Comment 0 for bug 1921880

QEMU added a separate model for EPYC-Milan in

https://lists.gnu.org/archive/html/qemu-devel/2021-02/msg03370.html

On the qemu side most bits are already present as far back as focal. The only things missing are the ibrs and svme-addr-chk flag.

On the libvirt side the same and fsrm (which is already in qemu)

fsrm
https://gitlab.com/libvirt/libvirt/-/commit/8c5c660b99101544d8cfcb8edbe48688c04bee25
svme-addr-chk (later patch fixed spelling)
https://gitlab.com/libvirt/libvirt/-/commit/5ac6ab2fde63881d3c5cc7372a0d0e59618feb55
ibrs
https://gitlab.com/libvirt/libvirt/-/commit/5c17a7ba41670f3182186c06e621995b5d03fc95
EPYC-Milan model
https://gitlab.com/libvirt/libvirt/-/commit/f321a4822e9fa6542e48a78611989ecd9acaa83a
https://gitlab.com/libvirt/libvirt/-/commit/d3de79dbfc20dc4dfc19154b16079861c542b71e
spelling fix for svme-addr-chk
https://gitlab.com/libvirt/libvirt/-/commit/b5abf9a192248b1005f63a7102d2627375d70fe5

Please consider adding/backporting these.

Of course there are a number of kernel commits, some/most listed in the qemu commit, that would need to be backported to enable all features. But even without them, this already works for the most part (tested on focal kernel 5.4.0-70).