[RFC PATCH V2 7/8] vhost: packed ring support

[Jason Wang]

Signed-off-by: Jason Wang 
---
 drivers/vhost/net.c   |   5 +-
 drivers/vhost/vhost.c | 530 ++
 drivers/vhost/vhost.h |   7 +-
 3 files changed, 505 insertions(+), 37 deletions(-)

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 7be8b55..84905d5 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -67,7 +67,8 @@ enum {
VHOST_NET_FEATURES = VHOST_FEATURES |
 (1ULL << VHOST_NET_F_VIRTIO_NET_HDR) |
 (1ULL << VIRTIO_NET_F_MRG_RXBUF) |
-(1ULL << VIRTIO_F_IOMMU_PLATFORM)
+(1ULL << VIRTIO_F_IOMMU_PLATFORM) |
+(1ULL << VIRTIO_F_RING_PACKED)
 };
 
 enum {
@@ -706,6 +707,8 @@ static void handle_rx(struct vhost_net *net)
vq_log = unlikely(vhost_has_feature(vq, VHOST_F_LOG_ALL)) ?
vq->log : NULL;
mergeable = vhost_has_feature(vq, VIRTIO_NET_F_MRG_RXBUF);
+   /* FIXME: workaround for current dpdk prototype */
+   mergeable = false;
 
while ((sock_len = vhost_net_rx_peek_head_len(net, sock->sk))) {
sock_len += sock_hlen;
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index dcac4d4..6177e4d 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -324,6 +324,7 @@ static void vhost_vq_reset(struct vhost_dev *dev,
vhost_reset_is_le(vq);
vhost_disable_cross_endian(vq);
vq->busyloop_timeout = 0;
+   vq->used_wrap_counter = true;
vq->umem = NULL;
vq->iotlb = NULL;
__vhost_vq_meta_reset(vq);
@@ -1136,10 +1137,22 @@ static int vhost_iotlb_miss(struct vhost_virtqueue *vq, 
u64 iova, int access)
return 0;
 }
 
-static int vq_access_ok(struct vhost_virtqueue *vq, unsigned int num,
-   struct vring_desc __user *desc,
-   struct vring_avail __user *avail,
-   struct vring_used __user *used)
+static int vq_access_ok_packed(struct vhost_virtqueue *vq, unsigned int num,
+  struct vring_desc __user *desc,
+  struct vring_avail __user *avail,
+  struct vring_used __user *used)
+{
+   struct vring_desc_packed *packed = (struct vring_desc_packed *)desc;
+
+   /* FIXME: check device area and driver area */
+   return access_ok(VERIFY_READ, packed, num * sizeof(*packed)) &&
+  access_ok(VERIFY_WRITE, packed, num * sizeof(*packed));
+}
+
+static int vq_access_ok_split(struct vhost_virtqueue *vq, unsigned int num,
+ struct vring_desc __user *desc,
+ struct vring_avail __user *avail,
+ struct vring_used __user *used)
 
 {
size_t s = vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;
@@ -1151,6 +1164,17 @@ static int vq_access_ok(struct vhost_virtqueue *vq, 
unsigned int num,
sizeof *used + num * sizeof *used->ring + s);
 }
 
+static int vq_access_ok(struct vhost_virtqueue *vq, unsigned int num,
+   struct vring_desc __user *desc,
+   struct vring_avail __user *avail,
+   struct vring_used __user *used)
+{
+   if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED))
+   return vq_access_ok_packed(vq, num, desc, avail, used);
+   else
+   return vq_access_ok_split(vq, num, desc, avail, used);
+}
+
 static void vhost_vq_meta_update(struct vhost_virtqueue *vq,
 const struct vhost_umem_node *node,
 int type)
@@ -1763,6 +1787,9 @@ int vhost_vq_init_access(struct vhost_virtqueue *vq)
 
vhost_init_is_le(vq);
 
+   if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED))
+   return 0;
+
r = vhost_update_used_flags(vq);
if (r)
goto err;
@@ -1836,7 +1863,8 @@ static int translate_desc(struct vhost_virtqueue *vq, u64 
addr, u32 len,
 /* Each buffer in the virtqueues is actually a chain of descriptors.  This
  * function returns the next descriptor in the chain,
  * or -1U if we're at the end. */
-static unsigned next_desc(struct vhost_virtqueue *vq, struct vring_desc *desc)
+static unsigned next_desc_split(struct vhost_virtqueue *vq,
+   struct vring_desc *desc)
 {
unsigned int next;
 
@@ -1849,11 +1877,17 @@ static unsigned next_desc(struct vhost_virtqueue *vq, 
struct vring_desc *desc)
return next;
 }
 
-static int get_indirect(struct vhost_virtqueue *vq,
-   struct iovec iov[], unsigned int iov_size,
-   unsigned int *out_num, unsigned int *in_num,
-   struct vhost_log *log, unsigned int *log_num,
-   struct vring_desc *indirect)
+static unsigned next_desc_packed(struct vhost_virtqueue *vq,
+   

