[PATCH] KVM: Fix assigned device with no irq

[Sheng Yang <sheng@linux.intel.com>]

Some device like VF of SRIOV only support MSI-X.

With this patch, SRIOV can be enabled with KVM assigned device(all kernel space
patches are ready).

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
---
 virt/kvm/kvm_main.c |   14 ++++++++++----
 1 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 4d2be16..ce80f3a 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -217,8 +217,11 @@ static void kvm_free_assigned_irq(struct kvm *kvm,
 		kvm_free_irq_source_id(kvm, assigned_dev->irq_source_id);
 	assigned_dev->irq_source_id = -1;
 
-	if (!assigned_dev->irq_requested_type)
+	if (!assigned_dev->irq_requested_type) {
+		if (assigned_dev->dev->msi_enabled)
+			pci_disable_msi(assigned_dev->dev);
 		return;
+	}
 
 	/*
 	 * In kvm_free_device_irq, cancel_work_sync return true if:
@@ -308,6 +311,10 @@ static int assigned_device_update_intx(struct kvm *kvm,
 	if (adev->irq_requested_type & KVM_ASSIGNED_DEV_HOST_INTX)
 		return 0;
 
+	/* IRQ 0 means uninitialized here */
+	if (airq->host_irq == 0)
+		return 0;
+
 	if (irqchip_in_kernel(kvm)) {
 		if (!msi2intx &&
 		    (adev->irq_requested_type & KVM_ASSIGNED_DEV_HOST_MSI)) {
@@ -529,9 +536,8 @@ static int kvm_vm_ioctl_assign_irq(struct kvm *kvm,
 			r = 0;
 		} else {
 			printk(KERN_WARNING
-			       "kvm: failed to enable MSI device!\n");
-			r = -ENOTTY;
-			goto out_release;
+			       "kvm: device didn't support INTx or MSI!\n");
+			r = 0;
 		}
 	} else {
 		/* Non-sharing INTx mode */
-- 
1.5.4.5