Re: [Qemu-devel] How to configure QEMU to support APIC virtualization

[ddm]

Hi, 


As i know, KVM is based on passthrough host cpu to implement 
full-virtualiztion, 
if host cpu doesn't support this feature, it's impossible to turn on this 
feature by KVM.
Wheher there are another ways in QEMU to emulate this feature，such as emulate 
it based on pure software, not rely on hardware.


Thanks!



At 2019-08-05 12:42:55, "Li Qiang" <address@hidden> wrote:





ddm <address@hidden> 于2019年8月5日周一 上午11:55写道：

Hi guys,


I have tried via modprobe kvmintel enable_apicv=Y  to adjust KVM parameter, but 
it doesn't effect,  and
cat /sys/module/kvm_intel/parameters/enable_apicv always return "N".
I don't know how to configure KVM or QEMU to support APIC virtualizaion feature?




AFAICT APICv is hardware feature, but I still don't know accurately after which 
CPU support it.
You may refer the code about 'enable_apicv' related code in kvm to see how to 
detect this capability.


Thanks,
Li Qiang
 

My host infos are as follows:
Architecture:          x86_64
CPU op-mode(s):        32-bit, 64-bit
Byte Order:            Little Endian
CPU(s):                1
On-line CPU(s) list:   0
Thread(s) per core:    1
Core(s) per socket:    1
Socket(s):             1
NUMA node(s):          1
Vendor ID:             GenuineIntel
CPU family:            6
Model:                 142
Model name:            Intel(R) Core(TM) i7-8650U CPU @ 1.90GHz
Stepping:              10
CPU MHz:               2112.001
BogoMIPS:              4224.00
Virtualization:        VT-x
Hypervisor vendor:     VMware
Virtualization type:   full
L1d cache:             32K
L1i cache:             32K
L2 cache:              256K
L3 cache:              8192K
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 ss syscall nx pdpe1gb rdtscp lm 
constant_tsc arch_perfmon nopl xtopology tsc_reliable nonstop_tsc cpuid pni 
pclmulqdq vmx ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt 
tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 
3dnowprefetch cpuid_fault invpcid_single pti ssbd ibrs ibpb stibp tpr_shadow 
vnmi ept vpid fsgsbase tsc_adjust bmi1 hle avx2 smep bmi2 invpcid rtm rdseed 
adx smap xsaveopt arat flush_l1d arch_capabilities


Could you tell me how to configure it?


Thanks!