From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 94F51C12002 for ; Wed, 21 Jul 2021 19:26:45 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4DAD4610F7 for ; Wed, 21 Jul 2021 19:26:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4DAD4610F7 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=whitecape.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 2B2FB6ECE3; Wed, 21 Jul 2021 19:26:44 +0000 (UTC) X-Greylist: delayed 441 seconds by postgrey-1.36 at gabe; Wed, 21 Jul 2021 19:26:42 UTC Received: from smtp119.ord1c.emailsrvr.com (smtp119.ord1c.emailsrvr.com [108.166.43.119]) by gabe.freedesktop.org (Postfix) with ESMTPS id 9FAAB6ECE3; Wed, 21 Jul 2021 19:26:42 +0000 (UTC) X-Auth-ID: kenneth@whitecape.org Received: by smtp15.relay.ord1c.emailsrvr.com (Authenticated sender: kenneth-AT-whitecape.org) with ESMTPSA id AE7BD20245; Wed, 21 Jul 2021 15:19:19 -0400 (EDT) From: Kenneth Graunke To: intel-gfx@lists.freedesktop.org, Matthew Auld Subject: Re: [PATCH 3/4] drm/i915/userptr: Probe existence of backing struct pages upon creation Date: Wed, 21 Jul 2021 12:18:55 -0700 Message-ID: <1839899.5eojKT8Dyj@mizzik> In-Reply-To: <20210715101536.2606307-4-matthew.auld@intel.com> References: <20210715101536.2606307-1-matthew.auld@intel.com> <20210715101536.2606307-4-matthew.auld@intel.com> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart5739491.D0ShQg1dhF"; micalg="pgp-sha256"; protocol="application/pgp-signature" X-Classification-ID: 6156cfba-c837-4735-a561-4dbc9dab694c-1-1 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Thomas =?ISO-8859-1?Q?Hellstr=F6m?= , Tvrtko Ursulin , Jordan Justen , dri-devel@lists.freedesktop.org, Chris Wilson , Jason Ekstrand , Daniel Vetter Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" --nextPart5739491.D0ShQg1dhF Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="iso-8859-1"; protected-headers="v1" From: Kenneth Graunke To: intel-gfx@lists.freedesktop.org, Matthew Auld Cc: dri-devel@lists.freedesktop.org, Chris Wilson , Thomas =?ISO-8859-1?Q?Hellstr=F6m?= , Maarten Lankhorst , Tvrtko Ursulin , Jordan Justen , Jason Ekstrand , Daniel Vetter , Ramalingam C Subject: Re: [PATCH 3/4] drm/i915/userptr: Probe existence of backing struct pages upon creation Date: Wed, 21 Jul 2021 12:18:55 -0700 Message-ID: <1839899.5eojKT8Dyj@mizzik> In-Reply-To: <20210715101536.2606307-4-matthew.auld@intel.com> References: <20210715101536.2606307-1-matthew.auld@intel.com> <20210715101536.2606307-4-matthew.auld@intel.com> Thanks for this! Series is: Acked-by: Kenneth Graunke https://gitlab.freedesktop.org/kwg/mesa/-/commits/iris-userptr-probe is an untested branch that uses the new probe API in Mesa. On Thursday, July 15, 2021 3:15:35 AM PDT Matthew Auld wrote: > From: Chris Wilson >=20 > Jason Ekstrand requested a more efficient method than userptr+set-domain > to determine if the userptr object was backed by a complete set of pages > upon creation. To be more efficient than simply populating the userptr > using get_user_pages() (as done by the call to set-domain or execbuf), > we can walk the tree of vm_area_struct and check for gaps or vma not > backed by struct page (VM_PFNMAP). The question is how to handle > VM_MIXEDMAP which may be either struct page or pfn backed... >=20 > With discrete are going to drop support for set_domain(), so offering a > way to probe the pages, without having to resort to dummy batches has > been requested. >=20 > v2: > - add new query param for the PROPBE flag, so userspace can easily > check if the kernel supports it(Jason). > - use mmap_read_{lock, unlock}. > - add some kernel-doc. >=20 > Testcase: igt/gem_userptr_blits/probe > Signed-off-by: Chris Wilson > Signed-off-by: Matthew Auld > Cc: Thomas Hellstr=F6m > Cc: Maarten Lankhorst > Cc: Tvrtko Ursulin > Cc: Jordan Justen > Cc: Kenneth Graunke > Cc: Jason Ekstrand > Cc: Daniel Vetter > Cc: Ramalingam C > --- > drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 40 ++++++++++++++++++++- > drivers/gpu/drm/i915/i915_getparam.c | 3 ++ > include/uapi/drm/i915_drm.h | 18 ++++++++++ > 3 files changed, 60 insertions(+), 1 deletion(-) >=20 > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c b/drivers/gpu/dr= m/i915/gem/i915_gem_userptr.c > index 56edfeff8c02..fd6880328596 100644 > --- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c > +++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c > @@ -422,6 +422,33 @@ static const struct drm_i915_gem_object_ops i915_gem= _userptr_ops =3D { > =20 > #endif > =20 > +static int > +probe_range(struct mm_struct *mm, unsigned long addr, unsigned long len) > +{ > + const unsigned long end =3D addr + len; > + struct vm_area_struct *vma; > + int ret =3D -EFAULT; > + > + mmap_read_lock(mm); > + for (vma =3D find_vma(mm, addr); vma; vma =3D vma->vm_next) { > + if (vma->vm_start > addr) > + break; > + > + if (vma->vm_flags & (VM_PFNMAP | VM_MIXEDMAP)) > + break; > + > + if (vma->vm_end >=3D end) { > + ret =3D 0; > + break; > + } > + > + addr =3D vma->vm_end; > + } > + mmap_read_unlock(mm); > + > + return ret; > +} > + > /* > * Creates a new mm object that wraps some normal memory from the process > * context - user memory. > @@ -477,7 +504,8 @@ i915_gem_userptr_ioctl(struct drm_device *dev, > } > =20 > if (args->flags & ~(I915_USERPTR_READ_ONLY | > - I915_USERPTR_UNSYNCHRONIZED)) > + I915_USERPTR_UNSYNCHRONIZED | > + I915_USERPTR_PROBE)) > return -EINVAL; > =20 > if (i915_gem_object_size_2big(args->user_size)) > @@ -504,6 +532,16 @@ i915_gem_userptr_ioctl(struct drm_device *dev, > return -ENODEV; > } > =20 > + if (args->flags & I915_USERPTR_PROBE) { > + /* > + * Check that the range pointed to represents real struct > + * pages and not iomappings (at this moment in time!) > + */ > + ret =3D probe_range(current->mm, args->user_ptr, args->user_size); > + if (ret) > + return ret; > + } > + > #ifdef CONFIG_MMU_NOTIFIER > obj =3D i915_gem_object_alloc(); > if (obj =3D=3D NULL) > diff --git a/drivers/gpu/drm/i915/i915_getparam.c b/drivers/gpu/drm/i915/= i915_getparam.c > index 24e18219eb50..d6d2e1a10d14 100644 > --- a/drivers/gpu/drm/i915/i915_getparam.c > +++ b/drivers/gpu/drm/i915/i915_getparam.c > @@ -163,6 +163,9 @@ int i915_getparam_ioctl(struct drm_device *dev, void = *data, > case I915_PARAM_PERF_REVISION: > value =3D i915_perf_ioctl_version(); > break; > + case I915_PARAM_HAS_USERPTR_PROBE: > + value =3D true; > + break; > default: > DRM_DEBUG("Unknown parameter %d\n", param->param); > return -EINVAL; > diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h > index e20eeeca7a1c..2e4112bf4d38 100644 > --- a/include/uapi/drm/i915_drm.h > +++ b/include/uapi/drm/i915_drm.h > @@ -674,6 +674,9 @@ typedef struct drm_i915_irq_wait { > */ > #define I915_PARAM_HAS_EXEC_TIMELINE_FENCES 55 > =20 > +/* Query if the kernel supports the I915_USERPTR_PROBE flag. */ > +#define I915_PARAM_HAS_USERPTR_PROBE 56 > + > /* Must be kept compact -- no holes and well documented */ > =20 > typedef struct drm_i915_getparam { > @@ -2178,12 +2181,27 @@ struct drm_i915_gem_userptr { > * through the GTT. If the HW can't support readonly access, an error is > * returned. > * > + * I915_USERPTR_PROBE: > + * > + * Probe the provided @user_ptr range and validate that the @user_ptr is > + * indeed pointing to normal memory and that the range is also valid. > + * For example if some garbage address is given to the kernel, then this > + * should complain. > + * > + * Returns -EFAULT if the probe failed. > + * > + * Note that this doesn't populate the backing pages. > + * > + * The kernel supports this feature if I915_PARAM_HAS_USERPTR_PROBE > + * returns a non-zero value. > + * > * I915_USERPTR_UNSYNCHRONIZED: > * > * NOT USED. Setting this flag will result in an error. > */ > __u32 flags; > #define I915_USERPTR_READ_ONLY 0x1 > +#define I915_USERPTR_PROBE 0x2 > #define I915_USERPTR_UNSYNCHRONIZED 0x80000000 > /** > * @handle: Returned handle for the object. >=20 --nextPart5739491.D0ShQg1dhF Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part. 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