When I use hv-time sub option and run CPU-Z or 3DMark (Physics Test) the Windows 7 guest stops with BSOD (SYSTEM_SERVICE_EXCEPTION). It can be easily reproduced by running CPU-Z. It will fail every second or third time you execute CPU-Z and fail during "PCI detection". If I disable hv-time I can run CPU-Z and 3DMark (Physics Test) without any problems. QEMU was called with the following options:
/usr/bin/taskset -c 4,5,6,7 /usr/bin/qemu-system-x86_64 \
-machine q35,accel=kvm,kernel_irqchip=on \
-enable-kvm \
-serial none \
-parallel none \
-monitor none \
-vga std \
-boot order=dc \
-cpu host,hv-time \
-smp cores=4,threads=1,sockets=1 \
-m 8192 \
-k de \
-rtc base=localtime \
-drive file=/srv/kvm/maggie-drive0.img,id=drive0,if=none,cache=none,aio=threads \
-mon chardev=monitor0 \
-chardev socket,id=monitor0,path=/tmp/maggie.monitor,nowait,server \
-netdev tap,id=net0,vhost=on,helper=/usr/lib/qemu/qemu-bridge-helper \
-device virtio-net-pci,netdev=net0,mac=00:00:00:02:01:01 \
-device virtio-blk-pci,drive=drive0,ioeventfd=on \
-device ioh3420,bus=pcie.0,id=pcie0,port=1,chassis=1,multifunction=on
I've removed the VFIO PCI passthrough line of my GPU to make reproduction easier. In any case it happens in both scenarios so VGA passthrough is not the root cause. It happens with linux-3.15-rc5 and linux-3.14.3 with patch from commit mentioned at https://bugzilla.kernel.org/show_bug.cgi?id=73721#c3
Forgot to mention. Used qemu version was 2.0.0.