[RFC 0/6] ifcvf/vDPA: support query device config space through

[RFC 0/6] ifcvf/vDPA: support query device config space through

[Zhu Lingshan]

This series allows userspace to query device config space through
netlink, to get multi-queue, feature bits, device features and
driver features.

This series also has fixed some issues of misusing
VDPA_ATTR_DEV_SUPPORTED_FEATURES, this should be used for virtio devices
than the management device.

Please help review.

Thanks!
Zhu Lingshan

Zhu Lingshan (6):
  vDPA/ifcvf: get_config_size should return a value no greater than dev
    implementation
  vDPA/ifcvf: support userspace to query features and MQ of a management
    device
  vDPA/ifcvf: support userspace to query device feature bits
  vDPA: !FEATURES_OK should not block querying device config space
  vDPA: answer num of queue pairs = 1 to userspace when VIRTIO_NET_F_MQ
    == 0
  vDPA: fix 'cast to restricted le16' warnings in
    vdpa_dev_net_config_fill()

 drivers/vdpa/ifcvf/ifcvf_base.c | 20 ++++++++++++++++++--
 drivers/vdpa/ifcvf/ifcvf_base.h |  3 +++
 drivers/vdpa/ifcvf/ifcvf_main.c |  3 +++
 drivers/vdpa/vdpa.c             | 32 +++++++++++++++-----------------
 include/uapi/linux/vdpa.h       |  1 +
 5 files changed, 40 insertions(+), 19 deletions(-)

-- 
2.31.1

[RFC 1/6] vDPA/ifcvf: get_config_size should return a value no greater than dev implementation

[Zhu Lingshan]

ifcvf_get_config_size() should return a virtio device type specific value,
however the ret_value should not be greater than the onboard size of
the device implementation. E.g., for virtio_net, config_size should be
the minimum value of sizeof(struct virtio_net_config) and the onboard
cap size.

Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
---
 drivers/vdpa/ifcvf/ifcvf_base.c | 8 ++++++--
 drivers/vdpa/ifcvf/ifcvf_base.h | 2 ++
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/vdpa/ifcvf/ifcvf_base.c b/drivers/vdpa/ifcvf/ifcvf_base.c
index 48c4dadb0c7c..6bccc8291c26 100644
--- a/drivers/vdpa/ifcvf/ifcvf_base.c
+++ b/drivers/vdpa/ifcvf/ifcvf_base.c
@@ -128,6 +128,7 @@ int ifcvf_init_hw(struct ifcvf_hw *hw, struct pci_dev *pdev)
 			break;
 		case VIRTIO_PCI_CAP_DEVICE_CFG:
 			hw->dev_cfg = get_cap_addr(hw, &cap);
+			hw->cap_dev_config_size = le32_to_cpu(cap.length);
 			IFCVF_DBG(pdev, "hw->dev_cfg = %p\n", hw->dev_cfg);
 			break;
 		}
@@ -233,15 +234,18 @@ int ifcvf_verify_min_features(struct ifcvf_hw *hw, u64 features)
 u32 ifcvf_get_config_size(struct ifcvf_hw *hw)
 {
 	struct ifcvf_adapter *adapter;
+	u32 net_config_size = sizeof(struct virtio_net_config);
+	u32 blk_config_size = sizeof(struct virtio_blk_config);
+	u32 cap_size = hw->cap_dev_config_size;
 	u32 config_size;
 
 	adapter = vf_to_adapter(hw);
 	switch (hw->dev_type) {
 	case VIRTIO_ID_NET:
-		config_size = sizeof(struct virtio_net_config);
+		config_size = cap_size >= net_config_size ? net_config_size : cap_size;
 		break;
 	case VIRTIO_ID_BLOCK:
-		config_size = sizeof(struct virtio_blk_config);
+		config_size = cap_size >= blk_config_size ? blk_config_size : cap_size;
 		break;
 	default:
 		config_size = 0;
diff --git a/drivers/vdpa/ifcvf/ifcvf_base.h b/drivers/vdpa/ifcvf/ifcvf_base.h
index 115b61f4924b..f5563f665cc6 100644
--- a/drivers/vdpa/ifcvf/ifcvf_base.h
+++ b/drivers/vdpa/ifcvf/ifcvf_base.h
@@ -87,6 +87,8 @@ struct ifcvf_hw {
 	int config_irq;
 	int vqs_reused_irq;
 	u16 nr_vring;
+	/* VIRTIO_PCI_CAP_DEVICE_CFG size */
+	u32 cap_dev_config_size;
 };
 