[RFC PATCH V2 7/8] vhost: packed ring support

[Jason Wang]

Signed-off-by: Jason Wang 
---
 drivers/vhost/net.c   |   5 +-
 drivers/vhost/vhost.c | 530 ++
 drivers/vhost/vhost.h |   7 +-
 3 files changed, 505 insertions(+), 37 deletions(-)

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 7be8b55..84905d5 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -67,7 +67,8 @@ enum {
VHOST_NET_FEATURES = VHOST_FEATURES |
 (1ULL << VHOST_NET_F_VIRTIO_NET_HDR) |
 (1ULL << VIRTIO_NET_F_MRG_RXBUF) |
-(1ULL << VIRTIO_F_IOMMU_PLATFORM)
+(1ULL << VIRTIO_F_IOMMU_PLATFORM) |
+(1ULL << VIRTIO_F_RING_PACKED)
 };
 
 enum {
@@ -706,6 +707,8 @@ static void handle_rx(struct vhost_net *net)
vq_log = unlikely(vhost_has_feature(vq, VHOST_F_LOG_ALL)) ?
vq->log : NULL;
mergeable = vhost_has_feature(vq, VIRTIO_NET_F_MRG_RXBUF);
+   /* FIXME: workaround for current dpdk prototype */
+   mergeable = false;
 
while ((sock_len = vhost_net_rx_peek_head_len(net, sock->sk))) {
sock_len += sock_hlen;
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index dcac4d4..6177e4d 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -324,6 +324,7 @@ static void vhost_vq_reset(struct vhost_dev *dev,
vhost_reset_is_le(vq);
vhost_disable_cross_endian(vq);
vq->busyloop_timeout = 0;
+   vq->used_wrap_counter = true;
vq->umem = NULL;
vq->iotlb = NULL;
__vhost_vq_meta_reset(vq);
@@ -1136,10 +1137,22 @@ static int vhost_iotlb_miss(struct vhost_virtqueue *vq, 
u64 iova, int access)
return 0;
 }
 
-static int vq_access_ok(struct vhost_virtqueue *vq, unsigned int num,
-   struct vring_desc __user *desc,
-   struct vring_avail __user *avail,
-   struct vring_used __user *used)
+static int vq_access_ok_packed(struct vhost_virtqueue *vq, unsigned int num,
+  struct vring_desc __user *desc,
+  struct vring_avail __user *avail,
+  struct vring_used __user *used)
+{
+   struct vring_desc_packed *packed = (struct vring_desc_packed *)desc;
+
+   /* FIXME: check device area and driver area */
+   return access_ok(VERIFY_READ, packed, num * sizeof(*packed)) &&
+  access_ok(VERIFY_WRITE, packed, num * sizeof(*packed));
+}
+
+static int vq_access_ok_split(struct vhost_virtqueue *vq, unsigned int num,
+ struct vring_desc __user *desc,
+ struct vring_avail __user *avail,
+ struct vring_used __user *used)
 
 {
size_t s = vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;
@@ -1151,6 +1164,17 @@ static int vq_access_ok(struct vhost_virtqueue *vq, 
unsigned int num,
sizeof *used + num * sizeof *used->ring + s);
 }
 
+static int vq_access_ok(struct vhost_virtqueue *vq, unsigned int num,
+   struct vring_desc __user *desc,
+   struct vring_avail __user *avail,
+   struct vring_used __user *used)
+{
+   if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED))
+   return vq_access_ok_packed(vq, num, desc, avail, used);
+   else
+   return vq_access_ok_split(vq, num, desc, avail, used);
+}
+
 static void vhost_vq_meta_update(struct vhost_virtqueue *vq,
 const struct vhost_umem_node *node,
 int type)
@@ -1763,6 +1787,9 @@ int vhost_vq_init_access(struct vhost_virtqueue *vq)
 
vhost_init_is_le(vq);
 
+   if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED))
+   return 0;
+
r = vhost_update_used_flags(vq);
if (r)
goto err;
@@ -1836,7 +1863,8 @@ static int translate_desc(struct vhost_virtqueue *vq, u64 
addr, u32 len,
 /* Each buffer in the virtqueues is actually a chain of descriptors.  This
  * function returns the next descriptor in the chain,
  * or -1U if we're at the end. */
-static unsigned next_desc(struct vhost_virtqueue *vq, struct vring_desc *desc)
+static unsigned next_desc_split(struct vhost_virtqueue *vq,
+   struct vring_desc *desc)
 {
unsigned int next;
 
@@ -1849,11 +1877,17 @@ static unsigned next_desc(struct vhost_virtqueue *vq, 
struct vring_desc *desc)
return next;
 }
 
-static int get_indirect(struct vhost_virtqueue *vq,
-   struct iovec iov[], unsigned int iov_size,
-   unsigned int *out_num, unsigned int *in_num,
-   struct vhost_log *log, unsigned int *log_num,
-   struct vring_desc *indirect)
+static unsigned next_desc_packed(struct vhost_virtqueue *vq,
+