KVM: 0.913
device: 0.782
debug: 0.782
other: 0.770
graphic: 0.743
semantic: 0.716
permissions: 0.659
performance: 0.621
boot: 0.529
PID: 0.452
network: 0.378
vnc: 0.371
files: 0.357
socket: 0.307

QEMU does not start when kvm enabled (SMM issue?)

Hi!

QEMU stopped working after "[355023f2010c4df619d88a0dd7012b4b9c74c12c] pc: add SMM property" on my server. It says "Guest has not initialized the display (yet)." and nothing happens. But only if I use -enable-kvm.

However, the problem gone after I hardcoded pc_machine_is_smm_enabled() to always return false (but I have little to no understanding of what SMM really is).

CMD line that reproduces the issue: qemu-system-x86_64 -enable-kvm -display curses . It doesn't work the server, but works perfectly on my laptop :(.

I'm using Arch Linux with all updates.
Some info:
Linux machine 4.2.2-1-ARCH #1 SMP PREEMPT Tue Sep 29 22:21:33 CEST 2015 x86_64 GNU/Linux
Qemu-2.4.0 (tried HEAD as well)
CPU: Intel(R) Core(TM) i7 CPU         950  @ 3.07GHz
Some messages from dmesg, just in case:
[    6.996297] kvm: VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL does not work properly. Using workaround
[ 6381.722990] kvm: zapping shadow pages for mmio generation wraparound


I'm more than happy to provide additional  information if needed.

Cheers,
Alex

This is a KVM bug, not a QEMU bug. It only happens with ept=1 and unrestricted_guest=0. A workaround is to disable SMM in QEMU (-machine smm=off) or to set kvm_intel's ept parameter to 0.

I'm closing the bug here because it is the wrong tracker (also I know about it, can reproduce, and hope to provide a fix later this week).