Features/Virt PCI Express Q35

Virt PCI Express Q35

Summary

Emulate PCI Express, preferably by default. PCI Express is required for Advanced Error Reporting support.

Down the road it will enable features such as alternative requester id, multiple pci domains.

Owner

• Name: Cole Robinson
• Email: crobinso@redhat.com
• Name: Michael Tsirkin
• Email: mst@redhat.com

Current status

• Targeted release: Fedora 19
• Last updated: Jan 26 2013
• Percentage of completion: 30%

Detailed Description

This is an infrastructure change. When working properly we get the same functionality as now by default.

When configured, Express Root port devices will be visible to guest.

XXX: More info here about why this is really interesting

Benefit to Fedora

• Express Root port devices will be visible to guest.
• Enhanced error reporting of assigned devices.
• Enables Native hotplug support.

XXX: explain these

Scope

• QEMU Q35 (available as of 1.3)
  • AHCI Migration issues? https://lists.gnu.org/archive/html/qemu-devel/2013-01/msg03103.html
  • No need to specify custom acpi tables (queued for 1.4)
  • Seabios support (DONE, in 1.7.2)
  • Will not be the default for 1.4 though...
    • Though sounds like there are still issues: http://www.seabios.org/pipermail/seabios/2013-January/005330.html
• Libvirt support (patches posted)

How To Test

XXX: fixme

User Experience

Express Root port devices will be visible to guest.

XXX: expand this

Dependencies

None.

Contingency Plan

Since this is brand new functionality, if it isn't ready in time, nothing has changed. We just drop this feature page.

Documentation

• http://www.linux-kvm.org/wiki/images/2/2e/2010-forum-Pci-express-in-qemu.pdf
• http://wiki.qemu.org/Features/Q35
• Libvirt patch posting

Release Notes

TBD

Comments and Discussion

• None yet