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CPU Virtualization in L4
by Mohamed Dawod 25 Nov '24

25 Nov '24

I know that Scheduling proxy in L4 is used to set cores and priority ranges for a dedicated task. For example, The below scheduling proxy makes the task runs on cores 1,2,3 with priority range [52,62]. scheduler = vmm.new_sched(0x50, 0xE) When I switch to debugging mode, I see that this task has priority = 52 in pr column! So why does scheduling proxy set priority range instead of a single value like Linux ? How does L4 use the priority range ? My second question is about the relationship between physical CPUs and virtual CPUs in L4. I know that CPU virtualization should give the ability to virtualize the available physical CPUs so that if we have single physical CPU core, CPU virtualization enables us to provide multiple virtual CPU cores for the VMs running ontop of the hypervisor. Actually I don't see this behaviour in the scheduling proxy in L4! instead, the cores parameter only takes a bitmap of the physical cores. Can I use the scheduling proxy or any other method/workarround to provide CPU Virtualization ? Thanks, Mohamed Dawod _______________________________________________ l4-hackers mailing list -- l4-hackers(a)os.inf.tu-dresden.de To unsubscribe send an email to l4-hackers-leave(a)os.inf.tu-dresden.de

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Porting apps to L4Re?
by Lonnie via l4-hackers 18 Nov '24

18 Nov '24

Hello All, As part of the project effort that I am working on with L4Re, I am considering 2 possible pathways of which both need graphics capabilities to interact with the uvmm for a guest OS: Possible pathways: 1. Use the framebuffer "spectrum" example and port something like FreeRDP, rdesktop or other, so that this will allow for a loabable RDP service VM whose only job is to connect to other VM's. This would be for having a Docker/Podman Container engine running and to be able to connect to a container via a web browser VM that has a graphic console in fullscreen mode. 2. Find a way to have L4Re be able to access the graphic console (VGA) of each uvmm guest directly and then be able to HotKey switch between active VM's. This might be like having multiple guest OS's running (i.e. Ubuntu 24.04 and Windows 10 for example) and then be able to switch the console between them. This is also an idea to allow L4Re to boot all of the OS's that might reside on a dualboot or multiboot system. I actually need something this is really a cross between both of these since in one configuration case will be (1) and in another case will be (2). Wanted to get any thoughts or suggestions that you might have towards this. Thanks and have a great day, Lonnie _______________________________________________ l4-hackers mailing list -- l4-hackers(a)os.inf.tu-dresden.de To unsubscribe send an email to l4-hackers-leave(a)os.inf.tu-dresden.de

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Generating EFI files
by Lonnie Cumberland 13 Nov '24

13 Nov '24

Hello All, While exploring and testing L4Re, I have also been testing some files from the AMD64 downloads: https://l4re.org/download/snapshots/pre-built-images/amd64/ While currently the only the elf32 file do run a bit and the efi files are now known to have some problems, I was wondering how the efi files were generated. I know that in the build for l4re that you can use "make -j24" to build the core as well as "make qemu" to show some available examples that I am trying to also get to work, but I was wondering how these above "pre-built-images" were generated? Also, I am very interested in the "l4re_vm-multi.efi" and "l4re_vm-multi-p2p.efi" in how they can be generated to run under QEMU as well as how to perhaps generate an x64 ISO that can be booted on real hardware. These interest me a great deal and I would really be interested if someone might be able to explain them more to me, especially the "p2p" one since have an interest in p2p networks as well. Thanks in advance and have a great day, Lonnie _______________________________________________ l4-hackers mailing list -- l4-hackers(a)os.inf.tu-dresden.de To unsubscribe send an email to l4-hackers-leave(a)os.inf.tu-dresden.de

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vm-basic-pci demo testing
by Mohamed Dawod 13 Nov '24

