[Qemu-devel] [PATCH] virtio: add support for in-order feature

[Ilya Maximets]

New feature bit for in-order feature of the upcoming
virtio 1.1. It's already supported by DPDK vhost-user
and virtio implementations. These changes required to
allow feature negotiation.

Signed-off-by: Ilya Maximets <address@hidden>
---

I just wanted to test this new feature in DPDK but failed
to found required patch for QEMU side. So, I implemented it.
At least it will be helpful for someone like me, who wants
to evaluate VIRTIO_F_IN_ORDER with DPDK.

 hw/net/vhost_net.c                             |  1 +
 include/hw/virtio/virtio.h                     | 12 +++++++-----
 include/standard-headers/linux/virtio_config.h |  7 +++++++
 3 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index e037db6..86879c5 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -78,6 +78,7 @@ static const int user_feature_bits[] = {
     VIRTIO_NET_F_MRG_RXBUF,
     VIRTIO_NET_F_MTU,
     VIRTIO_F_IOMMU_PLATFORM,
+    VIRTIO_F_IN_ORDER,
 
     /* This bit implies RARP isn't sent by QEMU out of band */
     VIRTIO_NET_F_GUEST_ANNOUNCE,
diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
index 9c1fa07..a422025 100644
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -254,16 +254,18 @@ typedef struct virtio_input_conf virtio_input_conf;
 typedef struct VirtIOSCSIConf VirtIOSCSIConf;
 typedef struct VirtIORNGConf VirtIORNGConf;
 
-#define DEFINE_VIRTIO_COMMON_FEATURES(_state, _field) \
+#define DEFINE_VIRTIO_COMMON_FEATURES(_state, _field)     \
     DEFINE_PROP_BIT64("indirect_desc", _state, _field,    \
                       VIRTIO_RING_F_INDIRECT_DESC, true), \
     DEFINE_PROP_BIT64("event_idx", _state, _field,        \
                       VIRTIO_RING_F_EVENT_IDX, true),     \
     DEFINE_PROP_BIT64("notify_on_empty", _state, _field,  \
-                      VIRTIO_F_NOTIFY_ON_EMPTY, true), \
-    DEFINE_PROP_BIT64("any_layout", _state, _field, \
-                      VIRTIO_F_ANY_LAYOUT, true), \
-    DEFINE_PROP_BIT64("iommu_platform", _state, _field, \
+                      VIRTIO_F_NOTIFY_ON_EMPTY, true),    \
+    DEFINE_PROP_BIT64("any_layout", _state, _field,       \
+                      VIRTIO_F_ANY_LAYOUT, true),         \
+    DEFINE_PROP_BIT64("in_order", _state, _field,         \
+                      VIRTIO_F_IN_ORDER, true),           \
+    DEFINE_PROP_BIT64("iommu_platform", _state, _field,   \
                       VIRTIO_F_IOMMU_PLATFORM, false)
 
 hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n);
diff --git a/include/standard-headers/linux/virtio_config.h 
b/include/standard-headers/linux/virtio_config.h
index b777069..d20398c 100644
--- a/include/standard-headers/linux/virtio_config.h
+++ b/include/standard-headers/linux/virtio_config.h
@@ -71,4 +71,11 @@
  * this is for compatibility with legacy systems.
  */
 #define VIRTIO_F_IOMMU_PLATFORM                33
+
+/*
+ * Inorder feature indicates that all buffers are used by the device
+ * in the same order in which they have been made available.
+ */
+#define VIRTIO_F_IN_ORDER 35
+
 #endif /* _LINUX_VIRTIO_CONFIG_H */
-- 
2.7.4