From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id E1C504119E6 for ; Wed, 29 Jul 2026 15:35:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785339328; cv=none; b=LUdbPoGq2d1X2I36SPvg1AkjW7Rx7eY06aQDRyh2wTAwYgG7MC2AoshqgS+kILbuh1B7kgQ+wZxMW55vhW7ku8puJrEgwtuErvpxEyMdyunGDOgVUWWGUdr1CAGmFLwL2pXdfA/BMW0aP+XzOgTm2C/m07AjskLlxNVSeHYODXg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785339328; c=relaxed/simple; bh=A9brKcdT9wwXKY8x1FMedMH2NJeeysPM9WP7OtXM6K0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=aig7783ESOtazaXUACHO6szSqUsn/2aOQRSZx/XQoBqOCzXaUL3pI/53InPiFXV+1e7YxNiVSqfqq4o3SZ7/ei4oGHMfQZ5gcicRBFXOi9+r1ZT2ZbqtdDBLXmf6Fi9TbCKEIc4puMAvcQ8/bxpKHp8QV5o85fJPRekj73LaciI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=lfttkp2q; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="lfttkp2q" 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 C6F761684; Wed, 29 Jul 2026 08:35:21 -0700 (PDT) Received: from [10.57.87.210] (unknown [10.57.87.210]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id EED2F3F763; Wed, 29 Jul 2026 08:35:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1785339325; bh=A9brKcdT9wwXKY8x1FMedMH2NJeeysPM9WP7OtXM6K0=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=lfttkp2qHpY4WOt8pxF0/Zwxe2AXNInkAoeGpGMlrVi4LTOHAC0LB7ixqYKxLhFZg AKLl3KnlL9Od/IjxmkESk2iIKqeG7bYK9vDIKSY0Mkn0qU+xdPd02JlwQdf8U+H4r2 LoHOyujpjzk1ILZzSoBEfVmhlMLRtH4IxUEt9X8c= Message-ID: Date: Wed, 29 Jul 2026 16:35:22 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v6 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: <20260720-vm_bind_checks-v6-0-c2c7dbe93a73@collabora.com> <20260720-vm_bind_checks-v6-1-c2c7dbe93a73@collabora.com> From: Steven Price Content-Language: en-GB In-Reply-To: <20260720-vm_bind_checks-v6-1-c2c7dbe93a73@collabora.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 20/07/2026 16:48, 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: 12cf826bf1dd ("drm/panthor: Support sparse mappings") > Fixes: 647810ec2476 ("drm/panthor: Add the MMU/VM logical block") > Reviewed-by: Boris Brezillon > Signed-off-by: Adrián Larumbe Reviewed-by: Steven Price I'll push both patches to drm-misc-next. 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 f45ef5824ff2..80a1dac40a6a 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 { > /** > @@ -2892,6 +2895,8 @@ 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; > @@ -2980,6 +2985,10 @@ 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)) { >