[PATCH V4 6/7] vDPA/ifcvf: verify mandatory feature bits for vDPA

[Zhu Lingshan <lingshan.zhu@xxxxxxxxx>]

vDPA requres VIRTIO_F_ACCESS_PLATFORM as a must, this commit
examines this when set features.

Signed-off-by: Zhu Lingshan <lingshan.zhu@xxxxxxxxx>
---
 drivers/vdpa/ifcvf/ifcvf_base.c | 12 ++++++++++++
 drivers/vdpa/ifcvf/ifcvf_base.h |  1 +
 drivers/vdpa/ifcvf/ifcvf_main.c |  5 +++++
 3 files changed, 18 insertions(+)

diff --git a/drivers/vdpa/ifcvf/ifcvf_base.c b/drivers/vdpa/ifcvf/ifcvf_base.c
index ea6a78791c9b..4f257c4b2f76 100644
--- a/drivers/vdpa/ifcvf/ifcvf_base.c
+++ b/drivers/vdpa/ifcvf/ifcvf_base.c
@@ -224,6 +224,18 @@ u64 ifcvf_get_features(struct ifcvf_hw *hw)
 	return hw->hw_features;
 }
 
+int ifcvf_verify_min_features(struct ifcvf_hw *hw, u64 features)
+{
+	struct ifcvf_adapter *ifcvf = vf_to_adapter(hw);
+
+	if (!(features & BIT_ULL(VIRTIO_F_ACCESS_PLATFORM)) && features) {
+		IFCVF_ERR(ifcvf->pdev, "VIRTIO_F_ACCESS_PLATFORM not negotiated\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 void ifcvf_read_net_config(struct ifcvf_hw *hw, u64 offset,
 			   void *dst, int length)
 {
diff --git a/drivers/vdpa/ifcvf/ifcvf_base.h b/drivers/vdpa/ifcvf/ifcvf_base.h
index dbb8c10aa3b1..f77239fc1644 100644
--- a/drivers/vdpa/ifcvf/ifcvf_base.h
+++ b/drivers/vdpa/ifcvf/ifcvf_base.h
@@ -123,6 +123,7 @@ void io_write64_twopart(u64 val, u32 *lo, u32 *hi);
 void ifcvf_reset(struct ifcvf_hw *hw);
 u64 ifcvf_get_features(struct ifcvf_hw *hw);
 u64 ifcvf_get_hw_features(struct ifcvf_hw *hw);
+int ifcvf_verify_min_features(struct ifcvf_hw *hw, u64 features);
 u16 ifcvf_get_vq_state(struct ifcvf_hw *hw, u16 qid);
 int ifcvf_set_vq_state(struct ifcvf_hw *hw, u16 qid, u16 num);
 struct ifcvf_adapter *vf_to_adapter(struct ifcvf_hw *hw);
diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c b/drivers/vdpa/ifcvf/ifcvf_main.c
index 25fb9dfe23f0..ea93ea7fd5df 100644
--- a/drivers/vdpa/ifcvf/ifcvf_main.c
+++ b/drivers/vdpa/ifcvf/ifcvf_main.c
@@ -179,6 +179,11 @@ static u64 ifcvf_vdpa_get_features(struct vdpa_device *vdpa_dev)
 static int ifcvf_vdpa_set_features(struct vdpa_device *vdpa_dev, u64 features)
 {
 	struct ifcvf_hw *vf = vdpa_to_vf(vdpa_dev);
+	int ret;
+
+	ret = ifcvf_verify_min_features(vf, features);
+	if (ret)
+		return ret;
 
 	vf->req_features = features;
 
-- 
2.27.0