From patchwork Thu Aug 11 13:53:50 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Eugenio Perez Martin X-Patchwork-Id: 12941454 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 64D41C3F6B0 for ; Thu, 11 Aug 2022 13:54:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234931AbiHKNyP (ORCPT ); Thu, 11 Aug 2022 09:54:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36282 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235135AbiHKNyJ (ORCPT ); Thu, 11 Aug 2022 09:54:09 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 36EB9642FE for ; Thu, 11 Aug 2022 06:54:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1660226047; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=5kJeSSsfCq2FY3f7RK2Q/BBcFFU0NepVqdZJEXZ6UQI=; b=EXWzPevJpBIHjqCvHHV41JmTVmrxLMgrywin7BQsp6von3JBsP8hLXBvBJ2Vuh6vbtE9A4 3cTTrusuTStoEgidCsoaUq8yYNNWJ4q9XaSH4hvGcVJtZvRNl4WNAvXWI0lmwe56uBAKtB 24xzByykDG7oo16KmlohocB0CI68P68= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-659-FQ17yzFNMV-zJv8IcbJuMg-1; Thu, 11 Aug 2022 09:54:03 -0400 X-MC-Unique: FQ17yzFNMV-zJv8IcbJuMg-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 87E2C1C04B6E; Thu, 11 Aug 2022 13:54:02 +0000 (UTC) Received: from eperezma.remote.csb (unknown [10.39.192.231]) by smtp.corp.redhat.com (Postfix) with ESMTP id CE41640D2827; Thu, 11 Aug 2022 13:53:55 +0000 (UTC) From: =?utf-8?q?Eugenio_P=C3=A9rez?= To: virtualization@lists.linux-foundation.org, Jason Wang , "Michael S. Tsirkin" , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Cc: ecree.xilinx@gmail.com, gautam.dawar@amd.com, Zhang Min , pabloc@xilinx.com, Piotr.Uminski@intel.com, Dan Carpenter , tanuj.kamde@amd.com, Zhu Lingshan , martinh@xilinx.com, Christophe JAILLET , lvivier@redhat.com, martinpo@xilinx.com, hanand@xilinx.com, Eli Cohen , lulu@redhat.com, habetsm.xilinx@gmail.com, Parav Pandit , Longpeng , Wu Zongyong , Si-Wei Liu , Stefano Garzarella , dinang@xilinx.com, Xie Yongji Subject: [PATCH v8 0/3] Implement vdpasim suspend operation Date: Thu, 11 Aug 2022 15:53:50 +0200 Message-Id: <20220811135353.2549658-1-eperezma@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.11.54.2 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Implement suspend operation for vdpa_sim devices, so vhost-vdpa will offer that backend feature and userspace can effectively suspend the device. This is a must before getting virtqueue indexes (base) for live migration, since the device could modify them after userland gets them. There are individual ways to perform that action for some devices (VHOST_NET_SET_BACKEND, VHOST_VSOCK_SET_RUNNING, ...) but there was no way to perform it for any vhost device (and, in particular, vhost-vdpa). After a successful return of ioctl the device must not process more virtqueue descriptors. The device can answer to read or writes of config fields as if it were not suspended. In particular, writing to "queue_enable" with a value of 1 will not make the device start processing virtqueue buffers. In the future, we will provide features similar to VHOST_USER_GET_INFLIGHT_FD so the device can save pending operations. Applied on top of vhost branch. Comments are welcome. v8: * v7 but incremental from vhost instead of isolated. v7: * Remove ioctl leftover argument and update doc accordingly. v6: * Remove the resume operation, making the ioctl simpler. We can always add another ioctl for VM_STOP/VM_RESUME operation later. * s/stop/suspend/ to differentiate more from reset. * Clarify scope of the suspend operation. v5: * s/not stop/resume/ in doc. v4: * Replace VHOST_STOP to VHOST_VDPA_STOP in vhost ioctl switch case too. v3: * s/VHOST_STOP/VHOST_VDPA_STOP/ * Add documentation and requirements of the ioctl above its definition. v2: * Replace raw _F_STOP with BIT_ULL(_F_STOP). * Fix obtaining of stop ioctl arg (it was not obtained but written). * Add stop to vdpa_sim_blk. [1] git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git Eugenio Pérez (3): vdpa: delete unreachable branch on vdpasim_suspend vdpa: Remove wrong doc of VHOST_VDPA_SUSPEND ioctl vhost: Remove invalid parameter of VHOST_VDPA_SUSPEND ioctl drivers/vdpa/vdpa_sim/vdpa_sim.c | 7 ------- include/linux/vdpa.h | 2 +- include/uapi/linux/vhost.h | 17 ++++++----------- 3 files changed, 7 insertions(+), 19 deletions(-)