[PATCH RFC 01/12] vhost-vdpa: add support for vDPA blk devices

[Stefano Garzarella <sgarzare@redhat.com>]

From: Max Gurtovoy <maxg@mellanox.com>

Currently only net devices can act as vDPA backends. Add an
infrastructure for block devices will basic feature list that will be
increased in the future.

Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
---
 drivers/vhost/vdpa.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index 2754f3069738..fb0411594963 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -22,6 +22,7 @@
 #include <linux/nospec.h>
 #include <linux/vhost.h>
 #include <linux/virtio_net.h>
+#include <linux/virtio_blk.h>
 
 #include "vhost.h"
 
@@ -194,6 +195,9 @@ static int vhost_vdpa_config_validate(struct vhost_vdpa *v,
 	case VIRTIO_ID_NET:
 		size = sizeof(struct virtio_net_config);
 		break;
+	case VIRTIO_ID_BLOCK:
+		size = sizeof(struct virtio_blk_config);
+		break;
 	}
 
 	if (c->len == 0)
@@ -975,12 +979,13 @@ static void vhost_vdpa_release_dev(struct device *device)
 static int vhost_vdpa_probe(struct vdpa_device *vdpa)
 {
 	const struct vdpa_config_ops *ops = vdpa->config;
+	u32 device_id = ops->get_device_id(vdpa);
 	struct vhost_vdpa *v;
 	int minor;
 	int r;
 
-	/* Currently, we only accept the network devices. */
-	if (ops->get_device_id(vdpa) != VIRTIO_ID_NET)
+	/* Currently, we only accept the network and block devices. */
+	if (device_id != VIRTIO_ID_NET && device_id != VIRTIO_ID_BLOCK)
 		return -ENOTSUPP;
 
 	v = kzalloc(sizeof(*v), GFP_KERNEL | __GFP_RETRY_MAYFAIL);
@@ -998,7 +1003,7 @@ static int vhost_vdpa_probe(struct vdpa_device *vdpa)
 	v->minor = minor;
 	v->vdpa = vdpa;
 	v->nvqs = vdpa->nvqs;
-	v->virtio_id = ops->get_device_id(vdpa);
+	v->virtio_id = device_id;
 
 	device_initialize(&v->dev);
 	v->dev.release = vhost_vdpa_release_dev;
-- 
2.26.2