 struct ifcvf_adapter {
-- 
2.31.1

[RFC 2/6] vDPA/ifcvf: support userspace to query features and MQ of a management device

[Zhu Lingshan]

Adapting to current netlink interfaces, this commit allows userspace
to query feature bits and MQ capability of a management device.

Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
---
 drivers/vdpa/ifcvf/ifcvf_base.c | 12 ++++++++++++
 drivers/vdpa/ifcvf/ifcvf_base.h |  1 +
 drivers/vdpa/ifcvf/ifcvf_main.c |  3 +++
 3 files changed, 16 insertions(+)

diff --git a/drivers/vdpa/ifcvf/ifcvf_base.c b/drivers/vdpa/ifcvf/ifcvf_base.c
index 6bccc8291c26..7be703b5d1f4 100644
--- a/drivers/vdpa/ifcvf/ifcvf_base.c
+++ b/drivers/vdpa/ifcvf/ifcvf_base.c
@@ -341,6 +341,18 @@ int ifcvf_set_vq_state(struct ifcvf_hw *hw, u16 qid, u16 num)
 	return 0;
 }
 
+u16 ifcvf_get_max_vq_pairs(struct ifcvf_hw *hw)
+{
+	struct virtio_net_config __iomem *config;
+	u16 val, mq;
+
+	config  = (struct virtio_net_config __iomem *)hw->dev_cfg;
+	val = vp_ioread16((__le16 __iomem *)&config->max_virtqueue_pairs);
+	mq = le16_to_cpu((__force __le16)val);
+
+	return mq;
+}
+
 static int ifcvf_hw_enable(struct ifcvf_hw *hw)
 {
 	struct virtio_pci_common_cfg __iomem *cfg;
diff --git a/drivers/vdpa/ifcvf/ifcvf_base.h b/drivers/vdpa/ifcvf/ifcvf_base.h
index f5563f665cc6..d54a1bed212e 100644
--- a/drivers/vdpa/ifcvf/ifcvf_base.h
+++ b/drivers/vdpa/ifcvf/ifcvf_base.h
@@ -130,6 +130,7 @@ 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);
+u16 ifcvf_get_max_vq_pairs(struct ifcvf_hw *hw);
 struct ifcvf_adapter *vf_to_adapter(struct ifcvf_hw *hw);
 int ifcvf_probed_virtio_net(struct ifcvf_hw *hw);
 u32 ifcvf_get_config_size(struct ifcvf_hw *hw);
diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c b/drivers/vdpa/ifcvf/ifcvf_main.c
index 4366320fb68d..0c3af30b297e 100644
--- a/drivers/vdpa/ifcvf/ifcvf_main.c
+++ b/drivers/vdpa/ifcvf/ifcvf_main.c
@@ -786,6 +786,9 @@ static int ifcvf_vdpa_dev_add(struct vdpa_mgmt_dev *mdev, const char *name,
 	vf->hw_features = ifcvf_get_hw_features(vf);
 	vf->config_size = ifcvf_get_config_size(vf);
 
+	ifcvf_mgmt_dev->mdev.max_supported_vqs = ifcvf_get_max_vq_pairs(vf);
+	ifcvf_mgmt_dev->mdev.supported_features = vf->hw_features;
+
 	adapter->vdpa.mdev = &ifcvf_mgmt_dev->mdev;
 	ret = _vdpa_register_device(&adapter->vdpa, vf->nr_vring);
 	if (ret) {
-- 
2.31.1

[RFC 3/6] vDPA/ifcvf: support userspace to query device feature bits

[Zhu Lingshan]

This commit supports userspace to query device feature bits
by filling the relevant netlink attribute.

