KVM/ARM: How to read the value of some physical address in HYP mode

KVM/ARM: How to read the value of some physical address in HYP mode

[harry]

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Hi, 


I want to read the value of some physical address in HYP mode. But maybe there isn't any interface to achieve this. I hope to get some ideas to achieve this.


And now I have a simple idea, but I don't know if it is possible. When the HYP mode is init, we create a mapping from one special virtual address to some physical address. And map the va to HYP mode. When we want to read the value of some PA, we modify the page table to let the special VA map to the PA, then we read the special VA and get the value of the PA. Because I only start to research on the KVM, so I am not sure if this can work. I hope to get help to achieve this.


Thanks and regards,
Harry

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Re: KVM/ARM: How to read the value of some physical address in HYP mode

[Christoffer Dall]

On Mon, Aug 17, 2015 at 09:59:20AM +0800, harry wrote:
> Hi, 
> 
> 
> I want to read the value of some physical address in HYP mode. But maybe there isn't any interface to achieve this. I hope to get some ideas to achieve this.
> 

If I understand your question correctly, you simply have to map the
physical address into hyp mode's virtual address space and read from
that address.

-Christoffer

> 
> And now I have a simple idea, but I don't know if it is possible. When the HYP mode is init, we create a mapping from one special virtual address to some physical address. And map the va to HYP mode. When we want to read the value of some PA, we modify the page table to let the special VA map to the PA, then we read the special VA and get the value of the PA. Because I only start to research on the KVM, so I am not sure if this can work. I hope to get help to achieve this.
> 
> 
> Thanks and regards,
> Harry

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