[PATCH 08/10] KVM: Add assigned_device_msi_dispatch()

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

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

(Any way to replace macro GET_VAL_FROM_SHIFT()?)

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
---
 virt/kvm/kvm_main.c |   45 +++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 45 insertions(+), 0 deletions(-)

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index ddfd7ac..be0f943 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -46,6 +46,7 @@
 #include <asm/io.h>
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
+#include <asm/msidef.h>
 
 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
 #include "coalesced_mmio.h"
@@ -78,6 +79,50 @@ static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl,
 bool kvm_rebooting;
 
 #ifdef KVM_CAP_DEVICE_ASSIGNMENT
+static void assigned_device_msi_dispatch(struct kvm_assigned_dev_kernel *dev)
+{
+#define GET_VAL_FROM_SHIFT(v, s) (((v) & (1 << s)) >> s)
+	int vcpu_id;
+	struct kvm_vcpu *vcpu;
+	struct kvm_ioapic *ioapic = ioapic_irqchip(dev->kvm);
+	u8 dest_id = MSI_ADDR_DEST_ID(dev->guest_msi_addr);
+	u8 vector = MSI_DATA_VECTOR(dev->guest_msi_data);
+	u8 dest_mode = GET_VAL_FROM_SHIFT(dev->guest_msi_addr,
+					  MSI_ADDR_DEST_MODE_SHIFT);
+	u8 trig_mode = GET_VAL_FROM_SHIFT(dev->guest_msi_data,
+					  MSI_DATA_TRIGGER_SHIFT);
+	u8 delivery_mode = GET_VAL_FROM_SHIFT(dev->guest_msi_data,
+					  MSI_DATA_DELIVERY_MODE_SHIFT);
+	u32 deliver_bitmask;
+
+	BUG_ON(!ioapic);
+
+	deliver_bitmask = ioapic_get_delivery_bitmask(ioapic,
+						      dest_id, dest_mode);
+	switch (delivery_mode) {
+	case MSI_DATA_DELIVERY_LOWPRI_VAL:
+		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 MSI_DATA_DELIVERY_FIXED_VAL:
+		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");
+	}
+}
+
 static struct kvm_assigned_dev_kernel *kvm_find_assigned_dev(struct list_head *head,
 						      int assigned_dev_id)
 {
-- 
1.5.4.5