[PATCH 09/26] drm/xe/pf: Expose VF migration data size over debugfs

Michał Winiarski
2025-10-11T19:40:59Z

The size is normally used to make a decision on when to stop the device
(mainly when it's in a pre_copy state).

Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
---
drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.c | 18 ++++++++++
drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.h | 2 ++
drivers/gpu/drm/xe/xe_sriov_pf_debugfs.c | 34 +++++++++++++++++++
drivers/gpu/drm/xe/xe_sriov_pf_migration.c | 30 ++++++++++++++++
drivers/gpu/drm/xe/xe_sriov_pf_migration.h | 1 +
5 files changed, 85 insertions(+)

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 582aaf062cbd4..50f09994e2854 100644
--- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.c
+++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.c
@@ -395,6 +395,24 @@ ssize_t xe_gt_sriov_pf_migration_write_guc_state(struct xe_gt *gt, unsigned int
}
#endif /* CONFIG_DEBUG_FS */

+/**
+ * xe_gt_sriov_pf_migration_size() - Total size of migration data from all components within a GT
+ * @gt: the &struct xe_gt
+ * @vfid: the VF identifier
+ *
+ * This function is for PF only.
+ *
+ * Return: total migration data size in bytes or a negative error code on failure.
+ */
+ssize_t xe_gt_sriov_pf_migration_size(struct xe_gt *gt, unsigned int vfid)
+{
+ ssize_t total = 0;
+
+ xe_gt_assert(gt, IS_SRIOV_PF(gt_to_xe(gt)));
+
+ return total;
+}
+
/**
* xe_gt_sriov_pf_migration_ring_empty() - Check if a migration ring is empty
* @gt: the &struct xe_gt
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 1e4dc46413823..e5298d35d7d7e 100644
--- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.h
+++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.h
@@ -15,6 +15,8 @@ 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);

+ssize_t xe_gt_sriov_pf_migration_size(struct xe_gt *gt, unsigned int vfid);
+
bool xe_gt_sriov_pf_migration_ring_empty(struct xe_gt *gt, unsigned int vfid);
int xe_gt_sriov_pf_migration_ring_produce(struct xe_gt *gt, unsigned int vfid,
struct xe_sriov_pf_migration_data *data);
diff --git a/drivers/gpu/drm/xe/xe_sriov_pf_debugfs.c b/drivers/gpu/drm/xe/xe_sriov_pf_debugfs.c
index ce780719760a6..b06e893fe54cf 100644
--- a/drivers/gpu/drm/xe/xe_sriov_pf_debugfs.c
+++ b/drivers/gpu/drm/xe/xe_sriov_pf_debugfs.c
@@ -13,6 +13,7 @@
#include "xe_sriov_pf_control.h"
#include "xe_sriov_pf_debugfs.h"
#include "xe_sriov_pf_helpers.h"
+#include "xe_sriov_pf_migration.h"
#include "xe_sriov_pf_migration_data.h"
#include "xe_sriov_pf_service.h"
#include "xe_sriov_printk.h"
@@ -203,6 +204,38 @@ static const struct file_operations data_vf_fops = {
.llseek = default_llseek,
};

+static ssize_t size_read(struct file *file, char __user *ubuf, size_t count, loff_t *ppos)
+{
+ struct dentry *dent = file_dentry(file);
+ struct dentry *vfdentry = dent->d_parent;
+ struct dentry *migration_dentry = vfdentry->d_parent;
+ unsigned int vfid = (uintptr_t)vfdentry->d_inode->i_private;
+ struct xe_device *xe = migration_dentry->d_inode->i_private;
+ char buf[21];
+ ssize_t ret;
+ int len;
+
+ xe_assert(xe, vfid);
+ xe_sriov_pf_assert_vfid(xe, vfid);
+
+ xe_pm_runtime_get(xe);
+ ret = xe_sriov_pf_migration_size(xe, vfid);
+ xe_pm_runtime_put(xe);
+ if (ret < 0)
+ return ret;
+
+ len = scnprintf(buf, sizeof(buf), "%zd\n", ret);
+
+ return simple_read_from_buffer(ubuf, count, ppos, buf, len);
+}
+
+static const struct file_operations size_vf_fops = {
+ .owner = THIS_MODULE,
+ .open = simple_open,
+ .read = size_read,
+ .llseek = default_llseek,
+};
+
static void pf_populate_vf(struct xe_device *xe, struct dentry *vfdent)
{
debugfs_create_file("pause", 0200, vfdent, xe, &pause_vf_fops);
@@ -212,6 +245,7 @@ static void pf_populate_vf(struct xe_device *xe, struct dentry *vfdent)
debugfs_create_file("save", 0600, vfdent, xe, &save_vf_fops);
debugfs_create_file("restore", 0600, vfdent, xe, &restore_vf_fops);
debugfs_create_file("migration_data", 0600, vfdent, xe, &data_vf_fops);
+ debugfs_create_file("migration_size", 0400, vfdent, xe, &size_vf_fops);
}

static void pf_populate_with_tiles(struct xe_device *xe, struct dentry *dent, unsigned int vfid)
diff --git a/drivers/gpu/drm/xe/xe_sriov_pf_migration.c b/drivers/gpu/drm/xe/xe_sriov_pf_migration.c
index a0cfac456ba0b..6b247581dec65 100644
--- a/drivers/gpu/drm/xe/xe_sriov_pf_migration.c
+++ b/drivers/gpu/drm/xe/xe_sriov_pf_migration.c
@@ -249,3 +249,33 @@ int xe_sriov_pf_migration_produce(struct xe_device *xe, unsigned int vfid,

return xe_gt_sriov_pf_migration_ring_produce(gt, vfid, data);
}
+
+/**
+ * xe_sriov_pf_migration_size() - Total size of migration data from all components within a device
+ * @xe: the &struct xe_device
+ * @vfid: the VF identifier
+ *
+ * This function is for PF only.
+ *
+ * Return: total migration data size in bytes or a negative error code on failure.
+ */
+ssize_t xe_sriov_pf_migration_size(struct xe_device *xe, unsigned int vfid)
+{
+ size_t size = 0;
+ struct xe_gt *gt;
+ ssize_t ret;
+ u8 gt_id;
+
+ xe_assert(xe, IS_SRIOV_PF(xe));
+
+ for_each_gt(gt, xe, gt_id) {
+ ret = xe_gt_sriov_pf_migration_size(gt, vfid);
+ if (ret < 0) {
+ size = ret;
+ break;
+ }
+ size += ret;
+ }
+
+ return size;
+}
diff --git a/drivers/gpu/drm/xe/xe_sriov_pf_migration.h b/drivers/gpu/drm/xe/xe_sriov_pf_migration.h
index f2020ba19c2da..887ea3e9632bd 100644
--- a/drivers/gpu/drm/xe/xe_sriov_pf_migration.h
+++ b/drivers/gpu/drm/xe/xe_sriov_pf_migration.h
@@ -14,6 +14,7 @@ struct xe_device;
#ifdef CONFIG_PCI_IOV
int xe_sriov_pf_migration_init(struct xe_device *xe);
bool xe_sriov_pf_migration_supported(struct xe_device *xe);
+ssize_t xe_sriov_pf_migration_size(struct xe_device *xe, unsigned int vfid);
struct xe_sriov_pf_migration_data *
xe_sriov_pf_migration_consume(struct xe_device *xe, unsigned int vfid);
int xe_sriov_pf_migration_produce(struct xe_device *xe, unsigned int vfid,
--
2.50.1