From nobody Mon Feb 9 12:01:43 2026 Received: from sender4-pp-f112.zoho.com (sender4-pp-f112.zoho.com [136.143.188.112]) (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 740FA25A658 for ; Sun, 26 Jan 2025 20:43:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=pass smtp.client-ip=136.143.188.112 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737924232; cv=pass; b=FPiVP+ZK1+3MItphsSclv/3+1dR9gcS8lKHN+BrJvR3xgC/6mq94y/qD78T+Q4Z6VzFA2Jdcri1D7mN98wqw5OXPy++ourD2IlLWc4r3Zlr2ArQklyaY7+ScEhN4SommZ2B6g/ZpQ4UiOAEar7l1bRUouPKK8oCICCjF/3UNS7U= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737924232; c=relaxed/simple; bh=B11DyAkG4xiXe3exx4mGsiz+9KwFFrM9qCLIGzZxAa0=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=ED0ina/3n93A3d/NO6XPFhxTfN2exWSOWOsDYoiiDVcBkvqoFk2+aG6oGqvx3lELo5p1vYKI/QO3ryDWyq+fs8WQlJC7QwrU28uGrs3o0fDveJJFnRF1CbSn/HnAvTGHIUwNY5KORHHxt155ZIjykGtSvlwEvGyoHeU6TEqWu60= 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=OFkV1SzK; arc=pass smtp.client-ip=136.143.188.112 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="OFkV1SzK" ARC-Seal: i=1; a=rsa-sha256; t=1737924191; cv=none; d=zohomail.com; s=zohoarc; b=l777d6OcriSjXUtiJXGcuYLZM81jfizOB4OST4XmXWq9M2v/ww1Igo2KNFDq0w8vAp4i7MXZGB/aWoq/jn1Psamp/EbmCbN6OTffJSR8D+RPYQgdrL7MInl2lHJy0yftZg8KAHYiOKzw9Q1mpG2qb0oMhJInuOm4Ndm16/JgpnA= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1737924191; h=Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:MIME-Version:Message-ID:Subject:Subject:To:To:Message-Id:Reply-To; bh=xEnBSKU8pnmvFJgSinvIT748Q11VxHBZbgkAD3qC4/s=; b=Xi8JMhT+qHL76BCTak6XS22qw4iDJzS7WM2BPKBx3h2/RJ/nfeMQd5awo5HWTJLyNevjx8gFxOHX0BVNuLoYGOuv8eDXPvB1oUqrT9ekAYegKS3jyXyBRp5JE+QrXkke/SVHn8GEUDGGKO516Mlctn71z7r0B7Nq3uVbzPq6jm0= 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=1737924190; s=zohomail; d=collabora.com; i=dmitry.osipenko@collabora.com; h=From:From:To:To:Cc:Cc:Subject:Subject:Date:Date:Message-ID:MIME-Version:Content-Transfer-Encoding:Message-Id:Reply-To; bh=xEnBSKU8pnmvFJgSinvIT748Q11VxHBZbgkAD3qC4/s=; b=OFkV1SzKmrSJ8ydyfdkeKRLA+cr0oCTYLJTEozi39l2lea5wDTRDwPx9vGkqFHXb TXJQdcc/UA3GnJcInUKYubJncTLGERyDoKZYfTUHkPIz5Zk17nSbdp5md9e1KmKhIUY oEpPrjum4cZbFeAhL2G6jzWreWHUL2F/S2Wd1RNI= Received: by mx.zohomail.com with SMTPS id 173792418632813.028427511580276; Sun, 26 Jan 2025 12:43:06 -0800 (PST) From: Dmitry Osipenko To: David Airlie , Gerd Hoffmann , Gurchetan Singh , Chia-I Wu , Rob Clark , Pierre-Eric Pelloux-Prayer , Asahi Lina , Alyssa Rosenzweig Cc: dri-devel@lists.freedesktop.org, virtualization@lists.linux.dev, linux-kernel@vger.kernel.org, kernel@collabora.com Subject: [PATCH v1] drm/virtio: Extend blob UAPI with deferred-mapping hinting Date: Sun, 26 Jan 2025 23:42:39 +0300 Message-ID: <20250126204239.474847-1-dmitry.osipenko@collabora.com> X-Mailer: git-send-email 2.47.