From: jiangdongxu1 jiangdongxu1@huawei.com
mainline inclusion from v6.3-rc1 commit 69106b6fb3d73bd4252daa48ae96e600c9701147 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I86ITO Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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Userspace knows if the device can be resumed or not by checking this feature bit.
It's only exposed if the vdpa driver backend implements the resume() operation callback. Userspace trying to negotiate this feature when it hasn't been exposed will result in an error.
Acked-by: Jason Wang jasowang@redhat.com Signed-off-by: Sebastien Boeuf sebastien.boeuf@intel.com Message-Id: b18db236ba3d990cdb41278eb4703be9201d9514.1672742878.git.sebastien.boeuf@intel.com Signed-off-by: Michael S. Tsirkin mst@redhat.com Reviewed-by: Stefano Garzarella sgarzare@redhat.com Signed-off-by: jiangdongxu1 jiangdongxu1@huawei.com --- drivers/vhost/vdpa.c | 16 +++++++++++++++- include/uapi/linux/vhost_types.h | 2 ++ 2 files changed, 17 insertions(+), 1 deletion(-)
diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c index e90a848cfffc..2a0288c019d0 100644 --- a/drivers/vhost/vdpa.c +++ b/drivers/vhost/vdpa.c @@ -359,6 +359,14 @@ static bool vhost_vdpa_can_suspend(const struct vhost_vdpa *v) return ops->suspend; }
+static bool vhost_vdpa_can_resume(const struct vhost_vdpa *v) +{ + struct vdpa_device *vdpa = v->vdpa; + const struct vdpa_config_ops *ops = vdpa->config; + + return ops->resume; +} + static long vhost_vdpa_get_features(struct vhost_vdpa *v, u64 __user *featurep) { struct vdpa_device *vdpa = v->vdpa; @@ -606,11 +614,15 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep, if (copy_from_user(&features, featurep, sizeof(features))) return -EFAULT; if (features & ~(VHOST_VDPA_BACKEND_FEATURES | - BIT_ULL(VHOST_BACKEND_F_SUSPEND))) + BIT_ULL(VHOST_BACKEND_F_SUSPEND) | + BIT_ULL(VHOST_BACKEND_F_RESUME))) return -EOPNOTSUPP; if ((features & BIT_ULL(VHOST_BACKEND_F_SUSPEND)) && !vhost_vdpa_can_suspend(v)) return -EOPNOTSUPP; + if ((features & BIT_ULL(VHOST_BACKEND_F_RESUME)) && + !vhost_vdpa_can_resume(v)) + return -EOPNOTSUPP; vhost_set_backend_features(&v->vdev, features); return 0; } @@ -662,6 +674,8 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep, features = VHOST_VDPA_BACKEND_FEATURES; if (vhost_vdpa_can_suspend(v)) features |= BIT_ULL(VHOST_BACKEND_F_SUSPEND); + if (vhost_vdpa_can_resume(v)) + features |= BIT_ULL(VHOST_BACKEND_F_RESUME); 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 1bdd6e363f4c..9e072926d633 100644 --- a/include/uapi/linux/vhost_types.h +++ b/include/uapi/linux/vhost_types.h @@ -163,5 +163,7 @@ struct vhost_vdpa_iova_range { #define VHOST_BACKEND_F_IOTLB_ASID 0x3 /* Device can be suspended */ #define VHOST_BACKEND_F_SUSPEND 0x4 +/* Device can be resumed */ +#define VHOST_BACKEND_F_RESUME 0x5
#endif