Meeting notes on Abel's presentation: Aim: improve vhost scalability Shared vhost thread ============== Problem: Linux scheduler does not see state of virtqueues, cannot make good scheduling decisions Solution: Shared thread serves multiple VMs and therefore influences "I/O scheduling" instead of kernel thread per vhost device Exitless communication ================= * Polling on host to notice guest vring updates without guest pio instruction * Use CPU affinity to bind vcpus to separate cores and let polling run on dedicated cores * Existless Interrupt (ELI) or future hardware APIC virtualization feature to inject virtual interrupts without vmexit and EOI See paper for performance results (impressive numbers): http://domino.research.ibm.com/library/cyberdig.nsf/papers/479E3578ED05BFAC85257B4200427735/$File/h-0319.pdf Abel will publish rebased code on GitHub but does not have time to upstream them. The next step: QEMU/KVM community can digest the paper + patches and decide on ideas to upstream. -- 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
