Re: [Qemu-devel] [Question] dump memory when host pci device is used by guest

[Paolo Bonzini]

On 10/25/2011 10:23 AM, Avi Kivity wrote:
> On 10/25/2011 10:06 AM, Wen Congyang wrote:
> > Hi, Avi Kivity, Dave Anderson
> >
> > I have two questions about it:
> >
> > 1. How to know the guest's physical base address in qemu?
>
> In fact, it's impossible.
>
> Perhaps crash can scan through the core looking for a signature.  Need
> to be careful since multiple signatures may be detected (a kdump kernel,
> a kernel image in pagecache, or a nested guest).

Crash uses a heuristic based on the IDT base to identify the base from 
migrate-to-file output.  It also needs CR3 in order to read from virtual 
address.

Paolo