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authorEugenio Pérez <eperezma@redhat.com>2022-08-10 19:15:10 +0200
committerMichael S. Tsirkin <mst@redhat.com>2022-08-11 04:31:14 -0400
commit0723f1df5c3ec8a1112d150dab98e149361ef488 (patch)
treee10aa979039b7eb2fe412faa09348376c852a9f7
parent848ecea184e1253758423b37cbfc1ed732ccf5b4 (diff)
vhost-vdpa: introduce SUSPEND backend feature bit
Userland knows if it can suspend the device or not by checking this feature bit. It's only offered if the vdpa driver backend implements the suspend() operation callback, and to offer it or userland to ack it if the backend does not offer that callback is an error. Signed-off-by: Eugenio Pérez <eperezma@redhat.com> Message-Id: <20220810171512.2343333-3-eperezma@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
-rw-r--r--drivers/vhost/vdpa.c16
-rw-r--r--include/uapi/linux/vhost_types.h2
2 files changed, 17 insertions, 1 deletions
diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index 2c997d77d266..092752fea8e1 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -347,6 +347,14 @@ static long vhost_vdpa_set_config(struct vhost_vdpa *v,
return 0;
}
+static bool vhost_vdpa_can_suspend(const struct vhost_vdpa *v)
+{
+ struct vdpa_device *vdpa = v->vdpa;
+ const struct vdpa_config_ops *ops = vdpa->config;
+
+ return ops->suspend;
+}
+
static long vhost_vdpa_get_features(struct vhost_vdpa *v, u64 __user *featurep)
{
struct vdpa_device *vdpa = v->vdpa;
@@ -577,7 +585,11 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep,
if (cmd == VHOST_SET_BACKEND_FEATURES) {
if (copy_from_user(&features, featurep, sizeof(features)))
return -EFAULT;
- if (features & ~VHOST_VDPA_BACKEND_FEATURES)
+ if (features & ~(VHOST_VDPA_BACKEND_FEATURES |
+ BIT_ULL(VHOST_BACKEND_F_SUSPEND)))
+ return -EOPNOTSUPP;
+ if ((features & BIT_ULL(VHOST_BACKEND_F_SUSPEND)) &&
+ !vhost_vdpa_can_suspend(v))
return -EOPNOTSUPP;
vhost_set_backend_features(&v->vdev, features);
return 0;
@@ -628,6 +640,8 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep,
break;
case VHOST_GET_BACKEND_FEATURES:
features = VHOST_VDPA_BACKEND_FEATURES;
+ if (vhost_vdpa_can_suspend(v))
+ features |= BIT_ULL(VHOST_BACKEND_F_SUSPEND);
if (copy_to_user(featurep, &features, sizeof(features)))
r = -EFAULT;
break;
diff --git a/include/uapi/linux/vhost_types.h b/include/uapi/linux/vhost_types.h
index 634cee485abb..1bdd6e363f4c 100644
--- a/include/uapi/linux/vhost_types.h
+++ b/include/uapi/linux/vhost_types.h
@@ -161,5 +161,7 @@ struct vhost_vdpa_iova_range {
* message
*/
#define VHOST_BACKEND_F_IOTLB_ASID 0x3
+/* Device can be suspended */
+#define VHOST_BACKEND_F_SUSPEND 0x4
#endif