THE VF FLR FLOW WITH GUC(9)

✨ The VF FLR Flow with GuC(9) ✨

okay so bestie, this is the Kernel API Manual page for The VF FLR Flow with GuC(9) and it's literally the whole flow, step by step. The VF FLR flow includes several steps:

                     PF                        GUC             PCI
            ========================================================
                     |                          |               |
            (1)      |                         [ ] <----- FLR --|
                     |                         [ ]              :
            (2)     [ ] <-------- NOTIFY FLR --[ ]
                    [ ]                         |
            (3)     [ ]                         |
                    [ ]                         |
                    [ ]-- START FLR ---------> [ ]
                     |                         [ ]
            (4)      |                         [ ]
                     |                         [ ]
                    [ ] <--------- FLR DONE -- [ ]
                    [ ]                         |
            (5)     [ ]                         |
                    [ ]                         |
                    [ ]-- FINISH FLR --------> [ ]
                     |                          |

• Step 1: PCI HW generates interrupt to the GuC about VF FLR
• Step 2: GuC FW sends G2H notification to the PF about VF FLR
• Step 2a: on some platforms G2H is only received from root GuC
• Step 3: PF sends H2G request to the GuC to start VF FLR sequence
• Step 3a: on some platforms PF must send H2G to all other GuCs
• Step 4: GuC FW performs VF FLR cleanups and notifies the PF when done
• Step 5: PF performs VF FLR cleanups and notifies the GuC FW when finished

✨ SEE ALSO ✨

• 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)
• The VF FLR state machine(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)
• xe_gt_sriov_pf_control_process_guc2pf(9)
• xe_gt_sriov_pf_control_init(9)
• xe_gt_sriov_pf_control_restart(9)

mwah 💋 — source/version: ./drivers/gpu/drm/xe, date: October 2026, page: The VF FLR Flow with GuC(9). That's the footer vibe, bestie 🫶✨