2015-05-28 11:00+0200, Paolo Bonzini: > On 27/05/2015 19:05, Paolo Bonzini wrote: > > This patch includes changes to the external API for SMM support. > > All the changes are predicated by the availability of a new > > capability, KVM_CAP_X86_SMM, which is added at the end of the > > patch series. > > > > Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> > > Radim, I forgot to change flags to u8 in this patch. However, I am > thinking that it's just as good to leave it as u16. The reason is that > the other two fields in this 32-bit word were just 1-bit flags that were > expanded to 8 bits for no particular reasons. (Yeah, it's sad that we have wasted all those bits.) > If we make it now > > u8 flags; > u8 padding2; > > chances are that in due time it will become simply > > u8 flags; > u8 flags2; True, I forgot that big endian exists, so we can't just say u16 later. (u8 avoids endianess problems of C bit-fields, but I wouldn't have brought it up when u8 isn't strictly better ...) > and then it's nicer to just have an u16. On the other hand, your > argument that KVM_RUN has very little free space is also a good one. Thinking more about it ... we don't forbid multi-bit flags, so u16 can be used fairly the same way. (u16 would be a bit worse for an 8 bit vector, but nicer for >8 bit vector.) > What do you think? I have already done the change in my local repo, but > I can change it back too. I'd be glad if we were more bit-field friendly, but whatever is the least work for you is the best :) -- 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
