[Qemu-devel] Unable to enable +x2apic for the guest cpus...

[Chegu Vinod]

Hello,

I am using a very recent upstream version of qemu.git along with kvm.git kernels (in the host and guest).
 [Guest kernel had been compiled with CONFIG_X86_X2APIC and CONFIG_IRQ_REMAP both set]

When I attempt to start a guest with +x2apic flag (pl. see the qemu cmd line below) I end up with a hang of the qemu and
a kernel BUG at /arch/x86/kvm/lapic.c:159 !    Pl. see the attached screen shot of the console for additional info.

I am able to boot the same guest without the +x2apic flag in the qemu cmd line. 

Not sure if this an issue (or) if I have something incorrectly specified in the qemu cmd line ? If its the latter...pl. advise the correct usage
for enabling x2apic for the guest cpus.. for the upstream bits.

Thanks
Vinod

----

/usr/local/bin/qemu-system-x86_64 \
-enable-kvm \
-machine kernel_irqchip=on \
-cpu Westmere,+rdtscp,+pdpe1gb,+dca,+pdcm,+xtpr,+tm2,+est,+smx,+vmx,+ds_cpl,+monitor,+dtes64,+pclmuldq,+pbe,+tm,+ht,+ss,+acpi,+ds,+vme,+x2apic \
-m 786432 -smp 80,sockets=80,cores=1,threads=1 \
-name vm1 \
-chardev socket,id=charmonitor,path=/var/lib/libvirt/qemu/vm1.monitor,server,nowait \
-drive file=/dev/libvirt_lvm/vm1,if=none,id=drive-virtio-disk0,format=raw,cache=none,aio=native \
-device virtio-blk-pci,scsi=off,bus=pci.0,addr=0x5,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1 \
-monitor stdio \
-net nic,macaddr=52:54:00:71:01:01 \
-net tap,ifname=tap0,script=no,downscript=no \
-vnc :4

kvm.JPG
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