. Regards, Anthony Liguori > >> > > Thanks for the suggestion :) > Laszlo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: KVM call agenda for 2013-05-28
On 05/31/13 16:08, David Woodhouse wrote: > On Fri, 2013-05-31 at 08:04 -0500, Anthony Liguori wrote: >> >> >> >> Fork OVMF, drop the fat module, and just add GPL code. It's an easily >> solvable problem. > > Heh. Actually it doesn't need to be a fork. It's modular, and the FAT > driver is just a single module. Which is actually included in *binary* > form in the EDK2 repository, I believe, and its source code is > elsewhere. Correct. > We could happily make a GPL¹ or LGPL implementation of a FAT module and > build our OVMF with that instead, and we wouldn't need to fork OVMF at > all. Yes, that's one plan, *if* someone can sort out, or is willing to shoulder, the perhaps illogical but still worrisome surroundings of FatPkg / FatBinPkg. (I don't intend to spread FUD!) For example, if your employer authorizes you to implement GplFatPkg from scratch, and distribute it as an external module, I -- as someone without any education in law though -- will give you a standing ovation and buy you a case of beer at KVM Forum 2013. Deal? :) (You proved to have great leverage by getting the efi compat table extended, so... :)) > ¹ If it's GPL, of course, then we mustn't include any *other* binary > blobs in our OVMF build. But the whole point in this conversation is > that we don't *want* to do that. So that's fine. Right. Eg. Shell1 is embedded as a pre-built binary, but that's just "convenience", you can build the in-tree Shell2 from source afresh and embed that instead (and ship its source too). Laszlo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: KVM call agenda for 2013-05-28
On Fri, 2013-05-31 at 08:04 -0500, Anthony Liguori wrote: > > > > Fork OVMF, drop the fat module, and just add GPL code. It's an easily > solvable problem. Heh. Actually it doesn't need to be a fork. It's modular, and the FAT driver is just a single module. Which is actually included in *binary* form in the EDK2 repository, I believe, and its source code is elsewhere. We could happily make a GPL¹ or LGPL implementation of a FAT module and build our OVMF with that instead, and we wouldn't need to fork OVMF at all. -- dwmw2 ¹ If it's GPL, of course, then we mustn't include any *other* binary blobs in our OVMF build. But the whole point in this conversation is that we don't *want* to do that. So that's fine. smime.p7s Description: S/MIME cryptographic signature
Re: KVM call agenda for 2013-05-28
Laszlo Ersek writes: > On 05/31/13 09:09, Jordan Justen wrote: > > Due to licensing differences I can't just port code from SeaBIOS to > OVMF Fork OVMF, drop the fat module, and just add GPL code. It's an easily solvable problem. Rewriting BSD implementations of everything is silly. Every other vendor that uses TianoCore has a proprietary fork. Maintaining a GPL fork seems just as reasonable. Regards, Anthony Liguori > (and I never have without explicit permission), so it's been a lot of > back and forth with acpidump / iasl -d in guests (massage OVMF, boot > guest, check guest dmesg / lspci, dump tables, compare, repeat), brain > picking colleagues, the ACPI and PIIX specs and so on. I have a page on > the RH intranet dedicated to this. When something around these parts is > being changed (or looks like it could be changed) in SeaBIOS, or between > qemu and SeaBIOS, I always must be alert and consider reimplementing it > in, or porting it with permission to, OVMF. (Most recent example: > pvpanic device -- currently only in SeaBIOS.) > > It worries me that if I slack off, or am busy with something else, or > simply don't notice, then the gap will widen again. I appreciate > learning a bunch about ACPI, and don't mind the days of work that went > into some of my simple-looking ACPI patches for OVMF, but had the tables > come from a common (programmatic) source, none of this would have been > an issue, and I wouldn't have felt even occasionally that ACPI patches > for OVMF were both duplicate work *and* futile (considering how much > ahead SeaBIOS was). > > I don't mind reimplementing stuff, or porting it with permission, going > forward, but the sophisticated parts in SeaBIOS are a hard nut. For > example I'll never be able to auto-extract offsets from generated AML > and patch the AML using those offsets; the edk2 build tools (a project > separate from edk2) don't support this, and it takes several months to > get a thing as simple as gcc-47 build