From nobody Mon Feb 9 22:19:53 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1495809202946549.6789295971738; Fri, 26 May 2017 07:33:22 -0700 (PDT) Received: from localhost ([::1]:37076 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dEGIq-0005W0-H1 for importer@patchew.org; Fri, 26 May 2017 10:33:20 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59795) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dEGFY-0001X0-NY for qemu-devel@nongnu.org; Fri, 26 May 2017 10:30:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dEGFX-0000fR-4D for qemu-devel@nongnu.org; Fri, 26 May 2017 10:29:56 -0400 Received: from mx1.redhat.com ([209.132.183.28]:41248) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dEGFW-0000cM-RX for qemu-devel@nongnu.org; Fri, 26 May 2017 10:29:55 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id CC29A7F4AF; Fri, 26 May 2017 14:29:53 +0000 (UTC) Received: from max-t460s.redhat.com (ovpn-112-29.ams2.redhat.com [10.36.112.29]) by smtp.corp.redhat.com (Postfix) with ESMTP id A24B171C94; Fri, 26 May 2017 14:29:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com CC29A7F4AF Authentication-Results: ext-mx02.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx02.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=maxime.coquelin@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com CC29A7F4AF From: Maxime Coquelin To: mst@redhat.com, peterx@redhat.com, marcandre.lureau@gmail.com, vkaplans@redhat.com, jasowang@redhat.com, wexu@redhat.com, yuanhan.liu@linux.intel.com, qemu-devel@nongnu.org, jfreiman@redhat.com Date: Fri, 26 May 2017 16:28:58 +0200 Message-Id: <20170526142858.19931-7-maxime.coquelin@redhat.com> In-Reply-To: <20170526142858.19931-1-maxime.coquelin@redhat.com> References: <20170526142858.19931-1-maxime.coquelin@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Fri, 26 May 2017 14:29:54 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v2 6/6] spec/vhost-user spec: Add IOMMU support X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Maxime Coquelin Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" This patch specifies and implements the master/slave communication to support device IOTLB in slave. The vhost_iotlb_msg structure introduced for kernel backends is re-used, making the design close between the two backends. An exception is the use of the secondary channel to enable the slave to send IOTLB miss requests to the master. Signed-off-by: Maxime Coquelin --- v2: - spec: fixed possible permission field values - spec: rewrote "IOMMU support" section docs/specs/vhost-user.txt | 86 +++++++++++++++++++++++++++++++++++++++++++= ++++ hw/virtio/vhost-user.c | 31 +++++++++++++++++ 2 files changed, 117 insertions(+) diff --git a/docs/specs/vhost-user.txt b/docs/specs/vhost-user.txt index 5fa7016..0799ef1 100644 --- a/docs/specs/vhost-user.txt +++ b/docs/specs/vhost-user.txt @@ -97,6 +97,25 @@ Depending on the request type, payload can be: log offset: offset from start of supplied file descriptor where logging starts (i.e. where guest address 0 would be logged) =20 + * An IOTLB message + --------------------------------------------------------- + | iova | size | user address | permissions flags | type | + --------------------------------------------------------- + + IOVA: a 64-bit I/O virtual address programmed by the guest + Size: a 64-bit size + User address: a 64-bit user address + Permissions: a 8-bit value: + - 0: No access + - 1: Read access + - 2: Write access + - 3: Read/Write access + Type: a 8-bit IOTLB message type: + - 1: IOTLB miss + - 2: IOTLB update + - 3: IOTLB invalidate + - 4: IOTLB access fail + In QEMU the vhost-user message is implemented with the following struct: =20 typedef struct VhostUserMsg { @@ -109,6 +128,7 @@ typedef struct VhostUserMsg { struct vhost_vring_addr addr; VhostUserMemory memory; VhostUserLog log; + struct vhost_iotlb_msg iotlb; }; } QEMU_PACKED VhostUserMsg; =20 @@ -253,6 +273,40 @@ Once the source has finished migration, rings will be = stopped by the source. No further update must be done before rings are restarted. =20 +IOMMU support +------------- + +When the VIRTIO_F_IOMMU_PLATFORM feature has been negotiated, the master +sends IOTLB entries update & invalidation by sending VHOST_USER_IOTLB_MSG +requests to the slave with a struct vhost_iotlb_msg as payload. For update +events, the iotlb payload has to be filled with the update message type (2= ), +the I/O virtual address, the size, the user virtual address, and the +permissions flags. Addresses and size must be within vhost memory regions = set +via the VHOST_USER_SET_MEM_TABLE request. For invalidation events, the iot= lb +payload has to be filled with the invalidation message type (3), the I/O v= irtual +address and the size. On success, the slave is expected to reply with a ze= ro +payload, non-zero otherwise. + +The slave relies on the slave communcation channel (see "Slave communicati= on" +section below) to send