[PATCH 06/16] drm/i915/vm_bind: Support for VM private BOs
Niranjana Vishwanathapura
niranjana.vishwanathapura at intel.com
Thu Sep 29 14:28:18 UTC 2022
On Wed, Sep 28, 2022 at 06:54:27PM +0100, Matthew Auld wrote:
>On 28/09/2022 07:19, Niranjana Vishwanathapura wrote:
>>Each VM creates a root_obj and shares it with all of its private objects
>>to use it as dma_resv object. This has a performance advantage as it
>>requires a single dma_resv object update for all private BOs vs list of
>>dma_resv objects update for shared BOs, in the execbuf path.
>>
>>VM private BOs can be only mapped on specified VM and cannot be dmabuf
>>exported. Also, they are supported only in vm_bind mode.
>>
>>Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura at intel.com>
>>Signed-off-by: Andi Shyti <andi.shyti at linux.intel.com>
>>---
>> drivers/gpu/drm/i915/gem/i915_gem_create.c | 41 ++++++++++++++++++-
>> drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c | 6 +++
>> .../gpu/drm/i915/gem/i915_gem_execbuffer.c | 4 ++
>> drivers/gpu/drm/i915/gem/i915_gem_object.c | 3 ++
>> .../gpu/drm/i915/gem/i915_gem_object_types.h | 3 ++
>> drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 3 ++
>> .../drm/i915/gem/i915_gem_vm_bind_object.c | 9 ++++
>> drivers/gpu/drm/i915/gt/intel_gtt.c | 4 ++
>> drivers/gpu/drm/i915/gt/intel_gtt.h | 2 +
>> drivers/gpu/drm/i915/i915_vma.c | 1 +
>> drivers/gpu/drm/i915/i915_vma_types.h | 2 +
>> include/uapi/drm/i915_drm.h | 30 ++++++++++++++
>> 12 files changed, 106 insertions(+), 2 deletions(-)
>>
>>diff --git a/drivers/gpu/drm/i915/gem/i915_gem_create.c b/drivers/gpu/drm/i915/gem/i915_gem_create.c
>>index 4aa7b5582b8e..692d95ef5d3e 100644
>>--- a/drivers/gpu/drm/i915/gem/i915_gem_create.c
>>+++ b/drivers/gpu/drm/i915/gem/i915_gem_create.c
>>@@ -11,6 +11,7 @@
>> #include "pxp/intel_pxp.h"
>> #include "i915_drv.h"
>>+#include "i915_gem_context.h"
>> #include "i915_gem_create.h"
>> #include "i915_trace.h"
>> #include "i915_user_extensions.h"
>>@@ -252,6 +253,7 @@ struct create_ext {
>> unsigned int n_placements;
>> unsigned int placement_mask;
>> unsigned long flags;
>>+ u32 vm_id;
>> };
>> static void repr_placements(char *buf, size_t size,
>>@@ -401,9 +403,24 @@ static int ext_set_protected(struct i915_user_extension __user *base, void *data
>> return 0;
>> }
>>+static int ext_set_vm_private(struct i915_user_extension __user *base,
>>+ void *data)
>>+{
>>+ struct drm_i915_gem_create_ext_vm_private ext;
>>+ struct create_ext *ext_data = data;
>>+
>>+ if (copy_from_user(&ext, base, sizeof(ext)))
>>+ return -EFAULT;
>>+
>>+ ext_data->vm_id = ext.vm_id;
>>+
>>+ return 0;
>>+}
>>+
>> static const i915_user_extension_fn create_extensions[] = {
>> [I915_GEM_CREATE_EXT_MEMORY_REGIONS] = ext_set_placements,
>> [I915_GEM_CREATE_EXT_PROTECTED_CONTENT] = ext_set_protected,
>>+ [I915_GEM_CREATE_EXT_VM_PRIVATE] = ext_set_vm_private,
>> };
>> /**
>>@@ -419,6 +436,7 @@ i915_gem_create_ext_ioctl(struct drm_device *dev, void *data,
>> struct drm_i915_private *i915 = to_i915(dev);
>> struct drm_i915_gem_create_ext *args = data;
>> struct create_ext ext_data = { .i915 = i915 };
>>+ struct i915_address_space *vm = NULL;
>> struct drm_i915_gem_object *obj;
>> int ret;
