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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 A9702103E185 for ; Thu, 19 Mar 2026 05:24:35 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1w35r2-0004qP-Ba; Thu, 19 Mar 2026 01:23:32 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1w35qz-0004p6-CI for qemu-devel@nongnu.org; Thu, 19 Mar 2026 01:23:30 -0400 Received: from mgamail.intel.com ([198.175.65.20]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1w35qx-0007uV-PC for qemu-devel@nongnu.org; Thu, 19 Mar 2026 01:23:29 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1773897808; x=1805433808; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=KCFgBlN8mCcR94ix8/h5CS5TPnxC4sjVKFQ7+WqdNrM=; b=HW6avqIuJk/DJOyhR2YByAVE4iqxR0PNER87Q/Va7XigS6TEmwPXrqF+ 2zO3EJBXMm2BBkC5idJRg6Np6mKGfgW8ezvEPniDB/zQBSsULCYINOhJM UAUFqv83qH3j+L+J/VR5kBMlkTT8w3XvO9X565BofrZ0BcXXWoIidS7KU QVpdKr7SlcsrbJU8QIvSfSXz0tAFlSI92kQv24LVqHoh1zyUuFaJNDNAE SsGkG9B94lT4P8nYjdE0fzhR3o6LbuOIP7mxNDiJaTeqiYBWJ4CDCUH/5 3Vb+5adZUvgRn5gO5rT402XoTlFRB7qEIioJNFpeNmhJbuMhKQGsS+J4R A==; X-CSE-ConnectionGUID: JKHVmEzoSP+OGxCnP3ifYg== X-CSE-MsgGUID: SDKS4TRuQ1Cxwx/6xROR2g== X-IronPort-AV: E=McAfee;i="6800,10657,11733"; a="74660402" X-IronPort-AV: E=Sophos;i="6.23,128,1770624000"; d="scan'208";a="74660402" Received: from fmviesa006.fm.intel.com ([10.60.135.146]) by orvoesa112.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Mar 2026 22:23:07 -0700 X-CSE-ConnectionGUID: WsQatj3kQDyw1ZRgc6OE6w== X-CSE-MsgGUID: 2zZ1xpVBRCS53YsBjKuoEw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.23,128,1770624000"; d="scan'208";a="218355539" Received: from vkasired-desk2.fm.intel.com ([10.105.128.132]) by fmviesa006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Mar 2026 22:23:04 -0700 From: Vivek Kasireddy To: qemu-devel@nongnu.org Cc: Vivek Kasireddy , =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , =?UTF-8?q?Alex=20Benn=C3=A9e?= , Akihiko Odaki , Dmitry Osipenko , Alex Williamson , =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= Subject: [PATCH v12 10/10] virtio-gpu-dmabuf: Create dmabuf for blobs associated with VFIO devices Date: Wed, 18 Mar 2026 22:15:59 -0700 Message-ID: <20260319052023.2088685-11-vivek.kasireddy@intel.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260319052023.2088685-1-vivek.kasireddy@intel.com> References: <20260319052023.2088685-1-vivek.kasireddy@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=198.175.65.20; envelope-from=vivek.kasireddy@intel.com; helo=mgamail.intel.com X-Spam_score_int: -26 X-Spam_score: -2.7 X-Spam_bar: -- X-Spam_report: (-2.7 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.819, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.903, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org In addition to memfd, a blob resource can also have its backing storage in a VFIO device region. Since, there is no effective way to determine where the backing storage is located, we first try to create a dmabuf assuming it is in memfd. If that fails, we try to create a dmabuf assuming it is in VFIO device region. So, we first call virtio_gpu_create_udmabuf() to check if the blob's backing storage is located in a memfd or not. If it is not, we invoke the vfio_device_create_dmabuf_fd() API which identifies the right VFIO device and eventually creates a dmabuf fd. Note that, for mmapping the dmabuf, we directly call mmap() if the dmabuf fd was created via virtio_gpu_create_udmabuf() since we know that the udmabuf driver supports mmap(). However, if the dmabuf was created via vfio_device_create_dmabuf_fd(), we use the vfio_device_mmap_dmabuf() API to get a mapping for the dmabuf. Cc: Marc-André Lureau Cc: Alex Bennée Cc: Akihiko Odaki Cc: Dmitry Osipenko Cc: Alex Williamson Cc: Cédric Le Goater Reviewed-by: Akihiko Odaki Signed-off-by: Vivek Kasireddy --- hw/display/virtio-gpu-dmabuf.c | 23 ++++++++++++++++++++--- 1 file changed, 20 insertions(+), 3 deletions(-) diff --git a/hw/display/virtio-gpu-dmabuf.c b/hw/display/virtio-gpu-dmabuf.c index 89aa487654..f953db0fbe 100644 --- a/hw/display/virtio-gpu-dmabuf.c +++ b/hw/display/virtio-gpu-dmabuf.c @@ -147,9 +147,26 @@ void virtio_gpu_init_dmabuf(struct virtio_gpu_simple_resource *res) if (res->dmabuf_fd == VFIO_DMABUF_CREATE_ERR_INVALID_IOV) { error_free_or_abort(&local_err); - qemu_log_mask(LOG_GUEST_ERROR, - "Cannot create dmabuf: incompatible memory\n"); - return; + res->dmabuf_fd = vfio_device_create_dmabuf_fd(res->iov, + res->iov_cnt, + res->blob_size, + &local_err); + if (res->dmabuf_fd == VFIO_DMABUF_CREATE_ERR_INVALID_IOV) { + error_free_or_abort(&local_err); + qemu_log_mask(LOG_GUEST_ERROR, + "Cannot create dmabuf: incompatible memory\n"); + return; + } + + if (res->dmabuf_fd >= 0) { + pdata = vfio_device_mmap_dmabuf(res->iov, res->iov_cnt, + res->blob_size, &local_err); + if (!pdata) { + virtio_gpu_destroy_dmabuf(res); + } + } else { + res->dmabuf_fd = -1; + } } else if (res->dmabuf_fd >= 0) { pdata = virtio_gpu_remap_dmabuf(res, &local_err); if (!pdata) { -- 2.53.0