13 Nov '24

Hi, I was trying the *vm-basic-pci* demo from l4Re version 24.08.0. The demo works and I could boot the Linux VM and login successfully, but I need to test the passed PCI bus to make sure that it works. I'm trying to test it using a *virtio-blk-pci* device from qemu which is expected to be mounted as a block device in */dev/vda*. but when I found no */dev/vda* file in the filesystem. Please find attached : * my ned scripts : vm-basic-pci.log * arm-virt64.io * the dts file : virt-basic_virt-64_pci.dts * and the full logs : vm-basic-pci.log Thanks in advance, Regards -- Mohamed Dawod *Software Engineer, *Avelabs Egypt *Cell Phone : (+20) 1117311726* -- *Driving Innovation! Visit our website www.avelabs.com <http://www.avelabs.com/>*, to read Avelabs Confidentiality Notice, follow this link: http://www.avelabs.com/email/disclaimer.html <http://www.avelabs.com/email/disclaimer.html> _______________________________________________ l4-hackers mailing list -- l4-hackers(a)os.inf.tu-dresden.de To unsubscribe send an email to l4-hackers-leave(a)os.inf.tu-dresden.de

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Debugging memory allocation in L4Re
by Paul Boddie 11 Nov '24

11 Nov '24

Hello, I thought I might as well ask this since the mailing list has been somewhat active recently. I have been testing some of my software, but after a certain period of time, I experience errors of the following form: l4re_kernel: ERROR: more-mem(1000): Cannot provide more memory. l4re_kernel: ERROR: mmap() called: unimplemented! size=100000 As far as I can tell, uclibc_morecore and mmap in... pkg/l4re-core/l4re_kernel/server/src/mem.cc ...are respectively responsible for these errors, the former being called by __malloc_trim, itself called by free in... pkg/l4re-core/uclibc/lib/contrib/uclibc/libc/stdlib/malloc-standard/free.c Looking at the uclibc_morecore implementation, it seems that the "program break" is defined only once, with a dataspace of 64 pages being allocated, and any subsequent sbrk call will not cause this allocated space to be extended further. Have I understood this situation correctly? As always, I assume that I am making some kind of mistake, in this case probably not deallocating memory when I should be and thus exhausting the available space. Are there any convenient ways of monitoring memory allocation in L4Re? Thanks for any advice offered! Paul _______________________________________________ l4-hackers mailing list -- l4-hackers(a)os.inf.tu-dresden.de To unsubscribe send an email to l4-hackers-leave(a)os.inf.tu-dresden.de

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Qemu Demos
by Lonnie Cumberland 11 Nov '24