flags into edk2-buildtools. > > Instead I have to write template ASL, compile it to AML, hexdump the > result, verify it against the AML grammar in the ACPI spec (offsets > aren't obvious, BytePrefix and friends are a joy), define & initialize a > packed struct or array in OVMF, and patch the template AML using fixed > field names or array subscripts. Workable, but dog slow. If the ACPI > payload came from up above, we might be as well provided with a list of > (canonical name, offset, size) triplets, and could perhaps blindly patch > the contents. (Not unlike Michael's linker code for connecting tables > into a hierarchy.) > > AFAIK most recently iasl got built-in support for offset extraction (and > in the process the current SeaBIOS build method was broken...), so that > part might get easier in the future. > > Oh well it's Friday, sorry about this rant! :) I'll happily do what I > can in the current status quo, but frequently, it won't amount to much. > > Thanks, > Laszlo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: KVM call agenda for 2013-05-28
On Fri, 2013-05-31 at 07:58 -0500, Anthony Liguori wrote: > What about a small change to the SeaBIOS build system to allow ACPI > table generation to be done via a "plugin". SeaBIOS already accepts ACPI tables from Coreboot or UEFI, and queries them to find things that it needs. > This could be as simple as moving acpi.c and *.dsl into the QEMU build > tree and then having a way to point the SeaBIOS makefiles to our copy > of it. > > Then the logic is maintained stays in firmware but the churn happens > in the QEMU tree instead of the SeaBIOS tree. Even if you get this working such that SeaBIOS and OVMF can both be built with ACPI tables that match the last qemu you built, that doesn't solve the issue of running a firmware that *wasn't* built to precisely match the version of qemu you're running today. -- dwmw2 smime.p7s Description: S/MIME cryptographic signature
Re: KVM call agenda for 2013-05-28
Kevin O'Connor writes: > On Tue, May 28, 2013 at 07:53:09PM -0400, Kevin O'Connor wrote: >> There were discussions on potentially introducing a middle component >> to generate the tables. Coreboot was raised as a possibility, and >> David thought it would be okay to use coreboot for both OVMF and >> SeaBIOS. The possibility was also raised of a "rom" that lives in the >> qemu repo, is run in the guest, and generates the tables (which is >> similar to the hvmloader approach that Xen uses). > > Given the objections to implementing ACPI directly in QEMU, one > possible way forward would be to split the current SeaBIOS rom into > two roms: "qvmloader" and "seabios". The "qvmloader" would do the > qemu specific platform init (pci init, smm init, mtrr init, bios > tables) and then load and run the regular seabios rom. With this > split, qvmloader could be committed into the QEMU repo and maintained > there. This would be analogous to Xen's hvmloader with the seabios > code used as a starting point to implement it. What about a small change to the SeaBIOS build system to allow ACPI table generation to be done via a "plugin". This could be as simple as moving acpi.c and *.dsl into the QEMU build tree and then having a way to point the SeaBIOS makefiles to our copy of it. Then the logic is maintained stays in firmware but the churn happens in the QEMU tree instead of the SeaBIOS tree. Regards, Anthony Liguori > > With both the hardware implementation and acpi descriptions for that > hardware in the same source code repository, it would be possible to > implement changes to both in a single patch series. The fwcfg entries > used to pass data between qemu and qvmloader could also be changed in > a single patch and thus those fwcfg entries would not need to be > considered a stable interface. The qvmloader code also wouldn't need > the 16bit handlers that seabios requires and thus wouldn't need the > full complexity of the seabios build. Finally, it's possible that > both ovmf and seabios could use a single qvmloader implementation. > > On the down side, reboots can be a bit goofy today in kvm, and that > would need to be settled before something like qvmloader could be > implemented. Also, it may be problematic to support passing of bios > tables from qvmloader to seabios for guests with only 1 meg of ram. > > Thoughts? > -Kevin -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: KVM call agenda for 2013-05-28
