From 0723f1df5c3ec8a1112d150dab98e149361ef488 Mon Sep 17 00:00:00 2001 From: Eugenio Pérez Date: Wed, 10 Aug 2022 19:15:10 +0200 Subject: vhost-vdpa: introduce SUSPEND backend feature bit MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Message-Id: <20220810171512.2343333-3-eperezma@redhat.com> Signed-off-by: Michael S. Tsirkin --- drivers/vhost/vdpa.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) (limited to 'drivers/vhost') 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; -- cgit