Re: [Qemu-discuss] Regarding QEMU Monitor "x /fmt addr" command

[Phil Jones]

Sorry, I meant address of an integer variable inside of a process. Thank you 
for the answers, that confirms my suspicions. If I were to translate guest 
process virtual address to Windows physical address, could I use that to read 
value?
________________________________
From: Peter Maydell <address@hidden>
Sent: Thursday, January 17, 2019 19:05
To: Phil Jones
Cc: address@hidden
Subject: Re: [Qemu-discuss] Regarding QEMU Monitor "x /fmt addr" command

On Thu, 17 Jan 2019 at 15:52, Phil Jones <address@hidden> wrote:
>
> Just to make double sure we're talking about the same thing because I'm 
> running into an issue. I am talking about QEMU running under Ubuntu which has 
> WIndows OS as running as guest accelerated by KVM. Inside the guest Windows 
> OS there is a process I am running whose address I got by running debugger 
> and which I want to read from Linux (host). When I try to do this using x 
> command I get "000000000072fe4c: Cannot access memory".


(I don't know what you mean by the "address of a process" here.)

The behaviour of the 'x' command will depend on what process
is actually running at the time in the guest (and also on
what Windows does with its page tables to some extent).

I think what you're really asking for here is a guest
process aware debug interface. QEMU doesn't provide that:
the monitor and gdbstub interfaces are really at the same
level as a hardware JTAG debug interface to a real CPU
would be -- they give you the view that the operating system
sees, not the view that an OS-aware debugger has of an
individual process.

thanks
-- PMM