On 05/31/13 09:09, Jordan Justen wrote: > Why is updating the ACPI tables in seabios viewed as such a burden? > Either qemu does it, or seabios... (And, OVMF too, but I don't think > you guys are concerned with that. :) I am :) > On the flip side, why is moving the ACPI tables to QEMU such an issue? > It seems like Xen and virtualbox both already do this. Why is running > iasl not an issue for them? I think something was mentioned about iasl having problems on BE machines? I could be easily wrong but I *guess* qemu's hosts x targets (emulate what on what) set is a proper superset of xen's and virtualbox's. Presumably if you want to run an x86 guest on a MIPS host, and also want to build qemu on the same MIPS (or SPARC) host, you'd have to run iasl there too. > Maybe we are doing lots of things horribly wrong in our OVMF ACPI > tables :) Impossible. :) In earnest, I think what we have now is (mostly) correct, just not extensive / flexible enough. No support for PCI hotplug or CPU hotplug, none for S3 (although all of these tie into UEFI deeply), no MTRR setup, no MPTABLE; let alone a non-PIIX chipset. (Well maybe I shouldn't lump these under the "ACPI umbrella".) > but I haven't seen it as much of a burden. (Of course, > Laszlo has helped out with many of the ACPI changes in OVMF, so his > opinion should be taken into consideration too. :) It hasn't been a "burden" in the sense of me not liking the activity; I actually like fiddling with knobs. It has certainly been extra work to bring OVMF's ACPI tables closer to SeaBIOS's functionality / flexibility (and we still lag behind it quite.). Due to licensing differences I can't just port code from SeaBIOS to OVMF (and I never have without explicit permission), so it's been a lot of back and forth with acpidump / iasl -d in guests (massage OVMF, boot guest, check guest dmesg / lspci, dump tables, compare, repeat), brain picking colleagues, the ACPI and PIIX specs and so on. I have a page on the RH intranet dedicated to this. When something around these parts is being changed (or looks like it could be changed) in SeaBIOS, or between qemu and SeaBIOS, I always must be alert and consider reimplementing it in, or porting it with permission to, OVMF. (Most recent example: pvpanic device -- currently only in SeaBIOS.) It worries me that if I slack off, or am busy with something else, or simply don't notice, then the gap will widen again. I appreciate learning a bunch about ACPI, and don't mind the days of work that went into some of my simple-looking ACPI patches for OVMF, but had the tables come from a common (programmatic) source, none of this would have been an issue, and I wouldn't have felt even occasionally that ACPI patches for OVMF were both duplicate work *and* futile (considering how much ahead SeaBIOS was). I don't mind reimplementing stuff, or porting it with permission, going forward, but the sophisticated parts in SeaBIOS are a hard nut. For example I'll never be able to auto-extract offsets from generated AML and patch the AML using those offsets; the edk2 build tools (a project separate from edk2) don't support this, and it takes several months to get a thing as simple as gcc-47 build flags into edk2-buildtools. Instead I have to write template ASL, compile it to AML, hexdump the result, verify it against the AML grammar in the ACPI spec (offsets aren't obvious, BytePrefix and friends are a joy), define & initialize a packed struct or array in OVMF, and patch the template AML using fixed field names or array subscripts. Workable, but dog slow. If the ACPI payload came from up above, we might be as well provided with a list of (canonical name, offset, size) triplets, and could perhaps blindly patch the contents. (Not unlike Michael's linker code for connecting tables into a hierarchy.) AFAIK most recently iasl got built-in support for offset extraction (and in the process the current SeaBIOS build method was broken...), so that part might get easier in the future. Oh well it's Friday, sorry about this rant! :) I'll happily do what I can in the current status quo, but frequently, it won't amount to much. Thanks, Laszlo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: KVM call agenda for 2013-05-28
