Comment 33 for bug 1853200

Tests with the PPA build using the patches sent by Jiri (and my addition of the noTSX types):

#1 virsh capabilities
Before:
Broadwell-noTSX-IBRS + 33 features

After:
Skylake-Client-noTSX-IBRS +24 features

=> good

#2 virsh domcapabilities
Before:
Skylake-Client-IBRS + 16 features

After:
Skylake-Client-IBRS + 16 features (unchanged as intended for compatibility)

#3 usable models
Before:
only older types

After:
now added "Skylake-Client-noTSX-IBRS" which is a more modern IBRS type than the others I had

My system isn't new enough to get the others added, but that is fine as a test.
Also the type "Skylake-Server-noTSX-IBRS" worked, auto-disabling the avx features my chip is missing.

I started a guest with such a type through libvirt and it looks as expected:
  -cpu Skylake-Client-noTSX-IBRS

#4 and finally the adapted tests still ran fien at build time.