On Mon, Apr 22, 2013 at 10:45:53PM +0900, Takuya Yoshikawa wrote: > On Mon, 22 Apr 2013 15:39:38 +0300 > Gleb Natapov <gleb@xxxxxxxxxx> wrote: > > > > > Do not want kvm_set_memory (cases: DELETE/MOVE/CREATES) to be > > > > suspectible to: > > > > > > > > vcpu 1 | kvm_set_memory > > > > create shadow page > > > > nuke shadow page > > > > create shadow page > > > > nuke shadow page > > > > > > > > Which is guest triggerable behavior with spinlock preemption algorithm. > > > > > > Not only guest triggerable as in the sense of a malicious guest, > > > but condition above can be induced by host workload with non-malicious > > > guest system. > > > > > Is the problem that newly created shadow pages are immediately zapped? > > Shouldn't generation number/kvm_mmu_zap_all_invalid() idea described here > > https://lkml.org/lkml/2013/4/22/111 solve this? > > I guess so. That's what Avi described when he tried to achieve > lockless TLB flushes. Mixing that idea with Xiao's approach will > achieve reasonably nice performance, I think. Yes. > Various improvements should be added later on top of that if needed. > > > > Also kvm_set_memory being relatively fast with huge memory guests > > > is nice (which is what Xiaos idea allows). > > I agree with this point. But if so, it should be actually measured on > such guests, even if the algorithm looks promising. Works for me. -- 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
