Hi, I can't access avx512* instruction set from virtual machines. I have made a one server compute cluster to test new hardware: oVirt 4.1.9 CentOS 7 Cluster CPU Type: Intel Skylake Family Compatibility Version: 4.1 HOST: CPU Model Name:Intel(R) Xeon(R) Platinum 8180 CPU @ 2.50GHz Family: Family CPU Type: Intel Skylake Family Virtual Machine settings A) VM: Custom CPU Type: Use cluster default(Intel Skylake Family) General Tab shows: Guest CPU Type: Skylake-Client avx512: NO B) VM: Custom CPU Type: Skylake-Client General Tab shows: Guest CPU Type: Skylake-Client avx512: NO C) VM: Custom CPU Type: Use cluster default(Intel Skylake Family) [grey - cannot modify] Migration mode: Do not allow migration Pass-Through Host CPU General Tab shows: Guest CPU Type: Skylake-Client avx512: YES ( cat /proc/cpuinfo |grep avx512: avx512f avx512dq avx512cd avx512bw avx512vl ) Using pass-through host cpu (disabling vm migration) is the only way to access avx512 in a VM, is it a bug or am I missing something? Regards, -- Marco Crociani Prisma Telecom Testing S.r.l. via Petrocchi, 4 20127 MILANO ITALY Phone: +39 02 26113507 Fax: +39 02 26113597 e-mail: marcoc@prismatelecomtesting.com web: http://www.prismatelecomtesting.com