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Commit 17a9422d authored by Alan Brady's avatar Alan Brady Committed by Jeff Kirsher
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i40e/i40evf: don't trust VF to reset itself 



When using 'ethtool -L' on a VF to change number of requested queues
from PF, we shouldn't trust the VF to reset itself after making the
request.  Doing it that way opens the door for a potentially malicious
VF to do nasty things to the PF which should never be the case.

This makes it such that after VF makes a successful request, PF will
then reset the VF to institute required changes.  Only if the request
fails will PF send a message back to VF letting it know the request was
unsuccessful.

Testing-hints:
There should be no real functional changes.  This is simply hardening
against a potentially malicious VF.

Signed-off-by: default avatarAlan Brady <alan.brady@intel.com>
Tested-by: default avatarAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: default avatarJeff Kirsher <jeffrey.t.kirsher@intel.com>
parent 8fdb69dd

drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c

+7 −2
Original line number Diff line number Diff line
@@ -2045,8 +2045,9 @@ static int i40e_vc_disable_queues_msg(struct i40e_vf *vf, u8 *msg, u16 msglen) 
 * @msglen: msg length

 *

 * VFs get a default number of queues but can use this message to request a

 * different number.  Will respond with either the number requested or the

 * maximum we can support.

 * different number.  If the request is successful, PF will reset the VF and

 * return 0.  If unsuccessful, PF will send message informing VF of number of

 * available queues and return result of sending VF a message.

 **/

static int i40e_vc_request_queues_msg(struct i40e_vf *vf, u8 *msg, int msglen)

{
@@ -2077,7 +2078,11 @@ static int i40e_vc_request_queues_msg(struct i40e_vf *vf, u8 *msg, int msglen) 
			 pf->queues_left);

		vfres->num_queue_pairs = pf->queues_left + cur_pairs;

	} else {

		/* successful request */

		vf->num_req_queues = req_pairs;

		i40e_vc_notify_vf_reset(vf);

		i40e_reset_vf(vf, false);

		return 0;

	}



	return i40e_vc_send_msg_to_vf(vf, VIRTCHNL_OP_REQUEST_QUEUES, 0,

drivers/net/ethernet/intel/i40evf/i40evf_virtchnl.c

+3 −4
Original line number Diff line number Diff line
@@ -407,6 +407,7 @@ int i40evf_request_queues(struct i40evf_adapter *adapter, int num) 
	vfres.num_queue_pairs = num;



	adapter->current_op = VIRTCHNL_OP_REQUEST_QUEUES;

	adapter->flags |= I40EVF_FLAG_REINIT_ITR_NEEDED;

	return i40evf_send_pf_msg(adapter, VIRTCHNL_OP_REQUEST_QUEUES,

				  (u8 *)&vfres, sizeof(vfres));

}
@@ -1098,15 +1099,13 @@ void i40evf_virtchnl_completion(struct i40evf_adapter *adapter, 
	case VIRTCHNL_OP_REQUEST_QUEUES: {

		struct virtchnl_vf_res_request *vfres =

			(struct virtchnl_vf_res_request *)msg;

		if (vfres->num_queue_pairs == adapter->num_req_queues) {

			adapter->flags |= I40EVF_FLAG_REINIT_ITR_NEEDED;

			i40evf_schedule_reset(adapter);

		} else {

		if (vfres->num_queue_pairs != adapter->num_req_queues) {

			dev_info(&adapter->pdev->dev,

				 "Requested %d queues, PF can support %d\n",

				 adapter->num_req_queues,

				 vfres->num_queue_pairs);

			adapter->num_req_queues = 0;

			adapter->flags &= ~I40EVF_FLAG_REINIT_ITR_NEEDED;

		}

		}

		break;

include/linux/avf/virtchnl.h

+2 −2
Original line number Diff line number Diff line
@@ -333,8 +333,8 @@ struct virtchnl_vsi_queue_config_info { 
 * additional queues must be negotiated.  This is a best effort request as it

 * is possible the PF does not have enough queues left to support the request.

 * If the PF cannot support the number requested it will respond with the

 * maximum number it is able to support; otherwise it will respond with the

 * number requested.

 * maximum number it is able to support.  If the request is successful, PF will

 * then reset the VF to institute required changes.

 */



/* VF resource request */