msix: add helper to unuse all msix entries

will be used by virtio on soft reset

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

hw/msix.c

diff --git a/hw/msix.c b/hw/msix.c
index 548ffd5..d499441 100644
--- a/hw/msix.c
+++ b/hw/msix.c
@@ -378,3 +378,10 @@
     if (vector < dev->msix_entries_nr && dev->msix_entry_used[vector])
         --dev->msix_entry_used[vector];
 }
+
+void msix_unuse_all_vectors(PCIDevice *dev)
+{
+    if (!(dev->cap_present & QEMU_PCI_CAP_MSIX))
+        return;
+    msix_free_irq_entries(dev);
+}

hw/msix.h

diff --git a/hw/msix.h b/hw/msix.h
index 39fa568..a9f7993 100644
--- a/hw/msix.h
+++ b/hw/msix.h
@@ -25,6 +25,7 @@
 
 int msix_vector_use(PCIDevice *dev, unsigned vector);
 void msix_vector_unuse(PCIDevice *dev, unsigned vector);
+void msix_unuse_all_vectors(PCIDevice *dev);
 
 void msix_notify(PCIDevice *dev, unsigned vector);