> -----Original Message----- > From: Liu, Jinsong > Sent: Saturday, December 07, 2013 6:13 AM > To: H. Peter Anvin; Paolo Bonzini; Ren, Qiaowei > Cc: kvm@xxxxxxxxxxxxxxx; x86@xxxxxxxxxx; Xudong Hao; > qemu-devel@xxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Ingo Molnar; Thomas > Gleixner > Subject: RE: [Qemu-devel] [PATCH v2 3/3] X86, mpx: Intel MPX xstate feature > definition > > H. Peter Anvin wrote: > > On 12/06/2013 12:05 PM, Liu, Jinsong wrote: > >>> > >>> Since Peter already said the same, please undo these changes. > >>> > >>> Also, how is XSTATE_EAGER used? Should MPX be disabled when > >>> xsaveopt is disabled on the kernel command line? (Liu, how would > >>> this affect the KVM patches, too?) > >>> > >>> Paolo > >> > >> Currently seems no, and if needed we can add a new patch at kvm side > >> accordingly when native mpx patches checked in. > >> > > > > We need to either disable these features in lazy mode, or we need to > > force eager mode if these features are to be supported. The problem > > with the latter is that it means forcing eager mode regardless of if > > anything actually *uses* these features. > > > > A third option would be to require applications to use a prctl() or > > similar to enable eager-save features. > > > > Thoughts? > > > > -hpa > > The third option seems better -- how does native mpx patches work, force > eager? > It should be the second option, as you can see xsave.c which we remove from this patch. :) Thanks, Qiaowei -- 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
