From 653055b9acd45d602435f2f70b7a85cb3130f018 Mon Sep 17 00:00:00 2001
From: Jason Wang <jasowang@redhat.com>
Date: Tue, 4 Aug 2020 19:20:39 +0300
Subject: [PATCH] vhost-vdpa: support get/set backend features
This patch makes userspace can get and set backend features to
vhost-vdpa.
Signed-off-by: Cindy Lu <lulu@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20200804162048.22587-4-eli@mellanox.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
drivers/vhost/vdpa.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index 01475bec6e0de..61c17d34cb392 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -26,6 +26,10 @@
#include "vhost.h"
+enum {
+ VHOST_VDPA_BACKEND_FEATURES = (1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2)
+};
+
/* Currently, only network backend w/o multiqueue is supported. */
#define VHOST_VDPA_VQ_MAX 2
@@ -347,6 +351,8 @@ static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
struct vdpa_callback cb;
struct vhost_virtqueue *vq;
struct vhost_vring_state s;
+ u64 __user *featurep = argp;
+ u64 features;
u32 idx;
long r;
@@ -369,6 +375,18 @@ static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
case VHOST_GET_VRING_BASE:
vq->last_avail_idx = ops->get_vq_state(v->vdpa, idx);
break;
+ case VHOST_GET_BACKEND_FEATURES:
+ features = VHOST_VDPA_BACKEND_FEATURES;
+ if (copy_to_user(featurep, &features, sizeof(features)))
+ return -EFAULT;
+ return 0;
+ case VHOST_SET_BACKEND_FEATURES:
+ if (copy_from_user(&features, featurep, sizeof(features)))
+ return -EFAULT;
+ if (features & ~VHOST_VDPA_BACKEND_FEATURES)
+ return -EOPNOTSUPP;
+ vhost_set_backend_features(&v->vdev, features);
+ return 0;
}
r = vhost_vring_ioctl(&v->vdev, cmd, argp);
--
2.30.2