Re: Avoid unneccessary %dr6 accesses in nested VM setups

[Jim Mattson <jmattson@xxxxxxxxxx>]

On Tue, Oct 16, 2018 at 1:37 PM, Christian Ehrhardt <lk@xxxxxxx> wrote:

> -       set_debugreg(0, 6);
> +       if (vcpu->arch.dr6 & ~DR6_RESERVED)
> +               set_debugreg(0, 6);

This will skip setting %dr6 when DR6.RTM is clear. That seems
incorrect, since DR6.RTM is active-low. Should this be:

        if (vcpu->arch.dr6 != DR6_RESERVED)
                set_debugreg(0, 6);