From ce0f3b032a960726c0dddfb4f81f223215179f26 Mon Sep 17 00:00:00 2001 From: Albert Esteve Date: Mon, 2 Oct 2023 08:57:06 +0200 Subject: [PATCH] libvhost-user: handle shared_object msg In the libvhost-user library we need to handle VHOST_USER_GET_SHARED_OBJECT requests, and add helper functions to allow sending messages to interact with the virtio shared objects hash table. Signed-off-by: Albert Esteve Message-Id: <20231002065706.94707-5-aesteve@redhat.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- subprojects/libvhost-user/libvhost-user.c | 120 ++++++++++++++++++++++ subprojects/libvhost-user/libvhost-user.h | 55 +++++++++- 2 files changed, 174 insertions(+), 1 deletion(-) diff --git a/subprojects/libvhost-user/libvhost-user.c b/subprojects/libvhost-user/libvhost-user.c index 49b57c7ef4..051a611da3 100644 --- a/subprojects/libvhost-user/libvhost-user.c +++ b/subprojects/libvhost-user/libvhost-user.c @@ -161,6 +161,7 @@ vu_request_to_string(unsigned int req) REQ(VHOST_USER_GET_MAX_MEM_SLOTS), REQ(VHOST_USER_ADD_MEM_REG), REQ(VHOST_USER_REM_MEM_REG), + REQ(VHOST_USER_GET_SHARED_OBJECT), REQ(VHOST_USER_MAX), }; #undef REQ @@ -901,6 +902,24 @@ vu_rem_mem_reg(VuDev *dev, VhostUserMsg *vmsg) { return false; } +static bool +vu_get_shared_object(VuDev *dev, VhostUserMsg *vmsg) +{ + int fd_num = 0; + int dmabuf_fd = -1; + if (dev->iface->get_shared_object) { + dmabuf_fd = dev->iface->get_shared_object( + dev, &vmsg->payload.object.uuid[0]); + } + if (dmabuf_fd != -1) { + DPRINT("dmabuf_fd found for requested UUID\n"); + vmsg->fds[fd_num++] = dmabuf_fd; + } + vmsg->fd_num = fd_num; + + return true; +} + static bool vu_set_mem_table_exec_postcopy(VuDev *dev, VhostUserMsg *vmsg) { @@ -1404,6 +1423,105 @@ bool vu_set_queue_host_notifier(VuDev *dev, VuVirtq *vq, int fd, return vu_process_message_reply(dev, &vmsg); } +bool +vu_lookup_shared_object(VuDev *dev, unsigned char uuid[UUID_LEN], + int *dmabuf_fd) +{ + bool result = false; + VhostUserMsg msg_reply; + VhostUserMsg msg = { + .request = VHOST_USER_BACKEND_SHARED_OBJECT_LOOKUP, + .size = sizeof(msg.payload.object), + .flags = VHOST_USER_VERSION | VHOST_USER_NEED_REPLY_MASK, + }; + + memcpy(msg.payload.object.uuid, uuid, sizeof(uuid[0]) * UUID_LEN); + + if (!vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_SHARED_OBJECT)) { + return false; + } + + pthread_mutex_lock(&dev->backend_mutex); + if (!vu_message_write(dev, dev->backend_fd, &msg)) { + goto out; + } + + if (!vu_message_read_default(dev, dev->backend_fd, &msg_reply)) { + goto out; + } + + if (msg_reply.request != msg.request) { + DPRINT("Received unexpected msg type. Expected %d, received %d", + msg.request, msg_reply.request); + goto out; + } + + if (msg_reply.fd_num != 1) { + DPRINT("Received unexpected number of fds. Expected 1, received %d", + msg_reply.fd_num); + goto out; + } + + *dmabuf_fd = msg_reply.fds[0]; + result = *dmabuf_fd > 0 && msg_reply.payload.u64 == 0; +out: + pthread_mutex_unlock(&dev->backend_mutex); + + return result; +} + +static bool +vu_send_message(VuDev *dev, VhostUserMsg *vmsg) +{ + bool result = false; + pthread_mutex_lock(&dev->backend_mutex); + if (!vu_message_write(dev, dev->backend_fd, vmsg)) { + goto