From d620448fb5673d0705e50e3f73b890a10cfe7c80 Mon Sep 17 00:00:00 2001 From: Michal Wajdeczko Date: Thu, 12 Sep 2024 22:38:16 +0200 Subject: [PATCH] drm/xe/pf: Allow to view and replace VF GuC state over debugfs MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit For feature enabling and testing purposes, allow to view saved VF GuC state and to replace it, but only under strict debug config. Signed-off-by: Michal Wajdeczko Cc: Michał Winiarski Cc: Tomasz Lis Reviewed-by: Michał Winiarski Link: https://patchwork.freedesktop.org/patch/msgid/20240912203817.1880-6-michal.wajdeczko@intel.com --- drivers/gpu/drm/xe/xe_gt_sriov_pf_debugfs.c | 46 ++++++++++ drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.c | 85 +++++++++++++++++++ drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.h | 7 ++ 3 files changed, 138 insertions(+) diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_debugfs.c b/drivers/gpu/drm/xe/xe_gt_sriov_pf_debugfs.c index 2290ddaf9594..e990a63ec998 100644 --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_debugfs.c +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_debugfs.c @@ -17,6 +17,7 @@ #include "xe_gt_sriov_pf_control.h" #include "xe_gt_sriov_pf_debugfs.h" #include "xe_gt_sriov_pf_helpers.h" +#include "xe_gt_sriov_pf_migration.h" #include "xe_gt_sriov_pf_monitor.h" #include "xe_gt_sriov_pf_policy.h" #include "xe_gt_sriov_pf_service.h" @@ -375,6 +376,44 @@ static const struct file_operations control_ops = { .llseek = default_llseek, }; +/* + * /sys/kernel/debug/dri/0/ + * ├── gt0 + * │   ├── vf1 + * │   │   ├── guc_state + */ +static ssize_t guc_state_read(struct file *file, char __user *buf, + size_t count, loff_t *pos) +{ + struct dentry *dent = file_dentry(file); + struct dentry *parent = dent->d_parent; + struct xe_gt *gt = extract_gt(parent); + unsigned int vfid = extract_vfid(parent); + + return xe_gt_sriov_pf_migration_read_guc_state(gt, vfid, buf, count, pos); +} + +static ssize_t guc_state_write(struct file *file, const char __user *buf, + size_t count, loff_t *pos) +{ + struct dentry *dent = file_dentry(file); + struct dentry *parent = dent->d_parent; + struct xe_gt *gt = extract_gt(parent); + unsigned int vfid = extract_vfid(parent); + + if (*pos) + return -EINVAL; + + return xe_gt_sriov_pf_migration_write_guc_state(gt, vfid, buf, count); +} + +static const struct file_operations guc_state_ops = { + .owner = THIS_MODULE, + .read = guc_state_read, + .write = guc_state_write, + .llseek = default_llseek, +}; + /** * xe_gt_sriov_pf_debugfs_register - Register SR-IOV PF specific entries in GT debugfs. * @gt: the &xe_gt to register @@ -423,5 +462,12 @@ void xe_gt_sriov_pf_debugfs_register(struct xe_gt *gt, struct dentry *root) pf_add_config_attrs(gt, vfdentry, VFID(n)); debugfs_create_file("control", 0600, vfdentry, NULL, &control_ops); + + /* for testing/debugging purposes only! */ + if (IS_ENABLED(CONFIG_DRM_XE_DEBUG)) { + debugfs_create_file("guc_state", + IS_ENABLED(CONFIG_DRM_XE_DEBUG_SRIOV) ? 