On Wed, Mar 10, 2021 at 03:50:07PM -0600, Jason Ekstrand wrote: > The Vulkan driver in Mesa for Intel hardware never uses relocations if > it's running on a version of i915 that supports at least softpin which > all versions of i915 supporting Gen12 do. On the OpenGL side, Gen12+ is > only supported by iris which never uses relocations. The older i965 > driver in Mesa does use relocations but it only supports Intel hardware > through Gen11 and has been deprecated for all hardware Gen9+. The > compute driver also never uses relocations. This only leaves the media > driver which is supposed to be switching to softpin going forward. > Making softpin a requirement for all future hardware seems reasonable. > > Rejecting relocations starting with Gen12 has the benefit that we don't > have to bother supporting it on platforms with local memory. Given how > much CPU touching of memory is required for relocations, not having to > do so on platforms where not all memory is directly CPU-accessible > carries significant advantages. > > v2 (Jason Ekstrand): > - Allow TGL-LP platforms as they've already shipped > > v3 (Jason Ekstrand): > - WARN_ON platforms with LMEM support in case the check is wrong
I was asked to review of this patch. It works along with expected IGT check https://patchwork.freedesktop.org/patch/423361/?series=82954&rev=25 Before I'll give you r-b - isn't i915_gem_execbuffer2_ioctl() better place to do for loop just after copy_from_user() and check relocation_count? We have an access to exec2_list there, we know the gen so we're able to say relocations are not supported immediate, without entering i915_gem_do_execbuffer(). -- Zbigniew > > Signed-off-by: Jason Ekstrand <ja...@jlekstrand.net> > Cc: Dave Airlie <airl...@redhat.com> > Cc: Daniel Vetter <daniel.vet...@intel.com> > --- > drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c | 15 ++++++++++++--- > 1 file changed, 12 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c > b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c > index 99772f37bff60..b02dbd16bfa03 100644 > --- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c > +++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c > @@ -1764,7 +1764,8 @@ eb_relocate_vma_slow(struct i915_execbuffer *eb, struct > eb_vma *ev) > return err; > } > > -static int check_relocations(const struct drm_i915_gem_exec_object2 *entry) > +static int check_relocations(const struct i915_execbuffer *eb, > + const struct drm_i915_gem_exec_object2 *entry) > { > const char __user *addr, *end; > unsigned long size; > @@ -1774,6 +1775,14 @@ static int check_relocations(const struct > drm_i915_gem_exec_object2 *entry) > if (size == 0) > return 0; > > + /* Relocations are disallowed for all platforms after TGL-LP */ > + if (INTEL_GEN(eb->i915) >= 12 && !IS_TIGERLAKE(eb->i915)) > + return -EINVAL; > + > + /* All discrete memory platforms are Gen12 or above */ > + if (WARN_ON(HAS_LMEM(eb->i915))) > + return -EINVAL; > + > if (size > N_RELOC(ULONG_MAX)) > return -EINVAL; > > @@ -1807,7 +1816,7 @@ static int eb_copy_relocations(const struct > i915_execbuffer *eb) > if (nreloc == 0) > continue; > > - err = check_relocations(&eb->exec[i]); > + err = check_relocations(eb, &eb->exec[i]); > if (err) > goto err; > > @@ -1880,7 +1889,7 @@ static int eb_prefault_relocations(const struct > i915_execbuffer *eb) > for (i = 0; i < count; i++) { > int err; > > - err = check_relocations(&eb->exec[i]); > + err = check_relocations(eb, &eb->exec[i]); > if (err) > return err; > } > -- > 2.29.2 > > _______________________________________________ > dri-devel mailing list > dri-de...@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx
