diff options
Diffstat (limited to 'drivers/net/ethernet/intel/ice/ice_sriov.c')
| -rw-r--r-- | drivers/net/ethernet/intel/ice/ice_sriov.c | 400 |
1 files changed, 399 insertions, 1 deletions
diff --git a/drivers/net/ethernet/intel/ice/ice_sriov.c b/drivers/net/ethernet/intel/ice/ice_sriov.c index 554f567476f3..aa11d07793d4 100644 --- a/drivers/net/ethernet/intel/ice/ice_sriov.c +++ b/drivers/net/ethernet/intel/ice/ice_sriov.c @@ -2,7 +2,6 @@ /* Copyright (c) 2018, Intel Corporation. */ #include "ice_common.h" -#include "ice_adminq_cmd.h" #include "ice_sriov.h" /** @@ -132,3 +131,402 @@ u32 ice_conv_link_speed_to_virtchnl(bool adv_link_support, u16 link_speed) return speed; } + +/* The mailbox overflow detection algorithm helps to check if there + * is a possibility of a malicious VF transmitting too many MBX messages to the + * PF. + * 1. The mailbox snapshot structure, ice_mbx_snapshot, is initialized during + * driver initialization in ice_init_hw() using ice_mbx_init_snapshot(). + * The struct ice_mbx_snapshot helps to track and traverse a static window of + * messages within the mailbox queue while looking for a malicious VF. + * + * 2. When the caller starts processing its mailbox queue in response to an + * interrupt, the structure ice_mbx_snapshot is expected to be cleared before + * the algorithm can be run for the first time for that interrupt. This can be + * done via ice_mbx_reset_snapshot(). + * + * 3. For every message read by the caller from the MBX Queue, the caller must + * call the detection algorithm's entry function ice_mbx_vf_state_handler(). + * Before every call to ice_mbx_vf_state_handler() the struct ice_mbx_data is + * filled as it is required to be passed to the algorithm. + * + * 4. Every time a message is read from the MBX queue, a VFId is received which + * is passed to the state handler. The boolean output is_malvf of the state + * handler ice_mbx_vf_state_handler() serves as an indicator to the caller + * whether this VF is malicious or not. + * + * 5. When a VF is identified to be malicious, the caller can send a message + * to the system administrator. The caller can invoke ice_mbx_report_malvf() + * to help determine if a malicious VF is to be reported or not. This function + * requires the caller to maintain a global bitmap to track all malicious VFs + * and pass that to ice_mbx_report_malvf() along with the VFID which was identified + * to be malicious by ice_mbx_vf_state_handler(). + * + * 6. The global bitmap maintained by PF can be cleared completely if PF is in + * reset or the bit corresponding to a VF can be cleared if that VF is in reset. + * When a VF is shut down and brought back up, we assume that the new VF + * brought up is not malicious and hence report it if found malicious. + * + * 7. The function ice_mbx_reset_snapshot() is called to reset the information + * in ice_mbx_snapshot for every new mailbox interrupt handled. + * + * 8. The memory allocated for variables in ice_mbx_snapshot is de-allocated + * when driver is unloaded. + */ +#define ICE_RQ_DATA_MASK(rq_data) ((rq_data) & PF_MBX_ARQH_ARQH_M) +/* Using the highest value for an unsigned 16-bit value 0xFFFF to indicate that + * the max messages check must be ignored in the algorithm + */ +#define ICE_IGNORE_MAX_MSG_CNT 0xFFFF + +/** + * ice_mbx_traverse - Pass through mailbox snapshot + * @hw: pointer to the HW struct + * @new_state: new algorithm state + * + * Traversing the mailbox static snapshot without checking + * for malicious VFs. + */ +static void +ice_mbx_traverse(struct ice_hw *hw, + enum ice_mbx_snapshot_state *new_state) +{ + struct ice_mbx_snap_buffer_data *snap_buf; + u32 num_iterations; + + snap_buf = &hw->mbx_snapshot.mbx_buf; + + /* As mailbox buffer is circular, applying a mask + * on the incremented iteration count. + */ + num_iterations = ICE_RQ_DATA_MASK(++snap_buf->num_iterations); + + /* Checking