failed to boot a customized kernel if emulating Broadwell/Skylake

[Shawn the R0ck]

Hardware: X86-64, Intel(R) Core(TM) i7-6500U( Skylake)
OS: Linux Mint 18
Host Kernel: 4.5.7 + PaX/Grsecurity
Qemu: QEMU emulator version 2.5.0 (Debian 1:2.5+dfsg-5ubuntu10.2)

[Reproduction Steps]
1, Install a Debian 8 in the guest
2, Install a customized kernel( using same config to Debian 8)
3, Reboot:
qemu-system-x86_64 -hda debian8-test.img -boot d -m 2048 -enable-kvm -usb -usbdevice tablet -net nic -net tap,ifname=tap0,script=no -cpu Broadwell -smp 2

or

qemu-system-x86_64 -hda debian8-test.img -boot d -m 2048 -enable-kvm -usb -usbdevice tablet -net nic -net tap,ifname=tap0,script=no -cpu host -smp 2

[Actual Result]
kernel panic or can't login in the system

[Workaround]
qemu-system-x86_64 -hda debian8-test.img -boot d -m 2048 -enable-kvm -usb -usbdevice tablet -net nic -net tap,ifname=tap0,script=no -cpu Haswell -smp 2

[Thomas Huth (th-huth)]

The QEMU project is currently considering to move its bug tracking to another system. For this we need to know which bugs are still valid and which could be closed already. Thus we are setting older bugs to "Incomplete" now.
If you still think this bug report here is valid, then please switch the state back to "New" within the next 60 days, otherwise this report will be marked as "Expired". Or mark it as "Fix Released" if the problem has be

[Launchpad Janitor (janitor)]

[Expired for QEMU because there has been no activity for 60 days.]