KVM: Add support to disable MSI for assigned device

MSI is always enabled by default for msi2intx=1. But if msi2intx=0, we
have to disable MSI if guest require to do so.

The patch also discard unnecessary msi2intx judgment if guest want to update
MSI state.

Notice KVM_DEV_IRQ_ASSIGN_MSI_ACTION is a mask which should cover all MSI
related operations, though we only got one for now.

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

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index ae7a12c77427..73f348066866 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -550,6 +550,7 @@ struct kvm_assigned_irq {
 
 #define KVM_DEV_ASSIGN_ENABLE_IOMMU     (1 << 0)
 
+#define KVM_DEV_IRQ_ASSIGN_MSI_ACTION   KVM_DEV_IRQ_ASSIGN_ENABLE_MSI
 #define KVM_DEV_IRQ_ASSIGN_ENABLE_MSI   (1 << 0)
 
 #endif