On Thu, Jul 19, 2012 at 04:34:50PM +0300, Avi Kivity wrote: > On 07/19/2012 01:49 PM, Gleb Natapov wrote: > >> All those exports suggest it's better to move the fast path into the > >> emulator. > > > > We've already being through that. Putting the code into emulator gives > > us nothing unless it also works on emulator context and working on > > partially initialized emulator context is first dangerous and second > > slower. > > We can make it work on an x86_pio_ctxt. What it gives us is common > code. (x86_emulate_ctxt can include a x86_pio_ctxt when it does pio). > My patches do similar thing, but instead of x86_pio_ctxt they use x86_linearize_ctx. The code is common. > > > >> Suppose we change register access to use callbacks instead of > >> bulk load/save, could we reuse the exising code? > >> > > I do not see that problem. This helper function do basic arithmetics > > on three values. The value itself will be fetched on demand by the emulator. > > I meant to reduce the emulator initialization cost, so it isn't slow. > > btw, I'm guessing that the main speedup comes not from avoiding the > decode, but by doing page-at-a-time instead of word-at-a-time. > And hacking emulator doing page at a time is not trivial an complicates it for no good reason. BTW you were the one who suggested implementing fast pio as a separate code path. -- Gleb. -- 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
