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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 113DEC4450A for ; Thu, 16 Jul 2026 09:27:51 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 7503D10E765; Thu, 16 Jul 2026 09:27:50 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=arm.com header.i=@arm.com header.b="O47M95eY"; dkim-atps=neutral Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by gabe.freedesktop.org (Postfix) with ESMTP id 277E810E765 for ; Thu, 16 Jul 2026 09:27:49 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 1D5DC2F; Thu, 16 Jul 2026 02:27:44 -0700 (PDT) Received: from [10.1.25.27] (e122027.cambridge.arm.com [10.1.25.27]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 971893F905; Thu, 16 Jul 2026 02:27:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1784194068; bh=Bu7ZjIC+SBup0yR+cdOqgWMFq8smhDp209QQlSlWMvo=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=O47M95eYmr0OFyDmlGygS2bez5TSiKqruo6nQ48CQNiRwi6hVoOhRA3SCXPV7v9a3 xoswA382vjCxFmIoiDVdp9Fh3QRgTU6D8ZQEPNELVwlhE8XbAxKHRXCmR3lzLyaEgq Tmd0ohbLuETubEGUwRagSzniqpZNig8N16VpHgIg= Message-ID: Date: Thu, 16 Jul 2026 10:27:45 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 1/2] drm/panthor: Add vm_bind region with kbo range overlap check To: =?UTF-8?Q?Adri=C3=A1n_Larumbe?= , Boris Brezillon , Liviu Dudau , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Heiko Stuebner , Grant Likely Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org References: <20260713-vm_bind_checks-v5-0-0d2314af8d9d@collabora.com> <20260713-vm_bind_checks-v5-1-0d2314af8d9d@collabora.com> From: Steven Price Content-Language: en-GB In-Reply-To: <20260713-vm_bind_checks-v5-1-0d2314af8d9d@collabora.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On 13/07/2026 09:48, Adrián Larumbe wrote: > When a VM is created, caller has to specify the range of the address space > carve-out set aside for mapping kernel BO's. That means vm_bind mappings of > UM-exposed BO's should not intersect with that region, but at the moment > we're not checking this. > > At first, I thought of giving these values to drm_gpuvm_init() through its > reserve_{offset, range} arguments, but it turns out that is meant for VM > address spans that are not managed through the usual drm_gpuvm split/merge > circuit, so storing the end of the user VA range at VM creation time and > doing a quick check in the vm_bind ioctl path was the simplest workaround. > > The new check also makes sure vm_bind range doesn't overflow the size of a > 64-bit unsigned integer. That was already being done further down the call > stack inside drm_gpuvm_sm_map -> drm_gpuvm_range_valid, but it's best to > fail early in the driver before GPUVM functions are invoked so that we > won't waste time allocating vm_bind context resources. > > Fixes: tag and reference the relevant sparse binding support commit. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Can you dig out the relevant commit ;) > Fixes: 647810ec2476 ("drm/panthor: Add the MMU/VM logical block") > Reviewed-by: Boris Brezillon > Signed-off-by: Adrián Larumbe Reviewed-by: Steven Price Thanks, Steve > --- > drivers/gpu/drm/panthor/panthor_mmu.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/panthor/panthor_mmu.c > index 31cc57029c12..910c8e579770 100644 > --- a/drivers/gpu/drm/panthor/panthor_mmu.c > +++ b/drivers/gpu/drm/panthor/panthor_mmu.c > @@ -310,6 +310,9 @@ struct panthor_vm { > u64 end; > } kernel_auto_va; > > + /** @user_va_range: Upper boundary of VAs VM users can map objects against. */ > + u64 user_va_range; > + > /** @as: Address space related fields. */ > struct { > /** > @@ -2893,6 +2896,8 @@ panthor_vm_create(struct panthor_device *ptdev, bool for_mcu, > va_range = full_va_range; > } > > + vm->user_va_range = kernel_va_start; > + > mutex_init(&vm->mm_lock); > drm_mm_init(&vm->mm, kernel_va_start, kernel_va_size); > vm->kernel_auto_va.start = auto_kernel_va_start; > @@ -2981,6 +2986,10 @@ panthor_vm_bind_prepare_op_ctx(struct drm_file *file, > if (!IS_ALIGNED(op->va | op->size | op->bo_offset, vm_pgsz)) > return -EINVAL; > > + /* We don't allow mappings that overlap with kbo's reserved range */ > + if (range_overflows(op->va, op->size, vm->user_va_range)) > + return -EINVAL; > + > switch (op->flags & DRM_PANTHOR_VM_BIND_OP_TYPE_MASK) { > case DRM_PANTHOR_VM_BIND_OP_TYPE_MAP: > if (!(op->flags & DRM_PANTHOR_VM_BIND_OP_MAP_SPARSE)) { >