From patchwork Mon Feb 17 16:40:08 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Albert Esteve X-Patchwork-Id: 13978287 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 3656DC021AA for ; Mon, 17 Feb 2025 16:42:33 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tk4C9-0004Xp-9L; Mon, 17 Feb 2025 11:42:09 -0500 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 1tk4C5-0004W2-0N for qemu-devel@nongnu.org; Mon, 17 Feb 2025 11:42:05 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tk4C2-0007wl-Ei for qemu-devel@nongnu.org; Mon, 17 Feb 2025 11:42:04 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1739810521; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ETv3rIMw2ZiMS20wCD23KE5549xc0CWPXx7VojiRKr0=; b=gQeYqiugvn0jSX4drnPV5nzXTe3s3zU3rcQRebR+orYPt6wx1oxzfJ6dEDz4yP5UIGwFsO 1jctp2d1e9NkyVlWjQ78JvsXdVlxcYMlfQAYUQyGstfUeeZ6mx711c08bbCxxcDQPPmcaZ qg5iR1Ti+mji4Ct/N8H9K25E5jXH7Cc= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-527-DkwQ77lBOLq1QSrxQJQjLA-1; Mon, 17 Feb 2025 11:40:47 -0500 X-MC-Unique: DkwQ77lBOLq1QSrxQJQjLA-1 X-Mimecast-MFC-AGG-ID: DkwQ77lBOLq1QSrxQJQjLA_1739810446 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 539831800874; Mon, 17 Feb 2025 16:40:46 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.45.225.252]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 3157C1800352; Mon, 17 Feb 2025 16:40:41 +0000 (UTC) From: Albert Esteve To: qemu-devel@nongnu.org Cc: slp@redhat.com, stevensd@chromium.org, =?utf-8?q?Alex_Benn=C3=A9e?= , Stefano Garzarella , stefanha@redhat.com, david@redhat.com, hi@alyssa.is, mst@redhat.com, jasowang@redhat.com, Albert Esteve Subject: [PATCH v4 5/9] vhost_user.rst: Add GET_SHMEM_CONFIG message Date: Mon, 17 Feb 2025 17:40:08 +0100 Message-ID: <20250217164012.246727-6-aesteve@redhat.com> In-Reply-To: <20250217164012.246727-1-aesteve@redhat.com> References: <20250217164012.246727-1-aesteve@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Received-SPF: pass client-ip=170.10.133.124; envelope-from=aesteve@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 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_NONE=-0.0001, RCVD_IN_MSPIKE_H2=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, 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: 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 Add GET_SHMEM_CONFIG vhost-user frontend message to the spec documentation. Reviewed-by: Alyssa Ross Signed-off-by: Albert Esteve Reviewed-by: Stefan Hajnoczi --- docs/interop/vhost-user.rst | 39 +++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) diff --git a/docs/interop/vhost-user.rst b/docs/interop/vhost-user.rst index c15d6ac467..96156f1900 100644 --- a/docs/interop/vhost-user.rst +++ b/docs/interop/vhost-user.rst @@ -350,6 +350,20 @@ Device state transfer parameters In the future, additional phases might be added e.g. to allow iterative migration while the device is running. +VIRTIO Shared Memory Region configuration +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + ++-------------+---------+------------+----+--------------+ +| num regions | padding | mem size 0 | .. | mem size 255 | ++-------------+---------+------------+----+--------------+ + +:num regions: a 32-bit number of regions + +:padding: 32-bit + +:mem size: contains `num regions` 64-bit fields representing the size of each + VIRTIO Shared Memory Region + C structure ----------- @@ -376,6 +390,7 @@ In QEMU the vhost-user message is implemented with the following struct: VhostUserShared object; VhostUserTransferDeviceState transfer_state; VhostUserMMap mmap; + VhostUserShMemConfig shmem; }; } QEMU_PACKED VhostUserMsg; @@ -1733,6 +1748,30 @@ Front-end message types Using this function requires prior negotiation of the ``VHOST_USER_PROTOCOL_F_DEVICE_STATE`` feature. +``VHOST_USER_GET_SHMEM_CONFIG`` + :id: 44 + :equivalent ioctl: N/A + :request payload: N/A + :reply payload: ``struct VhostUserShMemConfig`` + + When the ``VHOST_USER_PROTOCOL_F_SHMEM`` protocol feature has been + successfully negotiated, this message can be submitted by the front-end + to gather the VIRTIO Shared Memory Region configuration. The back-end will + respond with the number of VIRTIO Shared Memory Regions it requires, and + each shared memory region size in an array. The shared memory IDs are + represented by the array index. The information returned shall comply + with the following rules: + + * The shared information will remain valid and unchanged for the entire + lifetime of the connection. + + * The Shared Memory Region size must be a multiple of the page size + supported by mmap(2). + + * The size may be 0 if the region is unused. This can happen when the + device does not support an optional feature but does support a feature + that uses a higher shmid. + Back-end message types ----------------------