qemu 2.4.0 with --enable-kvm hangs, takes 100% CPU
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
QEMU |
New
|
Undecided
|
Unassigned |
Bug Description
When starting qemu-system-x86_64 from version 2.4.0 with --enable-kvm, it hangs and takes 100% CPU. The graphical display (SeaBIOS output) is not initialized.
There have been multiple reports of this issue in the following thread:
https:/
There is no need to load a certain image, it already hangs with the following command:
qemu-system-x86_64 --enable-kvm
There are three workarounds:
- Downgrading the kernel form 4.2.2 to 4.1.6 (according to the forum thread, have not tested this myself)
- Downgrading qemu to 2.3 (tested personally, works)
- passing -machine pc-i440fx-2.3 to qemu 2.4 (have not tested this myself, I will try that shortly)
modules kvm and kvm_intel are loaded and rmmod && modprobing them does not change the situation
I have an nvidia card and switching from official binary drivers to nouveau and back does not change the situation.
qemu is installed from Arch package. From the PKGBUILD you can see that is is built with the following configuration:
=======
export ARFLAGS="rv"
export CFLAGS+=' -fPIC'
./configure --prefix=/usr --sysconfdir=/etc --audio-
make V=99
=======
cpuinfo on my machine (for the first core only):
=======
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 30
model name : Intel(R) Core(TM) i7 CPU Q 820 @ 1.73GHz
stepping : 5
microcode : 0x7
cpu MHz : 1333.000
cache size : 8192 KB
physical id : 0
siblings : 8
core id : 0
cpu cores : 4
apicid : 0
initial apicid : 0
fpu : yes
fpu_exception : yes
cpuid level : 11
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf pni dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm sse4_1 sse4_2 popcnt lahf_lm ida dtherm tpr_shadow vnmi flexpriority ept vpid
bugs :
bogomips : 3459.21
clflush size : 64
cache_alignment : 64
address sizes : 36 bits physical, 48 bits virtual
=======
Is there more information I can provide you with to help debug this problem?
Thanks,
cptG
Just confirmed: passing -machine pc-i440fx-2.3 to qemu 2.4 works on my machine, too.
I guess I forgot about it before: Kernel version is 4.2.3