drm/xe/pf: Allow change PF and VFs EQ/PT using sysfs

On current platforms, in SR-IOV virtualization, the GPU is shared
between VFs on the time-slice basis. The 'execution quantum' (EQ)
and 'preemption timeout' (PT) are two main scheduling parameters
that could be set individually per each VF.

Add EQ/PT read-write attributes for the PF and all VFs.

By exposing those two parameters over sysfs, the admin can change
their default values (infinity) and let the GuC scheduler enforce
that settings.

 /sys/bus/pci/drivers/xe/BDF/
 ├── sriov_admin/
     ├── pf/
     │   └── profile
     │       ├── exec_quantum_ms	[RW] unsigned integer
     │       └── preempt_timeout_us	[RW] unsigned integer
     ├── vf1/
     │   └── profile
     │       ├── exec_quantum_ms	[RW] unsigned integer
     │       └── preempt_timeout_us	[RW] unsigned integer

Writing 0 to these files will set infinity EQ/PT for the VF on all
tiles/GTs. This is a default value. Writing non-zero integers to
these files will change EQ/PT to new value (in their respective
units: msec or usec).

Reading from these files will return EQ/PT as previously set on
all tiles/GTs. In case of inconsistent values detected, due to
errors or low-level configuration done using debugfs, -EUCLEAN
error will be returned.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Piotr Piórkowski <piotr.piorkowski@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patch.msgid.link/20251030222348.186658-6-michal.wajdeczko@intel.com

