On Thu, Jul 13, 2023 at 10:24:48AM +0000, Huang, Kai wrote: > On Thu, 2023-07-13 at 10:19 +0000, Huang, Kai wrote: > > On Thu, 2023-07-13 at 10:43 +0200, Peter Zijlstra wrote: > > > On Thu, Jul 13, 2023 at 08:02:54AM +0000, Huang, Kai wrote: > > > > > > > Sorry I am ignorant here. Won't "clearing ECX only" leave high bits of > > > > registers still containing guest's value? > > > > > > architecture zero-extends 32bit stores > > > > Sorry, where can I find this information? Looking at SDM I couldn't find :-( > > > > > > Hmm.. I think I found it -- it's in SDM vol 1: > > 3.4.1.1 General-Purpose Registers in 64-Bit Mode > > 32-bit operands generate a 32-bit result, zero-extended to a 64-bit result in > the destination general-purpose register. Yes, that's it.
