KVM: Add assigned_device_msi_dispatch()

The function is used to dispatch MSI to lapic according to MSI message
address and message data.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 55 insertions, 0 deletions

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 2089f8b68a16..228c1d18a614 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -47,6 +47,10 @@
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
 
+#ifdef CONFIG_X86
+#include <asm/msidef.h>
+#endif
+
 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
 #include "coalesced_mmio.h"
 #endif
@@ -78,6 +82,57 @@ static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl,
 bool kvm_rebooting;
 
 #ifdef KVM_CAP_DEVICE_ASSIGNMENT
+
+#ifdef CONFIG_X86
+static void assigned_device_msi_dispatch(struct kvm_assigned_dev_kernel *dev)
+{
+        int vcpu_id;
+        struct kvm_vcpu *vcpu;
+        struct kvm_ioapic *ioapic = ioapic_irqchip(dev->kvm);
+        int dest_id = (dev->guest_msi.address_lo & MSI_ADDR_DEST_ID_MASK)
+                        >> MSI_ADDR_DEST_ID_SHIFT;
+        int vector = (dev->guest_msi.data & MSI_DATA_VECTOR_MASK)
+                        >> MSI_DATA_VECTOR_SHIFT;
+        int dest_mode = test_bit(MSI_ADDR_DEST_MODE_SHIFT,
+                                (unsigned long *)&dev->guest_msi.address_lo);
+        int trig_mode = test_bit(MSI_DATA_TRIGGER_SHIFT,
+                                (unsigned long *)&dev->guest_msi.data);
+        int delivery_mode = test_bit(MSI_DATA_DELIVERY_MODE_SHIFT,
+                                (unsigned long *)&dev->guest_msi.data);
+        u32 deliver_bitmask;
+
+        BUG_ON(!ioapic);
+
+        deliver_bitmask = kvm_ioapic_get_delivery_bitmask(ioapic,
+                                dest_id, dest_mode);
+        /* IOAPIC delivery mode value is the same as MSI here */
+        switch (delivery_mode) {
+        case IOAPIC_LOWEST_PRIORITY:
+                vcpu = kvm_get_lowest_prio_vcpu(ioapic->kvm, vector,
+                                deliver_bitmask);
+                if (vcpu != NULL)
+                        kvm_apic_set_irq(vcpu, vector, trig_mode);
+                else
+                        printk(KERN_INFO "kvm: null lowest priority vcpu!\n");
+                break;
+        case IOAPIC_FIXED:
+                for (vcpu_id = 0; deliver_bitmask != 0; vcpu_id++) {
+                        if (!(deliver_bitmask & (1 << vcpu_id)))
+                                continue;
+                        deliver_bitmask &= ~(1 << vcpu_id);
+                        vcpu = ioapic->kvm->vcpus[vcpu_id];
+                        if (vcpu)
+                                kvm_apic_set_irq(vcpu, vector, trig_mode);
+                }
+                break;
+        default:
+                printk(KERN_INFO "kvm: unsupported MSI delivery mode\n");
+        }
+}
+#else
+static void assigned_device_msi_dispatch(struct kvm_assigned_dev_kernel *dev) {}
+#endif
+
 static struct kvm_assigned_dev_kernel *kvm_find_assigned_dev(struct list_head *head,
                                                       int assigned_dev_id)
 {