>>@@ -432,6 +450,12 @@ i915_gem_create_ext_ioctl(struct drm_device *dev, void *data,
>> if (ret)
>> return ret;
>>+ if (ext_data.vm_id) {
>>+ vm = i915_gem_vm_lookup(file->driver_priv, ext_data.vm_id);
>>+ if (unlikely(!vm))
>>+ return -ENOENT;
>>+ }
>>+
>> if (!ext_data.n_placements) {
>> ext_data.placements[0] =
>> intel_memory_region_by_type(i915, INTEL_MEMORY_SYSTEM);
>>@@ -458,8 +482,21 @@ i915_gem_create_ext_ioctl(struct drm_device *dev, void *data,
>> ext_data.placements,
>> ext_data.n_placements,
>> ext_data.flags);
>>- if (IS_ERR(obj))
>>- return PTR_ERR(obj);
>>+ if (IS_ERR(obj)) {
>>+ ret = PTR_ERR(obj);
>>+ goto vm_put;
>>+ }
>>+
>>+ if (vm) {
>>+ obj->base.resv = vm->root_obj->base.resv;
>>+ obj->priv_root = i915_gem_object_get(vm->root_obj);
>>+ i915_vm_put(vm);
>>+ }
>> return i915_gem_publish(obj, file, &args->size, &args->handle);
>>+vm_put:
>>+ if (vm)
>>+ i915_vm_put(vm);
>>+
>>+ return ret;
>> }
>>diff --git a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
>>index f5062d0c6333..6433173c3e84 100644
>>--- a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
>>+++ b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
>>@@ -218,6 +218,12 @@ struct dma_buf *i915_gem_prime_export(struct drm_gem_object *gem_obj, int flags)
>> struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
>> DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
>>+ if (obj->priv_root) {
>>+ drm_dbg(obj->base.dev,
>>+ "Exporting VM private objects is not allowed\n");
>>+ return ERR_PTR(-EINVAL);
>>+ }
>>+
>> exp_info.ops = &i915_dmabuf_ops;
>> exp_info.size = gem_obj->size;
>> exp_info.flags = flags;
>>diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
>>index f85f10cf9c34..33d989a20227 100644
>>--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
>>+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
>>@@ -864,6 +864,10 @@ static struct i915_vma *eb_lookup_vma(struct i915_execbuffer *eb, u32 handle)
>> if (unlikely(!obj))
>> return ERR_PTR(-ENOENT);
>>+ /* VM private objects are not supported here */
>>+ if (obj->priv_root)
>>+ return ERR_PTR(-EINVAL);
>>+
>> /*
>> * If the user has opted-in for protected-object tracking, make
>> * sure the object encryption can be used.
>>diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.c b/drivers/gpu/drm/i915/gem/i915_gem_object.c
>>index 7ff9c7877bec..271ad62b3245 100644
>>--- a/drivers/gpu/drm/i915/gem/i915_gem_object.c
>>+++ b/drivers/gpu/drm/i915/gem/i915_gem_object.c
>>@@ -108,6 +108,9 @@ void i915_gem_object_init(struct drm_i915_gem_object *obj,
>> */
>> void __i915_gem_object_fini(struct drm_i915_gem_object *obj)
>> {
>>+ if (obj->priv_root && !obj->ttm.created)
>>+ i915_gem_object_put(obj->priv_root);
>>+
>> mutex_destroy(&obj->mm.get_page.lock);
>> mutex_destroy(&obj->mm.get_dma_page.lock);
>> dma_resv_fini(&obj->base._resv);
>>diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
>>index 40305e2bcd49..2e79cfc0b06a 100644
>>--- a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
>>+++ b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
>>@@ -241,6 +241,9 @@ struct drm_i915_gem_object {
>> const struct drm_i915_gem_object_ops *ops;
>>+ /* For VM private BO, points to root_obj in VM. NULL otherwise */
>>+ struct drm_i915_gem_object *priv_root;
>>+
>> struct {
>> /**
