l4-hackers

l4-hackers@os.inf.tu-dresden.de

2 participants
2880 discussions

saving configuration to version control
by Baruch Burstein 09 Feb '25

09 Feb '25

Hello. After running `make config`, I am trying to save my configuration to git and later restore it. This is for both fiasco and l4. I found that the command `make savedefconfig` works (just like for linux kernel) to create a defconfig file for uploading to git, but the command `make defconfig` for restoring the configuration from this file doesn't work. What file should I be saving/restoring, or what is the process to save/restore my configuration? Either a defconfig or a full configuration would be ok. Thank you _______________________________________________ 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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Use HW random generator to kaslr-seed dtb on uvmm
by Flavio Erlich 04 Feb '25

04 Feb '25

Hi, According to Linux documentation, if I want to use kASLR I should add on my device tree, on the chosen node a kaslr-seed entry ( https://www.kernel.org/doc/Documentation/devicetree/bindings/chosen.txt). I'm running uvmm and I want to use the dt-modify argument to change the value on dtb to a value that comes from an HW random generator at runtime. I have written an application which reads a random sequence from the HW. How can I pass the random value from that application and pass the u64 value to the ned script which I can use as a seed? I can use the application exit code to read 32-bit and run it twice, but seems to be overkill to do that. I was thinking of sending a newer allocatted Dataspace to the application, it will fill it with random data, but I have no idea if it is possible to read this Dataspace and concatenate the result to the arguments to uvmm. Do you have any other suggestions? Thanks for your help, Flavio _______________________________________________ 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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USB on L4RE
by Flavio Erlich 25 Jan '25

25 Jan '25

I found this thesis defence post. https://tu-dresden.de/ing/informatik/sya/professur-fuer-betriebssysteme/die… Does anyone know if or where the code is available? Is the thesis paper available? Thanks, Flavio _______________________________________________ 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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emmc-driver imx8mp
by Alvaro Gallardo 08 Jan '25

08 Jan '25

Dear L4Re experts, I hope you are doing well and enjoying this time of the year. I would like to ask for your help or insights on how to use the emmc-driver in an imx8mp based board. In this platform, the usdhc nodes are located out of the pci bus, and they require an i2c device to work, as well as gpio and clocks. I am able to start the emmc server, which identifies one usdhc device and starts the server loop. I pass a virtual bus to the emmc driver with all required devices, as they usually work in the Virtual Machine to access the mmc. The driver scans all of them, finding the usdhc node. But, everything stops when I create a client, either using a dynamic way with: create(0, "device=...","ds-max=5); or declaring the client in the argument as: "emmc-drv -v --client cl1 --device=... --ds-max=5". For the second way, it stops when the Virtual Machine starts to configure the related virtio device (I am using a virtio_net node). I will be grateful if you can give me some information about the issue or some of the following questions: 1. how should the node in the device tree of the Virtual Machine be configured to work with the emmc client? 2. is it possible that the board's specific hardware configuration required for the mmc is stopping the emmc client to work? 3. Is there any way to test the driver before linking it to a virtual machine? I found an example with the "virtio-block-chksum-sync" module, but I could not find this module. I attach the configuration files, the output text and the base device tree structure. Thank you in advance for your attention. Kind regards, Alvaro Gallardo _______________________________________________ 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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Network failure when high traffic
by Mohamed Dawod 05 Dec '24

05 Dec '24

Hello, I created a new L4 setup with uvmm module and Linux kernel running on it. I added also virtio-net-device and created new tap devices to be able to communicate with the VM from outside of L4. The setup was done successfully and I could ping from my host machine to the Linux VM and vise versa. The problem appeared when I accelerated the ping using -i option : Ping 192.168.7.2 -i 0.01 It continue pings for a few minutes then it gives (Destination Host Unreachable)! I used the wrapper function vmm.start_virtio_switch() in me demo. Why did this issue happen ? And how can I fix it? Thanks, Mohamed _______________________________________________ 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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Video Error Reasons?
by Lonnie Cumberland via l4-hackers 27 Nov '24

27 Nov '24

Hello All, I have been experimenting with L4Re and was able to compile the latest snapshot that seems to work well for almost all of the examples in QEMU from the "make qemu" menu which is a very good start, I think. Lately, I have also used the "make grub2iso" which gives me the same menu of examples as the "make qemu" but for which it will generate an ISO of the example. I generated ISO's for all of the examples and tested them on 3 different x64 computer systems which are all Intel with 2 being NUC's and 1 being a Dell XPS 8950 but when I boot any of the generated L4Re ISO's, it seems to boot all of the core modules but then gets to an error message that seems to be related to the video mode. ------------------------------------------- error: no suitable video mode found ------------------------------------------- And then the screen shows a bunch of lines. I have been looking around though the L4Re code in the snapshot release, but I do not yet have a clue where how to change things so that these ISO's will boot completely on some hardware although things seem to boot up in QEMU. I am thinking that there might just be some setting somewhere that I need to adjust, or something. Any thoughts, suggestions, or ideas would be greatly appreciated. Have a great evening, 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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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

2 1

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

3 2

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

3 4

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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