Using a standard linux shell, I can use ps to get process information, including ram and cpu.
On the adb shell equivalent, I do not see CPU usage:
root#generic_x86:/ # ps
USER PID PPID VSIZE RSS WCHAN PC NAME
u0_a99 3129 947 1630132 156124 ffffffff b753f355 S com.example.app
How can I view CPU usage by app in the shell?
Related
I am planning to perform nested virtualization with GPU device. I have guest Ubuntu OS running and I have mapped GPU to it by enabling intel_iommu on the host, and configuring NVIDIA PCI as vfio-pci device. I am also able to install NVIDIA driver on the guest and use it for deep-learning.
However, now I want to run another VM inside the guest, let's call the guest that runs on host as L1 and the guest that runs on guest as L2, I want the GPU to be accessiable by the L2 guest, I came across vIOMMU supported on Q35 Qemu chipset, how do I enable IOMMU on L1 guest, so that I can pass the gpu directly to L2 guest??
Hardware :
Intel i7 8th Gen
NVIDIA GeForce 1070
Linux - Ubuntu 18.04,
Hypervisor - KVM
There are a couple of things to be done on KVM-QEMU to allow nested IOMMU
Use BIOS OVMF.fd, because default bios might not support the same
enable the chipset q35 with accel=kvm,kernel_irqchip=split
then check with dmesg | grep -e DMAR -e IOMMU and find /sys/kernel/iommu_groups/ -type l, for iommu groups inside the VM.
Hopefully with fs.py, but not necessarily.
For example, I have some x86 BIOS example that draw a line on the screen on QEMU, and I'd like to see that work on gem5 too.
Interested in all archs.
https://www.mail-archive.com/gem5-users#gem5.org/msg15455.html
arm
I have managed to get an image on the screen for ARM.
Here is a highly automated setup which does the following steps:
grab the ARM gem5 Linux kernel v4.15 fork from: https://gem5.googlesource.com/arm/linux/ and use the config file arch/arm/configs/gem5_defconfig from there.
The fork is required for the commit drm: Add component-aware simple encoder https://gem5.googlesource.com/arm/linux/ I believe, which adds the required option CONFIG_DRM_VIRT_ENCODER=y.
The other required option is CONFIG_DRM_HDLCD=y, which enables the HDLCD ARM IP that manages the display: http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0541c/CHDBAIDI.html
run gem5 at 49f96e7b77925837aa5bc84d4c3453ab5f07408e
with a command of type:
M5_PATH='/data/git/linux-kernel-module-cheat/out/common/gem5/system' \
'/data/git/linux-kernel-module-cheat/out/common/gem5/build/ARM/gem5.opt' \
--debug-file=trace.txt \
-d '/data/git/linux-kernel-module-cheat/out/arm/gem5/m5out' \
'/data/git/linux-kernel-module-cheat/gem5/gem5/configs/example/fs.py' \
--disk-image='/data/git/linux-kernel-module-cheat/out/arm/buildroot/images/rootfs.ext2' \
--kernel='/data/git/linux-kernel-module-cheat/out/arm/buildroot/build/linux-custom/vmlinux' \
--mem-size='256MB' \
--num-cpus='1' \
--script='/data/git/linux-kernel-module-cheat/data/readfile' \
--command-line='earlyprintk=pl011,0x1c090000 console=ttyAMA0 lpj=19988480 rw loglevel=8 mem=256MB root=/dev/sda console_msg_format=syslog nokaslr norandmaps printk.devkmsg=on printk.time=y' \
--dtb-file='/data/git/linux-kernel-module-cheat/out/common/gem5/system/arm/dt/armv7_gem5_v1_1cpu.dtb' \
--machine-type=VExpress_GEM5_V1 \
connect to the VNC server gem5 provides with your favorite client.
On Ubuntu 18.04, I like:
sudo apt-get install vinagre
vinagre localhost:5900
The port shows up on a gem5 message of type:
system.vncserver: Listening for connections on port 5900
and it takes up the first free port starting from 5900.
Only raw connections are supported currently.
Outcome:
after a few seconds, the VNC client shows up a little penguin on the screen! This is because our kernel was compiled with: CONFIG_LOGO=y.
the latest frame gets dumped to system.framebuffer.png, and it also contains the little penguin.
the Linux kernel dmesg shows on telnet 3456 terminal a messages like:
[ 0.152755] [drm] found ARM HDLCD version r0p0
[ 0.152790] hdlcd 2b000000.hdlcd: bound virt-encoder (ops 0x80935f94)
[ 0.152795] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
[ 0.152799] [drm] No driver support for vblank timestamp query.
[ 0.215179] Console: switching to colour frame buffer device 240x67
[ 0.230389] hdlcd 2b000000.hdlcd: fb0: frame buffer device
[ 0.230509] [drm] Initialized hdlcd 1.0.0 20151021 for 2b000000.hdlcd on minor 0
which shows that the HDLCD was enabled.
when we connect, gem5 shows on stdout:
info: VNC client attached
TODO: also get a shell working. Currently I only have a the little penguin, and my keystrokes do nothing. Likely have to tweak the console= kernel parameter or setup a tty console there on init? CONFIG_FRAMEBUFFER_CONSOLE=y is set. Maybe the answer is contained in: https://www.kernel.org/doc/Documentation/fb/fbcon.txt
aarch64
The aarch64 gem5 defconfig does not come with all required options, e.g. CONFIG_DRM_HDLCD=y.
