[PATCH v2 1/2] KVM: nVMX: Fix virtual interrupt delivery injection

[Wanpeng Li <wanpeng.li@linux.intel.com>]

From: Wanpeng Li <wanpeng.li@linux.intel.com>

This patch fix bug reported in https://bugzilla.kernel.org/show_bug.cgi?id=73331, 
after the patch http://www.spinics.net/lists/kvm/msg105230.html applied, there is
some progress and the L2 can boot up, however, slowly. The original idea of this 
fix vid injection patch is from "Zhang, Yang Z" <yang.z.zhang@intel.com>.

Interrupt which delivered by vid should be injected to L1 by L0 if current is in 
L1, or should be injected to L2 by L0 through the old injection way if L1 doesn't 
have set External-interrupt exiting bit. The current logic doen't consider these 
cases. This patch fix it by vid intr to L1 if current is L1 or L2 through old 
injection way if L1 doen't have External-interrupt exiting bit set.

Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Signed-off-by: "Zhang, Yang Z" <yang.z.zhang@intel.com>
---
v1 -> v2:
 * fix the typo in patch description

 arch/x86/kvm/vmx.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 021d84a..ad36646 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -7112,8 +7112,22 @@ static void vmx_hwapic_irr_update(struct kvm_vcpu *vcpu, int max_irr)
 {
 	if (max_irr == -1)
 		return;
-
-	vmx_set_rvi(max_irr);
+	if (!is_guest_mode(vcpu)) {
+		vmx_set_rvi(max_irr);
+	} else if (is_guest_mode(vcpu) && !nested_exit_on_intr(vcpu)) {
+		/*
+		 * Fall back to old way to inject the interrupt since there
+		 * is no vAPIC-v for L2.
+		 */
+		if (vcpu->arch.exception.pending ||
+				vcpu->arch.nmi_injected ||
+				vcpu->arch.interrupt.pending)
+			return;
+		else if (vmx_interrupt_allowed(vcpu)) {
+			kvm_queue_interrupt(vcpu, max_irr, false);
+			vmx_inject_irq(vcpu);
+		}
+	}
 }
 
 static void vmx_load_eoi_exitmap(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap)
-- 
1.9.1