>> * @vma.lock: protect the list/tree of vmas
>>diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
>>index e3fc38dd5db0..b4d8cb33df8e 100644
>>--- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
>>+++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
>>@@ -1153,6 +1153,9 @@ void i915_ttm_bo_destroy(struct ttm_buffer_object *bo)
>> mutex_destroy(&obj->ttm.get_io_page.lock);
>> if (obj->ttm.created) {
>>+ if (obj->priv_root)
>>+ i915_gem_object_put(obj->priv_root);
>>+
>> /*
>> * We freely manage the shrinker LRU outide of the mm.pages life
>> * cycle. As a result when destroying the object we should be
>>diff --git a/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c b/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c
>>index e529162abd2c..809c78455d2e 100644
>>--- a/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c
>>+++ b/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c
>>@@ -86,6 +86,7 @@ static void i915_gem_vm_bind_remove(struct i915_vma *vma, bool release_obj)
>> lockdep_assert_held(&vma->vm->vm_bind_lock);
>> list_del_init(&vma->vm_bind_link);
>>+ list_del_init(&vma->non_priv_vm_bind_link);
>> i915_vm_bind_it_remove(vma, &vma->vm->va);
>> /* Release object */
>>@@ -205,6 +206,11 @@ static int i915_gem_vm_bind_obj(struct i915_address_space *vm,
>> goto put_obj;
>> }
>>+ if (obj->priv_root && obj->priv_root != vm->root_obj) {
>>+ ret = -EINVAL;
>>+ goto put_obj;
>>+ }
>>+
>> ret = mutex_lock_interruptible(&vm->vm_bind_lock);
>> if (ret)
>> goto put_obj;
>>@@ -231,6 +237,9 @@ static int i915_gem_vm_bind_obj(struct i915_address_space *vm,
>> list_add_tail(&vma->vm_bind_link, &vm->vm_bound_list);
>> i915_vm_bind_it_insert(vma, &vm->va);
>>+ if (!obj->priv_root)
>>+ list_add_tail(&vma->non_priv_vm_bind_link,
>>+ &vm->non_priv_vm_bind_list);
>> /* Hold object reference until vm_unbind */
>> i915_gem_object_get(vma->obj);
>>diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.c b/drivers/gpu/drm/i915/gt/intel_gtt.c
>>index 0daa70c6ed0d..da4f9dee0397 100644
>>--- a/drivers/gpu/drm/i915/gt/intel_gtt.c
>>+++ b/drivers/gpu/drm/i915/gt/intel_gtt.c
>>@@ -177,6 +177,7 @@ int i915_vm_lock_objects(struct i915_address_space *vm,
>> void i915_address_space_fini(struct i915_address_space *vm)
>> {
>> drm_mm_takedown(&vm->mm);
>>+ i915_gem_object_put(vm->root_obj);
>> GEM_BUG_ON(!RB_EMPTY_ROOT(&vm->va.rb_root));
>> mutex_destroy(&vm->vm_bind_lock);
>> }
>>@@ -292,6 +293,9 @@ void i915_address_space_init(struct i915_address_space *vm, int subclass)
>> INIT_LIST_HEAD(&vm->vm_bind_list);
>> INIT_LIST_HEAD(&vm->vm_bound_list);
>> mutex_init(&vm->vm_bind_lock);
>>+ INIT_LIST_HEAD(&vm->non_priv_vm_bind_list);
>>+ vm->root_obj = i915_gem_object_create_internal(vm->i915, PAGE_SIZE);
>>+ GEM_BUG_ON(IS_ERR(vm->root_obj));
>> }
>> void *__px_vaddr(struct drm_i915_gem_object *p)
>>diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.h b/drivers/gpu/drm/i915/gt/intel_gtt.h
>>index b52061858161..3f2e87d3bf34 100644
>>--- a/drivers/gpu/drm/i915/gt/intel_gtt.h
>>+++ b/drivers/gpu/drm/i915/gt/intel_gtt.h
>>@@ -275,6 +275,8 @@ struct i915_address_space {
>> struct list_head vm_bound_list;
>> /* @va: tree of persistent vmas */
>> struct rb_root_cached va;
>>+ struct list_head non_priv_vm_bind_list;
