From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-111.freemail.mail.aliyun.com (out30-111.freemail.mail.aliyun.com [115.124.30.111]) (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 38D5D474255 for ; Tue, 1 Sep 2026 08:32:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.111 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788251574; cv=none; b=uraUros1iwOovelubzkwkixr5ZqxaFyjWT+SroARgve/s2/vQ9YPMCAcnJoSC1OytYrr+7ZZ3QcERmFPwcOBViZSoirhBl2G+CAUCOK0vOkS+yDHmLeKdaKBZh8I3M6s2lzNhP93fwv25s3fJJdxb9xbRt3EMD1BkNfLNf+ZiDY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788251574; c=relaxed/simple; bh=9tgnLdYl3CaRQm0w+UFFTLyy6mC/kMsQ8XZUV4Tmk/8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=K1dgBRgqkVgHGhTceQ22d0u/XhSmZhy18Hyzkj+396AYcbO0RBXhrXVlzTsaTrw+fIRw1tX2Y+rQz1FEy1ftQTpGzyg5Pm3AU8fQyx+E6JiZMl4SJuQxBfVCU/UG5blwY7084sNVOy3Sev76f9mpTpIFgjmtuchx5Jw3487efhM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=wBuGzghW; arc=none smtp.client-ip=115.124.30.111 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="wBuGzghW" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1788251569; h=From:To:Subject:Date:Message-ID:MIME-Version; bh=RNx/AB2rEnwXFgZop/G62OeBN0oID8kahxlVtyhWinw=; b=wBuGzghWxw+Z8/+X01lsT5vZmJTy+NRvWv40LrQO9BCtQB/4AlBlzIikJG8NtTDOj9eswYZuPdzRQFHZQcSG5xGqVVIKBIXP0N+VjI3kuE9tiKGsY8JdmHYa6WzUTgzRZjUFk6CBSDrtCbXIWoiyGaqrjk0N7Ts+FYeehp8/NuM= X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R721e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=maildocker-contentspam033032089153;MF=qinyuntan@linux.alibaba.com;NM=1;PH=DS;RN=17;SR=0;TI=SMTPD_---0XA5o3tj_1788251567; Received: from banye.tbsite.net(mailfrom:qinyuntan@linux.alibaba.com fp:SMTPD_---0XA5o3tj_1788251567 cluster:ay36) by smtp.aliyun-inc.com; Tue, 01 Sep 2026 16:32:48 +0800 From: Qinyun Tan To: dri-devel@lists.freedesktop.org Cc: tzimmermann@suse.de, airlied@redhat.com, jfalempe@redhat.com, kraxel@redhat.com, dmitry.osipenko@collabora.com, hansg@kernel.org, maarten.lankhorst@linux.intel.com, mripard@kernel.org, simona@ffwll.ch, leandro.ribeiro@collabora.com, daniels@collabora.com, pekka.paalanen@collabora.com, virtualization@lists.linux.dev, spice-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Qinyun Tan Subject: [PATCH v2 3/4] drm/virtio: create blend mode property on cursor plane Date: Tue, 1 Sep 2026 16:32:33 +0800 Message-ID: <20260901083234.1828755-4-qinyuntan@linux.alibaba.com> X-Mailer: git-send-email 2.43.7 In-Reply-To: <20260901083234.1828755-1-qinyuntan@linux.alibaba.com> References: <20260901083234.1828755-1-qinyuntan@linux.alibaba.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Since commit 860e748bddcc ("drm: ensure blend mode supported if pixel format with alpha exposed"), drm_mode_config_validate() warns when a plane exposes an alpha pixel format but not the "pixel blend mode" property. The virtio-gpu cursor plane (HOST_ARGB8888) trips this. The virtio-gpu specification does not define the cursor alpha semantics. The host forwards the cursor pixels verbatim to its display frontends, and the remote cursor protocols among them (SPICE alpha cursors, the VNC "Cursor With Alpha" encoding) both define pre-multiplied alpha, matching what userspace has always assumed when the property is not attached. Expose a "pixel blend mode" property advertising only DRM_MODE_BLEND_PREMULTI to make these semantics explicit and silence the warning. The primary plane only exposes HOST_XRGB8888, so the call is gated to the cursor. No functional change. Fixes: 860e748bddcc ("drm: ensure blend mode supported if pixel format with alpha exposed") Signed-off-by: Qinyun Tan --- v2: no code change; explain the protocol-level justification for PREMULTI in the commit message. drivers/gpu/drm/virtio/virtgpu_plane.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpu/drm/virtio/virtgpu_plane.c b/drivers/gpu/drm/virtio/virtgpu_plane.c index 1d1b27ece62a7..640815af40980 100644 --- a/drivers/gpu/drm/virtio/virtgpu_plane.c +++ b/drivers/gpu/drm/virtio/virtgpu_plane.c @@ -24,6 +24,7 @@ */ #include +#include #include #include #include @@ -609,6 +610,9 @@ struct drm_plane *virtio_gpu_plane_init(struct virtio_gpu_device *vgdev, if (type == DRM_PLANE_TYPE_PRIMARY) drm_plane_enable_fb_damage_clips(plane); + else if (type == DRM_PLANE_TYPE_CURSOR) + drm_plane_create_blend_mode_property(plane, + BIT(DRM_MODE_BLEND_PREMULTI)); return plane; } -- 2.43.7