either of the below conditions to exit snapshot traversal: + * Condition-1: If the number of iterations in the mailbox is equal to + * the mailbox head which would indicate that we have reached the end + * of the static snapshot. + * Condition-2: If the maximum messages serviced in the mailbox for a + * given interrupt is the highest possible value then there is no need + * to check if the number of messages processed is equal to it. If not + * check if the number of messages processed is greater than or equal + * to the maximum number of mailbox entries serviced in current work item. + */ + if (num_iterations == snap_buf->head || + (snap_buf->max_num_msgs_mbx < ICE_IGNORE_MAX_MSG_CNT && + ++snap_buf->num_msg_proc >= snap_buf->max_num_msgs_mbx)) + *new_state = ICE_MAL_VF_DETECT_STATE_NEW_SNAPSHOT; +} + +/** + * ice_mbx_detect_malvf - Detect malicious VF in snapshot + * @hw: pointer to the HW struct + * @vf_id: relative virtual function ID + * @new_state: new algorithm state + * @is_malvf: boolean output to indicate if VF is malicious + * + * This function tracks the number of asynchronous messages + * sent per VF and marks the VF as malicious if it exceeds + * the permissible number of messages to send. + */ +static enum ice_status +ice_mbx_detect_malvf(struct ice_hw *hw, u16 vf_id, + enum ice_mbx_snapshot_state *new_state, + bool *is_malvf) +{ + struct ice_mbx_snapshot *snap = &hw->mbx_snapshot; + + if (vf_id >= snap->mbx_vf.vfcntr_len) + return ICE_ERR_OUT_OF_RANGE; + + /* increment the message count in the VF array */ + snap->mbx_vf.vf_cntr[vf_id]++; + + if (snap->mbx_vf.vf_cntr[vf_id] >= ICE_ASYNC_VF_MSG_THRESHOLD) + *is_malvf = true; + + /* continue to iterate through the mailbox snapshot */ + ice_mbx_traverse(hw, new_state); + + return 0; +} + +/** + * ice_mbx_reset_snapshot - Reset mailbox snapshot structure + * @snap: pointer to mailbox snapshot structure in the ice_hw struct + * + * Reset the mailbox snapshot structure and clear VF counter array. + */ +static void ice_mbx_reset_snapshot(struct ice_mbx_snapshot *snap) +{ + u32 vfcntr_len; + + if (!snap || !snap->mbx_vf.vf_cntr) + return; + + /* Clear VF counters. */ + vfcntr_len = snap->mbx_vf.vfcntr_len; + if (vfcntr_len) + memset(snap->mbx_vf.vf_cntr, 0, + (vfcntr_len * sizeof(*snap->mbx_vf.vf_cntr))); + + /* Reset mailbox snapshot for a new capture. */ + memset(&snap->mbx_buf, 0, sizeof(snap->mbx_buf)); + snap->mbx_buf.state = ICE_MAL_VF_DETECT_STATE_NEW_SNAPSHOT; +} + +/** + * ice_mbx_vf_state_handler - Handle states of the overflow algorithm + * @hw: pointer to the HW struct + * @mbx_data: pointer to structure containing mailbox data + * @vf_id: relative virtual function (VF) ID + * @is_malvf: boolean output to indicate if VF is malicious + * + * The function serves as an entry point for the malicious VF + * detection algorithm by handling the different states and state + * transitions of the algorithm: + * New snapshot: This state is entered when creating a new static + * snapshot. The data from any previous mailbox snapshot is + * cleared and a new capture of the mailbox head and tail is + * logged. This will be the new static snapshot to detect + * asynchronous messages sent by VFs. On capturing the snapshot + * and depending on whether the number of pending messages in that + * snapshot exceed the watermark value, the state machine enters + * traverse or detect states. + * Traverse: If pending message count is below watermark then iterate + * through the snapshot without any action on VF. + * Detect: If pending message count exceeds watermark traverse + * the static snapshot and look for a malicious VF. + */ +enum ice_status +ice_mbx_vf_state_handler(struct ice_hw *hw, + struct ice_mbx_data *mbx_data, u16 vf_id, + bool *is_malvf) +{ + struct ice_mbx_snapshot *snap = &hw->mbx_snapshot; + struct ice_mbx_snap_buffer_data *snap_buf; + struct ice_ctl_q_info *cq = &hw->mailboxq; + enum ice_mbx_snapshot_state new_state; + enum ice_status status = 0; + + if (!is_malvf || !mbx_data) + return ICE_ERR_BAD_PTR; + + /* When entering the mailbox state machine assume that the VF + * is not malicious until detected. + */ + *is_malvf = false; + + /* Checking if max messages allowed to be processed while servicing current + * interrupt is not less than the defined AVF message threshold. + */ + if (mbx_data->max_num_msgs_mbx <= ICE_ASYNC_VF_MSG_THRESHOLD) + return ICE_ERR_INVAL_SIZE; + + /* The watermark value should not be lesser than the threshold limit + * set for the number of asynchronous messages a VF can send to mailbox + * nor should it be greater than the maximum number of messages in the + * mailbox serviced in current interrupt. + */ + if (mbx_data->async_watermark_val < ICE_ASYNC_VF_MSG_THRESHOLD || + mbx_data->async_watermark_val > mbx_data->max_num_msgs_mbx) + return ICE_ERR_PARAM; + + new_state = ICE_MAL_VF_DETECT_STATE_INVALID; + snap_buf = &snap->mbx_buf; + + switch (snap_buf->state) { + case ICE_MAL_VF_DETECT_STATE_NEW_SNAPSHOT: + /* Clear any previously held data in mailbox snapshot structure. */ + ice_mbx_reset_snapshot(snap); + + /* Collect the pending ARQ count, number of messages processed and + * the maximum number of messages allowed to be processed from the + * Mailbox for current interrupt. + */ + snap_buf->num_pending_arq = mbx_data->num_pending_arq; + snap_buf->num_msg_proc = mbx_data->num_msg_proc; + snap_buf->max_num_msgs_mbx = mbx_data->max_num_msgs_mbx; + + /* Capture a new static snapshot of the mailbox by logging the + * head and tail of snapshot and set num_iterations to the tail + * value to mark the start of the iteration through the snapshot. + */ + snap_buf->head = ICE_RQ_DATA_MASK(cq->rq.next_to_clean + + mbx_data->num_pending_arq); + snap_buf->tail = ICE_RQ_DATA_MASK(cq->rq.next_to_clean - 1); + snap_buf->num_iterations = snap_buf->tail; + + /* Pending ARQ messages returned by ice_clean_rq_elem + * is the difference between the head and tail of the + * mailbox queue. Comparing this value against the watermark + * helps to check if we potentially have malicious VFs. + */ + if (snap_buf->num_pending_arq >= + mbx_data->async_watermark_val) { + new_state = ICE_MAL_VF_DETECT_STATE_DETECT; + status = ice_mbx_detect_malvf(hw, vf_id, &new_state, is_malvf); + } else { + new_state = ICE_MAL_VF_DETECT_STATE_TRAVERSE; + ice_mbx_traverse(hw, &new_state); + } + break; + + case ICE_MAL_VF_DETECT_STATE_TRAVERSE: + new_state = ICE_MAL_VF_DETECT_STATE_TRAVERSE; + ice_mbx_traverse(hw, &new_state); + break; + + case ICE_MAL_VF_DETECT_STATE_DETECT: + new_state = ICE_MAL_VF_DETECT_STATE_DETECT; + status = ice_mbx_detect_malvf(hw, vf_id, &new_state, is_malvf); + break; + + default: + new_state = ICE_MAL_VF_DETECT_STATE_INVALID; + status = ICE_ERR_CFG; + } + + snap_buf->state = new_state; + + return status; +} + +/** + * ice_mbx_report_malvf - Track and note malicious VF + * @hw: pointer to the HW struct + * @all_malvfs: all malicious VFs tracked by PF + * @bitmap_len: length of bitmap in bits + * @vf_id: relative virtual function ID of the malicious VF + * @report_malvf: boolean to indicate if malicious VF must be reported + * + * This function will update a bitmap that keeps track of the malicious + * VFs attached to the PF. A malicious VF must be reported only once if + * discovered between VF resets or loading so the function checks + * the input vf_id against the bitmap to verify if the VF has been + * detected in any previous mailbox iterations. + */ +enum ice_status +ice_mbx_report_malvf(struct ice_hw *hw, unsigned long *all_malvfs, + u16 bitmap_len, u16 vf_id, bool *report_malvf) +{ + if (!all_malvfs || !report_malvf) + return ICE_ERR_PARAM; + + *report_malvf = false; + + if (bitmap_len < hw->mbx_snapshot.mbx_vf.vfcntr_len) + return ICE_ERR_INVAL_SIZE; + + if (vf_id >= bitmap_len) + return ICE_ERR_OUT_OF_RANGE; + + /* If the vf_id is found in the bitmap set bit and boolean to true */ + if (!test_and_set_bit(vf_id, all_malvfs)) + *report_malvf = true; + + return 0; +} + +/** + * ice_mbx_clear_malvf - Clear VF bitmap and counter for VF ID + * @snap: pointer to the mailbox snapshot structure + * @all_malvfs: all malicious VFs tracked by PF + * @bitmap_len: length of bitmap in bits + * @vf_id: relative virtual function ID of the malicious VF + * + * In case of a VF reset, this function can be called to clear + * the bit corresponding to the VF ID in the bitmap tracking all + * malicious VFs attached to the PF. The function also clears the + * VF counter array at the index of the VF ID. This is to ensure + * that the new VF loaded is not considered malicious before going + * through the overflow detection algorithm. + */ +enum ice_status +ice_mbx_clear_malvf(struct ice_mbx_snapshot *snap, unsigned long *all_malvfs, + u16 bitmap_len, u16 vf_id) +{ + if (!snap || !all_malvfs) + return ICE_ERR_PARAM; + + if (bitmap_len < snap->mbx_vf.vfcntr_len) + return ICE_ERR_INVAL_SIZE; + + /* Ensure VF ID value is not larger than bitmap or VF counter length */ + if (vf_id >= bitmap_len || vf_id >= snap->mbx_vf.vfcntr_len) + return ICE_ERR_OUT_OF_RANGE; + + /* Clear VF ID bit in the bitmap tracking malicious VFs attached to PF */ + clear_bit(vf_id, all_malvfs); + + /* Clear the VF counter in the mailbox snapshot structure for that VF ID. + * This is to ensure that if a VF is unloaded and a new one brought back + * up with the same VF ID for a snapshot currently in traversal or detect + * state the counter for that VF ID does not increment on top of existing + * values in the mailbox overflow detection algorithm. + */ + snap->mbx_vf.vf_cntr[vf_id] = 0; + + return 0; +} + +/** + * ice_mbx_init_snapshot - Initialize mailbox snapshot structure + * @hw: pointer to the hardware structure + * @vf_count: number of VFs allocated on a PF + * + * Clear the mailbox snapshot structure and allocate memory + * for the VF counter array based on the number of VFs allocated + * on that PF. + * + * Assumption: This function will assume ice_get_caps() has already been + * called to ensure that the vf_count can be compared against the number + * of VFs supported as defined in the functional capabilities of the device. + */ +enum ice_status ice_mbx_init_snapshot(struct ice_hw *hw, u16 vf_count) +{ + struct ice_mbx_snapshot *snap = &hw->mbx_snapshot; + + /* Ensure that the number of VFs allocated is non-zero and + * is not greater than the number of supported VFs defined in + * the functional capabilities of the PF. + */ + if (!vf_count || vf_count > hw->func_caps.num_allocd_vfs) + return ICE_ERR_INVAL_SIZE; + + snap->mbx_vf.vf_cntr = devm_kcalloc(ice_hw_to_dev(hw), vf_count, + sizeof(*snap->mbx_vf.vf_cntr), + GFP_KERNEL); + if (!snap->mbx_vf.vf_cntr) + return ICE_ERR_NO_MEMORY; + + /* Setting the VF counter length to the number of allocated + * VFs for given PF's functional capabilities. + */ + snap->mbx_vf.vfcntr_len = vf_count; + + /* Clear mbx_buf in the mailbox snaphot structure and setting the + * mailbox snapshot state to a new capture. + */ + memset(&snap->mbx_buf, 0, sizeof(snap->mbx_buf)); + snap->mbx_buf.state = ICE_MAL_VF_DETECT_STATE_NEW_SNAPSHOT; + + return 0; +} + +/** + * ice_mbx_deinit_snapshot - Free mailbox snapshot structure + * @hw: pointer to the hardware structure + * + * Clear the mailbox snapshot structure and free the VF counter array. + */ +void ice_mbx_deinit_snapshot(struct ice_hw *hw) +{ + struct ice_mbx_snapshot *snap = &hw->mbx_snapshot; + + /* Free VF counter array and reset VF counter length */ + devm_kfree(ice_hw_to_dev(hw), snap->mbx_vf.vf_cntr); + snap->mbx_vf.vfcntr_len = 0; + + /* Clear mbx_buf in the mailbox snaphot structure */ + memset(&snap->mbx_buf, 0, sizeof(snap->mbx_buf)); +} |