[Qemu-devel] need help

[Qemu-devel] need help

[oussema ben khedher]

hello 

im an engineer student and im working in my educational project implementation of hardware tinstructions trace in qemu 

i don't know where i can implement it in qemu 

thanks 

[Qemu-devel] need help

[oussema ben khedher]

hi i m using the log in_asm to get the assembly code of TB so when i searched inside qemu i find that the function "log_target_disas its the responsible to display assembly instruction but the problem that i did not find how really it works because i need to get all the branch address 
thank you 

[Qemu-devel] need help

[oussema ben khedher]

I am trying to understand the block chaining of QEMU. And I have a question about the branch direction of each executed TBs. Suppose the TB#1 has been executed now, and find the next_tb (TB#2). Then we know the direction is TB#1--->TB#2 and store the chain in code cache for speedup the execution next time. So, next time qemu find the next TB (which is TB#1), then TB#1--->TB#2 will be executed in code cache.
But I think that there are two branch direction of a TB.(branch taken/not taken) My question is how qemu ensure the direction is TB#1--->TB#2 next time?
Thanks all.

Re: [Qemu-devel] need help

[Peter Maydell]

On 1 March 2017 at 09:50, oussema ben khedher <oussemakeder@yahoo.fr> wrote:
> I am trying to understand the block chaining of QEMU. And I have
> a question about the branch direction of each executed TBs.
> Suppose the TB#1 has been executed now, and find the next_tb (TB#2).
> Then we know the direction is TB#1--->TB#2 and store the chain
> in code cache for speedup the execution next time. So, next time
> qemu find the next TB (which is TB#1), then TB#1--->TB#2 will be
> executed in code cache.
> But I think that there are two branch direction of a TB.(branch
> taken/not taken) My question is how qemu ensure the direction is
> TB#1--->TB#2 next time?

Every TB has two outbound links (though one may be unused for
an unconditional branch). When we chain a TB together we only
chain the link that we took. So if we do a "branch taken" exit
from TB1 and find that it goes to TB2, then we link TB1's
branch-taken code path directly to TB2. But that doesn't affect
the branch-not-taken codepath. Later if we do a branch-not-taken
exit from TB1 we may be able to chain it to a different TB.

(In fact the outbound links are just numbered 0 and 1, and
there's no requirement to use them for taken and not-taken
in any particular order.)

thanks
-- PMM

[Qemu-devel] need help

[oussema ben khedher]

hi 

im an embedded systems engineer and i need help for my educational project implementation of inqstruction trace on qemu 

 can you help me by documentation or advices ? 

[Qemu-devel] Need Help

[Tushar Bhardwaj]

Respected Sir,

I worked a lot bu not getting idea of how to setup experimental lab using
kvm qemu to implement the pre-copy live migration technique.

You are requested to mail me few steps for the same.

-- 

"Purity and Simplicity Reflects the Inner Beauty of soul"




*Thank you With Regards:Tushar Sharma,*


*IIT Kharagpur*