| Message ID | 20211018174508.2137279-5-matthew.auld@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/9] drm/i915: mark dmabuf objects as ALLOC_USER | expand |
On 10/18/21 19:45, Matthew Auld wrote: > Even though userptr objects are always coherent with the GPU, with no > way for userspace to change this with the set_caching ioctl, even on > non-LLC platforms, there is still the 'Bypass LCC' mocs setting, which > might permit reading the contents of main memory directly. > > Signed-off-by: Matthew Auld <matthew.auld@intel.com> > Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> > --- > drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c > index 887aca9e8dd2..3173c9f9a040 100644 > --- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c > +++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c > @@ -165,8 +165,11 @@ static int i915_gem_userptr_get_pages(struct drm_i915_gem_object *obj) > goto err; > } > > - sg_page_sizes = i915_sg_dma_sizes(st->sgl); > + WARN_ON_ONCE(!(obj->cache_coherent & I915_BO_CACHE_COHERENT_FOR_WRITE)); > + if (i915_gem_object_can_bypass_llc(obj)) > + obj->cache_dirty = true; > > + sg_page_sizes = i915_sg_dma_sizes(st->sgl); > __i915_gem_object_set_pages(obj, st, sg_page_sizes); > > return 0;
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c index 887aca9e8dd2..3173c9f9a040 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c @@ -165,8 +165,11 @@ static int i915_gem_userptr_get_pages(struct drm_i915_gem_object *obj) goto err; } - sg_page_sizes = i915_sg_dma_sizes(st->sgl); + WARN_ON_ONCE(!(obj->cache_coherent & I915_BO_CACHE_COHERENT_FOR_WRITE)); + if (i915_gem_object_can_bypass_llc(obj)) + obj->cache_dirty = true; + sg_page_sizes = i915_sg_dma_sizes(st->sgl); __i915_gem_object_set_pages(obj, st, sg_page_sizes); return 0;
Even though userptr objects are always coherent with the GPU, with no way for userspace to change this with the set_caching ioctl, even on non-LLC platforms, there is still the 'Bypass LCC' mocs setting, which might permit reading the contents of main memory directly. Signed-off-by: Matthew Auld <matthew.auld@intel.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> --- drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)