[RFC 13/27] vhost: add helper for IOTLB misses

[Maxime Coquelin]

This patch adds a helper for sending IOTLB misses as VDUSE
will use an ioctl while Vhost-user use a dedicated
Vhost-user backend request.

Signed-off-by: Maxime Coquelin <maxime.coque...@redhat.com>
---
 lib/vhost/vhost.c      | 13 ++++++++++++-
 lib/vhost/vhost.h      |  3 +++
 lib/vhost/vhost_user.c |  6 ++++--
 lib/vhost/vhost_user.h |  1 -
 4 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/lib/vhost/vhost.c b/lib/vhost/vhost.c
index 41f212315e..790eb06b28 100644
--- a/lib/vhost/vhost.c
+++ b/lib/vhost/vhost.c
@@ -52,6 +52,12 @@ static const struct vhost_vq_stats_name_off 
vhost_vq_stat_strings[] = {
 
 #define VHOST_NB_VQ_STATS RTE_DIM(vhost_vq_stat_strings)
 
+static int
+vhost_iotlb_miss(struct virtio_net *dev, uint64_t iova, uint8_t perm)
+{
+       return dev->backend_ops->iotlb_miss(dev, iova, perm);
+}
+
 uint64_t
 __vhost_iova_to_vva(struct virtio_net *dev, struct vhost_virtqueue *vq,
                    uint64_t iova, uint64_t *size, uint8_t perm)
@@ -86,7 +92,7 @@ __vhost_iova_to_vva(struct virtio_net *dev, struct 
vhost_virtqueue *vq,
                vhost_user_iotlb_rd_unlock(vq);
 
                vhost_user_iotlb_pending_insert(dev, iova, perm);
-               if (vhost_user_iotlb_miss(dev, iova, perm)) {
+               if (vhost_iotlb_miss(dev, iova, perm)) {
                        VHOST_LOG_DATA(dev->ifname, ERR,
                                "IOTLB miss req failed for IOVA 0x%" PRIx64 
"\n",
                                iova);
@@ -686,6 +692,11 @@ vhost_new_device(struct vhost_backend_ops *ops)
                return -1;
        }
 
+       if (ops->iotlb_miss == NULL) {
+               VHOST_LOG_CONFIG("device", ERR, "missing IOTLB miss backend 
op.\n");
+               return -1;
+       }
+
        pthread_mutex_lock(&vhost_dev_lock);
        for (i = 0; i < RTE_MAX_VHOST_DEVICE; i++) {
                if (vhost_devices[i] == NULL)
diff --git a/lib/vhost/vhost.h b/lib/vhost/vhost.h
index 2ad26f6951..ee7640e901 100644
--- a/lib/vhost/vhost.h
+++ b/lib/vhost/vhost.h
@@ -92,11 +92,14 @@
 struct virtio_net;
 typedef void (*vhost_iotlb_remove_notify)(uint64_t addr, uint64_t off, 
uint64_t size);
 
+typedef int (*vhost_iotlb_miss_cb)(struct virtio_net *dev, uint64_t iova, 
uint8_t perm);
+
 /**
  * Structure that contains backend-specific ops.
  */
 struct vhost_backend_ops {
        vhost_iotlb_remove_notify iotlb_remove_notify;
+       vhost_iotlb_miss_cb iotlb_miss;
 };
 
 /**
diff --git a/lib/vhost/vhost_user.c b/lib/vhost/vhost_user.c
index 2d5dec5bc1..6a9f32972a 100644
--- a/lib/vhost/vhost_user.c
+++ b/lib/vhost/vhost_user.c
@@ -3305,7 +3305,7 @@ vhost_user_msg_handler(int vid, int fd)
        return ret;
 }
 
-int
+static int
 vhost_user_iotlb_miss(struct virtio_net *dev, uint64_t iova, uint8_t perm)
 {
        int ret;
@@ -3465,7 +3465,9 @@ int rte_vhost_host_notifier_ctrl(int vid, uint16_t qid, 
bool enable)
        return ret;
 }
 
-static struct vhost_backend_ops vhost_user_backend_ops;
+static struct vhost_backend_ops vhost_user_backend_ops = {
+       .iotlb_miss = vhost_user_iotlb_miss,
+};
 
 int
 vhost_user_new_device(void)
diff --git a/lib/vhost/vhost_user.h b/lib/vhost/vhost_user.h
index 61456049c8..1ffeca92f3 100644
--- a/lib/vhost/vhost_user.h
+++ b/lib/vhost/vhost_user.h
@@ -179,7 +179,6 @@ struct __rte_packed vhu_msg_context {
 
 /* vhost_user.c */
 int vhost_user_msg_handler(int vid, int fd);
-int vhost_user_iotlb_miss(struct virtio_net *dev, uint64_t iova, uint8_t perm);
 
 /* socket.c */
 int read_fd_message(char *ifname, int sockfd, char *buf, int buflen, int *fds, 
int max_fds,
-- 
2.39.2