Stefan Hajnoczi <[email protected]> wrote on 09/04/2013 06:13:47 PM: > From: Stefan Hajnoczi <[email protected]> > To: Juan Quintela <[email protected]>, > Cc: qemu-devel qemu-devel <[email protected]>, KVM devel mailing > list <[email protected]> > Date: 09/04/2013 06:13 PM > Subject: Re: [Qemu-devel] KVM call agenda for 2013-04-09 > Sent by: [email protected] > > 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. It has been a while since this KVM call but the code for ELVIS and ELI is now available in github: https://github.com/abelg/virtual_io_acceleration/commits/ibm-io-acceleration-3.9-github Source-code contributors (in alphabetical order): Nadav Amit [email protected] Muli Ben-Yehuda [email protected] Abel Gordon [email protected] Nadav Har'El [email protected] Alex Landau [email protected] Each commit made in September 16th represents a separate and documented patch. Note this work is under development and more effort is required to make it upstream-ready. You are all welcome to join the upstreaming effort :) A short documentation can be found in the wiki page: https://github.com/abelg/virtual_io_acceleration/wiki/Virtual-I-O-acceleration-technologies-for-KVM Please note this work will be presented and discussed in the upcoming KVM forum (October 21-23, Edinburgh, UK) Regards, Abel.