On Thu, May 30, 2013 at 7:34 PM, Kevin O'Connor wrote: > On Tue, May 28, 2013 at 07:53:09PM -0400, Kevin O'Connor wrote: >> There were discussions on potentially introducing a middle component >> to generate the tables. Coreboot was raised as a possibility, and >> David thought it would be okay to use coreboot for both OVMF and >> SeaBIOS. The possibility was also raised of a "rom" that lives in the >> qemu repo, is run in the guest, and generates the tables (which is >> similar to the hvmloader approach that Xen uses). > > Given the objections to implementing ACPI directly in QEMU, one > possible way forward would be to split the current SeaBIOS rom into > two roms: "qvmloader" and "seabios". The "qvmloader" would do the > qemu specific platform init (pci init, smm init, mtrr init, bios > tables) and then load and run the regular seabios rom. With this > split, qvmloader could be committed into the QEMU repo and maintained > there. This would be analogous to Xen's hvmloader with the seabios > code used as a starting point to implement it. I think hvmloader is more closely tied to Xen, than the Xen firmware. I could be wrong, but thought it could do things like add memory to guest machine. ?? I don't think this model is analogous to Xen's model. I view the hvmloader as just a part of Xen. (Not part of the 'firmware' stack.) In adding this pre-firmware firmware, wouldn't Anthony's concern of iasl still be an issue? Why is updating the ACPI tables in seabios viewed as such a burden? Either qemu does it, or seabios... (And, OVMF too, but I don't think you guys are concerned with that. :) On the flip side, why is moving the ACPI tables to QEMU such an issue? It seems like Xen and virtualbox both already do this. Why is running iasl not an issue for them? I think overall I prefer the tables being built in the firmware, despite the extra thrash. Some things, such as the addresses where devices are configured at are re-programmable in QEMU, so a firmware can decide to use a different address, and thus invalidate the address qvmloader had set in the tables. Maybe we are doing lots of things horribly wrong in our OVMF ACPI tables :), but I haven't seen it as much of a burden. (Of course, Laszlo has helped out with many of the ACPI changes in OVMF, so his opinion should be taken into consideration too. :) -Jordan -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: KVM call agenda for 2013-05-28
On Tue, May 28, 2013 at 07:53:09PM -0400, Kevin O'Connor wrote: > There were discussions on potentially introducing a middle component > to generate the tables. Coreboot was raised as a possibility, and > David thought it would be okay to use coreboot for both OVMF and > SeaBIOS. The possibility was also raised of a "rom" that lives in the > qemu repo, is run in the guest, and generates the tables (which is > similar to the hvmloader approach that Xen uses). Given the objections to implementing ACPI directly in QEMU, one possible way forward would be to split the current SeaBIOS rom into two roms: "qvmloader" and "seabios". The "qvmloader" would do the qemu specific platform init (pci init, smm init, mtrr init, bios tables) and then load and run the regular seabios rom. With this split, qvmloader could be committed into the QEMU repo and maintained there. This would be analogous to Xen's hvmloader with the seabios code used as a starting point to implement it. With both the hardware implementation and acpi descriptions for that hardware in the same source code repository, it would be possible to implement changes to both in a single patch series. The fwcfg entries used to pass data between qemu and qvmloader could also be changed in a single patch and thus those fwcfg entries would not need to be considered a stable interface. The qvmloader code also wouldn't need the 16bit handlers that seabios requires and thus wouldn't need the full complexity of the seabios build. Finally, it's possible that both ovmf and seabios could use a single qvmloader implementation. On the down side, reboots can be a bit goofy today in kvm, and that would need to be settled before something like qvmloader could be implemented. Also, it may be problematic to support passing of bios tables from qvmloader to seabios for guests with only 1 meg of ram. Thoughts? -Kevin -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: KVM call agenda for 2013-05-28
