[PATCH v3 10/19] drm/xe: Implement madvise ioctl for xe
Ghimiray, Himal Prasad
himal.prasad.ghimiray at intel.com
Tue Jun 10 04:52:42 UTC 2025
On 31-05-2025 03:04, Matthew Brost wrote:
> On Tue, May 27, 2025 at 10:09:54PM +0530, Himal Prasad Ghimiray wrote:
>> This driver-specific ioctl enables UMDs to control the memory attributes
>> for GPU VMAs within a specified input range. If the start or end
>> addresses fall within an existing VMA, the VMA is split accordingly. The
>> attributes of the VMA are modified as provided by the users. The old
>> mappings of the VMAs are invalidated, and TLB invalidation is performed
>> if necessary.
>>
>> v2(Matthew brost)
>> - xe_vm_in_fault_mode can't be enabled by Mesa, hence allow ioctl in non
>> fault mode too
>> - fix tlb invalidation skip for same ranges in multiple op
>> - use helper for tlb invalidation
>> - use xe_svm_notifier_lock/unlock helper
>> - s/lockdep_assert_held/lockdep_assert_held_write
>> - Add kernel-doc
>>
>> Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray at intel.com>
>> ---
>> drivers/gpu/drm/xe/Makefile | 1 +
>> drivers/gpu/drm/xe/xe_device.c | 2 +
>> drivers/gpu/drm/xe/xe_vm_madvise.c | 264 +++++++++++++++++++++++++++++
>> drivers/gpu/drm/xe/xe_vm_madvise.h | 15 ++
>> 4 files changed, 282 insertions(+)
>> create mode 100644 drivers/gpu/drm/xe/xe_vm_madvise.c
>> create mode 100644 drivers/gpu/drm/xe/xe_vm_madvise.h
>>
>> diff --git a/drivers/gpu/drm/xe/Makefile b/drivers/gpu/drm/xe/Makefile
>> index c5d6681645ed..dc64bdcddfdc 100644
>> --- a/drivers/gpu/drm/xe/Makefile
>> +++ b/drivers/gpu/drm/xe/Makefile
>> @@ -117,6 +117,7 @@ xe-y += xe_bb.o \
>> xe_uc.o \
>> xe_uc_fw.o \
>> xe_vm.o \
>> + xe_vm_madvise.o \
>> xe_vram.o \
>> xe_vram_freq.o \
>> xe_vsec.o \
>> diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c
>> index d4b6e623aa48..b9791c614749 100644
>> --- a/drivers/gpu/drm/xe/xe_device.c
>> +++ b/drivers/gpu/drm/xe/xe_device.c
>> @@ -61,6 +61,7 @@
>> #include "xe_ttm_stolen_mgr.h"
>> #include "xe_ttm_sys_mgr.h"
>> #include "xe_vm.h"
>> +#include "xe_vm_madvise.h"
>> #include "xe_vram.h"
>> #include "xe_vsec.h"
>> #include "xe_wait_user_fence.h"
>> @@ -197,6 +198,7 @@ static const struct drm_ioctl_desc xe_ioctls[] = {
>> DRM_IOCTL_DEF_DRV(XE_WAIT_USER_FENCE, xe_wait_user_fence_ioctl,
>> DRM_RENDER_ALLOW),
>> DRM_IOCTL_DEF_DRV(XE_OBSERVATION, xe_observation_ioctl, DRM_RENDER_ALLOW),
>> + DRM_IOCTL_DEF_DRV(XE_MADVISE, xe_vm_madvise_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_vm_madvise.c b/drivers/gpu/drm/xe/xe_vm_madvise.c
>> new file mode 100644
>> index 000000000000..f7edefe5f6cf
>> --- /dev/null
>> +++ b/drivers/gpu/drm/xe/xe_vm_madvise.c
>> @@ -0,0 +1,264 @@
>> +// SPDX-License-Identifier: MIT
>> +/*
>> + * Copyright © 2024 Intel Corporation
>> + */
>> +
>> +#include "xe_vm_madvise.h"
>> +
>> +#include <linux/nospec.h>
