On 03/07/18 11:19, Kang, Luwei wrote: >>> --- a/xen/include/public/arch-x86/cpufeatureset.h >>> +++ b/xen/include/public/arch-x86/cpufeatureset.h >>> @@ -215,6 +215,7 @@ XEN_CPUFEATURE(SMAP, 5*32+20) /*S Supervisor >>> Mode Access Prevention */ >>> XEN_CPUFEATURE(AVX512IFMA, 5*32+21) /*A AVX-512 Integer Fused Multiply >>> Add */ >>> XEN_CPUFEATURE(CLFLUSHOPT, 5*32+23) /*A CLFLUSHOPT instruction */ >>> XEN_CPUFEATURE(CLWB, 5*32+24) /*A CLWB instruction */ >>> +XEN_CPUFEATURE(IPT, 5*32+25) /*H Intel Processor Trace */ >> Btw - introducing the feature flag here is certainly fine, but I think you >> should add the H annotation only once functionality is >> complete. That would then e.g. also reduce the impact of patch 8 adding >> functionality otherwise strictly necessary already in patch >> 7. > Sorry, not full understand here. Do you mean I need expose this feature to > guest after all is ready? That is move this patch after patch 7,8 ?
As an example, take my series adding SSBD support to Xen. First, https://xenbits.xen.org/gitweb/?p=xen.git;a=commitdiff;h=9df52a25e0e95a0b9971aa2fc26c5c6a5cbdf4ef which adds the new feature define so Xen can gain some code. Later https://xenbits.xen.org/gitweb/?p=xen.git;a=commitdiff;h=9df52a25e0e95a0b9971aa2fc26c5c6a5cbdf4ef the feature is offered to guests when all the Xen infrastructure is in place. ~Andrew _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
