From 27eca5c474f8c669fec3079db652df7533d83b55 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 11 Sep 2019 14:51:22 +0200 Subject: [PATCH] um: virtio: Implement VHOST_USER_PROTOCOL_F_REPLY_ACK Implement the VHOST_USER_PROTOCOL_F_REPLY_ACK extension for both slave requests (previous patch) where we have to reply and our own requests where it helps understand if the slave failed. Signed-off-by: Johannes Berg Signed-off-by: Richard Weinberger --- arch/um/drivers/vhost_user.h | 5 ++- arch/um/drivers/virtio_uml.c | 97 ++++++++++++++++++++++++++++++++++++-------- 2 files changed, 84 insertions(+), 18 deletions(-) diff --git a/arch/um/drivers/vhost_user.h b/arch/um/drivers/vhost_user.h index 8aee991..45ff5ea 100644 --- a/arch/um/drivers/vhost_user.h +++ b/arch/um/drivers/vhost_user.h @@ -6,9 +6,11 @@ /* Message flags */ #define VHOST_USER_FLAG_REPLY BIT(2) +#define VHOST_USER_FLAG_NEED_REPLY BIT(3) /* Feature bits */ #define VHOST_USER_F_PROTOCOL_FEATURES 30 /* Protocol feature bits */ +#define VHOST_USER_PROTOCOL_F_REPLY_ACK 3 #define VHOST_USER_PROTOCOL_F_SLAVE_REQ 5 #define VHOST_USER_PROTOCOL_F_CONFIG 9 /* Vring state index masks */ @@ -20,7 +22,8 @@ /* Supported transport features */ #define VHOST_USER_SUPPORTED_F BIT_ULL(VHOST_USER_F_PROTOCOL_FEATURES) /* Supported protocol features */ -#define VHOST_USER_SUPPORTED_PROTOCOL_F (BIT_ULL(VHOST_USER_PROTOCOL_F_SLAVE_REQ) | \ +#define VHOST_USER_SUPPORTED_PROTOCOL_F (BIT_ULL(VHOST_USER_PROTOCOL_F_REPLY_ACK) | \ + BIT_ULL(VHOST_USER_PROTOCOL_F_SLAVE_REQ) | \ BIT_ULL(VHOST_USER_PROTOCOL_F_CONFIG)) enum vhost_user_request { diff --git a/arch/um/drivers/virtio_uml.c b/arch/um/drivers/virtio_uml.c index ea4d9c1..fc8c52c 100644 --- a/arch/um/drivers/virtio_uml.c +++ b/arch/um/drivers/virtio_uml.c @@ -160,30 +160,64 @@ static int vhost_user_recv_req(struct virtio_uml_device *vu_dev, if (rc) return rc; - if (msg->header.flags != VHOST_USER_VERSION) + if ((msg->header.flags & ~VHOST_USER_FLAG_NEED_REPLY) != + VHOST_USER_VERSION) return -EPROTO; return 0; } static int vhost_user_send(struct virtio_uml_device *vu_dev, - struct vhost_user_msg *msg, + bool need_response, struct vhost_user_msg *msg, int *fds, size_t num_fds) { size_t size = sizeof(msg->header) + msg->header.size; + bool request_ack; + int rc; msg->header.flags |= VHOST_USER_VERSION; - return full_sendmsg_fds(vu_dev->sock, msg, size, fds, num_fds); + + /* + * The need_response flag indicates that we already need a response, + * e.g. to read the features. In these cases, don't request an ACK as + * it is meaningless. Also request an ACK only if supported. + */ + request_ack = !need_response; + if (!(vu_dev->protocol_features & + BIT_ULL(VHOST_USER_PROTOCOL_F_REPLY_ACK))) + request_ack = false; + + if (request_ack) + msg->header.flags |= VHOST_USER_FLAG_NEED_REPLY; + + rc = full_sendmsg_fds(vu_dev->sock, msg, size, fds, num_fds); + if (rc < 0) + return rc; + + if (request_ack) { + uint64_t status; + + rc = vhost_user_recv_u64(vu_dev, &status); + if (rc) + return rc; + + if (status) { + vu_err(vu_dev, "slave reports error: %llu\n", status); + return -EIO; + } + } + + return 0; } static int vhost_user_send_no_payload(struct virtio_uml_device *vu_dev, - u32 request) + bool need_response, u32 request) { struct vhost_user_msg msg = { .header.request = request, }; - return vhost_user_send(vu_dev, &msg, NULL, 0); + return vhost_user_send(vu_dev, need_response, &msg, NULL, 0); } static int vhost_user_send_no_payload_fd(struct virtio_uml_device *vu_dev, @@ -193,7 +227,7 @@ static int vhost_user_send_no_payload_fd(struct virtio_uml_device *vu_dev, .header.request = request, }; - return vhost_user_send(vu_dev, &msg, &fd, 1); + return vhost_user_send(vu_dev, false, &msg, &fd, 1); } static int vhost_user_send_u64(struct virtio_uml_device *vu_dev, @@ -205,18 +239,19 @@ static int vhost_user_send_u64(struct virtio_uml_device *vu_dev, .payload.integer = value, }; - return vhost_user_send(vu_dev, &msg, NULL, 0); + return vhost_user_send(vu_dev, false, &msg, NULL, 0); } static int vhost_user_set_owner(struct virtio_uml_device *vu_dev) { - return vhost_user_send_no_payload(vu_dev, VHOST_USER_SET_OWNER); + return