Comment 16 for bug 1329956

I'm able to reproduce this issue, but using latest debian 9.

Debian 9
qemu version: 1:2.8+dfsg-6+deb9u3
kernel version: Linux vm2 4.9.0-3-amd64 #1 SMP Debian 4.9.30-2+deb9u5 (2017-09-19) x86_64 GNU/Linux

I'm attempting to cold boot, or warm reboot, pfsense 2.4.2 amd64 iso image guest. If I have > 1 in virt-manager view -> details -> cpu -> allocation and maximum allocation, then the guest will not boot. My workaround was to set those both to 1, then in configuration I needed to uncheck "Copy Host CPU Configuration" (pfsense used to need this for hardware crypto support) and set the model to "clear cpu configuration" in order for it to boot. This doesn't appear to be Intel specific. I'm running amd ..

/proc/cpuinfo :

processor : 0
vendor_id : AuthenticAMD
cpu family : 21
model : 1
model name : AMD FX(tm)-8120 Eight-Core Processor
stepping : 2
microcode : 0x6000629
cpu MHz : 1400.000
cache size : 2048 KB
physical id : 0
siblings : 8
core id : 0
cpu cores : 4
apicid : 0
initial apicid : 0
fpu : yes
fpu_exception : yes
cpuid level : 13
wp : yes
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 mmxext fxsr_opt pdpe1gb rdtscp lm constant_tsc rep_good nopl nonstop_tsc extd_apicid aperfmperf eagerfpu pni pclmulqdq monitor ssse3 cx16 sse4_1 sse4_2 popcnt aes xsave avx lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs xop skinit wdt lwp fma4 nodeid_msr topoext perfctr_core perfctr_nb cpb hw_pstate vmmcall arat npt lbrv svm_lock nrip_save tsc_scale vmcb_clean flushbyasid decodeassists pausefilter pfthreshold
bugs : fxsave_leak sysret_ss_attrs null_seg
bogomips : 6241.40
TLB size : 1536 4K pages
clflush size : 64
cache_alignment : 64
address sizes : 48 bits physical, 48 bits virtual
power management: ts ttp tm 100mhzsteps hwpstate cpb