From: David Woodhouse <d...@amazon.co.uk>
They both do the same thing and just call sched_yield. This is enough to
stop the Linux guest panicking when running on a host kernel which doesn't
intercept SCHEDOP_poll and lets it reach userspace.
Signed-off-by: David Woodhouse <d...@amazon.co.uk>
---
target/i386/kvm/xen-emu.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/target/i386/kvm/xen-emu.c b/target/i386/kvm/xen-emu.c
index 5f2b55ef10..80005ea527 100644
--- a/target/i386/kvm/xen-emu.c
+++ b/target/i386/kvm/xen-emu.c
@@ -227,6 +227,18 @@ static bool kvm_xen_hcall_sched_op(struct kvm_xen_exit
*exit, X86CPU *cpu,
err = schedop_shutdown(cs, arg);
break;
+ case SCHEDOP_poll:
+ /*
+ * Linux will panic if this doesn't work. Just yield; it's not
+ * worth overthinking it because wWith event channel handling
+ * in KVM, the kernel will intercept this and it will never
+ * reach QEMU anyway.
+ */
+ case SCHEDOP_yield:
+ sched_yield();
+ err = 0;
+ break;
+
default:
return false;
}
--
2.35.3