diff --git a/drivers/gpu/drm/xe/xe_sriov_pf_provision.c b/drivers/gpu/drm/xe/xe_sriov_pf_provision.c
index 663fb0c045e9b9aa89a442dc9fe2bf7bd4c15ac6..8040747186d7b6e5d62635af417c6bfd0712360c 100644 (file)
--- a/drivers/gpu/drm/xe/xe_sriov_pf_provision.c
+++ b/drivers/gpu/drm/xe/xe_sriov_pf_provision.c
@@ -152,3 +152,138 @@ int xe_sriov_pf_provision_set_mode(struct xe_device *xe, enum xe_sriov_provision
        xe->sriov.pf.provision.mode = mode;
        return 0;
 }
+
+/**
+ * xe_sriov_pf_provision_apply_vf_eq() - Change VF's execution quantum.
+ * @xe: the PF &xe_device
+ * @vfid: the VF identifier
+ * @eq: execution quantum in [ms] to set
+ *
+ * Change VF's execution quantum (EQ) provisioning on all tiles/GTs.
+ *
+ * This function can only be called on PF.
+ *
+ * Return: 0 on success or a negative error code on failure.
+ */
+int xe_sriov_pf_provision_apply_vf_eq(struct xe_device *xe, unsigned int vfid, u32 eq)
+{
+       struct xe_gt *gt;
+       unsigned int id;
+       int result = 0;
+       int err;
+
+       guard(mutex)(xe_sriov_pf_master_mutex(xe));
+
+       for_each_gt(gt, xe, id) {
+               err = xe_gt_sriov_pf_config_set_exec_quantum_locked(gt, vfid, eq);
+               result = result ?: err;
+       }
+
+       return result;
+}
+
+static int pf_report_unclean(struct xe_gt *gt, unsigned int vfid,
+                            const char *what, u32 found, u32 expected)
+{
+       char name[8];
+
+       xe_sriov_dbg(gt_to_xe(gt), "%s on GT%u has %s=%u (expected %u)\n",
+                    xe_sriov_function_name(vfid, name, sizeof(name)),
+                    gt->info.id, what, found, expected);
+       return -EUCLEAN;
+}
+
+/**
+ * xe_sriov_pf_provision_query_vf_eq() - Query VF's execution quantum.
+ * @xe: the PF &xe_device
+ * @vfid: the VF identifier
+ * @eq: placeholder for the returned execution quantum in [ms]
+ *
+ * Query VF's execution quantum (EQ) provisioning from all tiles/GTs.
+ * If values across tiles/GTs are inconsistent then -EUCLEAN error will be returned.
+ *
+ * This function can only be called on PF.
+ *
+ * Return: 0 on success or a negative error code on failure.
+ */
+int xe_sriov_pf_provision_query_vf_eq(struct xe_device *xe, unsigned int vfid, u32 *eq)
+{
+       struct xe_gt *gt;
+       unsigned int id;
+       int count = 0;
+       u32 value;
+
+       guard(mutex)(xe_sriov_pf_master_mutex(xe));
+
+       for_each_gt(gt, xe, id) {
+               value = xe_gt_sriov_pf_config_get_exec_quantum_locked(gt, vfid);
+               if (!count++)
+                       *eq = value;
+               else if (value != *eq)
+                       return pf_report_unclean(gt, vfid, "EQ", value, *eq);
+       }
+
+       return !count ? -ENODATA : 0;
+}
+
+/**
+ * xe_sriov_pf_provision_apply_vf_pt() - Change VF's preemption timeout.
+ * @xe: the PF &xe_device
+ * @vfid: the VF identifier
+ * @pt: preemption timeout in [us] to set
+ *
+ * Change VF's preemption timeout (PT) provisioning on all tiles/GTs.
+ *
+ * This function can only be called on PF.
+ *
+ * Return: 0 on success or a negative error code on failure.
+ */
+int xe_sriov_pf_provision_apply_vf_pt(struct xe_device *xe, unsigned int vfid, u32 pt)
+{
+       struct xe_gt *gt;
+       unsigned int id;
+       int result = 0;
+       int err;
+
+       guard(mutex)(xe_sriov_pf_master_mutex(xe));
+
+       for_each_gt(gt, xe, id) {
+               err = xe_gt_sriov_pf_config_set_preempt_timeout_locked(gt, vfid, pt);
+               result = result ?: err;
+       }
+
+       return result;
+}
+
+/**
+ * xe_sriov_pf_provision_query_vf_pt() - Query VF's preemption timeout.
+ * @xe: the PF &xe_device
+ * @vfid: the VF identifier
+ * @pt: placeholder for the returned preemption timeout in [us]
+ *
+ * Query VF's preemption timeout (PT) provisioning from all tiles/GTs.
+ * If values across tiles/GTs are inconsistent then -EUCLEAN error will be returned.
+ *
+ * This function can only be called on PF.
+ *
+ * Return: 0 on success or a negative error code on failure.
+ */
+int xe_sriov_pf_provision_query_vf_pt(struct xe_device *xe, unsigned int vfid, u32 *pt)
+{
+       struct xe_gt *gt;
+       unsigned int id;
+       int count = 0;
+       u32 value;
+
+       guard(mutex)(xe_sriov_pf_master_mutex(xe));
+
+       for_each_gt(gt, xe, id) {
+               value = xe_gt_sriov_pf_config_get_preempt_timeout_locked(gt, vfid);
+               if (!count++)
+                       *pt = value;
+               else if (value != *pt)
+                       return pf_report_unclean(gt, vfid, "PT", value, *pt);
+       }
+
+       return !count ? -ENODATA : 0;
+}

diff --git a/drivers/gpu/drm/xe/xe_sriov_pf_provision.h b/drivers/gpu/drm/xe/xe_sriov_pf_provision.h
index cf3657a32e90c0bfe5d42c6df49bf9b13b6c7bae..cb81b5880930fbc5a205b5a85edeea9e32b973cd 100644 (file)
--- a/drivers/gpu/drm/xe/xe_sriov_pf_provision.h
+++ b/drivers/gpu/drm/xe/xe_sriov_pf_provision.h
@@ -6,10 +6,18 @@
 #ifndef _XE_SRIOV_PF_PROVISION_H_
 #define _XE_SRIOV_PF_PROVISION_H_
 
+#include <linux/types.h>
+
 #include "xe_sriov_pf_provision_types.h"
 
 struct xe_device;
 