vhost_user_send_no_payload(vu_dev, false, VHOST_USER_SET_OWNER); } static int vhost_user_get_features(struct virtio_uml_device *vu_dev, u64 *features) { - int rc = vhost_user_send_no_payload(vu_dev, VHOST_USER_GET_FEATURES); + int rc = vhost_user_send_no_payload(vu_dev, true, + VHOST_USER_GET_FEATURES); if (rc) return rc; @@ -232,7 +267,7 @@ static int vhost_user_set_features(struct virtio_uml_device *vu_dev, static int vhost_user_get_protocol_features(struct virtio_uml_device *vu_dev, u64 *protocol_features) { - int rc = vhost_user_send_no_payload(vu_dev, + int rc = vhost_user_send_no_payload(vu_dev, true, VHOST_USER_GET_PROTOCOL_FEATURES); if (rc) @@ -247,9 +282,32 @@ static int vhost_user_set_protocol_features(struct virtio_uml_device *vu_dev, protocol_features); } +static void vhost_user_reply(struct virtio_uml_device *vu_dev, + struct vhost_user_msg *msg, int response) +{ + struct vhost_user_msg reply = { + .payload.integer = response, + }; + size_t size = sizeof(reply.header) + sizeof(reply.payload.integer); + int rc; + + reply.header = msg->header; + reply.header.flags &= ~VHOST_USER_FLAG_NEED_REPLY; + reply.header.flags |= VHOST_USER_FLAG_REPLY; + reply.header.size = sizeof(reply.payload.integer); + + rc = full_sendmsg_fds(vu_dev->req_fd, &reply, size, NULL, 0); + + if (rc) + vu_err(vu_dev, + "sending reply to slave request failed: %d (size %zu)\n", + rc, size); +} + static irqreturn_t vu_req_interrupt(int irq, void *data) { struct virtio_uml_device *vu_dev = data; + int response = 1; struct { struct vhost_user_msg msg; u8 extra_payload[512]; @@ -266,6 +324,7 @@ static irqreturn_t vu_req_interrupt(int irq, void *data) switch (msg.msg.header.request) { case VHOST_USER_SLAVE_CONFIG_CHANGE_MSG: virtio_config_changed(&vu_dev->vdev); + response = 0; break; case VHOST_USER_SLAVE_IOTLB_MSG: /* not supported - VIRTIO_F_IOMMU_PLATFORM */ @@ -276,6 +335,9 @@ static irqreturn_t vu_req_interrupt(int irq, void *data) msg.msg.header.request); } + if (msg.msg.header.flags & VHOST_USER_FLAG_NEED_REPLY) + vhost_user_reply(vu_dev, &msg.msg, response); + return IRQ_HANDLED; } @@ -365,7 +427,7 @@ static void vhost_user_get_config(struct virtio_uml_device *vu_dev, msg->payload.config.offset = 0; msg->payload.config.size = cfg_size; - rc = vhost_user_send(vu_dev, msg, NULL, 0); + rc = vhost_user_send(vu_dev, true, msg, NULL, 0); if (rc) { vu_err(vu_dev, "sending VHOST_USER_GET_CONFIG failed: %d\n", rc); @@ -416,7 +478,7 @@ static void vhost_user_set_config(struct virtio_uml_device *vu_dev, msg->payload.config.size = len; memcpy(msg->payload.config.payload, buf, len); - rc = vhost_user_send(vu_dev, msg, NULL, 0); + rc = vhost_user_send(vu_dev, false, msg, NULL, 0); if (rc) vu_err(vu_dev, "sending VHOST_USER_SET_CONFIG failed: %d\n", rc); @@ -506,7 +568,8 @@ static int vhost_user_set_mem_table(struct virtio_uml_device *vu_dev) return rc; } - return vhost_user_send(vu_dev, &msg, fds, msg.payload.mem_regions.num); + return vhost_user_send(vu_dev, false, &msg, fds, + msg.payload.mem_regions.num); } static int vhost_user_set_vring_state(struct virtio_uml_device *vu_dev, @@ -519,7 +582,7 @@ static int vhost_user_set_vring_state(struct virtio_uml_device *vu_dev, .payload.vring_state.num = num, }; - return vhost_user_send(vu_dev, &msg, NULL, 0); + return vhost_user_send(vu_dev, false, &msg, NULL, 0); } static int vhost_user_set_vring_num(struct virtio_uml_device *vu_dev, @@ -550,7 +613,7 @@ static int vhost_user_set_vring_addr(struct virtio_uml_device *vu_dev, .payload.vring_addr.log = log, }; - return vhost_user_send(vu_dev, &msg, NULL, 0); + return vhost_user_send(vu_dev, false, &msg, NULL, 0); } static int vhost_user_set_vring_fd(struct virtio_uml_device *vu_dev, @@ -566,9 +629,9 @@ static int vhost_user_set_vring_fd(struct virtio_uml_device *vu_dev, return -EINVAL; if (fd < 0) { msg.payload.integer |= VHOST_USER_VRING_POLL_MASK; - return vhost_user_send(vu_dev, &msg, NULL, 0); + return vhost_user_send(vu_dev, false, &msg, NULL, 0); } - return vhost_user_send(vu_dev, &msg, &fd, 1); + return vhost_user_send(vu_dev, false, &msg, &fd, 1); } static int vhost_user_set_vring_call(struct virtio_uml_device *vu_dev, -- 2.7.4