11 Nov '24

Hello All, I am on an Intel NUC 13 NHNE (x64) running Ubuntu 23.10 and am working my way through the basic Qemu Demos after following the build instructions https://github.com/kernkonzept/manifest/wiki/BUILDING From there I am in the "~/l4re/build-amd64$" and have added "/l4re/l4/conf/examples" to the "l4/conf/Makeconf.boot" Now I do a "make qemu" and get the list: =============================================== │ │ │ 0 hello │ │ 1 hello-cfg │ │ 2 hello-2 │ │ 3 hello-shared │ │ 4 framebuffer-example │ │ 5 L4Linux-basic │ │ 6 L4Linux-mag │ │ 7 VM-basic │ │ 8 VM-multi │ │ 9 VM-multi-p2p │ │ 10 VM-basic-pci =============================================== For which I have been able to run items 0 - 3, but when I run (4) "framebuffer-example", I get an error about a missing "x86-lagacy.devs" file and I cannot find it anywhere in the sources or builds. =============================================== Could not find 'x86-legacy.devs' within paths /home/lonnie/l4re/build-amd64/assets /home/lonnie/l4re/build-amd64/bin/amd64_gen/l4f /home/lonnie/l4re/build-amd64/bin/amd64_gen/plain /home/lonnie/l4re/build-amd64/lib/amd64_gen/std/l4f /home/lonnie/l4re/build-amd64/lib/amd64_gen/std/plain /home/lonnie/l4re/build-fiasco-amd64 /home/lonnie/l4re/l4/conf/examples make[1]: *** [Makefile:693: qemu] Error 1 make[1]: Leaving directory '/home/lonnie/l4re/l4' make: *** [Makefile:6: do-all-make-goals] Error 2 =============================================== I then restarted "make qemu" and tried (7) VM-basic, but it seems to abort with the messages: =============================================== MOE: Starting: rom/ned rom/vm-basic.cfg MOE: loading 'rom/ned' Ned says: Hi World! Ned: loading file: 'rom/vm-basic.cfg' VMM[]: Created VCPU 0 @ 18000 VMM[]: >>> CAUTION: Support for AMD SVM is experimental, use at your own risk! <<< terminate called after throwing an instance of 'N2L413Runtime_errorE' what: Invalid request: SVM does not support next_rip save. Aborting! =============================================== In trying to run the other VM-????? choices, I also get similar messages: =============================================== vm-1 | VMM[]: Created VCPU 0 @ 18000 vm-1 | VMM[]: >>> CAUTION: Support for AMD SVM is experimental, use at your own risk! <<< vm-1 | terminate called after throwing an instance of 'N2L413Runtime_errorE' vm-2 | VMM[]: Created VCPU 0 @ 18000 vm-2 | VMM[]: >>> CAUTION: Support for AMD SVM is experimental, use at your own risk! <<< vm-3 | VMM[]: Created VCPU 0 @ 18000 vm-3 | VMM[]: >>> CAUTION: Support for AMD SVM is experimental, use at your own risk! <<< vm-2 | terminate called after throwing an instance of 'N2L413Runtime_errorE' vm-1 | what: Invalid request: SVM does not support next_rip save. Aborting! vm-3 | terminate called after throwing an instance of 'N2L413Runtime_errorE' vm-1 | vm-2 | what: Invalid request: SVM does not support next_rip save. Aborting! vm-2 | vm-3 | what: Invalid request: SVM does not support next_rip save. Aborting! vm-3 | ========================================================= Has anyone been able to get all of these to run? I am still exploring but would like to get the be able to compile and run the VM-multi examples on the x64 hardware like in the video. https://l4re.org/cast-multi-vm-qemu.html Any thoughts on how to test out some of these? Best and have a great weekend, Lonnie _______________________________________________ l4-hackers mailing list -- l4-hackers(a)os.inf.tu-dresden.de To unsubscribe send an email to l4-hackers-leave(a)os.inf.tu-dresden.de

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Building Screenshots and examples
by Lonnie Cumberland 10 Nov '24

10 Nov '24

Hello All, I hope that your day is going well. Recently, I have decided to explore L4Re as a microhypervisor and capabilities as a possible minimalist component-based microkernel OS. I have just set up Ubuntu 23.10 (x64) in an Intel NUC13 and would am reviewing as much documentation as I can find as well as am building the core L4Re according to the Github Wiki just to see how the process goes. https://github.com/kernkonzept/manifest/wiki/BUILDING As I am in the learning curve at the moment, I also would like to build some examples such as the "Screenshots" (https://l4re.org/screens.html) and demos from the Pre-Built section (https://l4re.org/download/snapshots/pre-built-images/amd64/) I did try to follow the direction on the pre-built sections and grabbed the "l4image" and all of the AMD64 EFI files to try and test, but when I launch them they just seem to hang and do nothing. I do have qemu (x64) installed as well, but still nothing seems to boot. What I would like to ask the mailinglist members is where can I get the source code to the "screenshots" examples as well as the AMD64 "pre-built" examples noted above so that I cam do a fresh compile to see them in action? Any help would be greatly appreciated. Thanks in advance and have a great day, Lonnie _______________________________________________ l4-hackers mailing list -- l4-hackers(a)os.inf.tu-dresden.de To unsubscribe send an email to l4-hackers-leave(a)os.inf.tu-dresden.de

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Multiple CPU support for uvmm on virt-arm64 qemu machine
by Mohamed Dawod 06 Nov '24

