mirrors/linux
2
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-05-16 03:11:11 -04:00
Code Issues Packages Projects Releases Wiki Activity

dma-buf: Always build with DMABUF_MOVE_NOTIFY

Browse Source 
DMABUF_MOVE_NOTIFY was introduced in 2018 and has been marked as
experimental and disabled by default ever since. Six years later,
all new importers implement this callback.

It is therefore reasonable to drop CONFIG_DMABUF_MOVE_NOTIFY and
always build DMABUF with support for it enabled.

Suggested-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://lore.kernel.org/r/20260124-dmabuf-revoke-v5-3-f98fca917e96@nvidia.com
Signed-off-by: Christian König <christian.koenig@amd.com>
This commit is contained in:
Leon Romanovsky
2026-01-24 21:14:15 +02:00
committed by Christian König
parent 95308225e5
commit 609fc8766d
6 changed files with 10 additions and 32 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
drivers/dma-buf/Kconfig
View File

@@ -40,18 +40,6 @@ config UDMABUF
A driver to let userspace turn memfd regions into dma-bufs.
Qemu can use this to create host dmabufs for guest framebuffers.
config DMABUF_MOVE_NOTIFY
bool "Move notify between drivers (EXPERIMENTAL)"
default n
depends on DMA_SHARED_BUFFER
help
Don't pin buffers if the dynamic DMA-buf interface is available on
both the exporter as well as the importer. This fixes a security
problem where userspace is able to pin unrestricted amounts of memory
through DMA-buf.
This is marked experimental because we don't yet have a consistent
execution context and memory management between drivers.
config DMABUF_DEBUG
bool "DMA-BUF debug checks"
depends on DMA_SHARED_BUFFER

3
drivers/dma-buf/dma-buf.c
View File

@@ -916,8 +916,7 @@ static bool
dma_buf_pin_on_map(struct dma_buf_attachment *attach)
{
return attach->dmabuf->ops->pin &&
(!dma_buf_attachment_is_dynamic(attach) ||
!IS_ENABLED(CONFIG_DMABUF_MOVE_NOTIFY));
!dma_buf_attachment_is_dynamic(attach);
}
/**

10
drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
View File

@@ -145,13 +145,9 @@ static int amdgpu_dma_buf_pin(struct dma_buf_attachment *attach)
* notifiers are disabled, only allow pinning in VRAM when move
* notiers are enabled.
*/
if (!IS_ENABLED(CONFIG_DMABUF_MOVE_NOTIFY)) {
domains &= ~AMDGPU_GEM_DOMAIN_VRAM;
} else {
list_for_each_entry(attach, &dmabuf->attachments, node)
if (!attach->peer2peer)
domains &= ~AMDGPU_GEM_DOMAIN_VRAM;
}
list_for_each_entry(attach, &dmabuf->attachments, node)
if (!attach->peer2peer)
domains &= ~AMDGPU_GEM_DOMAIN_VRAM;
if (domains & AMDGPU_GEM_DOMAIN_VRAM)
bo->flags |= AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED;

2
drivers/gpu/drm/amd/amdkfd/Kconfig
View File

@@ -27,7 +27,7 @@ config HSA_AMD_SVM
config HSA_AMD_P2P
bool "HSA kernel driver support for peer-to-peer for AMD GPU devices"
depends on HSA_AMD && PCI_P2PDMA && DMABUF_MOVE_NOTIFY
depends on HSA_AMD && PCI_P2PDMA
help
Enable peer-to-peer (P2P) communication between AMD GPUs over
the PCIe bus. This can improve performance of multi-GPU compute

3
drivers/gpu/drm/xe/tests/xe_dma_buf.c
View File

@@ -22,8 +22,7 @@ static bool p2p_enabled(struct dma_buf_test_params *params)
static bool is_dynamic(struct dma_buf_test_params *params)
{
return IS_ENABLED(CONFIG_DMABUF_MOVE_NOTIFY) && params->attach_ops &&
params->attach_ops->invalidate_mappings;
return params->attach_ops && params->attach_ops->invalidate_mappings;
}
static void check_residency(struct kunit *test, struct xe_bo *exported,

12
drivers/gpu/drm/xe/xe_dma_buf.c
View File

@@ -56,14 +56,10 @@ static int xe_dma_buf_pin(struct dma_buf_attachment *attach)
bool allow_vram = true;
int ret;
if (!IS_ENABLED(CONFIG_DMABUF_MOVE_NOTIFY)) {
allow_vram = false;
} else {
list_for_each_entry(attach, &dmabuf->attachments, node) {
if (!attach->peer2peer) {
allow_vram = false;
break;
}
list_for_each_entry(attach, &dmabuf->attachments, node) {
if (!attach->peer2peer) {
allow_vram = false;
break;
}
}