IOTLB miss and access failure events, by sending +VHOST_USER_SLAVE_IOTLB_MSG requests to the master with a struct vhost_iotl= b_msg +as payload. For miss events, the iotlb payload has to be filled with the m= iss +message type (1), the I/O virtual address and the permissions flags. For a= ccess +failure event, the iotlb payload has to be filled with the access failure +message type (4), the I/O virtual address and the permissions flags. +For synchronization purpose, the slave may rely on the reply-ack feature, +so the master may send a reply when operation is completed if the reply-ack +feature is negotiated and slaves requests a reply. For miss events, comple= ted +operation means either master sent an update message containing the IOTLB = entry +containing requested address and permission, or master sent nothing if the= IOTLB +miss message is invalid (invalid IOVA or permission). + +The master isn't generally expected to take the initiative to send IOTLB u= pdate +messages, as the slave sends IOTLB miss messages for the guest virtual mem= ory +areas it needs to access. The exception is the rings information addresses +shared with the VHOST_USER_SET_VRING_ADDR request, for which the master mu= st +send corresponding IOTLB updates before the rings are enabled. + Slave communication ------------------- =20 @@ -514,6 +568,38 @@ Master message types If VHOST_USER_PROTOCOL_F_REPLY_ACK is negotiated, slave must respond with zero for success, non-zero otherwise. =20 + * VHOST_USER_IOTLB_MSG + + Id: 22 + Equivalent ioctl: N/A (equivalent to VHOST_IOTLB_MSG message type) + Master payload: struct vhost_iotlb_msg + Slave payload: u64 + + Send IOTLB messages with struct vhost_iotlb_msg as payload. + Master sends such requests to update and invalidate entries in the d= evice + IOTLB. The slave has to acknowledge the request with sending zero as= u64 + payload for success, non-zero otherwise. + This request should be send only when VIRTIO_F_IOMMU_PLATFORM feature + has been successfully negotiated. + +Slave message types +------------------- + + * VHOST_USER_SLAVE_IOTLB_MSG + + Id: 1 + Equivalent ioctl: N/A (equivalent to VHOST_IOTLB_MSG message type) + Slave payload: struct vhost_iotlb_msg + Master payload: N/A + + Send IOTLB messages with struct vhost_iotlb_msg as payload. + Slave sends such requests to notify of an IOTLB miss, or an IOTLB + access failure. If VHOST_USER_PROTOCOL_F_REPLY_ACK is negotiated, + and slave set the VHOST_USER_NEED_REPLY flag, master must respond wi= th + zero when operation is successfully completed, or non-zero otherwise. + This request should be send only when VIRTIO_F_IOMMU_PLATFORM feature + has been successfully negotiated. + VHOST_USER_PROTOCOL_F_REPLY_ACK: ------------------------------- The original vhost-user specification only demands replies for certain diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c index ea988fe..170fa68 100644 --- a/hw/virtio/vhost-user.c +++ b/hw/virtio/vhost-user.c @@ -62,11 +62,13 @@ typedef enum VhostUserRequest { VHOST_USER_SEND_RARP =3D 19, VHOST_USER_NET_SET_MTU =3D 20, VHOST_USER_SET_SLAVE_REQ_FD =3D 21, + VHOST_USER_IOTLB_MSG =3D 22, VHOST_USER_MAX } VhostUserRequest; =20 typedef enum VhostUserSlaveRequest { VHOST_USER_SLAVE_NONE =3D 0, + VHOST_USER_SLAVE_IOTLB_MSG =3D 1, VHOST_USER_SLAVE_MAX } VhostUserSlaveRequest; =20 @@ -104,6 +106,7 @@ typedef struct VhostUserMsg { struct vhost_vring_addr addr; VhostUserMemory memory; VhostUserLog log; + struct vhost_iotlb_msg iotlb; } payload; } QEMU_PACKED VhostUserMsg; =20 @@ -615,6 +618,9 @@ static void slave_read(void *opaque) } =20 switch (msg.request) { + case VHOST_USER_SLAVE_IOTLB_MSG: + ret =3D vhost_backend_handle_iotlb_msg(dev, &msg.payload.iotlb); + break; default: error_report("Received unexpected msg type."); ret =3D -EINVAL; @@ -862,6 +868,29 @@ static int vhost_user_net_set_mtu(struct vhost_dev *de= v, uint16_t mtu) return 0; } =20 +static int vhost_user_send_device_iotlb_msg(struct vhost_dev *dev, + struct vhost_iotlb_msg *imsg) +{ + VhostUserMsg msg =3D { + .request =3D VHOST_USER_IOTLB_MSG, + .size =3D sizeof(msg.payload.iotlb), + .flags =3D VHOST_USER_VERSION | VHOST_USER_NEED_REPLY_MASK, + .payload.iotlb =3D *imsg, + }; + + if (vhost_user_write(dev, &msg, NULL, 0) < 0) { + return -EFAULT; + } + + return process_message_reply(dev, msg); +} + + +static void vhost_user_set_iotlb_callback(struct vhost_dev *dev, int enabl= ed) +{ + /* No-op as the receive channel is not dedicated to IOTLB messages. */ +} + const VhostOps user_ops =3D { .backend_type =3D VHOST_BACKEND_TYPE_USER, .vhost_backend_init =3D vhost_user_init, @@ -886,4 +915,6 @@ const VhostOps user_ops =3D { .vhost_migration_done =3D vhost_user_migration_done, .vhost_backend_can_merge =3D vhost_user_can_merge, .vhost_net_set_mtu =3D vhost_user_net_set_mtu, + .vhost_set_iotlb_callback =3D vhost_user_set_iotlb_callback, + .vhost_send_device_iotlb_msg =3D vhost_user_send_device_iotlb_msg, }; --=20 2.9.4