-cpu ...,+topoext works only with EPYC CPU model

[Eduardo Habkost]

See bug report at:
https://bugzilla.redhat.com/show_bug.cgi?id=1615682

Probably this is caused by the inconsistent legacy cache information on all CPU models except EPYC.

---------------------------------------------
Description of problem:
Guest should get 2 threads per core and all of them should be on-line when booting guest with old amd cpu model + smt

Steps to Reproduce:
1.Boot rhel7.6 guest with cli:
/usr/libexec/qemu-kvm -name rhel7.6 -m 16G -machine pc,accel=kvm \
        -S \
        -cpu Opteron_G3,+topoext,xlevel=0x8000001e,enforce \
        -smp 2,threads=2 \
        -monitor stdio \
        -qmp unix:/tmp/qmp2,server,nowait \
        -device VGA \
        -vnc :0 \
        -serial unix:/tmp/console2,server,nowait \
        -uuid 115e11b2-a869-41b5-91cd-6a32a907be7f \
        -drive file=rhel7.6-20180812.qcow2,if=none,id=drive-scsi-disk0,format=qcow2,cache=none,werror=stop,rerror=stop -device ide-hd,drive=drive-scsi-disk0,id=scsi-disk0 \
        -netdev tap,id=idinWyYY,vhost=on -device virtio-net-pci,mac=2e:39:fa:ff:88:a1,id=idlbq7eA,netdev=idinWyYY \

2.check cpu info inside guest
3.

Actual results:
Guest gets one online cpu, one offline cpu and one thread per core:
# lscpu
lscpu
Architecture: x86_64
CPU op-mode(s): 32-bit, 64-bit
Byte Order: Little Endian
CPU(s): 2
On-line CPU(s) list: 0
Off-line CPU(s) list: 1
Thread(s) per core: 1
Core(s) per socket: 1
Socket(s): 1
NUMA node(s): 1
Vendor ID: AuthenticAMD
CPU family: 16
Model: 2
Model name: AMD Opteron 23xx (Gen 3 Class Opteron)
Stepping: 3
CPU MHz: 2096.060
BogoMIPS: 4192.12
Hypervisor vendor: KVM
Virtualization type: full
L1d cache: 64K
L1i cache: 64K
L2 cache: 512K
L3 cache: 16384K
NUMA node0 CPU(s): 0
Flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx lm art rep_good nopl extd_apicid pni cx16 x2apic popcnt hypervisor lahf_lm cmp_legacy abm sse4a misalignsse topoext retpoline_amd ibp_disable vmmcall

Expected results:
Guest should get 2 threads per core and all of them should be on-line

---------------------------------------------

[Thomas Huth (th-huth)]

The QEMU project is currently considering to move its bug tracking to another system. For this we need to know which bugs are still valid and which could be closed already. Thus we are setting older bugs to "Incomplete" now.
If you still think this bug report here is valid, then please switch the state back to "New" within the next 60 days, otherwise this report will be marked as "Expired". Or mark it as "Fix Released" if the problem has been solved with a newer version of QEMU already. Thank you and sorry for the inconvenience.

[Launchpad Janitor (janitor)]

[Expired for QEMU because there has been no activity for 60 days.]