1 files changed, 54 insertions, 16 deletions

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index bf36ae9ae7df..54d25e6f6d2d 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -64,6 +64,9 @@
 MODULE_AUTHOR("Qumranet");
 MODULE_LICENSE("GPL");
 
+static int msi2intx = 1;
+module_param(msi2intx, bool, 0);
+
 DEFINE_SPINLOCK(kvm_lock);
 LIST_HEAD(vm_list);
 
@@ -250,7 +253,8 @@ static int assigned_device_update_intx(struct kvm *kvm,
                 return 0;
 
         if (irqchip_in_kernel(kvm)) {
-                if (adev->irq_requested_type & KVM_ASSIGNED_DEV_HOST_MSI) {
+                if (!msi2intx &&
+                    adev->irq_requested_type & KVM_ASSIGNED_DEV_HOST_MSI) {
                         free_irq(adev->host_irq, (void *)kvm);
                         pci_disable_msi(adev->dev);
                 }
@@ -285,21 +289,33 @@ static int assigned_device_update_msi(struct kvm *kvm,
 {
         int r;
 
-        /* x86 don't care upper address of guest msi message addr */
-        adev->guest_msi.address_lo = airq->guest_msi.addr_lo;
-        adev->guest_msi.data = airq->guest_msi.data;
-        adev->ack_notifier.gsi = -1;
+        if (airq->flags & KVM_DEV_IRQ_ASSIGN_ENABLE_MSI) {
+                /* x86 don't care upper address of guest msi message addr */
+                adev->irq_requested_type |= KVM_ASSIGNED_DEV_GUEST_MSI;
+                adev->irq_requested_type &= ~KVM_ASSIGNED_DEV_GUEST_INTX;
+                adev->guest_msi.address_lo = airq->guest_msi.addr_lo;
+                adev->guest_msi.data = airq->guest_msi.data;
+                adev->ack_notifier.gsi = -1;
+        } else if (msi2intx) {
+                adev->irq_requested_type |= KVM_ASSIGNED_DEV_GUEST_INTX;
+                adev->irq_requested_type &= ~KVM_ASSIGNED_DEV_GUEST_MSI;
+                adev->guest_irq = airq->guest_irq;
+                adev->ack_notifier.gsi = airq->guest_irq;
+        }
 
         if (adev->irq_requested_type & KVM_ASSIGNED_DEV_HOST_MSI)
                 return 0;
 
         if (irqchip_in_kernel(kvm)) {
-                if (adev->irq_requested_type & KVM_ASSIGNED_DEV_HOST_INTX)
-                        free_irq(adev->host_irq, (void *)adev);
-
-                r = pci_enable_msi(adev->dev);
-                if (r)
-                        return r;
+                if (!msi2intx) {
+                        if (adev->irq_requested_type &
+                                        KVM_ASSIGNED_DEV_HOST_INTX)
+                                free_irq(adev->host_irq, (void *)adev);
+
+                        r = pci_enable_msi(adev->dev);
+                        if (r)
+                                return r;
+                }
 
                 adev->host_irq = adev->dev->irq;
                 if (request_irq(adev->host_irq, kvm_assigned_dev_intr, 0,
@@ -307,8 +323,10 @@ static int assigned_device_update_msi(struct kvm *kvm,
                         return -EIO;
         }
 
-        adev->irq_requested_type = KVM_ASSIGNED_DEV_GUEST_MSI |
-                                   KVM_ASSIGNED_DEV_HOST_MSI;
+        if (!msi2intx)
+                adev->irq_requested_type = KVM_ASSIGNED_DEV_GUEST_MSI;
+
+        adev->irq_requested_type |= KVM_ASSIGNED_DEV_HOST_MSI;
         return 0;
 }
 #endif
@@ -346,10 +364,19 @@ static int kvm_vm_ioctl_assign_irq(struct kvm *kvm,
                                 goto out_release;
                         else
                                 match->irq_source_id = r;
+
+#ifdef CONFIG_X86
+                        /* Determine host device irq type, we can know the
+                         * result from dev->msi_enabled */
+                        if (msi2intx)
+                                pci_enable_msi(match->dev);
+#endif
                 }
         }
 
-        if (assigned_irq->flags & KVM_DEV_IRQ_ASSIGN_ENABLE_MSI) {
+        if ((!msi2intx &&
+             (assigned_irq->flags & KVM_DEV_IRQ_ASSIGN_ENABLE_MSI)) ||
+            (msi2intx && match->dev->msi_enabled)) {
 #ifdef CONFIG_X86
                 r = assigned_device_update_msi(kvm, match, assigned_irq);
                 if (r) {
@@ -362,8 +389,16 @@ static int kvm_vm_ioctl_assign_irq(struct kvm *kvm,
 #endif
         } else if (assigned_irq->host_irq == 0 && match->dev->irq == 0) {
                 /* Host device IRQ 0 means don't support INTx */
-                printk(KERN_WARNING "kvm: wait device to enable MSI!\n");
-                r = 0;
+                if (!msi2intx) {
+                        printk(KERN_WARNING
+                               "kvm: wait device to enable MSI!\n");
+                        r = 0;
+                } else {
+                        printk(KERN_WARNING
+                               "kvm: failed to enable MSI device!\n");
+                        r = -ENOTTY;
+                        goto out_release;
+                }
         } else {
                 /* Non-sharing INTx mode */
                 r = assigned_device_update_intx(kvm, match, assigned_irq);
@@ -2209,6 +2244,9 @@ int kvm_init(void *opaque, unsigned int vcpu_size,
 
         kvm_preempt_ops.sched_in = kvm_sched_in;
         kvm_preempt_ops.sched_out = kvm_sched_out;
+#ifndef CONFIG_X86
+        msi2intx = 0;
+#endif
 
         return 0;