On Wed, Sep 22, 2010, Gleb Natapov wrote about "Re: KVM call minutes for Sept 21": > There is only one outstanding serious issue from my point of view: event > injection path. I want it to be similar to how nested SVM handles it. I > don't see why it can't be done the same way for VMX too. The way nested SVM > does it looks cleaner and making code paths similar will allow us to > consolidate the logic in common code later. This issue is too > fundamental to be fixed after merge IMHO. Other nitpicks about missing > checks that real HW does, but emulation doesn't can be fixed any time > after merge. I'll try my best to accomodate your request, but I tried to explain in my previous mails (and so dir Orit Wasserman in her mails last year, by the way - I found a long thread in the mailing list...) that there appears to be a fundemental additional complexity in VMX that doesn't exist in SVM. In VMX, you might have to inject another exception (IDT_VECTORING_INFO_FIELD) at the same time that you're already trying to inject a page fault to L1, and this doesn't appear (?) to exist in SVM. However, since I didn't write this code myself, and didn't encounter all the problems myself, I still want to try to see whether I can get "cleaner" code to actually work. But I want it to be really cleaner - not just remove one somewhat-ugly intervention from vmx_complete_interrupts() and move it to an even uglier intervention somewhere else. In any case, while I obviously agree that it's your prerogative not to merge code that you consider ugly, I still don't see any particular problem to start with the current, working, code, and fix it later. It's not like we can never change this code after it's in - it's clearly marked with if(nested) and doesn't effect anything in the non-nested path. > I think the question was "why do we need nested virtualization" ;) Then why was nested SVM merged in the first place? Isn't it too late to ask this question now? :-) Anyway, I tried to answer this question in my previous email. I'm not sure what more I can say to answer this question better. Thanks, Nadav. -- Nadav Har'El | Wednesday, Sep 22 2010, 15 Tishri 5771 nyh@xxxxxxxxxxxxxxxxxxx |----------------------------------------- Phone +972-523-790466, ICQ 13349191 |Give Yogi a rifle. Support your right to http://nadav.harel.org.il |arm bears! -- 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
