Jeremy Fitzhardinge wrote: > H. Peter Anvin wrote: >> Yes, pretty much. There are enough evidence that you can't trust CPU >> architecture to stay sane. Inside Transmeta it was a constant battle, >> and we were a small company. >> > > Is there any indication that the msr or cpuid instructions will change > in this way? rd/wrmsr is pretty explicitly documented as taking the msr > in %ecx, and the value in %edx:eax; do you think that will change? And > likewise cpuid? CPUID already has changed: some CPUID levels are sensitive to %ecx event though CPUID was originally documented as being sensitive only to %eax, and I know from personal experience that there are undocumented CPUID levels in the wild which are sensitive to %ebx. I can't say for sure (at least on the record) if there are MSRs with nonarchitectural sensitivities in the wild, but if there aren't, I can guarantee that it will happen sooner or later, if only because some junior microcode designer thought it was a great idea. -hpa _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/virtualization
