[Bug 82211] Cannot boot Xen under KVM with X2APIC enabled

bugzilla-daemon
2015-03-17T17:02:07Z

Radim Krčmář <rkrcmar@redhat.com> changed:

What |Removed |Added
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CC| |rkrcmar@redhat.com

--- Comment #10 from Radim Krčmář <rkrcmar@redhat.com> ---
I can reproduce with kernel-4.0.0-0.rc3.git2.1.fc23.x86_64 and attached Xen.

qemu-kvm -kernel ./xen -initrd /boot/vmlinuz-[...] -cpu kvm64,+x2apic

Xen doesn't use x2APIC (which is good), but x2APIC enables directed EOI for
xAPIC, which doesn't work. All is good if we manually avoid it

qemu-kvm [...] -append ioapic_ack=new

KVM IOAPIC never gets EOI.

I'll take a look where the problem is.