[PATCH v2 1/2] i40e: Add helper for VF inited state check with timeout

[PATCH v2 1/2] i40e: Add helper for VF inited state check with timeout

[Ivan Vecera]

Move the check for VF inited state (with optional up-to 300ms
timeout to separate helper i40e_check_vf_init_timeout() that
will be used in the following commit.

Tested-by: Ma Yuying <yuma@redhat.com>
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
---
 .../ethernet/intel/i40e/i40e_virtchnl_pf.c    | 47 ++++++++++++-------
 1 file changed, 31 insertions(+), 16 deletions(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
index be59ba3774e1..ad30f9e99db9 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
@@ -4304,6 +4304,36 @@ static int i40e_validate_vf(struct i40e_pf *pf, int vf_id)
 	return ret;
 }
 
+/**
+ * i40e_check_vf_init_timeout
+ * @vf: the virtual function
+ *
+ * Check that the VF's initialization was successfully done and if not
+ * wait up to 300ms for its finish.
+ *
+ * Returns true when VF is initialized, false on timeout
+ **/
+static bool i40e_check_vf_init_timeout(struct i40e_vf *vf)
+{
+	int i;
+
+	/* When the VF is resetting wait until it is done.
+	 * It can take up to 200 milliseconds, but wait for
+	 * up to 300 milliseconds to be safe.
+	 */
+	for (i = 0; i < 15; i++)
+		if (!test_bit(I40E_VF_STATE_INIT, &vf->vf_states))
+			msleep(20);
+
+	if (!test_bit(I40E_VF_STATE_INIT, &vf->vf_states)) {
+		dev_err(&vf->pf->pdev->dev,
+			"VF %d still in reset. Try again.\n", vf->vf_id);
+		return false;
+	}
+
+	return true;
+}
+
 /**
  * i40e_ndo_set_vf_mac
  * @netdev: network interface device structure
@@ -4322,7 +4352,6 @@ int i40e_ndo_set_vf_mac(struct net_device *netdev, int vf_id, u8 *mac)
 	int ret = 0;
 	struct hlist_node *h;
 	int bkt;
-	u8 i;
 
 	if (test_and_set_bit(__I40E_VIRTCHNL_OP_PENDING, pf->state)) {
 		dev_warn(&pf->pdev->dev, "Unable to configure VFs, other operation is pending.\n");
@@ -4335,21 +4364,7 @@ int i40e_ndo_set_vf_mac(struct net_device *netdev, int vf_id, u8 *mac)
 		goto error_param;
 
 	vf = &pf->vf[vf_id];
-
-	/* When the VF is resetting wait until it is done.
-	 * It can take up to 200 milliseconds,
-	 * but wait for up to 300 milliseconds to be safe.
-	 * Acquire the VSI pointer only after the VF has been
-	 * properly initialized.
-	 */
-	for (i = 0; i < 15; i++) {
-		if (test_bit(I40E_VF_STATE_INIT, &vf->vf_states))
-			break;
-		msleep(20);
-	}
-	if (!test_bit(I40E_VF_STATE_INIT, &vf->vf_states)) {
-		dev_err(&pf->pdev->dev, "VF %d still in reset. Try again.\n",
-			vf_id);
+	if (!i40e_check_vf_init_timeout(vf)) {
 		ret = -EAGAIN;
 		goto error_param;
 	}
-- 
2.41.0

[PATCH v2 2/2] i40e: Wait for pending VF reset in VF set callbacks

[Ivan Vecera]

Commit 028daf80117376 ("i40e: Fix attach VF to VM issue") fixed
a race between i40e_ndo_set_vf_mac() and i40e_reset_vf() during
an attachment of VF device to VM. This issue is not related to
setting MAC address only but also VLAN assignment to particular
VF because the newer libvirt sets configured MAC address as well
as an optional VLAN. The same behavior is also for i40e's
.ndo_set_vf_rate and .ndo_set_vf_spoofchk where the callbacks
just check if the VF was initialized but not wait for the finish
of pending reset.

