Why SSM is disabled?

[jic5760]

patch file : https://git.proxmox.com/?p=pve-qemu...d521a7107cf419764cdf78399a0128dd15561;hb=HEAD

https://lists.proxmox.com/pipermail/pve-devel/2015-September/017486.html :

kernel 4.2 and qemu 2.4 machine introduce support for SMM
(system management support).

this is needed to manage uefi inside guest.

But it seem to hang on a lot of servers.

So for now, disable the feature in qemu side.

Could anyone please elaborate on this?
It's an old patch, does still need this patch?
This interferes with enabling Secure Boot.

 

[Stefan_R]

It's an old patch that's probably not needed anymore. But enabling secure boot is not as easy as just removing that flag, we also need to update our OVMF binaries and update the API/GUI to ensure a smooth experience. If you want to tinker with it yourself, it should be fine to remove that particular patch, but as for actual secure boot support - we're working on it