[PATCH 5/6] drm/xe/pf: Allow to view and replace VF GuC state over debugfs
Michal Wajdeczko
michal.wajdeczko at intel.com
Thu Sep 12 20:38:16 UTC 2024
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 <michal.wajdeczko at intel.com>
Cc: Michał Winiarski <michal.winiarski at intel.com>
Cc: Tomasz Lis <tomasz.lis at 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 8815fbde00cc..6a6eb396680e 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
--
2.43.0
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