[Qemu-devel] [PATCH 10/10] virtio: use ring structure from linux-headers

["Michael S. Tsirkin" <mst@redhat.com>]

We already have ring structure in virtio-ring.h for use by dataplane.
Use it in virtio.h as well, renaming some conflicting functions.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/virtio/virtio.c         | 23 +++++------------------
 include/hw/virtio/virtio.h | 45 +++------------------------------------------
 2 files changed, 8 insertions(+), 60 deletions(-)

diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 8176c14..20bb6c2 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -145,7 +145,7 @@ static inline uint16_t vring_avail_ring(VirtQueue *vq, int i)
     return lduw_phys(pa);
 }
 
-static inline uint16_t vring_used_event(VirtQueue *vq)
+static inline uint16_t vring_used_event_idx(VirtQueue *vq)
 {
     return vring_avail_ring(vq, vq->vring.num);
 }
@@ -192,7 +192,7 @@ static inline void vring_used_flags_unset_bit(VirtQueue *vq, int mask)
     stw_phys(pa, lduw_phys(pa) & ~mask);
 }
 
-static inline void vring_avail_event(VirtQueue *vq, uint16_t val)
+static inline void vring_avail_event_idx(VirtQueue *vq, uint16_t val)
 {
     hwaddr pa;
     if (!vq->notification) {
@@ -206,7 +206,7 @@ void virtio_queue_set_notification(VirtQueue *vq, int enable)
 {
     vq->notification = enable;
     if (vq->vdev->guest_features & (1 << VIRTIO_RING_F_EVENT_IDX)) {
-        vring_avail_event(vq, vring_avail_idx(vq));
+        vring_avail_event_idx(vq, vring_avail_idx(vq));
     } else if (enable) {
         vring_used_flags_unset_bit(vq, VRING_USED_F_NO_NOTIFY);
     } else {
@@ -448,7 +448,7 @@ int virtqueue_pop(VirtQueue *vq, VirtQueueElement *elem)
 
     i = head = virtqueue_get_head(vq, vq->last_avail_idx++);
     if (vq->vdev->guest_features & (1 << VIRTIO_RING_F_EVENT_IDX)) {
-        vring_avail_event(vq, vring_avail_idx(vq));
+        vring_avail_event_idx(vq, vring_avail_idx(vq));
     }
 
     if (vring_desc_flags(desc_pa, i) & VRING_DESC_F_INDIRECT) {
@@ -740,19 +740,6 @@ void virtio_irq(VirtQueue *vq)
     virtio_notify_vector(vq->vdev, vq->vector);
 }
 
-/* Assuming a given event_idx value from the other size, if
- * we have just incremented index from old to new_idx,
- * should we trigger an event? */
-static inline int vring_need_event(uint16_t event, uint16_t new, uint16_t old)
-{
-	/* Note: Xen has similar logic for notification hold-off
-	 * in include/xen/interface/io/ring.h with req_event and req_prod
-	 * corresponding to event_idx + 1 and new respectively.
-	 * Note also that req_event and req_prod in Xen start at 1,
-	 * event indexes in virtio start at 0. */
-	return (uint16_t)(new - event - 1) < (uint16_t)(new - old);
-}
-
 static bool vring_notify(VirtIODevice *vdev, VirtQueue *vq)
 {
     uint16_t old, new;
@@ -773,7 +760,7 @@ static bool vring_notify(VirtIODevice *vdev, VirtQueue *vq)
     vq->signalled_used_valid = true;
     old = vq->signalled_used;
     new = vq->signalled_used = vring_used_idx(vq);
-    return !v || vring_need_event(vring_used_event(vq), new, old);
+    return !v || vring_need_event(vring_used_event_idx(vq), new, old);
 }
 
 void virtio_notify(VirtIODevice *vdev, VirtQueue *vq)
diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
index a6c5c53..3ea634d 100644
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -22,50 +22,11 @@
 #ifdef CONFIG_VIRTFS
 #include "hw/virtio/virtio-9p.h"
 #endif
+#include "linux/virtio_config.h"
+#include "linux/virtio_ring.h"
 
-/* from Linux's linux/virtio_config.h */
-
-/* Status byte for guest to report progress, and synchronize features. */
-/* We have seen device and processed generic fields (VIRTIO_CONFIG_F_VIRTIO) */
-#define VIRTIO_CONFIG_S_ACKNOWLEDGE     1
-/* We have found a driver for the device. */
-#define VIRTIO_CONFIG_S_DRIVER          2
-/* Driver has used its parts of the config, and is happy */
-#define VIRTIO_CONFIG_S_DRIVER_OK       4
-/* We've given up on this device. */
-#define VIRTIO_CONFIG_S_FAILED          0x80
-
-/* Some virtio feature bits (currently bits 28 through 31) are reserved for the
- * transport being used (eg. virtio_ring), the rest are per-device feature bits. */
-#define VIRTIO_TRANSPORT_F_START        28
-#define VIRTIO_TRANSPORT_F_END          32
-
-/* We notify when the ring is completely used, even if the guest is suppressing
- * callbacks */
-#define VIRTIO_F_NOTIFY_ON_EMPTY        24
-/* We support indirect buffer descriptors */
-#define VIRTIO_RING_F_INDIRECT_DESC     28
-/* The Guest publishes the used index for which it expects an interrupt
- * at the end of the avail ring. Host should ignore the avail->flags field. */
-/* The Host publishes the avail index for which it expects a kick
- * at the end of the used ring. Guest should ignore the used->flags field. */
-#define VIRTIO_RING_F_EVENT_IDX         29
 /* A guest should never accept this.  It implies negotiation is broken. */
-#define VIRTIO_F_BAD_FEATURE		30
-
-/* from Linux's linux/virtio_ring.h */
-
-/* This marks a buffer as continuing via the next field. */
-#define VRING_DESC_F_NEXT       1
-/* This marks a buffer as write-only (otherwise read-only). */
-#define VRING_DESC_F_WRITE      2
-/* This means the buffer contains a list of buffer descriptors. */
-#define VRING_DESC_F_INDIRECT  4
-
-/* This means don't notify other side when buffer added. */
-#define VRING_USED_F_NO_NOTIFY  1
-/* This means don't interrupt guest when buffer consumed. */
-#define VRING_AVAIL_F_NO_INTERRUPT      1
+#define VIRTIO_F_BAD_FEATURE           30
 
 struct VirtQueue;
 
-- 
MST