There are two types of netlink attributes:
VDPA_ATTR_DEV_XXXX work for virtio devices config space, and
VDPA_ATTR_MGMTDEV_XXXX work for the management devices.

This commit fixes a misuse of VDPA_ATTR_DEV_SUPPORTED_FEATURES,
this attr is for a virtio device, not management devices.

Thus VDPA_ATTR_MGMTDEV_SUPPORTED_FEATURES is introduced for
reporting management device features, and VDPA_ATTR_DEV_SUPPORTED_FEATURES
for virtio devices feature bits.

Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
---
 drivers/vdpa/vdpa.c       | 15 ++++++++++-----
 include/uapi/linux/vdpa.h |  1 +
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
index 2b75c00b1005..c820dd2b0307 100644
--- a/drivers/vdpa/vdpa.c
+++ b/drivers/vdpa/vdpa.c
@@ -508,7 +508,7 @@ static int vdpa_mgmtdev_fill(const struct vdpa_mgmt_dev *mdev, struct sk_buff *m
 		err = -EMSGSIZE;
 		goto msg_err;
 	}
-	if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_SUPPORTED_FEATURES,
+	if (nla_put_u64_64bit(msg, VDPA_ATTR_MGMTDEV_SUPPORTED_FEATURES,
 			      mdev->supported_features, VDPA_ATTR_PAD)) {
 		err = -EMSGSIZE;
 		goto msg_err;
@@ -827,7 +827,7 @@ static int vdpa_dev_net_mq_config_fill(struct vdpa_device *vdev,
 static int vdpa_dev_net_config_fill(struct vdpa_device *vdev, struct sk_buff *msg)
 {
 	struct virtio_net_config config = {};
-	u64 features;
+	u64 features_device, features_driver;
 	u16 val_u16;
 
 	vdpa_get_config_unlocked(vdev, 0, &config, sizeof(config));
@@ -844,12 +844,17 @@ static int vdpa_dev_net_config_fill(struct vdpa_device *vdev, struct sk_buff *ms
 	if (nla_put_u16(msg, VDPA_ATTR_DEV_NET_CFG_MTU, val_u16))
 		return -EMSGSIZE;
 
-	features = vdev->config->get_driver_features(vdev);
-	if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_NEGOTIATED_FEATURES, features,
+	features_driver = vdev->config->get_driver_features(vdev);
+	if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_NEGOTIATED_FEATURES, features_driver,
 			      VDPA_ATTR_PAD))
 		return -EMSGSIZE;
 
-	return vdpa_dev_net_mq_config_fill(vdev, msg, features, &config);
+	features_device = vdev->config->get_device_features(vdev);
+	if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_SUPPORTED_FEATURES, features_device,
+			      VDPA_ATTR_PAD))
+		return -EMSGSIZE;
+
+	return vdpa_dev_net_mq_config_fill(vdev, msg, features_device, &config);
 }
 
 static int
diff --git a/include/uapi/linux/vdpa.h b/include/uapi/linux/vdpa.h
index 1061d8d2d09d..70a3672c288f 100644
--- a/include/uapi/linux/vdpa.h
+++ b/include/uapi/linux/vdpa.h
@@ -30,6 +30,7 @@ enum vdpa_attr {
 	VDPA_ATTR_MGMTDEV_BUS_NAME,		/* string */
 	VDPA_ATTR_MGMTDEV_DEV_NAME,		/* string */
 	VDPA_ATTR_MGMTDEV_SUPPORTED_CLASSES,	/* u64 */
+	VDPA_ATTR_MGMTDEV_SUPPORTED_FEATURES,	/* u64 */
 
 	VDPA_ATTR_DEV_NAME,			/* string */
 	VDPA_ATTR_DEV_ID,			/* u32 */
-- 
2.31.1

[RFC 4/6] vDPA: !FEATURES_OK should not block querying device config space

[Zhu Lingshan]

Users may want to query the config space of a vDPA device,
to choose a appropriate one for a certain guest. This means the
users need to read the config space before FEATURES_OK, and
the existence of config space contents does not depend on
FEATURES_OK.

