xe_sriov_vf.c

  1// SPDX-License-Identifier: MIT
  2/*
  3 * Copyright © 2023-2024 Intel Corporation
  4 */
  5
  6#include <drm/drm_debugfs.h>
  7#include <drm/drm_managed.h>
  8
  9#include "xe_gt.h"
 10#include "xe_gt_sriov_vf.h"
 11#include "xe_guc.h"
 12#include "xe_sriov_printk.h"
 13#include "xe_sriov_vf.h"
 14#include "xe_sriov_vf_ccs.h"
 15
 16/**
 17 * DOC: VF restore procedure in PF KMD and VF KMD
 18 *
 19 * Restoring previously saved state of a VF is one of core features of
 20 * SR-IOV. All major VM Management applications allow saving and restoring
 21 * the VM state, and doing that to a VM which uses SRIOV VF as one of
 22 * the accessible devices requires support from KMD on both PF and VF side.
 23 * VMM initiates all required operations through VFIO module, which then
 24 * translates them into PF KMD calls. This description will focus on these
 25 * calls, leaving out the module which initiates these steps (VFIO).
 26 *
 27 * In order to start the restore procedure, GuC needs to keep the VF in
 28 * proper state. The PF driver can ensure GuC set it to VF_READY state
 29 * by provisioning the VF, which in turn can be done after Function Level
 30 * Reset of said VF (or after it was freshly created - in that case FLR
 31 * is not needed). The FLR procedure ends with GuC sending message
 32 * `GUC_PF_NOTIFY_VF_FLR_DONE`, and then provisioning data is sent to GuC.
 33 * After the provisioning is completed, the VF needs to be paused, and
 34 * at that point the actual restore can begin.
 35 *
 36 * During VF Restore, state of several resources is restored. These may
 37 * include local memory content (system memory is restored by VMM itself),
 38 * values of MMIO registers, stateless compression metadata and others.
 39 * The final resource which also needs restoring is state of the VF
 40 * submission maintained within GuC. For that, `GUC_PF_OPCODE_VF_RESTORE`
 41 * message is used, with reference to the state blob to be consumed by
 42 * GuC.
 43 *
 44 * Next, when VFIO is asked to set the VM into running state, the PF driver
 45 * sends `GUC_PF_TRIGGER_VF_RESUME` to GuC. When sent after restore, this
 46 * changes VF state within GuC to `VF_RESFIX_BLOCKED` rather than the
 47 * usual `VF_RUNNING`. At this point GuC triggers an interrupt to inform
 48 * the VF KMD within the VM that it was migrated.
 49 *
 50 * As soon as Virtual GPU of the VM starts, the VF driver within receives
 51 * the MIGRATED interrupt and schedules post-migration recovery worker.
 52 * That worker queries GuC for new provisioning (using MMIO communication),
 53 * and applies fixups to any non-virtualized resources used by the VF.
 54 *
 55 * When the VF driver is ready to continue operation on the newly connected
 56 * hardware, it sends `VF2GUC_NOTIFY_RESFIX_DONE` which causes it to
 57 * enter the long awaited `VF_RUNNING` state, and therefore start handling
 58 * CTB messages and scheduling workloads from the VF::
 59 *
 60 *      PF                             GuC                              VF
 61 *     [ ]                              |                               |
 62 *     [ ] PF2GUC_VF_CONTROL(pause)     |                               |
 63 *     [ ]---------------------------> [ ]                              |
 64 *     [ ]                             [ ]  GuC sets new VF state to    |
 65 *     [ ]                             [ ]------- VF_READY_PAUSED       |
 66 *     [ ]                             [ ]      |                       |
 67 *     [ ]                             [ ] <-----                       |
 68 *     [ ] success                     [ ]                              |
 69 *     [ ] <---------------------------[ ]                              |
 70 *     [ ]                              |                               |
 71 *     [ ] PF loads resources from the  |                               |
 72 *     [ ]------- saved image supplied  |                               |
 73 *     [ ]      |                       |                               |
 74 *     [ ] <-----                       |                               |
 75 *     [ ]                              |                               |
 76 *     [ ] GUC_PF_OPCODE_VF_RESTORE     |                               |
 77 *     [ ]---------------------------> [ ]                              |
 78 *     [ ]                             [ ]  GuC loads contexts and CTB  |
 79 *     [ ]                             [ ]------- state from image      |
 80 *     [ ]                             [ ]      |                       |
 81 *     [ ]                             [ ] <-----                       |
 82 *     [ ]                             [ ]                              |
 83 *     [ ]                             [ ]  GuC sets new VF state to    |
 84 *     [ ]                             [ ]------- VF_RESFIX_PAUSED      |
 85 *     [ ]                             [ ]      |                       |
 86 *     [ ] success                     [ ] <-----                       |
 87 *     [ ] <---------------------------[ ]                              |
