On Thu, Dec 20, 2012 at 12:03:29AM +0100, Borislav Petkov wrote: > On Wed, Dec 19, 2012 at 04:59:41PM -0600, Jacob Shin wrote: > > I can check but right, they might be used up. But even if we had slots > > available, the memory range that needs to be covered is in large > > enough address and aligned in such a way that you cannot cover it with > > variable range MTRRs. > > Actually, if I'm not mistaken, you only need to cover the HT hole with > one MTRR - the rest remains WB. And in order the mask bits to work, we > could make it a little bigger - we waste some memory but that's nothing > in comparison to the MCE.
Actually all memory hole above 4GB and under TOM2 needs to be marked as UC, if the kernel just blanket calls init_memory_mapping from 4GB to top of memory. Right we would be loosing memory, and I think depending on the alignment of the boundary and how many MTRRs you have avaiable to use, significant chunks of memory could be lost. I need to go refresh on how variable range MTRRs are programmed, it has been a while. > > You might need to talk to hw guys about the feasibility of this deal > though. > > Thanks. > > -- > Regards/Gruss, > Boris. > > Sent from a fat crate under my desk. Formatting is fine. > -- > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
