On 10/27/2014 04:48 PM, Eduardo Habkost wrote: > On Fri, Oct 24, 2014 at 07:55:10AM +0200, Paolo Bonzini wrote: > [...] >> I think we can keep the macros. The actual cleanup would be to have a >> single member for the 32 512-bit ZMM registers, instead of splitting >> xmm/ymmh/zmmh/zmm_hi16. This will get rid of the YMM_* and ZMM_* >> registers. However, we could not use simple memcpy()s to marshal in and >> out of the XSAVE data. We can do it in 2.2. > > Now, about the actual 2.3 plans: I believe the xmm/ymmh/zmmh/zmm_hi16 > separation actually makes the code simpler, because the only code > touching those registers inside QEMU is xsave/vmstate state > loading/saving, where the bits of the ZMM registers are split into > different sections/fields exactly in the same way. > > We can still eliminate the YMM_* and ZMM_* macros while keeping > xmm/ymmh/zmmh/zmm_hi16 as separate fields, and having a single zmm_regs > member would just add unnecessary complexity to the > XSAVE<->CPUX86State<->VMState translation code. > > (But if one day TCG starts implementing AVX or AVX512, then it may be > worthwhile to move the ZMM registers into a single field.) Yes, exactly---or even sooner, if we start dumping the 256 or 512 byte registers. I think the current separation of xmm/ymmh/zmmh/zmm_hi16 is a KVM-ism. Let's see what the patches look like, once they are ready. Paolo -- 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
