Does KVM work on IBM POWER7 Big-Endian with Debian PPC64? - qemu

I have an IBM POWER7 Big-Endian with Debian-10-PPC64 host and Qemu-system-x86_64 (for running Linux x86 guests) installed. KVM module is present and loaded but I can't get it enabled.
Whatever attempts made result in "qemu-system-x86_64: invalid accelerator kvm". And "qemu-system-x86_64 -accel help" says that "Accelerators supported in QEMU binary: tcg"
Does Qemu in Debian PPC64 support KVM integration?
Is it possible compile Qemu from scratch and enable this feature? It would be necessary to compile kernel code too?
Thank you in advance.

KVM requires that the host and guest architecture are the same (because it is using the virtualization hardware of the host CPU). That means that you can't use it to run an x86-64 guest on a PPC host, and that's why qemu-system-x86_64 (when built for PPC hosts) says it does not have KVM support. You need to use qemu-system-ppc64 and a PPC64 guest OS.

Related

Installing QNX on aarch64 QEMU

I am trying to get a virtual machine running QNX on ARM64 virtual machine using QEMU.
I am not sure how to get installation iso. I don't know if am looking into the wrong direction.
QNX provides a virtual machine for VMware but not a generic way to create one for different architecture.
Please point me to a complete guide for the process if available.

Booting a QorIQ PowerPC firmware in Qemu

I have a QorIQ (P2041) processor based IoT device firmware. I have uBoot, Kernel and initrd ramdisk. Whatever I do with qemu-system-ppc I can't get it to work. I suspect that qemu-system-ppc doesn't support QorIQ processors. Is there anyway for me to load and boot this firmware in Qemu or any other emulator?
U-Boot has configuration file qemu-ppce500_defconfig. You should be able to run the U-Boot built with this configuration using command
qemu-system-ppc -nographic -bios u-boot -M ppce500
The CPU can be specified via the -cpu parameter as e500mc.
To run your kernel it will need drivers for the hardware provided by the emulated machine like the E1000 network card and the NS16550 console.
Use the fdt command of U-Boot to get an overview of the available devices in the emulated machine.
Firmware binaries are generally very closely tied to the hardware they're built to run on -- they make assumptions about what hardware is available, what addresses in memory it can be found at, and so on. You need to use a firmware blob that corresponds to the hardware you're asking QEMU to emulate. Since QEMU doesn't emulate whatever your random IoT device is, you need to use a u-boot which matches the hardware QEMU actually has (as for example suggested in Xypron's answer).
Once you have booting firmware, you will likely still find you have exactly the same problem with the kernel -- it is built to run on one bit of hardware, and you're trying to run it on something different, and this simply won't work.

Verifying CUDA-Capable GPU in Ubuntu

I downloaded and installed CUDA-7.5 and found that instruction that I need to check whether I have a CUDA-Capable GPU.
I did as
lin#lin-VirtualBox:/opt/caffe$ sudo update-pciids
Downloaded daily snapshot dated 2015-09-07 03:15:01
then why I type
lspci | grep -i nvidia
nothing comes out.
lin#lin-VirtualBox:/opt/caffe$ lspci | grep -i nvidia
lin#lin-VirtualBox:/opt/caffe$
I have NVIDIA graphic card GEFORCE GT750M.
What could be wrong?
My OS is Ubuntu14.04.
Thanks
It seems you are running in a VirtualBox VM (virtual machine) instance. With a typical VirtualBox setup, the graphics in the VM is virtualized; there is no physical GPU device present in the VM.
As a result, the GPU does not show up when you run lspci in the VM.
One possible approach to work around this would be to switch to a "baremetal" config; i.e. load Ubuntu directly on your laptop as the primary (or "host") OS, rather than in a VM. The GPU should show up that way.
Another possible approach would be to attempt to use VirtualBox PCI Passthrough to make the GPU "visible" in the VM. Whether or not this would work in a laptop scenario I don't know; there may be side effects of trying to pass through the laptop GPU to a VM; your laptop hypervisor and any other OS's would not have access to the GPU (or the laptop display) in this situation. I think there are a number of other requirements and restrictions with this approach. Your laptop hardware may or may not meet the requirements, and I think it is expected that the host OS uses some specific flavors of linux (kernel); you may have windows as the host OS on your laptop.
In any event, how to configure your machine with VirtualBox and/or PCI Passthrough is not a programming question, and I think is off-topic for SO. You might try askubuntu or another similar forum, for related questions.

