As a POC, add an xe_madvise_prefer_devmem IOCTL so that the user
can set the preferred pagemap to migrate to for a given memory
region (in this POC, the memory region is the whole GPU VM).
This is intended to be replaced by a proper madvise IOCTL, probably
with improved functionality
Signed-off-by: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx>
---
drivers/gpu/drm/xe/xe_device.c | 2 +
drivers/gpu/drm/xe/xe_svm.c | 72 ++++++++++++++++++++++++++++++++++
drivers/gpu/drm/xe/xe_svm.h | 9 +++++
include/uapi/drm/xe_drm.h | 10 +++++
4 files changed, 93 insertions(+)
diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c
index 160b3c189de0..a6ac699e9d12 100644
--- a/drivers/gpu/drm/xe/xe_device.c
+++ b/drivers/gpu/drm/xe/xe_device.c
@@ -196,6 +196,8 @@ static const struct drm_ioctl_desc xe_ioctls[] = {
DRM_RENDER_ALLOW),
DRM_IOCTL_DEF_DRV(XE_OBSERVATION, xe_observation_ioctl, DRM_RENDER_ALLOW),
DRM_IOCTL_DEF_DRV(XE_DEVMEM_OPEN, xe_devmem_open_ioctl, DRM_RENDER_ALLOW),
+ DRM_IOCTL_DEF_DRV(XE_MADVISE_PREFER_DEVMEM, xe_madvise_prefer_devmem_ioctl,
+ DRM_RENDER_ALLOW),
};
static long xe_drm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
diff --git a/drivers/gpu/drm/xe/xe_svm.c b/drivers/gpu/drm/xe/xe_svm.c
index ebdd27b02be7..56c2c731be27 100644
--- a/drivers/gpu/drm/xe/xe_svm.c
+++ b/drivers/gpu/drm/xe/xe_svm.c
@@ -1338,3 +1338,75 @@ void xe_svm_vma_fini(struct xe_svm_vma *svma)
svma->pref_dpagemap = NULL;
}
}
+
+/**
+ * xe_madvise_prefer_devmem_ioctl() - POC IOCTL callback implementing a rudimentary
+ * version of a madvise prefer_devmem() functionality.
+ * @dev: The struct drm_device.
+ * @data: The ioctl argurment.
+ * @file: The drm file.
+ *
+ * For the given gpu vm, look up all SVM gpu vmas and assign the preferred
+ * drm pagemap for migration to the one associated with the file-descriptor
+ * given by this function. If a negative (invalid) file descriptor is given,
+ * the function instead clears the preferred drm pagemap, meaning that at
+ * fault time, the drm pagemap associated with the same tile as the client
+ * is used.
+ *
+ * Return: %0 on success. Negative error code on failure.
+ */
+int xe_madvise_prefer_devmem_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
+{
+ struct xe_device *xe = to_xe_device(dev);
+ struct xe_file *xef = to_xe_file(file);
+ struct drm_xe_madvise_prefer_devmem *args = data;
+ struct xe_vm *vm;
+ struct drm_pagemap *dpagemap;
+ struct drm_gpuva *gpuva;
+ struct xe_vma *gvma;
+ int err = 0;
+
+ if (XE_IOCTL_DBG(xe, args->extensions) ||
+ XE_IOCTL_DBG(xe, args->reserved[0] || args->reserved[1]))
+ return -EINVAL;
+
+ vm = xe_vm_lookup(xef, args->vm_id);
+ if (XE_IOCTL_DBG(xe, !vm))
+ return -EINVAL;
+
+ if (args->devmem_fd < 0) {
+ dpagemap = NULL;
+ } else {
+ dpagemap = drm_pagemap_from_fd(args->devmem_fd);
