[PATCH 4.6 077/203] kvm: vmx: check apicv is active before using VT-d posted interrupt

[Greg Kroah-Hartman]

4.6-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Yang Zhang <yang.zhang.wz@xxxxxxxxx>

commit a0052191624e9bf8a8f9dc41b92ab5f252566c3c upstream.

VT-d posted interrupt is relying on the CPU side's posted interrupt.
Need to check whether VCPU's APICv is active before enabing VT-d
posted interrupt.

Fixes: d62caabb41f33d96333f9ef15e09cd26e1c12760
Signed-off-by: Yang Zhang <yang.zhang.wz@xxxxxxxxx>
Signed-off-by: Shengge Ding <shengge.dsg@xxxxxxxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 arch/x86/kvm/vmx.c |   15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2072,7 +2072,8 @@ static void vmx_vcpu_pi_load(struct kvm_
 	unsigned int dest;
 
 	if (!kvm_arch_has_assigned_device(vcpu->kvm) ||
-		!irq_remapping_cap(IRQ_POSTING_CAP))
+		!irq_remapping_cap(IRQ_POSTING_CAP)  ||
+		!kvm_vcpu_apicv_active(vcpu))
 		return;
 
 	do {
@@ -2180,7 +2181,8 @@ static void vmx_vcpu_pi_put(struct kvm_v
 	struct pi_desc *pi_desc = vcpu_to_pi_desc(vcpu);
 
 	if (!kvm_arch_has_assigned_device(vcpu->kvm) ||
-		!irq_remapping_cap(IRQ_POSTING_CAP))
+		!irq_remapping_cap(IRQ_POSTING_CAP)  ||
+		!kvm_vcpu_apicv_active(vcpu))
 		return;
 
 	/* Set SN when the vCPU is preempted */
@@ -10702,7 +10704,8 @@ static int vmx_pre_block(struct kvm_vcpu
 	struct pi_desc *pi_desc = vcpu_to_pi_desc(vcpu);
 
 	if (!kvm_arch_has_assigned_device(vcpu->kvm) ||
-		!irq_remapping_cap(IRQ_POSTING_CAP))
+		!irq_remapping_cap(IRQ_POSTING_CAP)  ||
+		!kvm_vcpu_apicv_active(vcpu))
 		return 0;
 
 	vcpu->pre_pcpu = vcpu->cpu;
@@ -10768,7 +10771,8 @@ static void vmx_post_block(struct kvm_vc
 	unsigned long flags;
 
 	if (!kvm_arch_has_assigned_device(vcpu->kvm) ||
-		!irq_remapping_cap(IRQ_POSTING_CAP))
+		!irq_remapping_cap(IRQ_POSTING_CAP)  ||
+		!kvm_vcpu_apicv_active(vcpu))
 		return;
 
 	do {
@@ -10821,7 +10825,8 @@ static int vmx_update_pi_irte(struct kvm
 	int idx, ret = -EINVAL;
 
 	if (!kvm_arch_has_assigned_device(kvm) ||
-		!irq_remapping_cap(IRQ_POSTING_CAP))
+		!irq_remapping_cap(IRQ_POSTING_CAP) ||
+		!kvm_vcpu_apicv_active(kvm->vcpus[0]))
 		return 0;
 
 	idx = srcu_read_lock(&kvm->irq_srcu);