Anyone can introduce some primers about qemu-kvm and kvm?

I am a fresh man in kvm,qemu-kvm and kvm are both very complicated now.
Anyone can introduce some primers about qemu-kvm and kvm?
thanks very much!
KVM stands for kernel based virtual machine. it enables you to create as many number of virtual machine as you like. These machine can be of two types LVM based or Non-LVM based.
Those machine which are LVM based you can take live backup for them. for non-lvm based VM you cannot take live backup i.e. they will be paused when you take backup for them. please refer KVM home page KVM Home Page.
QEMU is a generic and open source machine emulator and virtualizer.When used as a machine emulator, QEMU can run OSes and programs made for one machine (e.g. an ARM board) on a different machine (e.g. your own PC). By using dynamic translation, it achieves very good performance. When used as a virtualizer, QEMU achieves near native performances by executing the guest code directly on the host CPU. QEMU supports virtualization when executing under the Xen hypervisor or using the KVM kernel module in Linux. When using KVM, QEMU can virtualize x86, server and embedded PowerPC, and S390 guests.
For managing the KVM VM's you need to install Libvirt which is the virtualization library. It provides you the tools for starting, suspending, resuming, cloning, restarting, listing of virtual machine. Please refer Libvirt home page for more reference.
If you are working on some backup or recovery process then I suggest you to go through this excellent perl script as well it will give a fair idea of how the backup and snapshot is being taken for KVM VM's.
KVM based virtual machines are not complicated once you go through the theory of them and start implementing them. I believe once you start working on them you will find fun in managing them.
Putting in a nutshell
QEMU : An emulator which translates the instruction of guest operating system to host operating system. As you can guess that translation has a certain cost, you will not see Guest machine working as fast as host machine.
For more info see the QEMU wiki
KVM (Kernal Virtual Machine): A module in Kernel which support Virtual Machine (host operating system) in hardware. By support I mean that if your guest architecture is same as host architecture, then certainly there is no need to translate the instructions as they can directly be executed by host. For this modern hardware are equipped with special registers and storage location which is leveraged by KVM. Also KVM is a module, some driver is needed to use the KVM, which is qemu also.
For more info see the KVM section in the same wiki.
QEMU-KVM : As I above mentioned, KVM is a module only, qemu is needed (or other) to use KVM. When KVM is used with QEMU, control transfers from QEMU to KVM and vice-versa over the execution.
Talking about KVM is talking about virtualization technology or about kernel modules (kvm.ko, kvm-intel.ko or kvm-amd-ko). Sometimes KVM is mentioned as a virtual machine, this is not correct, because KVM does not provide virtualized hardware.
Source

CUDA Debugging - VS on windows workstation, GPUs on Linux server?

Has anyone had any experience debugging CUDA code on a server while coding on a workstation?
My laptop (Thinkpad T400) doesn't support CUDA, but I have access to a server with pair of NVIDIA GTX 295 cards that runs Linux.
Can I use NVidia's Visual Studio tools to debug remotely on the server?
Failing that, I also have an Ubuntu VM running on my laptop. Is there a debugger that I can use under Linux to debug on the server?
I really don't want to have to buy another laptop with dual NVidia cards.
Developing in c on a remote linux machine (like your server) is quite common. You can ssh onto the server from any client (like your laptop) to compile and run the code just as you would if you were sitting at the machine, and you can use gdb to debug your code in a terminal. You can also use ddd as a graphical front end to gdb or a linux IDE such as eclipse by forwarding X11 over ssh.
You can use cuda-gdb to debug your CUDA code in a terminal in exactly the same way. Unfortunately, there is not a visual cuda debugger for linux yet. However, it appears you can use ddd with cuda-gdb [source], as you have two gpus. I'm not sure about using cuda-gdb in eclipse.
Yes you can but you need to buy the Parallel Nsight Studio from Nvidia
After installing on the remote machine the NsightDebugServer you can upload and debug programs from
your cuda-less laptop.
Update
Turns out This solution requires a WINDOWS server in order to run the NsightDebugServer.
To connect to the linux machine from your laptop, use a remote connection.
install putty and a Xserver for windows and just login with
ssh -X username#cudaserver.
The environment would not be fancy as Visual Studio but you can do the basic steps of debugging.
Eclipse "might" have some support for remote gdb servers. Never experimented that (Emacs + gdb is sufficient for me)