From patchwork Fri Jun 2 16:34:51 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Michael S. Tsirkin" X-Patchwork-Id: 770507 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3wfVM1739tz9s2P for ; Sat, 3 Jun 2017 02:40:29 +1000 (AEST) Received: from localhost ([::1]:50732 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dGpcg-0004Q4-02 for incoming@patchwork.ozlabs.org; Fri, 02 Jun 2017 12:40:26 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34570) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dGpXP-0008BY-48 for qemu-devel@nongnu.org; Fri, 02 Jun 2017 12:35:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dGpXM-0006VE-FN for qemu-devel@nongnu.org; Fri, 02 Jun 2017 12:34:59 -0400 Received: from mx1.redhat.com ([209.132.183.28]:39854) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dGpXM-0006Up-5N for qemu-devel@nongnu.org; Fri, 02 Jun 2017 12:34:56 -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 37FA820B14; Fri, 2 Jun 2017 16:34:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 37FA820B14 Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=mst@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 37FA820B14 Received: from redhat.com (ovpn-125-45.rdu2.redhat.com [10.10.125.45]) by smtp.corp.redhat.com (Postfix) with SMTP id 3CD295C550; Fri, 2 Jun 2017 16:34:52 +0000 (UTC) Date: Fri, 2 Jun 2017 19:34:51 +0300 From: "Michael S. Tsirkin" To: qemu-devel@nongnu.org Message-ID: <1496421247-857-9-git-send-email-mst@redhat.com> References: <1496421247-857-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1496421247-857-1-git-send-email-mst@redhat.com> X-Mutt-Fcc: =sent 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 [10.5.110.30]); Fri, 02 Jun 2017 16:34:55 +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] [PULL 8/8] 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: Peter Maydell , Maxime Coquelin , Jason Wang Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Maxime Coquelin 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 Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- docs/specs/vhost-user.txt | 84 +++++++++++++++++++++++++++++++++++++++++++++++ hw/net/vhost_net.c | 1 + hw/virtio/vhost-user.c | 48 +++++++++++++++++++++++++-- 3 files changed, 130 insertions(+), 3 deletions(-) diff --git a/docs/specs/vhost-user.txt b/docs/specs/vhost-user.txt index 5fa7016..481ab56 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) + * 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: 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; @@ -253,6 +273,38 @@ Once the source has finished migration, rings will be stopped by the source. No further update must be done before rings are restarted. +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 iotlb +payload has to be filled with the invalidation message type (3), the I/O virtual +address and the size. On success, the slave is expected to reply with a zero +payload, non-zero otherwise. + +The slave relies on the slave communcation channel (see "Slave communication" +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_iotlb_msg +as payload. For miss events, the iotlb payload has to be filled with the miss +message type (1), the I/O virtual address and the permissions flags. For access +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, completed +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 expected to take the initiative to send IOTLB update messages, +as the slave sends IOTLB miss messages for the guest virtual memory areas it +needs to access. + Slave communication ------------------- @@ -514,6 +566,38 @@ Master message types If VHOST_USER_PROTOCOL_F_REPLY_ACK is negotiated, slave must respond with zero for success, non-zero otherwise. + * 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 device + 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 with + 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/net/vhost_net.c b/hw/net/vhost_net.c index 22874a9..e037db6 100644 --- a/hw/net/vhost_net.c +++ b/hw/net/vhost_net.c @@ -77,6 +77,7 @@ static const int user_feature_bits[] = { VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_MTU, + VIRTIO_F_IOMMU_PLATFORM, /* This bit implies RARP isn't sent by QEMU out of band */ VIRTIO_NET_F_GUEST_ANNOUNCE, diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c index 6a35600..7a9bb1d 100644 --- a/hw/virtio/vhost-user.c +++ b/hw/virtio/vhost-user.c @@ -62,11 +62,13 @@ typedef enum VhostUserRequest { VHOST_USER_SEND_RARP = 19, VHOST_USER_NET_SET_MTU = 20, VHOST_USER_SET_SLAVE_REQ_FD = 21, + VHOST_USER_IOTLB_MSG = 22, VHOST_USER_MAX } VhostUserRequest; typedef enum VhostUserSlaveRequest { VHOST_USER_SLAVE_NONE = 0, + VHOST_USER_SLAVE_IOTLB_MSG = 1, VHOST_USER_SLAVE_MAX } VhostUserSlaveRequest; @@ -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; @@ -615,6 +618,9 @@ static void slave_read(void *opaque) } switch (msg.request) { + case VHOST_USER_SLAVE_IOTLB_MSG: + ret = vhost_backend_handle_iotlb_msg(dev, &msg.payload.iotlb); + break; default: error_report("Received unexpected msg type."); ret = -EINVAL; @@ -697,7 +703,7 @@ out: static int vhost_user_init(struct vhost_dev *dev, void *opaque) { - uint64_t features; + uint64_t features, protocol_features; struct vhost_user *u; int err; @@ -717,12 +723,13 @@ static int vhost_user_init(struct vhost_dev *dev, void *opaque) dev->backend_features |= 1ULL << VHOST_USER_F_PROTOCOL_FEATURES; err = vhost_user_get_u64(dev, VHOST_USER_GET_PROTOCOL_FEATURES, - &features); + &protocol_features); if (err < 0) { return err; } - dev->protocol_features = features & VHOST_USER_PROTOCOL_FEATURE_MASK; + dev->protocol_features = + protocol_features & VHOST_USER_PROTOCOL_FEATURE_MASK; err = vhost_user_set_protocol_features(dev, dev->protocol_features); if (err < 0) { return err; @@ -736,6 +743,16 @@ static int vhost_user_init(struct vhost_dev *dev, void *opaque) return err; } } + + if (virtio_has_feature(features, VIRTIO_F_IOMMU_PLATFORM) && + !(virtio_has_feature(dev->protocol_features, + VHOST_USER_PROTOCOL_F_SLAVE_REQ) && + virtio_has_feature(dev->protocol_features, + VHOST_USER_PROTOCOL_F_REPLY_ACK))) { + error_report("IOMMU support requires reply-ack and " + "slave-req protocol features."); + return -1; + } } if (dev->migration_blocker == NULL && @@ -862,6 +879,29 @@ static int vhost_user_net_set_mtu(struct vhost_dev *dev, uint16_t mtu) return 0; } +static int vhost_user_send_device_iotlb_msg(struct vhost_dev *dev, + struct vhost_iotlb_msg *imsg) +{ + VhostUserMsg msg = { + .request = VHOST_USER_IOTLB_MSG, + .size = sizeof(msg.payload.iotlb), + .flags = VHOST_USER_VERSION | VHOST_USER_NEED_REPLY_MASK, + .payload.iotlb = *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 enabled) +{ + /* No-op as the receive channel is not dedicated to IOTLB messages. */ +} + const VhostOps user_ops = { .backend_type = VHOST_BACKEND_TYPE_USER, .vhost_backend_init = vhost_user_init, @@ -886,4 +926,6 @@ const VhostOps user_ops = { .vhost_migration_done = vhost_user_migration_done, .vhost_backend_can_merge = vhost_user_can_merge, .vhost_net_set_mtu = vhost_user_net_set_mtu, + .vhost_set_iotlb_callback = vhost_user_set_iotlb_callback, + .vhost_send_device_iotlb_msg = vhost_user_send_device_iotlb_msg, };