This commit removes FEATURES_OK blocker in vdpa_dev_config_fill()
which calls vdpa_dev_net_config_fill() for virtio-net

Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
---
 drivers/vdpa/vdpa.c | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
index c820dd2b0307..030d96bdeed2 100644
--- a/drivers/vdpa/vdpa.c
+++ b/drivers/vdpa/vdpa.c
@@ -863,17 +863,9 @@ vdpa_dev_config_fill(struct vdpa_device *vdev, struct sk_buff *msg, u32 portid,
 {
 	u32 device_id;
 	void *hdr;
-	u8 status;
 	int err;
 
 	mutex_lock(&vdev->cf_mutex);
-	status = vdev->config->get_status(vdev);
-	if (!(status & VIRTIO_CONFIG_S_FEATURES_OK)) {
-		NL_SET_ERR_MSG_MOD(extack, "Features negotiation not completed");
-		err = -EAGAIN;
-		goto out;
-	}
-
 	hdr = genlmsg_put(msg, portid, seq, &vdpa_nl_family, flags,
 			  VDPA_CMD_DEV_CONFIG_GET);
 	if (!hdr) {
-- 
2.31.1

[RFC 5/6] vDPA: answer num of queue pairs = 1 to userspace when VIRTIO_NET_F_MQ == 0

[Zhu Lingshan]

If VIRTIO_NET_F_MQ == 0, the virtio device should have one queue pair,
so when userspace querying queue pair numbers, it should return mq=1
than zero

Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
---
 drivers/vdpa/vdpa.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
index 030d96bdeed2..50a11ece603e 100644
--- a/drivers/vdpa/vdpa.c
+++ b/drivers/vdpa/vdpa.c
@@ -818,9 +818,10 @@ static int vdpa_dev_net_mq_config_fill(struct vdpa_device *vdev,
 	u16 val_u16;
 
 	if ((features & BIT_ULL(VIRTIO_NET_F_MQ)) == 0)
-		return 0;
+		val_u16 = 1;
+	else
+		val_u16 = le16_to_cpu((__force __le16)config->max_virtqueue_pairs);
 
-	val_u16 = le16_to_cpu(config->max_virtqueue_pairs);
 	return nla_put_u16(msg, VDPA_ATTR_DEV_NET_CFG_MAX_VQP, val_u16);
 }
 
-- 
2.31.1

[RFC 6/6] vDPA: fix 'cast to restricted le16' warnings in vdpa_dev_net_config_fill()

[Zhu Lingshan]

This commit fixes spars warnings: cast to restricted __le16
in function vdpa_dev_net_config_fill()

Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
---
 drivers/vdpa/vdpa.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
index 50a11ece603e..2719ce9962fc 100644
--- a/drivers/vdpa/vdpa.c
+++ b/drivers/vdpa/vdpa.c
@@ -837,11 +837,11 @@ static int vdpa_dev_net_config_fill(struct vdpa_device *vdev, struct sk_buff *ms
 		    config.mac))
 		return -EMSGSIZE;
 
-	val_u16 = le16_to_cpu(config.status);
+	val_u16 = le16_to_cpu((__force __le16)config.status);
 	if (nla_put_u16(msg, VDPA_ATTR_DEV_NET_STATUS, val_u16))
 		return -EMSGSIZE;
 
-	val_u16 = le16_to_cpu(config.mtu);
+	val_u16 = le16_to_cpu((__force __le16)config.mtu);
 	if (nla_put_u16(msg, VDPA_ATTR_DEV_NET_CFG_MTU, val_u16))
 		return -EMSGSIZE;
 
-- 
2.31.1