On Wed, May 29, 2013 at 11:12:06AM -0500, Anthony Liguori wrote: > "Michael S. Tsirkin" writes: > > > On Tue, May 28, 2013 at 07:53:09PM -0400, Kevin O'Connor wrote: > >> On Thu, May 23, 2013 at 03:41:32PM +0300, Michael S. Tsirkin wrote: > >> > Juan is not available now, and Anthony asked for > >> > agenda to be sent early. > >> > So here comes: > >> > > >> > Agenda for the meeting Tue, May 28: > >> > > >> > - Generating acpi tables > >> > >> I didn't see any meeting notes, but I thought it would be worthwhile > >> to summarize the call. This is from memory so correct me if I got > >> anything wrong. > >> > >> Anthony believes that the generation of ACPI tables is the task of the > >> firmware. Reasons cited include security implications of running more > >> code in qemu vs the guest context, complexities in running iasl on > >> big-endian machines, possible complexity of having to regenerate > >> tables on a vm reboot, overall sloppiness of doing it in QEMU. Raised > >> that QOM interface should be sufficient. > >> > >> Kevin believes that the bios table code should be moved up into QEMU. > >> Reasons cited include the churn rate in SeaBIOS for this QEMU feature > >> (15-20% of all SeaBIOS commits since integrating with QEMU have been > >> for bios tables; 20% of SeaBIOS commits in last year), complexity of > >> trying to pass all the content needed to generate the tables (eg, > >> device details, power tree, irq routing), complexity of scheduling > >> changes across different repos and synchronizing their rollout, > >> complexity of implemeting the code in both OVMF and SeaBIOS. Kevin > >> wasn't aware of a requirement to regenerate acpi tables on a vm > >> reboot. > > > > I think this last one is based on a misunderstanding: it's based > > on assumption that we we change hardware by hotplug > > we should regenerate the tables to match. > > But there's no management that can take advantage of > > this. > > Two possible reasonable things we can tell management: > > - hotplug for device XXX is not supported: restart qemu > > to make guest use the device > > - hotplug for device XXX is supported > > This introduces an assumption: that the device model never radically > changes across resets. > > Why should this be true? Shouldn't we be allowed to increase the amount > of memory the guest has across reboots? That's equivalent to adding > another DIMM after power off. > You can argue the same thing about non hotpluggable devices: you might be able to replace them when guest is powered off. It's not supported ATM and if/when it is, there's a bunch of code to be written. > Not generating tables on reset does limit what we can do in a pretty > fundamental way. Even if you can argue it in the short term, I don't > think it's viable in the long term. > > Regards, > > Anthony Liguori No because that's not "at reset". We need a separate state for power off. You power off the machine, add DIMM, restart it. Its not something you can do from inside the guest, unlike reset. At the moment, the only way to implement this is by exiting from QEMU. So we are not introducing any regressions here. When qemu gains power off state we can add a handler and regenerate the tables. -- MST -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: KVM call agenda for 2013-05-28
"Michael S. Tsirkin" writes: > On Tue, May 28, 2013 at 07:53:09PM -0400, Kevin O'Connor wrote: >> On Thu, May 23, 2013 at 03:41:32PM +0300, Michael S. Tsirkin wrote: >> > Juan is not available now, and Anthony asked for >> > agenda to be sent early. >> > So here comes: >> > >> > Agenda for the meeting Tue, May 28: >> > >> > - Generating acpi tables >> >> I didn't see any meeting notes, but I thought it would be worthwhile >> to summarize the call. This is from memory so correct me if I got >> anything wrong. >> >> Anthony believes that the generation of ACPI tables is the task of the >> firmware. Reasons cited include security implications of running more >> code in qemu vs the guest context, complexities in running iasl on >> big-endian machines, possible complexity of having to regenerate >> tables on a vm reboot, overall sloppiness of doing it in QEMU. Raised >> that QOM interface should be sufficient. >> >> Kevin believes that the bios table code should be moved up into QEMU. >> Reasons cited include the churn rate in SeaBIOS for this QEMU feature >> (15-20% of all SeaBIOS commits since integrating with QEMU have been >> for bios tables; 20% of SeaBIOS commits in last year), complexity of >> trying to pass all the content needed to generate the tables (eg, >> device details, power tree, irq routing), complexity of scheduling >> changes across different repos and synchronizing their rollout, >> complexity of implemeting the code in both OVMF and SeaBIOS. Kevin >> wasn't aware of a requirement to regenerate acpi tables on a vm >> reboot. > > I think this last one is based on a misunderstanding: it's based > on assumption that we we change hardware by hotplug > we should regenerate the tables to match. > But there's no management that can take advantage of > this. > Two possible reasonable things