THE VF FLR STATE MACHINE(9)

💅 The VF FLR state machine 💅

okay bestie, welcome to the Kernel API Manual page for The VF FLR state machine(9) — yes, the title ate and the manual name is folded in right here so we don't have to copy that header line like it's a group chat screenshot. This page is literally here to show you the state machine, and we are keeping every arrow, every state, and every transition exactly as it is, no cap. 🫶

The VF FLR state machine looks like this, bestie:

             (READY,PAUSED,STOPPED)<------------<--------------o
                |             |                                         flr           prepare                                      |             |                                        ....V.............V............FLR_WIP...........           :   |             |                             :            :   |    FLR_PREPARE                            :        |
            :   |    /                                      :        |
            :      flr                                     :        |
            :     /                                        :        |
            :        o----<----busy                        :        |
            :       /            /                         :        |
            :       FLR_SEND_START---failed----->-----------o--->(FLR_FAILED)<---o
            :        |                                     :        |           |
            :      acked           rejected----->-----------o--->(MISMATCH)      |
            :        |                                      :        ^           |
            :        v                                      :        |           |
            :       FLR_WAIT_GUC                            :        |           |
            :        |                                      :        |           |
            :       done                                    :        |           |
            :        |                                      :        |           |
            :        v                                      :        |           |
            :       FLR_GUC_DONE                            :        |           |
            :        |                                      :        |           |
            :        | o--<--sync                           :        |           |
            :        |/        /                            :        |           |
            :       FLR_SYNC--o                             :        |           |
            :        |                                      :        |           |
            :       FLR_RESET_CONFIG---failed--->-----------o--------+-----------o
            :        |                                      :        |           |
            :       FLR_RESET_DATA                          :        |           |
            :        |                                      :        |           |
            :       FLR_RESET_MMIO                          :        |           |
            :        |                                      :        |           |
            :        | o----<----busy                       :        |           |
            :        |/            /                        :        |           |
            :       FLR_SEND_FINISH----failed--->-----------o--------+-----------o
            :       /                                      :        |
            :     acked            rejected----->-----------o--------o
            :     /                                         :
            :....o..............................o...........:
                 |                              |
              completed                       restart
                 |                             /
                 V                            /
              (READY)<----------<------------o

If you want the full state machine view, see The VF state machine_ — that's the main-character map, iykyk. ✨

🌈 SEE ALSO 🌈

omg the whole friend group is here, and you should absolutely go say hi:

• Kernel file ./drivers/gpu/drm/xe/xe_gt_sriov_pf_control.c
• The VF state machine(9)
• The VF PAUSE state machine(9)
• xe_gt_sriov_pf_control_pause_vf(9)
• The VF RESUME state machine(9)
• xe_gt_sriov_pf_control_resume_vf(9)
• The VF SAVE state machine(9)
• xe_gt_sriov_pf_control_check_save_data_done(9)
• xe_gt_sriov_pf_control_check_save_failed(9)
• xe_gt_sriov_pf_control_process_save_data(9)
• xe_gt_sriov_pf_control_trigger_save_vf(9)
• xe_gt_sriov_pf_control_finish_save_vf(9)
• The VF RESTORE state machine(9)
• xe_gt_sriov_pf_control_check_restore_failed(9)
• xe_gt_sriov_pf_control_restore_data_done(9)
• xe_gt_sriov_pf_control_process_restore_data(9)
• xe_gt_sriov_pf_control_trigger_restore_vf(9)
• xe_gt_sriov_pf_control_finish_restore_vf(9)
• The VF STOP state machine(9)
• xe_gt_sriov_pf_control_stop_vf(9)
• xe_gt_sriov_pf_control_prepare_flr(9)
• xe_gt_sriov_pf_control_trigger_flr(9)
• xe_gt_sriov_pf_control_sync_flr(9)
• xe_gt_sriov_pf_control_wait_flr(9)
• The VF FLR Flow with GuC(9)
• xe_gt_sriov_pf_control_process_guc2pf(9)
• xe_gt_sriov_pf_control_init(9)
• xe_gt_sriov_pf_control_restart(9)

— source/version ./drivers/gpu/drm/xe, dated October 2026, page The VF FLR state machine(9) 💜