Jim Keniston wrote: > > For user-space probing, we've been concentrating on native-built > executables. Am I correct in thinking that we'll see 16-bit or V86 mode > only on legacy apps built elsewhere? In any case, it only makes sense > to build on the kvm folks' work in this regard. > That's a fair assumption; you will of course need to test it and take appropriate action if it doesn't pan out. > > As noted, the INAT tables follow the kvm model of one fat bitmap of > attributes per opcode, rather than the kprobes/uprobes model of one or > two 256-bit tables per attribute. (This latter approach was due to the > gradual accumulation of tables over the years.) > > I like the bitmap-per-opcode approach because it's relatively easy to > see in one place everything you're saying about a particular opcode. > But with all the potential clients for this service, it's not clear that > we'll get by with a single bitmap for every opcode. (x86 kvm uses 32 > bits per opcode, I think, and the INAT tables use 10. Seems like we > could overrun 64 bits pretty quickly.) So I guess that means we'll have > to get a little creative as to how we expose these attribute sets to the > client. > This is another very good reason to use an instruction table which is preprocessed into a usable format: it means that if the internal data structures change -- and they almost certainly will have to at some point -- the raw data isn't lost. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
