Add a comment to explain why KVM treats vCPUs with pending interrupts as in-kernel when a vCPU wants to yield to a vCPU that was preempted while running in kernel mode. Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx> --- virt/kvm/kvm_main.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 6326852bfb3d..4a9e7513c585 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -4089,6 +4089,13 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me, bool yield_to_kernel_mode) continue; if (kvm_vcpu_is_blocking(vcpu) && !vcpu_dy_runnable(vcpu)) continue; + + /* + * Treat the target vCPU as being in-kernel if it has a + * pending interrupt, as the vCPU trying to yield may + * be spinning waiting on IPI delivery, i.e. the target + * vCPU is in-kernel for the purposes of directed yield. + */ if (READ_ONCE(vcpu->preempted) && yield_to_kernel_mode && !kvm_arch_dy_has_pending_interrupt(vcpu) && !kvm_arch_vcpu_preempted_in_kernel(vcpu)) -- 2.43.0.472.g3155946c3a-goog