>> +#include <drm/ttm/ttm_tt.h>
>> +#include <drm/xe_drm.h>
>> +
>> +#include "xe_bo.h"
>> +#include "xe_gt_tlb_invalidation.h"
>> +#include "xe_pt.h"
>> +#include "xe_svm.h"
>> +
>> +static struct xe_vma **get_vmas(struct xe_vm *vm, int *num_vmas,
>> + u64 addr, u64 range)
>> +{
>> + struct xe_vma **vmas, **__vmas;
>> + struct drm_gpuva *gpuva;
>> + int max_vmas = 8;
>> +
>> + lockdep_assert_held(&vm->lock);
>> +
>> + *num_vmas = 0;
>> + vmas = kmalloc_array(max_vmas, sizeof(*vmas), GFP_KERNEL);
>> + if (!vmas)
>> + return NULL;
>> +
>> + vm_dbg(&vm->xe->drm, "VMA's in range: start=0x%016llx, end=0x%016llx", addr, addr + range);
>> +
>> + drm_gpuvm_for_each_va_range(gpuva, &vm->gpuvm, addr, addr + range) {
>> + struct xe_vma *vma = gpuva_to_vma(gpuva);
>> +
>> + if (*num_vmas == max_vmas) {
>> + max_vmas <<= 1;
>> + __vmas = krealloc(vmas, max_vmas * sizeof(*vmas), GFP_KERNEL);
>> + if (!__vmas) {
>> + kfree(vmas);
>> + return NULL;
>> + }
>> + vmas = __vmas;
>> + }
>> +
>> + vmas[*num_vmas] = vma;
>> + (*num_vmas)++;
>> + }
>> +
>> + vm_dbg(&vm->xe->drm, "*num_vmas = %d\n", *num_vmas);
>> +
>> + if (!*num_vmas) {
>> + kfree(vmas);
>> + return NULL;
>> + }
>> +
>> + return vmas;
>> +}
>> +
>> +static int madvise_preferred_mem_loc(struct xe_device *xe, struct xe_vm *vm,
>> + struct xe_vma **vmas, int num_vmas,
>> + struct drm_xe_madvise_ops ops)
>> +{
>> + /* Implementation pending */
>> + return 0;
>> +}
>> +
>> +static int madvise_atomic(struct xe_device *xe, struct xe_vm *vm,
>> + struct xe_vma **vmas, int num_vmas,
>> + struct drm_xe_madvise_ops ops)
>> +{
>> + /* Implementation pending */
>> + return 0;
>> +}
>> +
>> +static int madvise_pat_index(struct xe_device *xe, struct xe_vm *vm,
>> + struct xe_vma **vmas, int num_vmas,
>> + struct drm_xe_madvise_ops ops)
>> +{
>> + /* Implementation pending */
>> + return 0;
>> +}
>> +
>> +static int madvise_purgeable_state(struct xe_device *xe, struct xe_vm *vm,
>> + struct xe_vma **vmas, int num_vmas,
>> + struct drm_xe_madvise_ops ops)
>> +{
>> + /* Implementation pending */
>> + return 0;
>> +}
>> +
>> +typedef int (*madvise_func)(struct xe_device *xe, struct xe_vm *vm,
>> + struct xe_vma **vmas, int num_vmas, struct drm_xe_madvise_ops ops);
>> +
>> +static const madvise_func madvise_funcs[] = {
>> + [DRM_XE_VMA_ATTR_PREFERRED_LOC] = madvise_preferred_mem_loc,
>> + [DRM_XE_VMA_ATTR_ATOMIC] = madvise_atomic,
>> + [DRM_XE_VMA_ATTR_PAT] = madvise_pat_index,
>> + [DRM_XE_VMA_ATTR_PURGEABLE_STATE] = madvise_purgeable_state,
>> +};
>> +
>> +static void xe_zap_ptes_in_madvise_range(struct xe_vm *vm, u64 start, u64 end, u8 *tile_mask)
>> +{
>> + struct drm_gpuva *gpuva;
>> + struct xe_tile *tile;
>> + u8 id;
>> +
>> + lockdep_assert_held_write(&vm->lock);
>> +
>> + if (dma_resv_wait_timeout(xe_vm_resv(vm), DMA_RESV_USAGE_BOOKKEEP,
>> + false, MAX_SCHEDULE_TIMEOUT) <= 0)
>> + XE_WARN_ON(1);