Reproducer:
[root@host ~]# virsh attach-interface guest hostdev --managed 0000:02:02.0 --mac 52:54:00:b4:aa:bb
error: Failed to attach interface
error: Cannot set interface MAC/vlanid to 52:54:00:b4:aa:bb/0 for ifname enp2s0f0 vf 0: Resource temporarily unavailable

Fix this issue by using i40e_check_vf_init_timeout() helper to check
whether a reset of particular VF was finished in i40e's
.ndo_set_vf_vlan, .ndo_set_vf_rate and .ndo_set_vf_spoofchk callbacks.

Tested-by: Ma Yuying <yuma@redhat.com>
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
---
 .../net/ethernet/intel/i40e/i40e_virtchnl_pf.c   | 16 +++++-----------
 1 file changed, 5 insertions(+), 11 deletions(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
index ad30f9e99db9..87207fc546b7 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
@@ -4466,13 +4466,11 @@ int i40e_ndo_set_vf_port_vlan(struct net_device *netdev, int vf_id,
 	}
 
 	vf = &pf->vf[vf_id];
-	vsi = pf->vsi[vf->lan_vsi_idx];
-	if (!test_bit(I40E_VF_STATE_INIT, &vf->vf_states)) {
-		dev_err(&pf->pdev->dev, "VF %d still in reset. Try again.\n",
-			vf_id);
+	if (!i40e_check_vf_init_timeout(vf)) {
 		ret = -EAGAIN;
 		goto error_pvid;
 	}
+	vsi = pf->vsi[vf->lan_vsi_idx];
 
 	if (le16_to_cpu(vsi->info.pvid) == vlanprio)
 		/* duplicate request, so just return success */
@@ -4616,13 +4614,11 @@ int i40e_ndo_set_vf_bw(struct net_device *netdev, int vf_id, int min_tx_rate,
 	}
 
 	vf = &pf->vf[vf_id];
-	vsi = pf->vsi[vf->lan_vsi_idx];
-	if (!test_bit(I40E_VF_STATE_INIT, &vf->vf_states)) {
-		dev_err(&pf->pdev->dev, "VF %d still in reset. Try again.\n",
-			vf_id);
+	if (!i40e_check_vf_init_timeout(vf)) {
 		ret = -EAGAIN;
 		goto error;
 	}
+	vsi = pf->vsi[vf->lan_vsi_idx];
 
 	ret = i40e_set_bw_limit(vsi, vsi->seid, max_tx_rate);
 	if (ret)
@@ -4789,9 +4785,7 @@ int i40e_ndo_set_vf_spoofchk(struct net_device *netdev, int vf_id, bool enable)
 	}
 
 	vf = &(pf->vf[vf_id]);
-	if (!test_bit(I40E_VF_STATE_INIT, &vf->vf_states)) {
-		dev_err(&pf->pdev->dev, "VF %d still in reset. Try again.\n",
-			vf_id);
+	if (!i40e_check_vf_init_timeout(vf)) {
 		ret = -EAGAIN;
 		goto out;
 	}
-- 
2.41.0

Re: [PATCH v2 1/2] i40e: Add helper for VF inited state check with timeout

[Jakub Kicinski]

On Wed, 12 Jul 2023 15:32:46 +0200 Ivan Vecera wrote:
> +	for (i = 0; i < 15; i++)
> +		if (!test_bit(I40E_VF_STATE_INIT, &vf->vf_states))
> +			msleep(20);
> +
> +	if (!test_bit(I40E_VF_STATE_INIT, &vf->vf_states)) {
> +		dev_err(&vf->pf->pdev->dev,
> +			"VF %d still in reset. Try again.\n", vf->vf_id);
> +		return false;

I like my loop more but if you want to have the msleep() indented just
add an else { return true; } branch. Take advantage of the fact this is
a function, now, and you can just return.