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authorSi-Wei Liu <si-wei.liu@oracle.com>2023-10-18 19:14:42 +0200
committerMichael S. Tsirkin <mst@redhat.com>2023-11-01 14:19:55 +0100
commit7db0d6027e69f47431800b510192436563ba415b (patch)
tree8e59125cf20af68e38ef87fc121767d2f44c00f8 /drivers/vhost
parentvdpa: introduce dedicated descriptor group for virtqueue (diff)
downloadlinux-7db0d6027e69f47431800b510192436563ba415b.tar.xz
linux-7db0d6027e69f47431800b510192436563ba415b.zip
vhost-vdpa: introduce descriptor group backend feature
Userspace knows if the device has dedicated descriptor group or not by checking this feature bit. It's only exposed if the vdpa driver backend implements the .get_vq_desc_group() operation callback. Userspace trying to negotiate this feature when it or the dependent _F_IOTLB_ASID feature hasn't been exposed will result in an error. Signed-off-by: Si-Wei Liu <si-wei.liu@oracle.com> Acked-by: Eugenio PĂ©rez <eperezma@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Message-Id: <20231018171456.1624030-5-dtatulea@nvidia.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Si-Wei Liu <si-wei.liu@oracle.com> Tested-by: Si-Wei Liu <si-wei.liu@oracle.com> Tested-by: Lei Yang <leiyang@redhat.com>
Diffstat (limited to 'drivers/vhost')
-rw-r--r--drivers/vhost/vdpa.c17
1 files changed, 17 insertions, 0 deletions
diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index 78379ffd2336..2f21798a37ee 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -389,6 +389,14 @@ static bool vhost_vdpa_can_resume(const struct vhost_vdpa *v)
return ops->resume;
}
+static bool vhost_vdpa_has_desc_group(const struct vhost_vdpa *v)
+{
+ struct vdpa_device *vdpa = v->vdpa;
+ const struct vdpa_config_ops *ops = vdpa->config;
+
+ return ops->get_vq_desc_group;
+}
+
static long vhost_vdpa_get_features(struct vhost_vdpa *v, u64 __user *featurep)
{
struct vdpa_device *vdpa = v->vdpa;
@@ -690,6 +698,7 @@ 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_DESC_ASID) |
BIT_ULL(VHOST_BACKEND_F_SUSPEND) |
BIT_ULL(VHOST_BACKEND_F_RESUME) |
BIT_ULL(VHOST_BACKEND_F_ENABLE_AFTER_DRIVER_OK)))
@@ -700,6 +709,12 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep,
if ((features & BIT_ULL(VHOST_BACKEND_F_RESUME)) &&
!vhost_vdpa_can_resume(v))
return -EOPNOTSUPP;
+ if ((features & BIT_ULL(VHOST_BACKEND_F_DESC_ASID)) &&
+ !(features & BIT_ULL(VHOST_BACKEND_F_IOTLB_ASID)))
+ return -EINVAL;
+ if ((features & BIT_ULL(VHOST_BACKEND_F_DESC_ASID)) &&
+ !vhost_vdpa_has_desc_group(v))
+ return -EOPNOTSUPP;
vhost_set_backend_features(&v->vdev, features);
return 0;
}
@@ -753,6 +768,8 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep,
features |= BIT_ULL(VHOST_BACKEND_F_SUSPEND);
if (vhost_vdpa_can_resume(v))
features |= BIT_ULL(VHOST_BACKEND_F_RESUME);
+ if (vhost_vdpa_has_desc_group(v))
+ features |= BIT_ULL(VHOST_BACKEND_F_DESC_ASID);
features |= vhost_vdpa_get_backend_features(v);
if (copy_to_user(featurep, &features, sizeof(features)))
r = -EFAULT;