>> +
>> + *tile_mask = xe_svm_ranges_zap_ptes_in_range(vm, start, end);
>> +
>> + drm_gpuvm_for_each_va_range(gpuva, &vm->gpuvm, start, end) {
>> + struct xe_vma *vma = gpuva_to_vma(gpuva);
>> +
>> + if (xe_vma_is_cpu_addr_mirror(vma))
>> + continue;
>> +
>> + if (xe_vma_is_userptr(vma)) {
>> + WARN_ON_ONCE(!mmu_interval_check_retry
>> + (&to_userptr_vma(vma)->userptr.notifier,
>> + to_userptr_vma(vma)->userptr.notifier_seq));
>> +
>> + WARN_ON_ONCE(!dma_resv_test_signaled(xe_vm_resv(xe_vma_vm(vma)),
>> + DMA_RESV_USAGE_BOOKKEEP));
>> + }
>> +
>> + if (xe_vma_bo(vma))
>> + xe_bo_lock(xe_vma_bo(vma), false);
>> +
>> + for_each_tile(tile, vm->xe, id) {
>> + if (xe_pt_zap_ptes(tile, vma))
>> + *tile_mask |= BIT(id);
>> + }
>> +
>> + if (xe_vma_bo(vma))
>> + xe_bo_unlock(xe_vma_bo(vma));
>> + }
>> +}
>> +
>> +static int xe_vm_invalidate_madvise_range(struct xe_vm *vm, u64 start, u64 end)
>> +{
>> + u8 tile_mask = 0;
>> +
>> + xe_zap_ptes_in_madvise_range(vm, start, end, &tile_mask);
>> + if (!tile_mask)
>> + return 0;
>> +
>> + xe_device_wmb(vm->xe);
>> +
>> + return xe_vm_range_tilemask_tlb_invalidation(vm, start, end, tile_mask);
>> +}
>> +
>> +static int input_ranges_same(struct drm_xe_madvise_ops *old,
>> + struct drm_xe_madvise_ops *new)
>> +{
>> + return (new->start == old->start && new->range == old->range);
>> +}
>> +
>> +/**
>> + * xe_vm_madvise_ioctl - Handle MADVise ioctl for a VM
>> + * @dev: DRM device pointer
>> + * @data: Pointer to ioctl data (drm_xe_madvise*)
>> + * @file: DRM file pointer
>> + *
>> + * Handles the MADVISE ioctl to provide memory advice for vma's within
>> + * input range.
>> + *
>> + * Return: 0 on success or a negative error code on failure.
>> + */
>> +int xe_vm_madvise_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_ops *advs_ops;
>> + struct drm_xe_madvise *args = data;
>> + struct xe_vm *vm;
>> + struct xe_vma **vmas = NULL;
>> + int num_vmas, err = 0;
>> + int i, j, attr_type;
>> + bool needs_invalidation;
>> +
>> + if (XE_IOCTL_DBG(xe, args->num_ops < 1))
>> + return -EINVAL;
>> +
>> + vm = xe_vm_lookup(xef, args->vm_id);
>> + if (XE_IOCTL_DBG(xe, !vm))
>> + return -EINVAL;
>> +
>> + down_write(&vm->lock);
>> +
>> + if (XE_IOCTL_DBG(xe, xe_vm_is_closed_or_banned(vm))) {
>> + err = -ENOENT;
>> + goto unlock_vm;
>> + }
>> +
>> + if (args->num_ops > 1) {
>> + u64 __user *madvise_user = u64_to_user_ptr(args->vector_of_ops);
>> +
>> + advs_ops = kvmalloc_array(args->num_ops, sizeof(struct drm_xe_madvise_ops),
>> + GFP_KERNEL | __GFP_ACCOUNT |
>> + __GFP_RETRY_MAYFAIL | __GFP_NOWARN);
>> + if (!advs_ops) {
>> + err = args->num_ops > 1 ? -ENOBUFS : -ENOMEM;
>> + goto unlock_vm;
>> + }
>> +
>> + err = __copy_from_user(advs_ops, madvise_user,
>> + sizeof(struct drm_xe_madvise_ops) *
>> + args->num_ops);
>> + if (XE_IOCTL_DBG(xe, err)) {
>> + err = -EFAULT;
>> + goto free_advs_ops;
