From c5f048d8fb69ae9b52a02ff4435b403b2ba19db7 Mon Sep 17 00:00:00 2001 From: Maxime Coquelin Date: Sat, 10 Dec 2016 16:30:36 +0100 Subject: [PATCH] vhost-user: Add MTU protocol feature and op This patch implements VHOST_USER_PROTOCOL_F_NET_MTU protocol feature and VHOST_USER_NET_SET_MTU request so that the backend gets notified of the user defined host MTU. If backend supports VHOST_USER_PROTOCOL_F_REPLY_ACK, QEMU assumes MTU is valid if success is returned. Vhost-net driver sends this request through a new vhost_net_set_mtu vhost_ops entry. Cc: Michael S. Tsirkin Cc: Aaron Conole Signed-off-by: Maxime Coquelin Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- docs/specs/vhost-user.txt | 16 +++++++++++++++ hw/virtio/vhost-user.c | 34 +++++++++++++++++++++++++++++++ include/hw/virtio/vhost-backend.h | 2 ++ 3 files changed, 52 insertions(+) diff --git a/docs/specs/vhost-user.txt b/docs/specs/vhost-user.txt index d70bd83b13..036890feb0 100644 --- a/docs/specs/vhost-user.txt +++ b/docs/specs/vhost-user.txt @@ -259,6 +259,7 @@ Protocol features #define VHOST_USER_PROTOCOL_F_LOG_SHMFD 1 #define VHOST_USER_PROTOCOL_F_RARP 2 #define VHOST_USER_PROTOCOL_F_REPLY_ACK 3 +#define VHOST_USER_PROTOCOL_F_MTU 4 Message types ------------- @@ -470,6 +471,21 @@ Message types The first 6 bytes of the payload contain the mac address of the guest to allow the vhost user backend to construct and broadcast the fake RARP. + * VHOST_USER_NET_SET_MTU + + Id: 20 + Equivalent ioctl: N/A + Master payload: u64 + + Set host MTU value exposed to the guest. + This request should be sent only when VIRTIO_NET_F_MTU feature has been + successfully negotiated, VHOST_USER_F_PROTOCOL_FEATURES is present in + VHOST_USER_GET_FEATURES and protocol feature bit + VHOST_USER_PROTOCOL_F_NET_MTU is present in + VHOST_USER_GET_PROTOCOL_FEATURES. + If VHOST_USER_PROTOCOL_F_REPLY_ACK is negotiated, slave must respond + with zero in case the specified MTU is valid, or non-zero otherwise. + 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 7ee92b32c5..9334a8ae22 100644 --- a/hw/virtio/vhost-user.c +++ b/hw/virtio/vhost-user.c @@ -32,6 +32,7 @@ enum VhostUserProtocolFeature { VHOST_USER_PROTOCOL_F_LOG_SHMFD = 1, VHOST_USER_PROTOCOL_F_RARP = 2, VHOST_USER_PROTOCOL_F_REPLY_ACK = 3, + VHOST_USER_PROTOCOL_F_NET_MTU = 4, VHOST_USER_PROTOCOL_F_MAX }; @@ -59,6 +60,7 @@ typedef enum VhostUserRequest { VHOST_USER_GET_QUEUE_NUM = 17, VHOST_USER_SET_VRING_ENABLE = 18, VHOST_USER_SEND_RARP = 19, + VHOST_USER_NET_SET_MTU = 20, VHOST_USER_MAX } VhostUserRequest; @@ -186,6 +188,7 @@ static bool vhost_user_one_time_request(VhostUserRequest request) case VHOST_USER_RESET_OWNER: case VHOST_USER_SET_MEM_TABLE: case VHOST_USER_GET_QUEUE_NUM: + case VHOST_USER_NET_SET_MTU: return true; default: return false; @@ -685,6 +688,36 @@ static bool vhost_user_can_merge(struct vhost_dev *dev, return mfd == rfd; } +static int vhost_user_net_set_mtu(struct vhost_dev *dev, uint16_t mtu) +{ + VhostUserMsg msg; + bool reply_supported = virtio_has_feature(dev->protocol_features, + VHOST_USER_PROTOCOL_F_REPLY_ACK); + + if (!(dev->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_NET_MTU))) { + return 0; + } + + msg.request = VHOST_USER_NET_SET_MTU; + msg.payload.u64 = mtu; + msg.size = sizeof(msg.payload.u64); + msg.flags = VHOST_USER_VERSION; + if (reply_supported) { + msg.flags |= VHOST_USER_NEED_REPLY_MASK; + } + + if (vhost_user_write(dev, &msg, NULL, 0) < 0) { + return -1; + } + + /* If reply_ack supported, slave has to ack specified MTU is valid */ + if (reply_supported) { + return process_message_reply(dev, msg.request); + } + + return 0; +} + const VhostOps user_ops = { .backend_type = VHOST_BACKEND_TYPE_USER, .vhost_backend_init = vhost_user_init, @@ -708,4 +741,5 @@ const VhostOps user_ops = { .vhost_requires_shm_log = vhost_user_requires_shm_log, .vhost_migration_done = vhost_user_migration_done, .vhost_backend_can_merge = vhost_user_can_merge, + .vhost_net_set_mtu = vhost_user_net_set_mtu, }; diff --git a/include/hw/virtio/vhost-backend.h b/include/hw/virtio/vhost-backend.h index 6e90703cad..30abc11cf1 100644 --- a/include/hw/virtio/vhost-backend.h +++ b/include/hw/virtio/vhost-backend.h @@ -32,6 +32,7 @@ typedef int (*vhost_backend_memslots_limit)(struct vhost_dev *dev); typedef int (*vhost_net_set_backend_op)(struct vhost_dev *dev, struct vhost_vring_file *file); +typedef int (*vhost_net_set_mtu_op)(struct vhost_dev *dev, uint16_t mtu); typedef int (*vhost_scsi_set_endpoint_op)(struct vhost_dev *dev, struct vhost_scsi_target *target); typedef int (*vhost_scsi_clear_endpoint_op)(struct vhost_dev *dev, @@ -83,6 +84,7 @@ typedef struct VhostOps { vhost_backend_cleanup vhost_backend_cleanup; vhost_backend_memslots_limit vhost_backend_memslots_limit; vhost_net_set_backend_op vhost_net_set_backend; + vhost_net_set_mtu_op vhost_net_set_mtu; vhost_scsi_set_endpoint_op vhost_scsi_set_endpoint; vhost_scsi_clear_endpoint_op vhost_scsi_clear_endpoint; vhost_scsi_get_abi_version_op vhost_scsi_get_abi_version;