[RFC PATCH 3/3] util/vfio-helpers: Let qemu_vfio_pci_init_irq take IRQ index argument

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

Add a new 'index' argument to qemu_vfio_pci_init_irq() to be able
to initialize other IRQs than IRQ #0. Adapt the single user of this
API in nvme_init().

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
 include/qemu/vfio-helpers.h |  2 +-
 block/nvme.c                |  2 +-
 util/vfio-helpers.c         | 12 +++++++++---
 3 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/include/qemu/vfio-helpers.h b/include/qemu/vfio-helpers.h
index 1f057c2b9e..ff63e75096 100644
--- a/include/qemu/vfio-helpers.h
+++ b/include/qemu/vfio-helpers.h
@@ -27,6 +27,6 @@ void *qemu_vfio_pci_map_bar(QEMUVFIOState *s, int index,
 void qemu_vfio_pci_unmap_bar(QEMUVFIOState *s, int index, void *bar,
                              uint64_t offset, uint64_t size);
 int qemu_vfio_pci_init_irq(QEMUVFIOState *s, EventNotifier *e,
-                           int irq_type, Error **errp);
+                           int irq_type, unsigned index, Error **errp);
 
 #endif
diff --git a/block/nvme.c b/block/nvme.c
index 374e268915..2b3986b66d 100644
--- a/block/nvme.c
+++ b/block/nvme.c
@@ -757,7 +757,7 @@ static int nvme_init(BlockDriverState *bs, const char *device, int namespace,
     }
 
     ret = qemu_vfio_pci_init_irq(s->vfio, &s->irq_notifier,
-                                 VFIO_PCI_MSIX_IRQ_INDEX, errp);
+                                 VFIO_PCI_MSIX_IRQ_INDEX, 0, errp);
     if (ret) {
         goto out;
     }
diff --git a/util/vfio-helpers.c b/util/vfio-helpers.c
index 3ad7e6be52..ba9a869364 100644
--- a/util/vfio-helpers.c
+++ b/util/vfio-helpers.c
@@ -173,10 +173,11 @@ void qemu_vfio_pci_unmap_bar(QEMUVFIOState *s, int index, void *bar,
 }
 
 /**
- * Initialize device IRQ with @irq_type and register an event notifier.
+ * Initialize device IRQ @index with @irq_type
+ * and register an event notifier.
  */
 int qemu_vfio_pci_init_irq(QEMUVFIOState *s, EventNotifier *e,
-                           int irq_type, Error **errp)
+                           int irq_type, unsigned index, Error **errp)
 {
     int r;
     struct vfio_irq_set *irq_set;
@@ -193,6 +194,11 @@ int qemu_vfio_pci_init_irq(QEMUVFIOState *s, EventNotifier *e,
         return -EINVAL;
     }
     trace_qemu_vfio_pci_init_irq(irq_info.count);
+    if (index >= irq_info.count) {
+        error_setg(errp, "Device has %"PRIu32" interrupts (requested index %u)",
+                   irq_info.count, index);
+        return -EINVAL;
+    }
 
     irq_set_size = sizeof(*irq_set) + sizeof(int32_t);
     irq_set = g_malloc0(irq_set_size);
@@ -202,7 +208,7 @@ int qemu_vfio_pci_init_irq(QEMUVFIOState *s, EventNotifier *e,
         .argsz = irq_set_size,
         .flags = VFIO_IRQ_SET_DATA_EVENTFD | VFIO_IRQ_SET_ACTION_TRIGGER,
         .index = irq_info.index,
-        .start = 0,
+        .start = index,
         .count = 1,
     };
 
-- 
2.21.3