>> + }
>> + } else {
>> + advs_ops = &args->ops;
>> + }
>> +
>> + for (i = 0; i < args->num_ops; i++) {
>> + xe_vm_alloc_madvise_vma(vm, advs_ops[i].start, advs_ops[i].range);
>> +
>> + vmas = get_vmas(vm, &num_vmas, advs_ops[i].start, advs_ops[i].range);
>> + if (!vmas) {
>> + err = -ENOMEM;
>> + goto free_advs_ops;
>> + }
>> +
>> + attr_type = array_index_nospec(advs_ops[i].type, ARRAY_SIZE(madvise_funcs));
>> + err = madvise_funcs[attr_type](xe, vm, vmas, num_vmas, advs_ops[i]);
>> +
>> + kfree(vmas);
>> + vmas = NULL;
>> +
>> + if (err)
>> + goto free_advs_ops;
>> + }
>> +
>> + for (i = 0; i < args->num_ops; i++) {
>> + needs_invalidation = true;
>> + for (j = i + 1; j < args->num_ops; ++j) {
>> + if (input_ranges_same(&advs_ops[j], &advs_ops[i])) {
>> + needs_invalidation = false;
>> + break;
>> + }
>> + }
>> + if (needs_invalidation) {
>> + err = xe_vm_invalidate_madvise_range(vm, advs_ops[i].start,
>> + advs_ops[i].start + advs_ops[i].range);
>> + if (err)
>> + goto free_advs_ops;
>
> In additional to all the other comments around invalidations - you don't
> always need to issue TLB invalidations.
>
> - For pat_index, only if the VMAs pat_index changed + valid page tables
> - For atomic, only if the VMAs atomic mode changed + valid page tables +
> current placement would cause issues
> - Purgeable - never
> - Preferred placement - valid page tables + current placement != desired
> placement
>
> We likley can set a temp bit in the vfuncs in either the VMA (BO,
> userptr based) or the SVM range(s) which the invalidation func can parse
> / clear indicating an invalidation is required.
In the current implementation, I’m zapping PTEs for SVM ranges and
BO/Userptr-based VMAs within the madvise range, and issuing a TLB
invalidation for the entire madvise range. Should we instead issue TLB
invalidations at the granularity of the SVM range or the individual VMA
(BO or Userptr)? I don’t see how we can avoid TLB invalidation if some
VMAs require it and others don’t, given that we’re currently
invalidating the entire range.
>
> Matt
>
>> + }
>> + }
>> +
>> +free_advs_ops:
>> + if (args->num_ops > 1)
>> + kvfree(advs_ops);
>> +unlock_vm:
>> + up_write(&vm->lock);
>> + xe_vm_put(vm);
>> + return err;
>> +}
>> diff --git a/drivers/gpu/drm/xe/xe_vm_madvise.h b/drivers/gpu/drm/xe/xe_vm_madvise.h
>> new file mode 100644
>> index 000000000000..c5cdd058c322
>> --- /dev/null
>> +++ b/drivers/gpu/drm/xe/xe_vm_madvise.h
>> @@ -0,0 +1,15 @@
>> +/* SPDX-License-Identifier: MIT */
>> +/*
>> + * Copyright © 2024 Intel Corporation
>> + */
>> +
>> +#ifndef _XE_VM_MADVISE_H_
>> +#define _XE_VM_MADVISE_H_
>> +
>> +struct drm_device;
>> +struct drm_file;
>> +
>> +int xe_vm_madvise_ioctl(struct drm_device *dev, void *data,
>> + struct drm_file *file);
>> +
>> +#endif
>> --
>> 2.34.1
>>
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