Hypervisor SMP Issue - hypervisor

previously thank you for read my Question.
I'm implementing 'SMP' work on my hypervisor project.
What i want to do is like bellow.
One virtual machine have two vcpus. And this Virtual Machine is working on 2 pCPU.
For example, one linux has 2 cpu as SMP.
Firstly, what i tried is set pc value as 0x80500000.
(zIamge is on 0x80500000 address)
when both pcpu run, pcpu0 works fine. but pcpu1 got a error like bellow.
It means 'prefetch abort' from Virtual Machine. and it's occurred when access level 3 as iss indicate 'f'.
I don't know how to access this problem to solve.
If you need any specific information, please tell me. i will add more information.
Please tell me any tips and check point to solve this.
Lastly, thank you.!!

Related

what are the full steps to considere in order to put the Raspberry pi SD card in read only reliably?

Intro
I wanna give a last chance to this board before put it in a trash haha :). Right now I prefer use standard motherboards, Ubuntu server, automatic main power switch and perif. to have something reliable over the time though.
Raspberry Pi wanted configuration
-wanna use Rasbian 11.
-no boot from external hdrive.
-will mount external hdrive using the UUID for the data
My questions
1 - Enable overlay and readOnly mode (in raspi-config) doesn't seem good enough- With this method rootfs parition in fstab is not 'ro'. So what?
2 - Is it more reliable to have the both partiton in readOnly (boot and rootfs) ?
3 - What about the log, temp, ram,...? Is there anything else to think about? What would be the complete list with a bit of explanation?
Thank you!
I have try to edit fstab, and add 'ro' to the rootfs partition but doesn't keep after a reboot.

How to get Device Instance Path from Windows kernel driver?

Take a look at this example: a USB device in Windows 7 is reported to have Device instance path(DevinstPath) USB\VID_1EAB&PID_0501\7&25C389C1&0&1 and I know exactly that it corresponds to the so-called hardware-key(hwkey) in registry.
Now my question is: When my KMDF driver code has WDFDEVICE handle for that USB device, how can I know its DevinstPath?
I know I can
send a BusQueryDeviceID to achieve the so-called device-id USB\VID_1EAB&PID_0501;
send a BusQueryInstanceID to achieve the so-called instance-id 1 .
But I don't know how to get the so-called "instance-path". Could some kernel guru kindly tell me how I can get that?
MSDN doc seems really vague on this!
BTW: I also realize that user-layer function SetupDiGetDeviceInstanceId actually returns the DevinstPath -- although it is named "InstanceId".
Device instance path can be queried using DEVPKEY_Device_InstanceId, using either WdfDeviceAllocAndQueryPropertyEx or IoGetDevicePropertyData (passing the WDM physical device object)
Device Instance id is autoincrement sequence.
You can find HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum in registry;
Rules:NextPareneID.XXXXXXXX.N
XXXXXX use UUID Calculation crc32 values(test ok)
N is 1~9
Device Instance id format is N&PareneID&random's number&index
enter image description here

Siemens S7-1200. TRCV_С. Error code: 893A; Event ID 02:253A

Please, help to solve the problem with communication establishment between PC and 1211C (6ES7-211-1BD30-0XB0 Firmware: V 2.0.2). I feel that I've made a stupid mistake somewhere, but can't figure out where exactly it is.
So, I'm using function TRCV_С...
The configuration seems to be okay:
When i set the CONT=1, the connection establishes without any problems...
But, when i set EN_R=1, I'm getting "error 893A".
That's what I have in my diagnostic buffer: (DB9 - is a block where the received data is supposed to be written)
There is an explanation given for "893A" in the manuals: Parameter contains the number of a DB that is not loaded. In diag. buffer its also written that DB9 is not loaded. But in my case it is loaded! So what should I do in this case?
it seems that DB were created or edited manually due to which they are miss aligned with FB instances try removing and DB and FB instances and then add again instances of FBs with automatically created DBs and do a offline dowonload

Virtual Com-Port communication through Matlab

While connecting my Com-port using matlab, many a times(4 out of 5) I get an error
??? Error using ==> serial.fopen at 72
Port: COM21 is not available. Available ports: COM3,
COM10, COM17, COM18.
However , sometimes it gets connected and responds as expected.
Can anyone tell me whats the problem with this?
By the way , I am using this snippet to connect my microcontroller to PC through USB
s = serial('COM21'); // code to initialize the req COM i.e. COM21 for me
fopen(s);
I ran into this issue before. It turns out MATLAB doesn't really handle plug-and-play very well, as evidenced by this thread:
http://www.mathworks.com/matlabcentral/newsreader/view_thread/311133
Long story short: if you want MATLAB to detect a hardware change, you need to restart it. MATLAB seems to only look for devices when it starts up.

Getting the IO count

I am using xen hypervisor. I am trying to get the IO count of the VMs running on top of the xen hypervisor. Can someone suggest me some way or tool to get the IO count ? I tried using xenmon and virt-top. Virt-top doesnt give any value and xenmon always shows 0. Any suggestions to get the number of read or write calls made by a VM or the read and write(Block IO) bandwidth of a particular VM. Thanks !
Regards,
Sethu
You can read this directly from sysfs on most systems. You want to open the following directory:
/sys/devices/xen-backend
And look for directories starting with vbd-
The nomenclature is:
vbd-{domain_id}-{vbd_id}/statistics
Inside, you'll find what you need, which is:
br_req - Number of block read requests
oo_req - Number of 'out of' requests (no room left in list to service any given request)
rd_req - Number of read requests
rd_sect - Number of sectors read
wr_sect - Number of sectors written
The br_req will be an aggregate count of things like write barriers, aborts, etc.
Note, for this to work, The kernel has to be told to export Xen attributes via sysfs, but most Xen packages have this enabled. Additionally, the location in sysfs might be different with earlier versions of Xen.
have you tried xentop?
There is also bwm-ng (check your distro). It shows block utilization per disk (real/virtual). If you know the name of the virtual disk attached to the VM, then you can use bwm-ng to get those stats.