>>+ struct drm_i915_gem_object *root_obj;
>> /* Global GTT */
>> bool is_ggtt:1;
>>diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
>>index 33f910473263..89c276163916 100644
>>--- a/drivers/gpu/drm/i915/i915_vma.c
>>+++ b/drivers/gpu/drm/i915/i915_vma.c
>>@@ -240,6 +240,7 @@ vma_create(struct drm_i915_gem_object *obj,
>> mutex_unlock(&vm->mutex);
>> INIT_LIST_HEAD(&vma->vm_bind_link);
>>+ INIT_LIST_HEAD(&vma->non_priv_vm_bind_link);
>> return vma;
>> err_unlock:
>>diff --git a/drivers/gpu/drm/i915/i915_vma_types.h b/drivers/gpu/drm/i915/i915_vma_types.h
>>index f56ac07c6cfa..3d5ffc3e666b 100644
>>--- a/drivers/gpu/drm/i915/i915_vma_types.h
>>+++ b/drivers/gpu/drm/i915/i915_vma_types.h
>>@@ -298,6 +298,8 @@ struct i915_vma {
>> /** @vm_bind_link: node for the vm_bind related lists of vm */
>> struct list_head vm_bind_link;
>>+ /* @non_priv_vm_bind_link: Link in non-private persistent VMA list */
>>+ struct list_head non_priv_vm_bind_link;
>> /** Interval tree structures for persistent vma */
>>diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
>>index 9760564b4693..3eee3071ad60 100644
>>--- a/include/uapi/drm/i915_drm.h
>>+++ b/include/uapi/drm/i915_drm.h
>>@@ -3601,9 +3601,13 @@ struct drm_i915_gem_create_ext {
>> *
>> * For I915_GEM_CREATE_EXT_PROTECTED_CONTENT usage see
>> * struct drm_i915_gem_create_ext_protected_content.
>>+ *
>>+ * For I915_GEM_CREATE_EXT_VM_PRIVATE usage see
>>+ * struct drm_i915_gem_create_ext_vm_private.
>> */
>> #define I915_GEM_CREATE_EXT_MEMORY_REGIONS 0
>> #define I915_GEM_CREATE_EXT_PROTECTED_CONTENT 1
>>+#define I915_GEM_CREATE_EXT_VM_PRIVATE 2
>> __u64 extensions;
>> };
>>@@ -3721,6 +3725,32 @@ struct drm_i915_gem_create_ext_protected_content {
>> /* ID of the protected content session managed by i915 when PXP is active */
>> #define I915_PROTECTED_CONTENT_DEFAULT_SESSION 0xf
>>+/**
>>+ * struct drm_i915_gem_create_ext_vm_private - Extension to make the object
>>+ * private to the specified VM.
>>+ *
>>+ * See struct drm_i915_gem_create_ext.
>>+ *
>>+ * By default, BOs can be mapped on multiple VMs and can also be dma-buf
>>+ * exported. Hence these BOs are referred to as Shared BOs.
>>+ * During each execbuf3 submission, the request fence must be added to the
>>+ * dma-resv fence list of all shared BOs mapped on the VM.
>>+ *
>>+ * Unlike Shared BOs, these VM private BOs can only be mapped on the VM they
>>+ * are private to and can't be dma-buf exported. All private BOs of a VM share
>>+ * the dma-resv object. Hence during each execbuf3 submission, they need only
>>+ * one dma-resv fence list updated. Thus, the fast path (where required
>>+ * mappings are already bound) submission latency is O(1) w.r.t the number of
>>+ * VM private BOs.
>>+ */
>>+struct drm_i915_gem_create_ext_vm_private {
>>+ /** @base: Extension link. See struct i915_user_extension. */
>>+ struct i915_user_extension base;
>>+
>>+ /** @vm_id: Id of the VM to which Object is private */
>>+ __u32 vm_id;
>
>Does this not leave a hole? At a glannce I would have assumed we need
>explciit __u32 pad somewhere...
>
Ok, will add the padding.
Regards,
Niranjana
>>+};
>>+
>> /**
>> * struct drm_i915_gem_vm_bind - VA to object mapping to bind.
>> *
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