we can tell management: > - hotplug for device XXX is not supported: restart qemu > to make guest use the device > - hotplug for device XXX is supported This introduces an assumption: that the device model never radically changes across resets. Why should this be true? Shouldn't we be allowed to increase the amount of memory the guest has across reboots? That's equivalent to adding another DIMM after power off. Not generating tables on reset does limit what we can do in a pretty fundamental way. Even if you can argue it in the short term, I don't think it's viable in the long term. Regards, Anthony Liguori -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: KVM call agenda for 2013-05-28
On Tue, May 28, 2013 at 07:53:09PM -0400, Kevin O'Connor wrote: > On Thu, May 23, 2013 at 03:41:32PM +0300, Michael S. Tsirkin wrote: > > Juan is not available now, and Anthony asked for > > agenda to be sent early. > > So here comes: > > > > Agenda for the meeting Tue, May 28: > > > > - Generating acpi tables > > I didn't see any meeting notes, but I thought it would be worthwhile > to summarize the call. This is from memory so correct me if I got > anything wrong. > > Anthony believes that the generation of ACPI tables is the task of the > firmware. Reasons cited include security implications of running more > code in qemu vs the guest context, complexities in running iasl on > big-endian machines, Forgot to mention: my patchset actually solves this by keeping pre-generated ACPI tables in QEMU. This means you need to have iasl to do ACPI development but that's nothing new. However, generating the tables in QEMU actually opens up the possibility of linking in a library for generating ACPI tables, if such surfaces, and dropping the iasl dependency. While my patchset does not do this, it's not unheard of. This would not be practical for bios. > possible complexity of having to regenerate > tables on a vm reboot, overall sloppiness of doing it in QEMU. Raised > that QOM interface should be sufficient. > > Kevin believes that the bios table code should be moved up into QEMU. > Reasons cited include the churn rate in SeaBIOS for this QEMU feature > (15-20% of all SeaBIOS commits since integrating with QEMU have been > for bios tables; 20% of SeaBIOS commits in last year), complexity of > trying to pass all the content needed to generate the tables (eg, > device details, power tree, irq routing), complexity of scheduling > changes across different repos and synchronizing their rollout, > complexity of implemeting the code in both OVMF and SeaBIOS. Kevin > wasn't aware of a requirement to regenerate acpi tables on a vm > reboot. > > There were discussions on potentially introducing a middle component > to generate the tables. Coreboot was raised as a possibility, and > David thought it would be okay to use coreboot for both OVMF and > SeaBIOS. The possibility was also raised of a "rom" that lives in the > qemu repo, is run in the guest, and generates the tables (which is > similar to the hvmloader approach that Xen uses). > > Anthony requested that patches be made that generate the ACPI tables > in QEMU for the upcoming hotplug work, so that they could be evaluated > to see if they truly do need to live in QEMU or if the code could live > in the firmware. There were no objections. > > -Kevin -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: KVM call agenda for 2013-05-28
On Tue, May 28, 2013 at 07:53:09PM -0400, Kevin O'Connor wrote: > On Thu, May 23, 2013 at 03:41:32PM +0300, Michael S. Tsirkin wrote: > > Juan is not available now, and Anthony asked for > > agenda to be sent early. > > So here comes: > > > > Agenda for the meeting Tue, May 28: > > > > - Generating acpi tables > > I didn't see any meeting notes, but I thought it would be worthwhile > to summarize the call. This is from memory so correct me if I got > anything wrong. > > Anthony believes that the generation of ACPI tables is the task of the > firmware. Reasons cited include security implications of running more > code in qemu vs the guest context, complexities in running iasl on > big-endian machines, possible complexity of having to regenerate > tables on a vm reboot, overall sloppiness of doing it in QEMU. Raised > that QOM interface should be sufficient. > > Kevin believes that the bios table code should be moved up into QEMU. > Reasons cited include the churn rate in SeaBIOS for this QEMU feature > (15-20% of all SeaBIOS commits since integrating with QEMU have been > for bios tables; 20% of SeaBIOS commits