Michał Cłapiński wrote: > On Tue, Jul 1, 2025 at 2:05 PM Michał Cłapiński <[email protected]> wrote: > > > > On Wed, Jun 25, 2025 at 11:16 PM Ira Weiny <[email protected]> wrote: > > > > > > Michal Clapinski wrote: > > > > This includes: > > > > 1. Splitting one e820 entry into many regions. > > > > 2. Conversion to devdax during boot. > > > > > > > > This change is needed for the hypervisor live update. VMs' memory will > > > > be backed by those emulated pmem devices. To support various VM shapes > > > > I want to create devdax devices at 1GB granularity similar to hugetlb. > > > > Also detecting those devices as devdax during boot speeds up the whole > > > > process. Conversion in userspace would be much slower which is > > > > unacceptable while trying to minimize > > > > > > Did you explore the NFIT injection strategy which Dan suggested?[1] > > > > > > [1] > > > https://lore.kernel.org/all/[email protected]/ > > > > > > If so why did it not work? > > > > I'm new to all this so I might be off on some/all of the things. > > > > My issues with NFIT: > > 1. I can either go with custom bios or acpi nfit injection. Custom > > bios sounds rather aggressive to me and I'd prefer to avoid this. The > > NFIT injection is done via initramfs, right? If a system doesn't use > > initramfs at the moment, that would introduce another step in the boot > > process. One of the requirements of the hypervisor live update project > > is that the boot process has to be blazing fast and I'm worried > > introducing initramfs would go against this requirement. > > 2. If I were to create an NFIT, it would have to contain thousands of > > entries. That would have to be parsed on every boot. Again, I'm > > worried about the performance. > > > > Do you think an NFIT solution could be as fast as the simple command > > line solution? > > Hello, > just a follow up email. I'd like to receive some feedback on this.
Apologies. I'm not keen on adding kernel parameters so I'm curious what you think about Mike's new driver?[1] [1] https://lore.kernel.org/all/[email protected]/ Ira
