On 16/07/18 10:37, Roger Pau Monné wrote: > On Fri, Jul 13, 2018 at 09:03:02PM +0100, Andrew Cooper wrote: >> More than the bottom two bits are now defined, and the MSR policy work has >> shown that using non-architectural representations turns out to be >> problematic >> for more than just asm code. As the architectural representation is the >> expected default, we don't need to justify why we are using it. > If that's indeed the architectural representation shouldn't you use a > uint64_t instead?
For MSR_SPEC_CTRL specifically, it makes a meaningful difference in the complexity of the asm, but in general, there no point wasting space storing 32 bits of 0's when we don't need to. ~Andrew _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
