[Qemu-devel] Adding a custom monitoring device to virt machine

[Qemu-devel] Adding a custom monitoring device to virt machine

[Nassim Corteggiani]

Hi all,


This is the first time I am playing with QEmu.


I made a custom qemu device in oder to monitor all memory accesses (sdram, flash, peripherals, gpio, ...).


The device is parent of TYPE_SYS_BUS_DEVICE and implements a MemoryRegionOps with read/write functions.


The device is part of virt machine, so I called my device contructor from virt.c (fct machvirt_init line 1256).

The constructor set the mmio device range from 0 to RAMLIMIT_BYTES.


The device is well initialized but read/write functions are never called...


Did I miss something ?


If I want to create a dynamically allocated device that can be used by all QEmu machine without adding the device constructor for each machine, how can I process ?


Thank you a lot for any help.


Best regards,

Nassim.

Re: [Qemu-devel] Adding a custom monitoring device to virt machine

[Stefan Hajnoczi]

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On Tue, Aug 23, 2016 at 07:31:53AM +0000, Nassim Corteggiani wrote:
> Hi all,
> 
> 
> This is the first time I am playing with QEmu.
> 
> 
> I made a custom qemu device in oder to monitor all memory accesses (sdram, flash, peripherals, gpio, ...).
> 
> 
> The device is parent of TYPE_SYS_BUS_DEVICE and implements a MemoryRegionOps with read/write functions.
> 
> 
> The device is part of virt machine, so I called my device contructor from virt.c (fct machvirt_init line 1256).
> 
> The constructor set the mmio device range from 0 to RAMLIMIT_BYTES.
> 
> 
> The device is well initialized but read/write functions are never called...
> 
> 
> Did I miss something ?
> 
> 
> If I want to create a dynamically allocated device that can be used by all QEmu machine without adding the device constructor for each machine, how can I process ?

That's probably not the way to go about monitoring memory accesses.

What are you trying to do?

Stefan

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Re: [Qemu-devel] Adding a custom monitoring device to virt machine

[Nassim Corteggiani]

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On Tue, Aug 23, 2016 at 07:31:53AM +0000, Nassim Corteggiani wrote:

> Hi all,
>
>
> This is the first time I am playing with QEmu.
>
>
> I made a custom qemu device in oder to monitor all memory accesses (sdram, flash, peripherals, gpio, ...).
>
>
> The device is parent of TYPE_SYS_BUS_DEVICE and implements a MemoryRegionOps with read/write functions.
>
>
> The device is part of virt machine, so I called my device contructor from virt.c (fct machvirt_init line 1256).
>
> The constructor set the mmio device range from 0 to RAMLIMIT_BYTES.
>
>
> The device is well initialized but read/write functions are never called...
>
>
> Did I miss something ?
>
>
> If I want to create a dynamically allocated device that can be used by all QEmu machine without adding the device constructor for each machine, how can I process ?

> That's probably not the way to go about monitoring memory accesses.

> What are you trying to do?

> Stefan

Thank you for your reply Stefan.

I tried to add my MMIO device on an existing machine thinking that memory area could be "handled" by different devices.
I thought that MMIO device was just notified when IO on a 'monitored' address space occurs.

I solved the problem by creating a QEmu machine. Then I added my Device as a MMIO memory space.

Nassim



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