From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sender6-op-o11.zoho.com (sender6-op-o11.zoho.com [165.173.180.11]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 69C9D3F0AB7 for ; Thu, 8 Oct 2026 07:34:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=pass smtp.client-ip=165.173.180.11 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791444866; cv=pass; b=q4dpTKl4jVy256qC/jKV189Phk8fNzAs+t4f/YoOl83/1jTzf8JuatrrVmI579moVqhOQL5AX2tBbDHTfJhYI53PXs+fguLDxOq5pt9ueZcn1h5MHxeOhl2HsXLMJJT+lLS02jbgWr1i3s/LnjB9qJwMEHnSKqQkR1RJOCtKIfs= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791444866; c=relaxed/simple; bh=poW2hJOolFF/fNYHQtxj9zyIw1Fphk+8AKVZ10FxhXE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=UuJAeUmXjdck2m9OhHGUx9oE+esr/HFA/nCs783y2iFo3n+YZdpOTWh4eRrpUt2X4ROawBoX3hQcCoLj4VG8M+7pOdb9xZVIP1BU0OGl5RLusPZqYsaeni6tNB2SwYdJfp4c+OCyY9ontd9bZor67zWEhamvsCZodYivF97l+JY= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (1024-bit key) header.d=collabora.com header.i=dmitry.osipenko@collabora.com header.b=VfMI44Yg; arc=pass smtp.client-ip=165.173.180.11 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=collabora.com header.i=dmitry.osipenko@collabora.com header.b="VfMI44Yg" ARC-Seal: i=1; a=rsa-sha256; t=1791444796; cv=none; d=zohomail.com; s=zohoarc; b=mTXh61NiLKraP85kc4UaugKyB1TEwN0hWZoFoa6N2LdPKFsF8F+1gyhuph+qjOCSOfEXwlHiykBA4oE+cdgOHN/eaCw24q5M7SZa6TP0b7VMAE4+e8Po9eZUUnQ2z3+SK9qJwpqCckEjYMtngq2P+voMJk1mSvbRVc4Bpsu8+4A= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1791444796; h=Content-Type:Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:MIME-Version:Message-ID:Subject:Subject:To:To:Message-Id:Reply-To; bh=NT1FtZat0efjcSWI1PONK/4auTqiGUlP1uANOzVuEYM=; b=IPfureZKksdFt+/6AE8DFadXNrbxuNSVKhggKc40JShVTWe1CL+3ARyFSsbMNTkDVXKumS2DMZuxq+gtHJRptw0Sn3XrZrraqoyDaNjuZm8zpIVfnkuzfMefBpagyTymCm8zWWEvvnlFge8L+CEiHkAtFQfXRVV5q9DqCMSWRGk= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=collabora.com; spf=pass smtp.mailfrom=dmitry.osipenko@collabora.com; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1791444796; s=zohomail; d=collabora.com; i=dmitry.osipenko@collabora.com; h=Message-ID:Date:Date:MIME-Version:Subject:Subject:To:To:Cc:Cc:From:From:In-Reply-To:Content-Type:Content-Transfer-Encoding:Message-Id:Reply-To; bh=NT1FtZat0efjcSWI1PONK/4auTqiGUlP1uANOzVuEYM=; b=VfMI44Yg7//sz5ycJDAf9JSZtWZSa1pmQYKPNq22N9ciru+ejpI9JPpfntufUJpC C5r/FM+5sI59fLzbrExFMAzaor0PkEok3LmCTyyGxuTZdMoI9av/P/w56f5hQbqlV7Z wwQTdkhjyMuevhBOL0sqlvYuwINU5/A0WM5xiDR8= Received: by smtp.zohomail.com with SMTPS id 1791444795885952.4681401339243; Thu, 8 Oct 2026 00:33:15 -0700 (PDT) Message-ID: <8b0fbe1a-1410-42d7-8031-611795ae39d9@collabora.com> Date: Thu, 8 Oct 2026 10:33:11 +0300 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 v2] drm/virtio: do not enforce blob_alignment in cross-domain contexts To: Val Packett , David Airlie , Gerd Hoffmann , Gurchetan Singh , Chia-I Wu , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Simona Vetter , Sergio Lopez Cc: dri-devel@lists.freedesktop.org, virtualization@lists.linux.dev, linux-kernel@vger.kernel.org References: <20261006154913.2689067-2-val@invisiblethingslab.com> Content-Language: en-US From: Dmitry Osipenko In-Reply-To: <20261006154913.2689067-2-val@invisiblethingslab.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-ZohoMailClient: External On 10/6/26 18:42, Val Packett wrote: > VIRTIO_GPU_F_BLOB_ALIGNMENT is designed for GPU rendering context types, > however VIRTIO_GPU_CAPSET_CROSS_DOMAIN is not one of those. Resources > created under cross-domain contexts are arbitrary shared system memory > files, which includes unusual things like Wayland keymaps received > from the host compositor. Do not enforce alignment requirements there. > > Fixes: 47248e0d8264 ("drm/virtio: honor blob_alignment requirements") > Signed-off-by: Val Packett > --- > > v2: also check has_virgl_3d to prevent dereferencing NULL vfpriv > v1: https://lore.kernel.org/all/20261006004044.2242154-1-val@invisiblethingslab.com/ > > ~val > > --- > drivers/gpu/drm/virtio/virtgpu_ioctl.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c b/drivers/gpu/drm/virtio/virtgpu_ioctl.c > index 3ddd5481d6bc..4d5ae062834d 100644 > --- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c > +++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c > @@ -551,7 +551,9 @@ static int verify_blob(struct virtio_gpu_device *vgdev, > params->blob_flags = rc_blob->blob_flags; > params->blob_hints = rc_blob->blob_hints; > > - if (vgdev->has_blob_alignment && > + if (vgdev->has_blob_alignment && vgdev->has_virgl_3d && > + (vfpriv->context_init & VIRTIO_GPU_CONTEXT_INIT_CAPSET_ID_MASK) != > + VIRTIO_GPU_CAPSET_CROSS_DOMAIN && > !IS_ALIGNED(params->size, vgdev->blob_alignment)) > return -EINVAL; > What userspace has this problem and why it re-purposes virtio-gpu to act as udmabuf for arbitrary data that never reaches host? -- Best regards, Dmitry