Adding the following options, either by hacking or with a config fragment made it work:
CONFIG_DRM=y
CONFIG_DRM_HDLCD=y
CONFIG_DRM_VIRT_ENCODER=y
I've seen a lot of examples how to run a QEMU ARM board emulator. In every case, besides SD card image param, QEMU was also always supplied with kernel param, i.e.:
qemu-system-arm -M versatilepb \
-kernel vmlinuz-2.6.18-6-versatile \ #KERNEL PARAM HERE
-initrd initrd.gz \
-hda hda.img -append "root=/dev/ram"
I am palying with bootloaders and want to create my own bootable SD card, but don't have a real board yet and want to learn with an emulated one. However, if run as described above, QEMU skips bootloader stage and runs kernel.
So what should I do to emulate a full boot sequence on QEMU so that it executes bootloader? Should I get a ROM dump and pass it as a -bios param?
You can do that by feeding the uboot image. I never used ROM dump.
QEMU BOOT SEQUENCE:
On real, physical boards the boot process usually involves a non-volatile memory (e.g. a Flash) containing a boot-loader and the operating system. On power on, the core loads and runs the boot-loader, that in turn loads and runs the operating system.
QEMU has the possibility to emulate Flash memory on many platforms, but not on the VersatilePB. There are patches ad procedures available that can add flash support, but for now I wanted to leave QEMU as it is.
QEMU can load a Linux kernel using the -kernel and -initrd options; at a low level, these options have the effect of loading two binary files into the emulated memory: the kernel binary at address 0x10000 (64KiB) and the ramdisk binary at address 0x800000 (8MiB).
Then QEMU prepares the kernel arguments and jumps at 0x10000 (64KiB) to execute Linux. I wanted to recreate this same situation using U-Boot, and to keep the situation similar to a real one I wanted to create a single binary image containing the whole system, just like having a Flash on board. The -kernel option in QEMU will be used to load the Flash binary into the emulated memory, and this means the starting address of the binary image will be 0x10000 (64KiB).
This example is based of ARM versatilepb board
make CROSS_COMPILE=arm-none-eabi- versatilepb_config
make CROSS_COMPILE=arm-none-eabi- all
Creating the Flash image
* download u-boot-xxx.x source tree and extract it
* cd into the source tree directory and build it
mkimage -A arm -C none -O linux -T kernel -d zImage -a 0x00010000 -e 0x00010000 zImage.uimg
mkimage -A arm -C none -O linux -T ramdisk -d rootfs.img.gz -a 0x00800000 -e 0x00800000 rootfs.uimg
dd if=/dev/zero of=flash.bin bs=1 count=6M
dd if=u-boot.bin of=flash.bin conv=notrunc bs=1
dd if=zImage.uimg of=flash.bin conv=notrunc bs=1 seek=2M
dd if=rootfs.uimg of=flash.bin conv=notrunc bs=1 seek=4M
Booting Linux
To boot Linux we can finally call:
qemu-system-arm -M versatilepb -m 128M -kernel flash.bin -serial stdio
You will need to pass it some kind of bootloader image via -bios (or a pflash option), yes. I doubt that a ROM dump would work though -- typically the ROM will assume much closer fidelity to the real hardware than QEMU provides. You'd want a bootloader written and tested to work with QEMU. One example of that is if you use the 'virt' board and a UEFI image which is built for QEMU.
Otherwise QEMU will use its "built in bootloader" which is a handful of instructions that are capable of booting the kernel you pass it with -kernel.
I have an application which I want to monitor it via perf stat when running inside a kvm VM.
After Googling I have found that perf kvm stat can do this. However there is an error by running the command:
sudo perf kvm stat record -p appPID
which results in help representation ...
usage: perf kvm stat record [<options>]
-p, --pid <pid> record events on existing process id
-t, --tid <tid> record events on existing thread id
-r, --realtime <n> collect data with this RT SCHED_FIFO priority
--no-buffering collect data without buffering
-a, --all-cpus system-wide collection from all CPUs
-C, --cpu <cpu> list of cpus to monitor
-c, --count <n> event period to sample
-o, --output <file> output file name
-i, --no-inherit child tasks do not inherit counters
-m, --mmap-pages <pages[,pages]>
number of mmap data pages and AUX area tracing mmap pages
-v, --verbose be more verbose (show counter open errors, etc)
-q, --quiet don't print any message
Does any one know what is the problem?
Use kvm with vPMU (virtualization of PMU counters) - https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/Virtualization_Tuning_and_Optimization_Guide/sect-Virtualization_Tuning_Optimization_Guide-Monitoring_Tools-vPMU.html "2.2. VIRTUAL PERFORMANCE MONITORING UNIT (VPMU)"). Then run perf record -p $pid and perf stat -p $pid inside the guest.
Host system has no knowledge (tables) of guest processes (they are managed by guest kernel, which can be non Linux, or different version of linux with incompatible table format), so host kernel can't profile some specific guest process. It only can profile whole guest (and there is perf kvm command - https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/Virtualization_Tuning_and_Optimization_Guide/chap-Virtualization_Tuning_Optimization_Guide-Monitoring_Tools.html#sect-Virtualization_Tuning_Optimization_Guide-Monitoring_Tools-perf_kvm)
I just created an USB drive and would like to check if it's correctly bootable without rebooting my actual computer. How should I do?
Under Linux, you have to know which device path got the drive with for example with dmesg | tail after insertion, let's assume it's /dev/sdb.
Qemu
sudo qemu -hda /dev/sdb or sudo qemu-system-x86_64 -hda /dev/sdb for 64 bits.
VirtualBox
VBoxManage internalcommands createrawvmdk -filename ~/usb.vmdk -rawdisk /dev/sdb
sudo chmod 666 /dev/sdb*
then add ~/usb.vmdk as a disk in a VM and boot on it
Don't hesitate to add other ways to do.
While it won't show if the stuff on the filesystem is capable of handling the whole boot thing you can check the boot flag with fdisk -l <drive> from a shell on a reasonably good *nix. (Which essentially tells the bios if it should try to boot the thingie or not.)