06 Nov '24

Hello, I'm trying to provide multiple CPUs for a linux VM on top of L4. I'm using the qemu virt machine and building for aarch64. so I used *-smp* option to provide more CPUs. > $ qemu-system-aarch64 -M virt,virtualization=true -cpu cortex-a57 -smp 4 > -m 1024 -kernel ....etc.... Unfortunately, This didn't work. I tried to add more CPU device nodes to the dts file *virt-arm_virt-64.dts *but it also didn't work. I think that it's because of the provided interrupt-controller with *virt-arm_virt-64.dts* in *l4/pkg/uvmm/conf/dts* which mentioned that it supports only one CPU. > icsoc { > compatible = "simple-bus"; > #address-cells = <2>; > #size-cells = <2>; > ranges; > > /* Uvmm will adapt the compatible string depending on the present > gic > * version. It expects reg entries that provide enough space for > the > * Cpu/Dist interface for gicv2 (at least 0x1000, 0x1000) or the > * Dist/Redist interface for gicv3 (0x10000, 0x20000 * number of > cpus). > * > *The entries provided here support any gicv2 setup or a gicv3 setup > * with one Cpu.* > */ > gic: interrupt-controller { > compatible = "arm,gic-400", "arm,cortex-a15-gic", > "arm,cortex-a9-gic"; > #interrupt-cells = <3>; > #address-cells = <0>; > interrupt-controller; > reg = <0 0x40000 0 0x10000>, > <0 0x50000 0 0x20000>; > }; > }; > My question now, is there any workaround to support multiple CPUs for virt machine on arm64 ? Thanks, Regards -- Mohamed Dawod *Software Engineer, *Cairo Egypt -- *Driving Innovation! Visit our website www.avelabs.com <http://www.avelabs.com/>*, to read Avelabs Confidentiality Notice, follow this link: http://www.avelabs.com/email/disclaimer.html <http://www.avelabs.com/email/disclaimer.html> _______________________________________________ l4-hackers mailing list -- l4-hackers(a)os.inf.tu-dresden.de To unsubscribe send an email to l4-hackers-leave(a)os.inf.tu-dresden.de

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[FOSDEM 2025] Call for Participation: Microkernel and Component-Based OS Devroom
by Udo Steinberg 30 Oct '24

