The default case in __apic_accept_irq() has carried a printk("TODO:
unsupported delivery mode") since the original LAPIC emulation was
introduced in commit 97222cc83163 ("KVM: Emulate local APIC in
kernel").

The switch now handles all eight delivery modes defined by the x86
architecture and is always constrained to the three-bit field
defined by the architecture: Either by masking with APIC_MODE_MASK,
by three-bit bitfield widths in the IOAPIC and MSI structs, or by
using APIC_DM_* constants directly.

Replace the unreachable printk with WARN_ON_ONCE(1) to match the
existing pattern for impossible defaults elsewhere in the same file.

Signed-off-by: Tim Wiederhake <twiederh@redhat.com>
---
 arch/x86/kvm/lapic.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 4078e624ca66..c775789dbdb3 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1485,8 +1485,7 @@ static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
 		break;
 
 	default:
-		printk(KERN_ERR "TODO: unsupported delivery mode %x\n",
-		       delivery_mode);
+		WARN_ON_ONCE(1);
 		break;
 	}
 	return result;
-- 
2.52.0