0600 : 0400, + vfdentry, NULL, &guc_state_ops); + } } } diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.c b/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.c index b7188fa6ac07..c712111aa30d 100644 --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.c +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.c @@ -297,6 +297,91 @@ int xe_gt_sriov_pf_migration_restore_guc_state(struct xe_gt *gt, unsigned int vf return ret; } +#ifdef CONFIG_DEBUG_FS +/** + * xe_gt_sriov_pf_migration_read_guc_state() - Read a GuC VF state. + * @gt: the &xe_gt + * @vfid: the VF identifier + * @buf: the user space buffer to read to + * @count: the maximum number of bytes to read + * @pos: the current position in the buffer + * + * This function is for PF only. + * + * This function reads up to @count bytes from the saved VF GuC state buffer + * at offset @pos into the user space address starting at @buf. + * + * Return: the number of bytes read or a negative error code on failure. + */ +ssize_t xe_gt_sriov_pf_migration_read_guc_state(struct xe_gt *gt, unsigned int vfid, + char __user *buf, size_t count, loff_t *pos) +{ + struct xe_gt_sriov_state_snapshot *snapshot; + ssize_t ret; + + xe_gt_assert(gt, IS_SRIOV_PF(gt_to_xe(gt))); + xe_gt_assert(gt, vfid != PFID); + xe_gt_assert(gt, vfid <= xe_sriov_pf_get_totalvfs(gt_to_xe(gt))); + + if (!pf_migration_supported(gt)) + return -ENOPKG; + + mutex_lock(pf_migration_mutex(gt)); + snapshot = pf_pick_vf_snapshot(gt, vfid); + if (snapshot->guc.size) + ret = simple_read_from_buffer(buf, count, pos, snapshot->guc.buff, + snapshot->guc.size); + else + ret = -ENODATA; + mutex_unlock(pf_migration_mutex(gt)); + + return ret; +} + +/** + * xe_gt_sriov_pf_migration_write_guc_state() - Write a GuC VF state. + * @gt: the &xe_gt + * @vfid: the VF identifier + * @buf: the user space buffer with GuC VF state + * @size: the size of GuC VF state (in bytes) + * + * This function is for PF only. + * + * This function reads @size bytes of the VF GuC state stored at user space + * address @buf and writes it into a internal VF state buffer. + * + * Return: the number of bytes used or a negative error code on failure. + */ +ssize_t xe_gt_sriov_pf_migration_write_guc_state(struct xe_gt *gt, unsigned int vfid, + const char __user *buf, size_t size) +{ + struct xe_gt_sriov_state_snapshot *snapshot; + loff_t pos = 0; + ssize_t ret; + + xe_gt_assert(gt, IS_SRIOV_PF(gt_to_xe(gt))); + xe_gt_assert(gt, vfid != PFID); + xe_gt_assert(gt, vfid <= xe_sriov_pf_get_totalvfs(gt_to_xe(gt))); + + if (!pf_migration_supported(gt)) + return -ENOPKG; + + mutex_lock(pf_migration_mutex(gt)); + snapshot = pf_pick_vf_snapshot(gt, vfid); + ret = pf_alloc_guc_state(gt, snapshot, size); + if (!ret) { + ret = simple_write_to_buffer(snapshot->guc.buff, size, &pos, buf, size); + if (ret < 0) + pf_free_guc_state(gt, snapshot); + else + pf_dump_guc_state(gt, snapshot); + } + mutex_unlock(pf_migration_mutex(gt)); + + return ret; +} +#endif /* CONFIG_DEBUG_FS */ + static bool pf_check_migration_support(struct xe_gt *gt) { /* GuC 70.25 with save/restore v2 is required */ diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.h b/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.h index 6643d730a9ab..09faeae00ddb 100644 --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.h +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.h @@ -14,4 +14,11 @@ int xe_gt_sriov_pf_migration_init(struct xe_gt *gt); int xe_gt_sriov_pf_migration_save_guc_state(struct xe_gt *gt, unsigned int vfid); int xe_gt_sriov_pf_migration_restore_guc_state(struct xe_gt *gt, unsigned int vfid); +#ifdef CONFIG_DEBUG_FS +ssize_t xe_gt_sriov_pf_migration_read_guc_state(struct xe_gt *gt, unsigned int vfid, + char __user *buf, size_t count, loff_t *pos); +ssize_t xe_gt_sriov_pf_migration_write_guc_state(struct xe_gt *gt, unsigned int vfid, + const char __user *buf, size_t count); +#endif + #endif -- 2.50.1