> -----Original Message-----
> From: Paolo Bonzini <[email protected]>
> Sent: Wednesday, July 29, 2020 6:12 PM
> To: Jim Mattson <[email protected]>; Moger, Babu
> <[email protected]>
> Cc: Vitaly Kuznetsov <[email protected]>; Wanpeng Li
> <[email protected]>; Sean Christopherson
> <[email protected]>; kvm list <[email protected]>; Joerg
> Roedel <[email protected]>; the arch/x86 maintainers <[email protected]>; LKML
> <[email protected]>; Ingo Molnar <[email protected]>; Borislav
> Petkov <[email protected]>; H . Peter Anvin <[email protected]>; Thomas Gleixner
> <[email protected]>
> Subject: Re: [PATCH v3 03/11] KVM: SVM: Change intercept_dr to generic
> intercepts
> 
> On 29/07/20 01:59, Jim Mattson wrote:
> >>         case SVM_EXIT_READ_DR0 ... SVM_EXIT_WRITE_DR7: {
> >> -               u32 bit = 1U << (exit_code - SVM_EXIT_READ_DR0);
> >> -               if (svm->nested.ctl.intercept_dr & bit)
> >> +               if (__is_intercept(&svm->nested.ctl.intercepts,
> >> + exit_code))
> > Can I assume that all of these __<function> calls will become
> > <function> calls when the grand unification is done? (Maybe I should
> > just look ahead.)
> >
> 
> The <function> calls are reserved for the active VMCB while these take a 
> vector.
> Probably it would be nicer to call them vmcb_{set,clr,is}_intercept and make
> them take a struct vmcb_control_area*, but apart from that the concept is fine
> 
> Once we do the vmcb01/vmcb02/vmcb12 work, there will not be anymore
> &svm->nested.ctl (replaced by &svm->nested.vmcb12->ctl) and we will be able
> to change them to take a struct vmcb*.  Then is_intercept would for example be
> simply:
Yea. True. It makes the code even cleaner. Also we can avoid calling
recalc_intercepts every time we set or clear a bit inside the same
function(like init_vmcb).

Let me try to understand.

vmcb01 is &svm->vmcb->control;l
vmcb02 is &svm->nested.hsave->control
vmcb12 is  &svm->nested.ctl;

The functions set_intercept and clr_intercept calls get_host_vmcb to get
the vmcb address.

static inline struct vmcb *get_host_vmcb(struct vcpu_svm *svm)
{
        if (is_guest_mode(&svm->vcpu))
                return svm->nested.hsave;
        else
                return svm->vmcb;
}

I need to study little bit when is_guest_mode Is on or off.  Let me take a
look at.

Thanks

> 
>       return vmcb_is_intercept(svm->vmcb, nr);
> 
> as expected.
> 
> Paolo

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