LBR and Virtualization

LBR and Virtualization

I'm using LBR to trace guest execution, each time before vm_enter I overwrite the MSR_LASTBRANCH_(N-1)_FROM_IP/TO values with a magic value (0xdeadbabe) and execute a few instructions and read out the values. sometimes a record is skipped in the LBR and contains the magic value.
why would this ever happen? I've look at the errata for haswell and didn't see anything similar, and running a similar code on the host outputs a perfect sequential trace. could this be an hardware bug related to vmx?

2 posts / 0 nouveau(x)
Dernière contribution
Reportez-vous à notre Notice d'optimisation pour plus d'informations sur les choix et l'optimisation des performances dans les produits logiciels Intel.

You might want to check with open-source community to see how they would handle the issue that you are having. 

Here are some examples of Virtualization code:


Laisser un commentaire

Veuillez ouvrir une session pour ajouter un commentaire. Pas encore membre ? Rejoignez-nous dès aujourd’hui