On Tue, May 12, 2026 at 05:57:19PM -0600, Alex Williamson wrote: > On Tue, May 12, 2026, at 5:12 PM, Michael S. Tsirkin wrote: > > On Tue, May 12, 2026 at 05:06:50PM -0600, Alex Williamson wrote: > >> If we agree that homogeneous hierarchies (no mixing of EA and > >> programmable BARs) is a reasonable constraint, and possibly extend that > >> to homogeneous per host bridge to simplify the CRS mapping, we have the > >> following work items: > >> > >> * Extend Linux EA support to program bridge apertures for subordinate > >> homogeneous EA hierarchies. > >> > >> * Develop options to virtualize programmable BARs as EA for vfio-pci > >> devices, if not generically for the benefit of testing. > >> > >> * Implement a way to poke holes in the VM address space and plumb > >> through to account for addresses used by EA devices. > >> > >> * Provide those same ranges to the guest via CRS (but not via DT to > >> EDK2), or alternatively expose them through additional PXB host > >> bridges. > >> > >> Does that shape roughly seem accurate? Are there additional gaps I've > >> missed? Thanks, > > > > just one question why not do it in firmware so windows > > is thinkably also handled? > > I suppose someone could chime in if they have a similar requirement > for Windows guests. Otherwise, the incremental effort to extend > Linux EA support seems smaller, though I also don't know what, if > any support Windows has for EA to bother. Regardless, improving > Linux EA support might help elsewhere and doesn't preclude edk2 > support in the future. Thanks,
I think there are specific already deployed distros that need to work under qemu though - so I would discount anything that needs kernel changes to work Jason -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#121948): https://edk2.groups.io/g/devel/message/121948 Mute This Topic: https://groups.io/mt/119221703/21656 Group Owner: [email protected] Unsubscribe: https://edk2.groups.io/g/devel/unsub [[email protected]] -=-=-=-=-=-=-=-=-=-=-=-