in last year), complexity of > trying to pass all the content needed to generate the tables (eg, > device details, power tree, irq routing), complexity of scheduling > changes across different repos and synchronizing their rollout, > complexity of implemeting the code in both OVMF and SeaBIOS. Kevin > wasn't aware of a requirement to regenerate acpi tables on a vm > reboot. I think this last one is based on a misunderstanding: it's based on assumption that we we change hardware by hotplug we should regenerate the tables to match. But there's no management that can take advantage of this. Two possible reasonable things we can tell management: - hotplug for device XXX is not supported: restart qemu to make guest use the device - hotplug for device XXX is supported What is proposed here instead is a third option: - hotplug is supported but device is not functional. reboot guest to make it fully functional This will naturally lead to requirement to regenerate tables on reset. And this is what would happen with guest-generated tables, and I consider this a bug, not a feature. If you really wanted to update tables dynamically, without restarting qemu, don't stop there, add an interface for guest to update them without reset. I think that's over-endineering and a requirement that's best avoided. > There were discussions on potentially introducing a middle component > to generate the tables. Coreboot was raised as a possibility, and > David thought it would be okay to use coreboot for both OVMF and > SeaBIOS. The possibility was also raised of a "rom" that lives in the > qemu repo, is run in the guest, and generates the tables (which is > similar to the hvmloader approach that Xen uses). > > Anthony requested that patches be made that generate the ACPI tables > in QEMU for the upcoming hotplug work, so that they could be evaluated > to see if they truly do need to live in QEMU or if the code could live > in the firmware. There were no objections. > > -Kevin I volunteered to implement this. It was also mentioned that this patch does not yet have to fix the cross-version migration issue with fw_cfg. If we agree on a direction, we will fix it then. Lastly, a proposal was made by Michael to make the call bi-weekly instead of weekly, as we were cancelling it too much. There were no objections. Thus, the next call is planned for June 11, 2013. -- MST -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: KVM call agenda for 2013-05-28
On Thu, May 23, 2013 at 03:41:32PM +0300, Michael S. Tsirkin wrote: > Juan is not available now, and Anthony asked for > agenda to be sent early. > So here comes: > > Agenda for the meeting Tue, May 28: > > - Generating acpi tables I didn't see any meeting notes, but I thought it would be worthwhile to summarize the call. This is from memory so correct me if I got anything wrong. Anthony believes that the generation of ACPI tables is the task of the firmware. Reasons cited include security implications of running more code in qemu vs the guest context, complexities in running iasl on big-endian machines, possible complexity of having to regenerate tables on a vm reboot, overall sloppiness of doing it in QEMU. Raised that QOM interface should be sufficient. Kevin believes that the bios table code should be moved up into QEMU. Reasons cited include the churn rate in SeaBIOS for this QEMU feature (15-20% of all SeaBIOS commits since integrating with QEMU have been for bios tables; 20% of SeaBIOS commits in last year), complexity of trying to pass all the content needed to generate the tables (eg, device details, power tree, irq routing), complexity of scheduling changes across different repos and synchronizing their rollout, complexity of implemeting the code in both OVMF and SeaBIOS. Kevin wasn't aware of a requirement to regenerate acpi tables on a vm reboot. There were discussions on potentially introducing a middle component to generate the tables. Coreboot was raised as a possibility, and David thought it would be okay to use coreboot for both OVMF and SeaBIOS. The possibility was also raised of a "rom" that lives in the qemu repo, is run in the guest, and generates the tables (which is similar to the hvmloader approach that Xen uses). Anthony requested that patches be made that generate the ACPI tables in QEMU for the upcoming hotplug work, so that they could be evaluated to see if they truly do need to live in QEMU or if the code could live in the firmware. There were no objections. -Kevin -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
