From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48740) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cz5EM-0004dM-6W for qemu-devel@nongnu.org; Fri, 14 Apr 2017 13:41:59 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cz5EK-00061v-Mz for qemu-devel@nongnu.org; Fri, 14 Apr 2017 13:41:58 -0400 Received: from mx1.redhat.com ([209.132.183.28]:41222) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cz5EK-00060t-EN for qemu-devel@nongnu.org; Fri, 14 Apr 2017 13:41:56 -0400 From: Maxime Coquelin Date: Fri, 14 Apr 2017 19:40:56 +0200 Message-Id: <20170414174056.28946-5-maxime.coquelin@redhat.com> In-Reply-To: <20170414174056.28946-1-maxime.coquelin@redhat.com> References: <20170414174056.28946-1-maxime.coquelin@redhat.com> Subject: [Qemu-devel] [RFC v2 4/4] spec/vhost-user spec: Add IOMMU support List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: mst@redhat.com, marcandre.lureau@gmail.com, vkaplans@redhat.com, jasowang@redhat.com, wexu@redhat.com, peterx@redhat.com, yuanhan.liu@linux.intel.com, qemu-devel@nongnu.org Cc: 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 --- docs/specs/vhost-user.txt | 74 +++++++++++++++++++++++++++++++++++ hw/virtio/vhost-user.c | 98 +++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 172 insertions(+) diff --git a/docs/specs/vhost-user.txt b/docs/specs/vhost-user.txt index 49c6293..a16dc44 100644 --- a/docs/specs/vhost-user.txt +++ b/docs/specs/vhost-user.txt @@ -97,6 +97,23 @@ 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 guest I/O virtual address + Size: a 64-bit size + User address: a 64-bit user address + Permissions flags: a 8-bit bit field: + - Bit 0: Read access + - Bit 1: 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 +126,7 @@ typedef struct VhostUserMsg { struct vhost_vring_addr addr; VhostUserMemory memory; VhostUserLog log; + struct vhost_iotlb_msg iotlb; }; } QEMU_PACKED VhostUserMsg; @@ -253,6 +271,30 @@ 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 has +to send IOTLB entries update & invalidation by sending VHOST_USER_IOTLB_MSG +requests to the slave with a struct vhost_iotlb_msg 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. For invalidation events, the iotlb payload has to be filled with the +update 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. + +When the VHOST_USER_PROTOCOL_F_SLAVE_REQ is supported by the slave, and the +master initiated the slave to master communication channel using the +VHOST_USER_SET_SLAVE_REQ_FD request, the slave can send IOTLB miss and access +failure events by sending VHOST_USER_SLAVE_IOTLB_MSG requests to the master +with a struct vhost_iotlb_msg 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. + Slave communication ------------------- @@ -512,6 +554,38 @@ Master message types has been negotiated, and protocol feature bit VHOST_USER_PROTOCOL_F_SLAVE_REQ bit is present in VHOST_USER_GET_PROTOCOL_FEATURES. + * 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/virtio/vhost-user.c b/hw/virtio/vhost-user.c index f26f11b..d06886b 100644 --- a/hw/virtio/vhost-user.c +++ b/hw/virtio/vhost-user.c @@ -63,11 +63,13 @@ 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; @@ -105,6 +107,7 @@ typedef struct VhostUserMsg { struct vhost_vring_addr addr; VhostUserMemory memory; VhostUserLog log; + struct vhost_iotlb_msg iotlb; } payload; } QEMU_PACKED VhostUserMsg; @@ -582,6 +585,31 @@ static int vhost_user_reset_device(struct vhost_dev *dev) return 0; } +static int vhost_user_iotlb_read(struct vhost_dev *dev, VhostUserMsg *msg) +{ + struct vhost_iotlb_msg *imsg = &msg->payload.iotlb; + int ret = 0; + + switch (imsg->type) { + case VHOST_IOTLB_MISS: + ret = vhost_device_iotlb_miss(dev, imsg->iova, + imsg->perm != VHOST_ACCESS_RO); + break; + case VHOST_IOTLB_ACCESS_FAIL: + /* FIXME: report device iotlb error */ + ret = -ENOTSUP; + break; + case VHOST_IOTLB_UPDATE: + case VHOST_IOTLB_INVALIDATE: + default: + error_report("Unexpected IOTLB message type"); + ret = -EINVAL; + break; + } + + return ret; +} + static void slave_read(void *opaque) { struct vhost_dev *dev = opaque; @@ -611,6 +639,8 @@ static void slave_read(void *opaque) } switch (msg.request) { + ret = vhost_user_iotlb_read(dev, &msg); + break; default: error_report("Received unexpected msg type."); ret = -EINVAL; @@ -848,6 +878,71 @@ static int vhost_user_net_set_mtu(struct vhost_dev *dev, uint16_t mtu) return 0; } +static int vhost_user_update_device_iotlb(struct vhost_dev *dev, + uint64_t iova, uint64_t uaddr, + uint64_t len, + IOMMUAccessFlags perm) +{ + VhostUserMsg msg = { + .request = VHOST_USER_IOTLB_MSG, + .size = sizeof(msg.payload.iotlb), + .flags = VHOST_USER_VERSION | VHOST_USER_NEED_REPLY_MASK, + .payload.iotlb = { + .iova = iova, + .uaddr = uaddr, + .size = len, + .type = VHOST_IOTLB_UPDATE, + }, + }; + + switch (perm) { + case IOMMU_RO: + msg.payload.iotlb.perm = VHOST_ACCESS_RO; + break; + case IOMMU_WO: + msg.payload.iotlb.perm = VHOST_ACCESS_WO; + break; + case IOMMU_RW: + msg.payload.iotlb.perm = VHOST_ACCESS_RW; + break; + default: + g_assert_not_reached(); + } + + if (vhost_user_write(dev, &msg, NULL, 0) < 0) { + return -1; + } + + return process_message_reply(dev, msg.request); +} + +static int vhost_user_invalidate_device_iotlb(struct vhost_dev *dev, + uint64_t iova, uint64_t len) +{ + VhostUserMsg msg = { + .request = VHOST_USER_IOTLB_MSG, + .size = sizeof(msg.payload.iotlb), + .flags = VHOST_USER_VERSION | VHOST_USER_NEED_REPLY_MASK, + .payload.iotlb = { + .iova = iova, + .size = len, + .type = VHOST_IOTLB_INVALIDATE, + }, + }; + + if (vhost_user_write(dev, &msg, NULL, 0) < 0) { + return -1; + } + + return process_message_reply(dev, msg.request); +} + + +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, @@ -872,4 +967,7 @@ 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_update_device_iotlb = vhost_user_update_device_iotlb, + .vhost_invalidate_device_iotlb = vhost_user_invalidate_device_iotlb, }; -- 2.9.3