On Tue, May 06, 2014 at 01:46:41AM -0700, Christoffer Dall wrote: > Hi all, > > Apologies for not sending out a request for agenda items. > > Eric, Alvise, and Antionios would like to coordinate efforts related > to VFIO and device assignment, so we will host a call today for that > purpose at lease. > > If anyone else has anything to discuss, feel free to let me know and > join the meeting. > Somwhat unpolished minutes from today's call, please feel free to expand and/or clarify. KVM/ARM Sync-Up Call - May 6, 2014 ================================== Present ======= - Peter Maydell - Alvise Rigo - Antonios Motakis - Eric Auger - Christoffer Topics ====== Device Passthrough ------------------ - Christoffer gave an introduction to the work Linaro is currently doing in this area. - Antonios says device specific prototype was just to unblock the work. - Alvise is working on the QEMU side of things - Antionios' focus is IRQFD and interrupts - Will make things faster to avoid user space involvement for interrupt passthrough - Antonios argues that priority drop will not be the default behavior for VFIO, but that it should be something extra to a default behavior doing masking. Priority drop is specific to ARM. - Eric is using resamplefd to unmask the vfio interrupts. Working on using the HW bit in the link register to avoid the maintenance interrupts. - The whole thing requires us to progress incrementally, first step is using eventfds to user space for IRQs, next step is to use irqfds, next step is to try to get rid of eventfds. - The vfio-pci driver duplicates a lot of code from eventfd, and Eric was wondering why. Antionios will look into this. - Antonios said that they are further working on IRQ Routing for the KVM side for ARM. - VOS will also work on vfio-amba in addition to vfio-platform. - As far as the VFIO-platform kernel patches, eventfd is key for them to be upstreamable. - Christoffer asked if everything is going to be sent in a single patch series, because of timing. For the next version, v6, should be relatively limited. VOS plans on posting a v6 within a month. - Antonios can send some VFIO-platform patches alone sooner, so that Eric can continue working. - Christoffer suggests that we should share some git trees and post our WIP continously so people are aware what others are doing. - Antonios asked that since there is overlap on irqfds, if VOS should push VFIO-platform before KVM irqfds to ensure progress. - Antonios and Eric brought up ioeventfds, Antonios said that he feels it is orthogonal to the device passthrough but targets features such as vhost. - Nikolai from VOS working on vhost. - For further meetings, please ask Christoffer to have Linaro host something. - Christoffer asked about the state of QEMU VFIO-platform patches. Alvise is going to send out a new version of the contributions over Eric's patches. Eric plans on working on the v3 of the QEMU device patches next week, taking into account the comments from Kim and Alex Williamson. Eric will include the compatible strings patch, but will need to sync with Alvise at the end of this week or beginning of next. - Antonios asked if Kim Phillips is still working in the area of platform device binding. Christoffer will check on the status. _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
