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Description of problem: If a RHEL KVM guest is currently run on a POWER8NVL host, it ends up in POWER7 compatibility mode (according to /proc/cpuinfo). This happens because the guests currently do not announce support for POWER8NVL directly (see BZ 1340445 for details), and because QEMU does not support the PowerISA 2.07 compatibility mode in the "ibm,client-architecture-support" firmware call. So the guests end up in PowerISA 2.06 mode, which equals to POWER7. While BZ 1340445 tracks the modifications to the guest kernel, this ticket here is used to track the fixes for QEMU to properly provide the PowerISA 2.07 compatibility mode for guests, too. Version-Release number of selected component (if applicable): qemu-kvm-rhev-2.6.0-4.el7.ppc64le How reproducible: 100% Steps to Reproduce: 1. Boot a RHEL 7.2 on a POWER8NVL KVM host 2. Check /proc/cpuinfo. Actual results: If /proc/cpuinfo contains POWER7, it is the wrong setting. Expected results: /proc/cpuinfo should say something about POWER8 instead.
I've now backported the upstream patch series: http://git.qemu.org/?p=qemu.git;a=commitdiff;h=7386ae6372cc07c77a39cb http://git.qemu.org/?p=qemu.git;a=commitdiff;h=8cd2ce7aaa3c3fadc561f4 http://git.qemu.org/?p=qemu.git;a=commitdiff;h=52b2519c4ea9a6aa4df7ab http://git.qemu.org/?p=qemu.git;a=commitdiff;h=eac4fba965136f61cc239a http://git.qemu.org/?p=qemu.git;a=commitdiff;h=b30ff227c27c931155f768
Fix included in qemu-kvm-rhev-2.6.0-8.el7
Reproduced the problem with the set up as follows: --------------------------------------------------- Host: garrison cpu: POWER8NVL on host check cpu type: [root@ibm-p8-garrison-01 ~]# cat /proc/cpuinfo processor : 0 cpu : POWER8NVL (raw), altivec supported clock : 4023.000000MHz revision : 1.0 (pvr 004c 0100) processor : 8 cpu : POWER8NVL (raw), altivec supported clock : 4023.000000MHz revision : 1.0 (pvr 004c 0100) ... qemu-kvm-rhev-2.6.0-7.el7 guest: ppc64 and ppc64le --------------------------------------------------- Boot up the ppc64 guest , and check the cpu info [root@dhcp71-27 ~]# cat /proc/cpuinfo processor : 0 cpu : POWER7 (architected), altivec supported clock : 3259.000000MHz revision : 1.0 (pvr 004c 0100) processor : 1 cpu : POWER7 (architected), altivec supported clock : 3259.000000MHz revision : 1.0 (pvr 004c 0100) ... It is POWER7 cpu. Boot up the ppc64le guest ,and check the cpu info [root@dhcp112-244 ~]# cat /proc/cpuinfo processor : 0 cpu : POWER7 (architected), altivec supported clock : 3259.000000MHz revision : 1.0 (pvr 004c 0100) processor : 1 cpu : POWER7 (architected), altivec supported clock : 3259.000000MHz revision : 1.0 (pvr 004c 0100) ... It is POWER7 cpu ---------------------------------------------------------- Update the qemu-kvm version to qemu-kvm-rhev-2.6.0-8.el7 start ppc64 guest again. check the cpu info: [root@dhcp71-27 ~]# cat /proc/cpuinfo processor : 0 cpu : POWER8 (architected), altivec supported clock : 3259.000000MHz revision : 1.0 (pvr 004c 0100) processor : 1 cpu : POWER8 (architected), altivec supported clock : 3259.000000MHz revision : 1.0 (pvr 004c 0100) ... start ppc64le guest again. check the cpu info: [root@dhcp112-244 ~]# cat /proc/cpuinfo processor : 0 cpu : POWER8 (architected), altivec supported clock : 3259.000000MHz revision : 1.0 (pvr 004c 0100) processor : 1 cpu : POWER8 (architected), altivec supported clock : 3259.000000MHz revision : 1.0 (pvr 004c 0100) ... It is POWER8 related cpu as expected. So this bug is verified.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://rhn.redhat.com/errata/RHBA-2016-2673.html