+ if (XE_IOCTL_DBG(xe, IS_ERR(dpagemap))) {
+ err = PTR_ERR(dpagemap);
+ goto out_no_dpagemap;
+ }
+
+ if (XE_IOCTL_DBG(xe, drm_dev_is_unplugged(dpagemap->drm))) {
+ err = -ENODEV;
+ goto out_no_lock;
+ }
+ }
+
+ err = down_write_killable(&vm->lock);
+ if (err)
+ goto out_no_lock;
+
+ drm_gpuvm_for_each_va(gpuva, &vm->gpuvm) {
+ gvma = gpuva_to_vma(gpuva);
+ if (!xe_vma_is_cpu_addr_mirror(gvma))
+ continue;
+
+ if (dpagemap != gvma->svm.pref_dpagemap) {
+ drm_pagemap_put(gvma->svm.pref_dpagemap);
+ gvma->svm.pref_dpagemap = drm_pagemap_get(dpagemap);
+ }
+ }
+ up_write(&vm->lock);
+out_no_lock:
+ drm_pagemap_put(dpagemap);
+out_no_dpagemap:
+ xe_vm_put(vm);
+ return err;
+}
diff --git a/drivers/gpu/drm/xe/xe_svm.h b/drivers/gpu/drm/xe/xe_svm.h
index 4f1a9e410dad..7c076c36c1c5 100644
--- a/drivers/gpu/drm/xe/xe_svm.h
+++ b/drivers/gpu/drm/xe/xe_svm.h
@@ -146,6 +146,8 @@ static inline void xe_svm_vma_assign_dpagemap(struct xe_svm_vma *svma,
svma->pref_dpagemap = drm_pagemap_get(dpagemap);
}
+int xe_madvise_prefer_devmem_ioctl(struct drm_device *dev, void *data, struct drm_file *file);
+
#else
#include <linux/interval_tree.h>
@@ -237,6 +239,12 @@ static inline void xe_svm_notifier_unlock(struct xe_vm *vm)
#define xe_svm_vma_assign_dpagemap(...) do {} while (0)
+static inline int
+xe_madvise_prefer_devmem_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
+{
+ return -EOPNOTSUPP;
+}
+
#endif
#if IS_ENABLED(CONFIG_DRM_XE_PAGEMAP)
@@ -259,6 +267,7 @@ static inline int xe_devmem_open_ioctl(struct drm_device *dev, void *data, struc
{
return -EOPNOTSUPP;
}
+
#endif
#endif
diff --git a/include/uapi/drm/xe_drm.h b/include/uapi/drm/xe_drm.h
index bb22413713f0..d9572cfb5a10 100644
--- a/include/uapi/drm/xe_drm.h
+++ b/include/uapi/drm/xe_drm.h
@@ -103,6 +103,7 @@ extern "C" {
#define DRM_XE_WAIT_USER_FENCE 0x0a
#define DRM_XE_OBSERVATION 0x0b
#define DRM_XE_DEVMEM_OPEN 0x0c
+#define DRM_XE_MADVISE_PREFER_DEVMEM 0x0d
/* Must be kept compact -- no holes */
@@ -119,6 +120,7 @@ extern "C" {
#define DRM_IOCTL_XE_WAIT_USER_FENCE DRM_IOWR(DRM_COMMAND_BASE + DRM_XE_WAIT_USER_FENCE, struct drm_xe_wait_user_fence)
#define DRM_IOCTL_XE_OBSERVATION DRM_IOW(DRM_COMMAND_BASE + DRM_XE_OBSERVATION, struct drm_xe_observation_param)
#define DRM_IOCTL_XE_DEVMEM_OPEN DRM_IOWR(DRM_COMMAND_BASE + DRM_XE_DEVMEM_OPEN, struct drm_xe_devmem_open)
+#define DRM_IOCTL_XE_MADVISE_PREFER_DEVMEM DRM_IOW(DRM_COMMAND_BASE + DRM_XE_MADVISE_PREFER_DEVMEM, struct drm_xe_madvise_prefer_devmem)
/**
* DOC: Xe IOCTL Extensions
@@ -1990,6 +1992,14 @@ struct drm_xe_devmem_open {
__u64 reserved[2];
};
+struct drm_xe_madvise_prefer_devmem {
+ /** @extensions: Pointer to the first extension struct, if any */
+ __u64 extensions;
+ __u32 vm_id;
+ __u32 devmem_fd;
+ __u64 reserved[2];
+};
+
#if defined(__cplusplus)
}
#endif
--
2.48.1
