If L1 doesn't intercept L2 HLT (doesn't set CPU_BASED_HLT_EXITING),
then when L2 executes HLT instruction, KVM will block vCPU from
further execution (just like what happens when L1 executes HLT).
Thus, when some CPU sends nested-posted-interrupt to a halted
L2 vCPU, vmx_deliver_nested_posted_interrupt() notes that
vcpu->mode != IN_GUEST_MODE and therefore doesn't send a physical IPI.
Because the dest vCPU is blocked by HLT, we should kick it.
Fixes: 705699a13994 ("KVM: nVMX: Enable nested posted interrupt
processing")
Signed-off-by: Liran Alon <liran.alon@xxxxxxxxxx>
Reviewed-by: Nikita Leshenko <nikita.leshchenko@xxxxxxxxxx>
Reviewed-by: Liam Merwick <liam.merwick@xxxxxxxxxx>
Signed-off-by: Liam Merwick <liam.merwick@xxxxxxxxxx>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
---
arch/x86/kvm/vmx.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 5f82cd9fc500..c2d012d9d16d 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -5090,7 +5090,8 @@ static int vmx_deliver_nested_posted_interrupt(struct kvm_vcpu *vcpu,
*/
vmx->nested.pi_pending = true;
/* the PIR and ON have been set by L1. */
- kvm_vcpu_trigger_posted_interrupt(vcpu, true);
+ if (!kvm_vcpu_trigger_posted_interrupt(vcpu, true))
+ kvm_vcpu_kick(vcpu);
return 0;
}
return -1;
--
1.9.1