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ZohoMailClient: External Content-Type: text/plain; charset="utf-8" If userspace never maps GEM object, then BO wastes hostmem space because VirtIO-GPU driver maps VRAM BO at the BO's creating time. Make mappings on-demand by adding new RESOURCE_CREATE_BLOB IOCTL/UAPI hinting flag telling that host mapping should be deferred until first mapping is made when the flag is set by userspace. Signed-off-by: Dmitry Osipenko Reviewed-by: Rob Clark vma_node); drm_gem_object_put(gobj); return 0; diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c b/drivers/gpu/drm/virti= o/virtgpu_ioctl.c index e4f76f315550..51544ee8d3c3 100644 --- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c +++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c @@ -489,6 +489,7 @@ static int verify_blob(struct virtio_gpu_device *vgdev, params->size =3D rc_blob->size; params->blob =3D true; params->blob_flags =3D rc_blob->blob_flags; + params->blob_hints =3D rc_blob->blob_hints; return 0; } =20 diff --git a/drivers/gpu/drm/virtio/virtgpu_vram.c b/drivers/gpu/drm/virtio= /virtgpu_vram.c index 25df81c02783..d72c93e06a4a 100644 --- a/drivers/gpu/drm/virtio/virtgpu_vram.c +++ b/drivers/gpu/drm/virtio/virtgpu_vram.c @@ -41,6 +41,11 @@ static int virtio_gpu_vram_mmap(struct drm_gem_object *o= bj, if (!(bo->blob_flags & VIRTGPU_BLOB_FLAG_USE_MAPPABLE)) return -EINVAL; =20 + virtio_gpu_vram_map_deferred(vram); + + if (vram->map_state =3D=3D STATE_INITIALIZING) + virtio_gpu_notify(vgdev); + wait_event(vgdev->resp_wq, vram->map_state !=3D STATE_INITIALIZING); if (vram->map_state !=3D STATE_OK) return -EINVAL; @@ -215,14 +220,29 @@ int virtio_gpu_vram_create(struct virtio_gpu_device *= vgdev, =20 virtio_gpu_cmd_resource_create_blob(vgdev, &vram->base, params, NULL, 0); - if (params->blob_flags & VIRTGPU_BLOB_FLAG_USE_MAPPABLE) { - ret =3D virtio_gpu_vram_map(&vram->base); - if (ret) { - virtio_gpu_vram_free(obj); - return ret; + if (!(params->blob_hints & DRM_VIRTGPU_BLOB_FLAG_HINT_DEFER_MAPPING)) { + if (params->blob_flags & VIRTGPU_BLOB_FLAG_USE_MAPPABLE) { + ret =3D virtio_gpu_vram_map(&vram->base); + if (ret) { + virtio_gpu_vram_free(obj); + return ret; + } } } =20 *bo_ptr =3D &vram->base; return 0; } + +void virtio_gpu_vram_map_deferred(struct virtio_gpu_object_vram *vram) +{ + static DEFINE_MUTEX(map_lock); + + if (!(vram->base.blob_flags & VIRTGPU_BLOB_FLAG_USE_MAPPABLE)) + return; + + mutex_lock(&map_lock); + if (!drm_mm_node_allocated(&vram->vram_node)) + virtio_gpu_vram_map(&vram->base); + mutex_unlock(&map_lock); +} diff --git a/include/uapi/drm/virtgpu_drm.h b/include/uapi/drm/virtgpu_drm.h index c2ce71987e9b..3004a1d08570 100644 --- a/include/uapi/drm/virtgpu_drm.h +++ b/include/uapi/drm/virtgpu_drm.h @@ -194,6 +194,10 @@ struct drm_virtgpu_resource_create_blob { __u32 cmd_size; __u64 cmd; __u64 blob_id; + +#define DRM_VIRTGPU_BLOB_FLAG_HINT_DEFER_MAPPING 0x0001 + __u32 blob_hints; + __u32 pad2; }; =20 #define VIRTGPU_CONTEXT_PARAM_CAPSET_ID 0x0001 --=20 2.47.1