+int xe_sriov_pf_provision_apply_vf_eq(struct xe_device *xe, unsigned int vfid, u32 eq);
+int xe_sriov_pf_provision_query_vf_eq(struct xe_device *xe, unsigned int vfid, u32 *eq);
+
+int xe_sriov_pf_provision_apply_vf_pt(struct xe_device *xe, unsigned int vfid, u32 pt);
+int xe_sriov_pf_provision_query_vf_pt(struct xe_device *xe, unsigned int vfid, u32 *pt);
+
 int xe_sriov_pf_provision_vfs(struct xe_device *xe, unsigned int num_vfs);
 int xe_sriov_pf_unprovision_vfs(struct xe_device *xe, unsigned int num_vfs);
 

diff --git a/drivers/gpu/drm/xe/xe_sriov_pf_sysfs.c b/drivers/gpu/drm/xe/xe_sriov_pf_sysfs.c
index 439a0cd02a864d6746f024e5bdd813329d8fbb20..f12d6752e9f1e74a56b81bcf3d9126162f854b97 100644 (file)
--- a/drivers/gpu/drm/xe/xe_sriov_pf_sysfs.c
+++ b/drivers/gpu/drm/xe/xe_sriov_pf_sysfs.c
@@ -13,6 +13,7 @@
 #include "xe_sriov.h"
 #include "xe_sriov_pf.h"
 #include "xe_sriov_pf_helpers.h"
+#include "xe_sriov_pf_provision.h"
 #include "xe_sriov_pf_sysfs.h"
 #include "xe_sriov_printk.h"
 
@@ -23,10 +24,14 @@
  *     ├── ...
  *     ├── pf/
  *     │   ├── ...
- *     │   └── ...
+ *     │   └── profile
+ *     │       ├── exec_quantum_ms
+ *     │       └── preempt_timeout_us
  *     ├── vf1/
  *     │   ├── ...
- *     │   └── ...
+ *     │   └── profile
+ *     │       ├── exec_quantum_ms
+ *     │       └── preempt_timeout_us
  *     ├── vf2/
  *     :
  *     └── vfN/
@@ -85,7 +90,52 @@ static const struct attribute_group *xe_sriov_dev_attr_groups[] = {
 
 /* and VF-level attributes go here */
 
+#define DEFINE_SIMPLE_PROVISIONING_SRIOV_VF_ATTR(NAME, ITEM, TYPE, FORMAT)             \
+static ssize_t xe_sriov_vf_attr_##NAME##_show(struct xe_device *xe, unsigned int vfid, \
+                                             char *buf)                                \
+{                                                                                      \
+       TYPE value = 0;                                                                 \
+       int err;                                                                        \
+                                                                                       \
+       err = xe_sriov_pf_provision_query_vf_##ITEM(xe, vfid, &value);                  \
+       if (err)                                                                        \
+               return err;                                                             \
+                                                                                       \
+       return sysfs_emit(buf, FORMAT, value);                                          \
+}                                                                                      \
+                                                                                       \
+static ssize_t xe_sriov_vf_attr_##NAME##_store(struct xe_device *xe, unsigned int vfid,        \
+                                              const char *buf, size_t count)           \
+{                                                                                      \
+       TYPE value;                                                                     \
+       int err;                                                                        \
+                                                                                       \
+       err = kstrto##TYPE(buf, 0, &value);                                             \
+       if (err)                                                                        \
+               return err;                                                             \
+                                                                                       \
+       err = xe_sriov_pf_provision_apply_vf_##ITEM(xe, vfid, value);                   \
+       return err ?: count;                                                            \
+}                                                                                      \
+                                                                                       \
+static XE_SRIOV_VF_ATTR(NAME)
+
+DEFINE_SIMPLE_PROVISIONING_SRIOV_VF_ATTR(exec_quantum_ms, eq, u32, "%u\n");
+DEFINE_SIMPLE_PROVISIONING_SRIOV_VF_ATTR(preempt_timeout_us, pt, u32, "%u\n");
+
+static struct attribute *profile_vf_attrs[] = {
+       &xe_sriov_vf_attr_exec_quantum_ms.attr,
+       &xe_sriov_vf_attr_preempt_timeout_us.attr,
+       NULL
+};
+
+static const struct attribute_group profile_vf_attr_group = {
+       .name = "profile",
+       .attrs = profile_vf_attrs,
+};
+
 static const struct attribute_group *xe_sriov_vf_attr_groups[] = {
+       &profile_vf_attr_group,
        NULL
 };