Re: [PATCH v5 1/8] KVM: x86: Add helper to provide intercept linear addresses

[Tina Zhang]

On 9/5/2026 6:34 AM, Jim Mattson wrote:
> > +static u64 get_intercept_linear_addr(struct x86_emulate_ctxt *ctxt,
> > +                                    enum x86_intercept intercept)
> > +{
> > +       u64 la;
> > +
> > +       if (intercept != x86_intercept_invlpg)
> > +               return 0;
> > +
> > +       la = seg_base(ctxt, ctxt->src.addr.mem.seg) + ctxt->src.addr.mem.ea;
> > +       return ctxt->mode == X86EMUL_MODE_PROT64 ? la : (u32)la;
> > +}
>
> The linear address calculation here is replicated from __linearize().
> Perhaps something like:
> static u64 get_invlpg_linear_addr(struct x86_emulate_ctxt *ctxt)
> {
>          unsigned int max_size;
>          ulong linear;
>
>          if (intercept != x86_intercept_invlpg)
>                  return 0;
>
>          __linearize(ctxt, ctxt->src.addr.mem, &max_size, 1,
> ctxt->mode, &linear, X86EMUL_F_INVLPG);
>          return linear;
> }

I initially used the minimal calculation needed for EXITINFO1 because I 
thought some of the additional processing in __linearize() was 
unnecessary when reporting the linear address to L1.  However, reusing 
__linearize() keeps the intercepted path consistent with em_invlpg().  I 
will switch to __linearize() with X86EMUL_F_INVLPG.


> >   static int emulator_check_intercept(struct x86_emulate_ctxt *ctxt,
> >                                      enum x86_intercept intercept,
> >                                      enum x86_intercept_stage stage)
> > @@ -427,6 +447,7 @@ static int emulator_check_intercept(struct x86_emulate_ctxt *ctxt,
> >                  .src_type   = ctxt->src.type,
> >                  .dst_type   = ctxt->dst.type,
> >                  .ad_bytes   = ctxt->ad_bytes,
> > +               .intercept_linear_addr = get_intercept_linear_addr(ctxt, intercept),
>
> Maybe:
> +               .invlpg_linear_addr = get_invlpg_linear_addr(ctxt, intercept),

Yes, this is clearer.


Thanks,
Tina