30 Oct '24

Hi all, below is the official CfP for the microkernel devroom at FOSDEM 2025. I am looking forward to a strong participation from all microkernel/unikernel research groups and companies, not only in the form of attendance, but also in the form of great talks :) Cheers, Udo We are happy to announce the CfP for the "Microkernel and Component-Based OS" devroom at the upcoming FOSDEM 2025. Developers and users of various free and open-source microkernel-based, unikernel-based and component-based operating systems will meet again at FOSDEM (https://fosdem.org) during the weekend of February 1/2, 2025 and will share a developer room. The microkernel and component-based OS devroom is currently looking for your participation in the form of proposals for talks, demos and other related activities. Possible topics for the devroom include, but are not limited to: * introduction of a specific OS or framework * design of subsystems and the general architecture of an OS * languages, tools and toolchains used * enabling support for hardware architectures, devices and programming languages * development processes, debugging * maintenance, testing and release engineering * safety, security and robustness * trends and challenges * research and open questions * community and governance * use cases, experiences and status updates * best practices and lessons learned * live demos Important Dates The deadline for submitting proposals is December 1, 2024 (23:55 CET). Please use the FOSDEM website at https://fosdem.org/submit, select the track "Microkernel and Component-Based OS" and include at least the following information: * title of your proposal * short abstract (one or two paragraphs) * duration (20 - 40 minutes, including demos and Q&A) * your full name * your short bio The devroom schedule (with accepted talks) will be announced on the devroom website at https://fosdem.org/2025/schedule/track/microkernel by December 15, 2024. The schedule will also be posted to the devroom mailing list and the speakers will be notified via email. Like previous years, the devroom will take place as an in-person event at the ULB Campus Solbosch in Brussels, Belgium during the second half of February 1, 2025 (Saturday). Due to the high number of submissions that FOSDEM received this year, our devroom has only been allocated half a day. Therefore, the final decision on the duration of the talks will be made by the devroom organizers based on the number of accepted proposals. Requirements The communication language of the devroom is English. All content must relate to free and open-source software. By participating in the event, you agree to the publication of your talk recordings, slides and other content provided under the same CC-BY license as all other FOSDEM content. All participants are expected to adhere to the Code of Conduct: https://fosdem.org/2025/practical/conduct/ Contact For the 2025 edition, the organizers of the devroom are * Udo Steinberg (udo [at] hypervisor.org) * Alexander van der Grinten (alexander.vandergrinten [at] gmail.com) For any comments, questions and suggestions, please do not hesitate to contact us directly or via microkernel-devroom-manager(a)fosdem.org. About the Devroom Since the first Microkernel OS Devroom at FOSDEM 2012, this devroom has been a part of each subsequent FOSDEM (with slight variations of the name). The focus gradually widened to include component-based, unikernel-based and other operating systems. It has now become a somewhat institutionalized tradition for the open-source operating systems community, a kind of "extended family meeting" and it is one of the places where microkernel and unikernel enthusiasts meet regularly. To date, over two dozen projects have participated in one way or another. Many of the projects face similar challenges but come up with partially different solutions. Therefore, the goal of the devroom is to bring the various projects together, let them exchange ideas, cross-pollinate and socialize. As in the past, the devroom will offer the stage both to established community members and to newcomers. Our goal is to select talks in an inclusive manner and to create a balanced and unbiased schedule, while keeping the quality of the devroom as high as in previous years. About FOSDEM FOSDEM is a two-day conference organized by volunteers to promote the widespread use of free and open-source software. FOSDEM is widely recognized as one of the largest and best such events worldwide. FOSDEM covers a wide spectrum of free and open-source software and hardware projects and offers a platform for people to collaborate. To this end, FOSDEM has set up developer rooms (devrooms) where teams can meet and showcase their projects. Devrooms are a place for teams to discuss, hack and publicly present new ideas, latest results, lightning talks, news and proposals. Besides developer rooms, FOSDEM also offers main tracks, lightning talks, certification exams and project stands. In recent years, FOSDEM has been hosting more than 8000 developers annually at the ULB Solbosch Campus in Brussels, Belgium. The participation in FOSDEM is totally free and requires no registration, although the organizers gratefully accept donations and sponsorship. Devroom Dinner Over the years, it has become a tradition that devroom speakers and enthusiasts meet for dinner somewhere in Brussels on Saturday evening to continue discussions, socialize and meet old and new friends. We plan to follow that tradition in 2025 and will inform you about the exact arrangements later. Hope to see all of you in Brussels! _______________________________________________ l4-hackers mailing list -- l4-hackers(a)os.inf.tu-dresden.de To unsubscribe send an email to l4-hackers-leave(a)os.inf.tu-dresden.de

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vm-basic-pci demo is not working for arm64
by Mohamed Dawod 29 Oct '24

29 Oct '24

Hi, I was trying to run the L4 demo *vm-basic-pci* for *arm64* using the command $ make qemu E=vm-basic-pci but It didn't work because of the missing 2 files : * virt-arm_virt-64_pci.dtb : which is requested by the *modules.list* file in the line : > module[arch=arm64,fname=virt-pci.dtb] dtb/virt-arm_virt-64_pci.dtb * virt-pci.dtbo : which is requested by the *vm-basic-pci.cfg* by the configuration > if (L4.Info.arch() == "arm64") then > dt = "-drom/.fdt" > overlay = "*-drom/virt-pci.dtbo*" > else > dt = "-drom/virt-pci.dtb" > overlay = "" > end I searched for both files in the whole *l4re-snapshot-23.10.1* directory but I couldn't find them Where can I find those necessary files to run *vm-basic-pc*i demo? Thanks in advance, Regards -- Mohamed Dawod *Software Engineer,* Cairo Egypt -- *Driving Innovation! Visit our website www.avelabs.com <http://www.avelabs.com/>*, to read Avelabs Confidentiality Notice, follow this link: http://www.avelabs.com/email/disclaimer.html <http://www.avelabs.com/email/disclaimer.html> _______________________________________________ l4-hackers mailing list -- l4-hackers(a)os.inf.tu-dresden.de To unsubscribe send an email to l4-hackers-leave(a)os.inf.tu-dresden.de

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