diff options
Diffstat (limited to 'drivers/gpu/drm/xe/xe_sriov_vf.c')
| -rw-r--r-- | drivers/gpu/drm/xe/xe_sriov_vf.c | 263 |
1 files changed, 263 insertions, 0 deletions
diff --git a/drivers/gpu/drm/xe/xe_sriov_vf.c b/drivers/gpu/drm/xe/xe_sriov_vf.c new file mode 100644 index 000000000000..c1275e64aa9c --- /dev/null +++ b/drivers/gpu/drm/xe/xe_sriov_vf.c @@ -0,0 +1,263 @@ +// SPDX-License-Identifier: MIT +/* + * Copyright © 2023-2024 Intel Corporation + */ + +#include <drm/drm_managed.h> + +#include "xe_assert.h" +#include "xe_device.h" +#include "xe_gt_sriov_printk.h" +#include "xe_gt_sriov_vf.h" +#include "xe_pm.h" +#include "xe_sriov.h" +#include "xe_sriov_printk.h" +#include "xe_sriov_vf.h" + +/** + * DOC: VF restore procedure in PF KMD and VF KMD + * + * Restoring previously saved state of a VF is one of core features of + * SR-IOV. All major VM Management applications allow saving and restoring + * the VM state, and doing that to a VM which uses SRIOV VF as one of + * the accessible devices requires support from KMD on both PF and VF side. + * VMM initiates all required operations through VFIO module, which then + * translates them into PF KMD calls. This description will focus on these + * calls, leaving out the module which initiates these steps (VFIO). + * + * In order to start the restore procedure, GuC needs to keep the VF in + * proper state. The PF driver can ensure GuC set it to VF_READY state + * by provisioning the VF, which in turn can be done after Function Level + * Reset of said VF (or after it was freshly created - in that case FLR + * is not needed). The FLR procedure ends with GuC sending message + * `GUC_PF_NOTIFY_VF_FLR_DONE`, and then provisioning data is sent to GuC. + * After the provisioning is completed, the VF needs to be paused, and + * at that point the actual restore can begin. + * + * During VF Restore, state of several resources is restored. These may + * include local memory content (system memory is restored by VMM itself), + * values of MMIO registers, stateless compression metadata and others. + * The final resource which also needs restoring is state of the VF + * submission maintained within GuC. For that, `GUC_PF_OPCODE_VF_RESTORE` + * message is used, with reference to the state blob to be consumed by + * GuC. + * + * Next, when VFIO is asked to set the VM into running state, the PF driver + * sends `GUC_PF_TRIGGER_VF_RESUME` to GuC. When sent after restore, this + * changes VF state within GuC to `VF_RESFIX_BLOCKED` rather than the + * usual `VF_RUNNING`. At this point GuC triggers an interrupt to inform + * the VF KMD within the VM that it was migrated. + * + * As soon as Virtual GPU of the VM starts, the VF driver within receives + * the MIGRATED interrupt and schedules post-migration recovery worker. + * That worker queries GuC for new provisioning (using MMIO communication), + * and applies fixups to any non-virtualized resources used by the VF. + * + * When the VF driver is ready to continue operation on the newly connected + * hardware, it sends `VF2GUC_NOTIFY_RESFIX_DONE` which causes it to + * enter the long awaited `VF_RUNNING` state, and therefore start handling + * CTB messages and scheduling workloads from the VF:: + * + * PF GuC VF + * [ ] | | + * [ ] PF2GUC_VF_CONTROL(pause) | | + * [ ]---------------------------> [ ] | + * [ ] [ ] GuC sets new VF state to | + * [ ] [ ]------- VF_READY_PAUSED | + * [ ] [ ] | | + * [ ] [ ] <----- | + * [ ] success [ ] | + * [ ] <---------------------------[ ] | + * [ ] | | + * [ ] PF loads resources from the | | + * [ ]------- saved image supplied | | + * [ ] | | | + * [ ] <----- | | + * [ ] | | + * [ ] GUC_PF_OPCODE_VF_RESTORE | | + * [ ]---------------------------> [ ] | + * [ ] [ ] GuC loads contexts and CTB | + * [ ] [ ]------- state from image | + * [ ] [ ] | | + * [ ] [ ] <----- | + * [ ] [ ] | + * [ ] [ ] GuC sets new VF state to | + * [ ] [ ]------- VF_RESFIX_PAUSED | + * [ ] [ ] | | + * [ ] success [ ] <----- | + * [ ] <---------------------------[ ] | + * [ ] | | + * [ ] GUC_PF_TRIGGER_VF_RESUME | | + * [ ]---------------------------> [ ] | + * [ ] [ ] GuC sets new VF state to | + * [ ] [ ]------- VF_RESFIX_BLOCKED | + * [ ] [ ] | | + * [ ] [ ] <----- | + * [ ] [ ] | + * [ ] [ ] GUC_INTR_SW_INT_0 | + * [ ] success [ ]---------------------------> [ ] + * [ ] <---------------------------[ ] [ ] + * | | VF2GUC_QUERY_SINGLE_KLV [ ] + * | [ ] <---------------------------[ ] + * | [ ] [ ] + * | [ ] new VF provisioning [ ] + * | [ ]---------------------------> [ ] + * | | [ ] + * | | VF driver applies post [ ] + * | | migration fixups -------[ ] + * | | | [ ] + * | | -----> [ ] + * | | [ ] + * | | VF2GUC_NOTIFY_RESFIX_DONE [ ] + * | [ ] <---------------------------[ ] + * | [ ] [ ] + * | [ ] GuC sets new VF state to [ ] + * | [ ]------- VF_RUNNING [ ] + * | [ ] | [ ] + * | [ ] <----- [ ] + * | [ ] success [ ] + * | [ ]---------------------------> [ ] + * | | | + * | | | + */ + +static void migration_worker_func(struct work_struct *w); + +/** + * xe_sriov_vf_init_early - Initialize SR-IOV VF specific data. + * @xe: the &xe_device to initialize + */ +void xe_sriov_vf_init_early(struct xe_device *xe) +{ + INIT_WORK(&xe->sriov.vf.migration.worker, migration_worker_func); +} + +/** + * vf_post_migration_requery_guc - Re-query GuC for current VF provisioning. + * @xe: the &xe_device struct instance + * + * After migration, we need to re-query all VF configuration to make sure + * they match previous provisioning. Note that most of VF provisioning + * shall be the same, except GGTT range, since GGTT is not virtualized per-VF. + * + * Returns: 0 if the operation completed successfully, or a negative error + * code otherwise. + */ +static int vf_post_migration_requery_guc(struct xe_device *xe) +{ + struct xe_gt *gt; + unsigned int id; + int err, ret = 0; + + for_each_gt(gt, xe, id) { + err = xe_gt_sriov_vf_query_config(gt); + ret = ret ?: err; + } + + return ret; +} + +/* + * vf_post_migration_imminent - Check if post-restore recovery is coming. + * @xe: the &xe_device struct instance + * + * Return: True if migration recovery worker will soon be running. Any worker currently + * executing does not affect the result. + */ +static bool vf_post_migration_imminent(struct xe_device *xe) +{ + return xe->sriov.vf.migration.gt_flags != 0 || + work_pending(&xe->sriov.vf.migration.worker); +} + +/* + * Notify all GuCs about resource fixups apply finished. + */ +static void vf_post_migration_notify_resfix_done(struct xe_device *xe) +{ + struct xe_gt *gt; + unsigned int id; + + for_each_gt(gt, xe, id) { + if (vf_post_migration_imminent(xe)) + goto skip; + xe_gt_sriov_vf_notify_resfix_done(gt); + } + return; + +skip: + drm_dbg(&xe->drm, "another recovery imminent, skipping notifications\n"); +} + +static void vf_post_migration_recovery(struct xe_device *xe) +{ + int err; + + drm_dbg(&xe->drm, "migration recovery in progress\n"); + xe_pm_runtime_get(xe); + err = vf_post_migration_requery_guc(xe); + if (vf_post_migration_imminent(xe)) + goto defer; + if (unlikely(err)) + goto fail; + + /* FIXME: add the recovery steps */ + vf_post_migration_notify_resfix_done(xe); + xe_pm_runtime_put(xe); + drm_notice(&xe->drm, "migration recovery ended\n"); + return; +defer: + xe_pm_runtime_put(xe); + drm_dbg(&xe->drm, "migration recovery deferred\n"); + return; +fail: + xe_pm_runtime_put(xe); + drm_err(&xe->drm, "migration recovery failed (%pe)\n", ERR_PTR(err)); + xe_device_declare_wedged(xe); +} + +static void migration_worker_func(struct work_struct *w) +{ + struct xe_device *xe = container_of(w, struct xe_device, + sriov.vf.migration.worker); + + vf_post_migration_recovery(xe); +} + +static bool vf_ready_to_recovery_on_all_gts(struct xe_device *xe) +{ + struct xe_gt *gt; + unsigned int id; + + for_each_gt(gt, xe, id) { + if (!test_bit(id, &xe->sriov.vf.migration.gt_flags)) { + xe_gt_sriov_dbg_verbose(gt, "still not ready to recover\n"); + return false; + } + } + return true; +} + +/** + * xe_sriov_vf_start_migration_recovery - Start VF migration recovery. + * @xe: the &xe_device to start recovery on + * + * This function shall be called only by VF. + */ +void xe_sriov_vf_start_migration_recovery(struct xe_device *xe) +{ + bool started; + + xe_assert(xe, IS_SRIOV_VF(xe)); + + if (!vf_ready_to_recovery_on_all_gts(xe)) + return; + + WRITE_ONCE(xe->sriov.vf.migration.gt_flags, 0); + /* Ensure other threads see that no flags are set now. */ + smp_mb(); + + started = queue_work(xe->sriov.wq, &xe->sriov.vf.migration.worker); + drm_info(&xe->drm, "VF migration recovery %s\n", started ? + "scheduled" : "already in progress"); +} |