 88 *     [ ]                              |                               |
 89 *     [ ] GUC_PF_TRIGGER_VF_RESUME     |                               |
 90 *     [ ]---------------------------> [ ]                              |
 91 *     [ ]                             [ ]  GuC sets new VF state to    |
 92 *     [ ]                             [ ]------- VF_RESFIX_BLOCKED     |
 93 *     [ ]                             [ ]      |                       |
 94 *     [ ]                             [ ] <-----                       |
 95 *     [ ]                             [ ]                              |
 96 *     [ ]                             [ ] GUC_INTR_SW_INT_0            |
 97 *     [ ] success                     [ ]---------------------------> [ ]
 98 *     [ ] <---------------------------[ ]                             [ ]
 99 *      |                               |      VF2GUC_QUERY_SINGLE_KLV [ ]
100 *      |                              [ ] <---------------------------[ ]
101 *      |                              [ ]                             [ ]
102 *      |                              [ ]        new VF provisioning  [ ]
103 *      |                              [ ]---------------------------> [ ]
104 *      |                               |                              [ ]
105 *      |                               |       VF driver applies post [ ]
106 *      |                               |      migration fixups -------[ ]
107 *      |                               |                       |      [ ]
108 *      |                               |                       -----> [ ]
109 *      |                               |                              [ ]
110 *      |                               |    VF2GUC_NOTIFY_RESFIX_DONE [ ]
111 *      |                              [ ] <---------------------------[ ]
112 *      |                              [ ]                             [ ]
113 *      |                              [ ]  GuC sets new VF state to   [ ]
114 *      |                              [ ]------- VF_RUNNING           [ ]
115 *      |                              [ ]      |                      [ ]
116 *      |                              [ ] <-----                      [ ]
117 *      |                              [ ]                     success [ ]
118 *      |                              [ ]---------------------------> [ ]
119 *      |                               |                               |
120 *      |                               |                               |
121 */
122
123/**
124 * xe_sriov_vf_migration_supported - Report whether SR-IOV VF migration is
125 * supported or not.
126 * @xe: the &xe_device to check
127 *
128 * Returns: true if VF migration is supported, false otherwise.
129 */
130bool xe_sriov_vf_migration_supported(struct xe_device *xe)
131{
132	xe_assert(xe, IS_SRIOV_VF(xe));
133	return !xe->sriov.vf.migration.disabled;
134}
135
136/**
137 * xe_sriov_vf_migration_disable - Turn off VF migration with given log message.
138 * @xe: the &xe_device instance.
139 * @fmt: format string for the log message, to be combined with following VAs.
140 */
141void xe_sriov_vf_migration_disable(struct xe_device *xe, const char *fmt, ...)
142{
143	struct va_format vaf;
144	va_list va_args;
145
146	xe_assert(xe, IS_SRIOV_VF(xe));
147
148	va_start(va_args, fmt);
149	vaf.fmt = fmt;
150	vaf.va  = &va_args;
151	xe_sriov_notice(xe, "migration disabled: %pV\n", &vaf);
152	va_end(va_args);
153
154	xe->sriov.vf.migration.disabled = true;
155}
156
157static void vf_migration_init_early(struct xe_device *xe)
158{
159	if (!xe_device_has_memirq(xe))
160		return xe_sriov_vf_migration_disable(xe, "requires memory-based IRQ support");
161
162}
163
164/**
165 * xe_sriov_vf_init_early - Initialize SR-IOV VF specific data.
166 * @xe: the &xe_device to initialize
167 */
168void xe_sriov_vf_init_early(struct xe_device *xe)
169{
170	vf_migration_init_early(xe);
171}
172
173/**
174 * xe_sriov_vf_init_late() - SR-IOV VF late initialization functions.
175 * @xe: the &xe_device to initialize
176 *
177 * This function initializes code for CCS migration.
178 *
179 * Return: 0 on success or a negative error code on failure.
180 */
181int xe_sriov_vf_init_late(struct xe_device *xe)
182{
183	return xe_sriov_vf_ccs_init(xe);
184}
185
186static int sa_info_vf_ccs(struct seq_file *m, void *data)
187{
188	struct drm_info_node *node = m->private;
189	struct xe_device *xe = to_xe_device(node->minor->dev);
190	struct drm_printer p = drm_seq_file_printer(m);
191
192	xe_sriov_vf_ccs_print(xe, &p);
193	return 0;
194}
195
196static const struct drm_info_list debugfs_list[] = {
197	{ .name = "sa_info_vf_ccs", .show = sa_info_vf_ccs },
198};
199
200/**
201 * xe_sriov_vf_debugfs_register - Register VF debugfs attributes.
202 * @xe: the &xe_device
203 * @root: the root &dentry
204 *
205 * Prepare debugfs attributes exposed by the VF.
206 */
207void xe_sriov_vf_debugfs_register(struct xe_device *xe, struct dentry *root)
208{
209	drm_debugfs_create_files(debugfs_list, ARRAY_SIZE(debugfs_list),
210				 root, xe->drm.primary);
211}