From patchwork Mon Feb 17 16:40:06 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Albert Esteve X-Patchwork-Id: 13978288 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 31579C021A9 for ; Mon, 17 Feb 2025 16:42:57 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tk4Bt-0004Rt-JK; Mon, 17 Feb 2025 11:41:53 -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 1tk4Br-0004Q2-3K for qemu-devel@nongnu.org; Mon, 17 Feb 2025 11:41:51 -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 1tk4Bp-0007ub-E9 for qemu-devel@nongnu.org; Mon, 17 Feb 2025 11:41:50 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1739810508; 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=Uw+kJrcc03MeOrITLQiE+ix6zWcHlf6Spg7JUuKfvQo=; b=c/3qmZQCoAnSP9OQ5ZWQHvq/nS2IrFMq1So4/yEGTvJQ2vtuJibfNC00191Iz0u7z/Xtol mdJQGGh6vyN2Mdr7icvqLoiWrREZRme2O9u3VKLusMujiakU3PkruNTfCPto+DFSK/jz6y Vli3CELgj7ce8YvCYw3ptnkdpUbK6Ho= Received: from mx-prod-mc-06.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-442-lMYQWpJ4O4OyNhBZn4ZmJQ-1; Mon, 17 Feb 2025 11:40:38 -0500 X-MC-Unique: lMYQWpJ4O4OyNhBZn4ZmJQ-1 X-Mimecast-MFC-AGG-ID: lMYQWpJ4O4OyNhBZn4ZmJQ_1739810437 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-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 111501800989; Mon, 17 Feb 2025 16:40:37 +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 41A871800358; Mon, 17 Feb 2025 16:40:31 +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 3/9] vhost_user.rst: Add SHMEM_MAP/_UNMAP to spec Date: Mon, 17 Feb 2025 17:40:06 +0100 Message-ID: <20250217164012.246727-4-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 SHMEM_MAP/_UNMAP request to the vhost-user spec documentation. Reviewed-by: Stefan Hajnoczi Signed-off-by: Albert Esteve --- docs/interop/vhost-user.rst | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) diff --git a/docs/interop/vhost-user.rst b/docs/interop/vhost-user.rst index 436a94c0ee..c15d6ac467 100644 --- a/docs/interop/vhost-user.rst +++ b/docs/interop/vhost-user.rst @@ -375,6 +375,7 @@ In QEMU the vhost-user message is implemented with the following struct: VhostUserInflight inflight; VhostUserShared object; VhostUserTransferDeviceState transfer_state; + VhostUserMMap mmap; }; } QEMU_PACKED VhostUserMsg; @@ -1057,6 +1058,7 @@ Protocol features #define VHOST_USER_PROTOCOL_F_XEN_MMAP 17 #define VHOST_USER_PROTOCOL_F_SHARED_OBJECT 18 #define VHOST_USER_PROTOCOL_F_DEVICE_STATE 19 + #define VHOST_USER_PROTOCOL_F_SHMEM 20 Front-end message types ----------------------- @@ -1865,6 +1867,38 @@ is sent by the front-end. when the operation is successful, or non-zero otherwise. Note that if the operation fails, no fd is sent to the backend. +``VHOST_USER_BACKEND_SHMEM_MAP`` + :id: 9 + :equivalent ioctl: N/A + :request payload: fd and ``struct VhostUserMMap`` + :reply payload: N/A + + When the ``VHOST_USER_PROTOCOL_F_SHMEM`` protocol feature has been + successfully negotiated, this message can be submitted by the backends to + advertise a new mapping to be made in a given VIRTIO Shared Memory Region. + Upon receiving the message, the front-end will mmap the given fd into the + VIRTIO Shared Memory Region with the requested ``shmid``. A reply is + generated indicating whether mapping succeeded. + + Mapping over an already existing map is not allowed and request shall fail. + Therefore, the memory range in the request must correspond with a valid, + free region of the VIRTIO Shared Memory Region. Also, note that mappings + consume resources and that the request can fail when there are no resources + available. + +``VHOST_USER_BACKEND_SHMEM_UNMAP`` + :id: 10 + :equivalent ioctl: N/A + :request payload: ``struct VhostUserMMap`` + :reply payload: N/A + + When the ``VHOST_USER_PROTOCOL_F_SHMEM`` protocol feature has been + successfully negotiated, this message can be submitted by the backends so + that the front-end un-mmap a given range (``shm_offset``, ``len``) in the + VIRTIO Shared Memory Region with the requested ``shmid``. Note that the + given range shall correspond to the entirety of a valid mapped region. + A reply is generated indicating whether unmapping succeeded. + .. _reply_ack: VHOST_USER_PROTOCOL_F_REPLY_ACK