out; + } + + result = true; +out: + pthread_mutex_unlock(&dev->backend_mutex); + + return result; +} + +bool +vu_add_shared_object(VuDev *dev, unsigned char uuid[UUID_LEN]) +{ + VhostUserMsg msg = { + .request = VHOST_USER_BACKEND_SHARED_OBJECT_ADD, + .size = sizeof(msg.payload.object), + .flags = VHOST_USER_VERSION, + }; + + memcpy(msg.payload.object.uuid, uuid, sizeof(uuid[0]) * UUID_LEN); + + if (!vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_SHARED_OBJECT)) { + return false; + } + + return vu_send_message(dev, &msg); +} + +bool +vu_rm_shared_object(VuDev *dev, unsigned char uuid[UUID_LEN]) +{ + VhostUserMsg msg = { + .request = VHOST_USER_BACKEND_SHARED_OBJECT_REMOVE, + .size = sizeof(msg.payload.object), + .flags = VHOST_USER_VERSION, + }; + + memcpy(msg.payload.object.uuid, uuid, sizeof(uuid[0]) * UUID_LEN); + + if (!vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_SHARED_OBJECT)) { + return false; + } + + return vu_send_message(dev, &msg); +} + static bool vu_set_vring_call_exec(VuDev *dev, VhostUserMsg *vmsg) { @@ -1944,6 +2062,8 @@ vu_process_message(VuDev *dev, VhostUserMsg *vmsg) return vu_add_mem_reg(dev, vmsg); case VHOST_USER_REM_MEM_REG: return vu_rem_mem_reg(dev, vmsg); + case VHOST_USER_GET_SHARED_OBJECT: + return vu_get_shared_object(dev, vmsg); default: vmsg_close_fds(vmsg); vu_panic(dev, "Unhandled request: %d", vmsg->request); diff --git a/subprojects/libvhost-user/libvhost-user.h b/subprojects/libvhost-user/libvhost-user.h index 708370c5f5..b36a42a7ca 100644 --- a/subprojects/libvhost-user/libvhost-user.h +++ b/subprojects/libvhost-user/libvhost-user.h @@ -64,7 +64,8 @@ enum VhostUserProtocolFeature { VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD = 12, VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS = 14, VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS = 15, - + /* Feature 16 is reserved for VHOST_USER_PROTOCOL_F_STATUS. */ + VHOST_USER_PROTOCOL_F_SHARED_OBJECT = 17, VHOST_USER_PROTOCOL_F_MAX }; @@ -109,6 +110,7 @@ typedef enum VhostUserRequest { VHOST_USER_GET_MAX_MEM_SLOTS = 36, VHOST_USER_ADD_MEM_REG = 37, VHOST_USER_REM_MEM_REG = 38, + VHOST_USER_GET_SHARED_OBJECT = 41, VHOST_USER_MAX } VhostUserRequest; @@ -119,6 +121,9 @@ typedef enum VhostUserBackendRequest { VHOST_USER_BACKEND_VRING_HOST_NOTIFIER_MSG = 3, VHOST_USER_BACKEND_VRING_CALL = 4, VHOST_USER_BACKEND_VRING_ERR = 5, + VHOST_USER_BACKEND_SHARED_OBJECT_ADD = 6, + VHOST_USER_BACKEND_SHARED_OBJECT_REMOVE = 7, + VHOST_USER_BACKEND_SHARED_OBJECT_LOOKUP = 8, VHOST_USER_BACKEND_MAX } VhostUserBackendRequest; @@ -172,6 +177,12 @@ typedef struct VhostUserInflight { uint16_t queue_size; } VhostUserInflight; +#define UUID_LEN 16 + +typedef struct VhostUserShared { + unsigned char uuid[UUID_LEN]; +} VhostUserShared; + #if defined(_WIN32) && (defined(__x86_64__) || defined(__i386__)) # define VU_PACKED __attribute__((gcc_struct, packed)) #else @@ -199,6 +210,7 @@ typedef struct VhostUserMsg { VhostUserConfig config; VhostUserVringArea area; VhostUserInflight inflight; + VhostUserShared object; } payload; int fds[VHOST_MEMORY_BASELINE_NREGIONS]; @@ -232,6 +244,7 @@ typedef int (*vu_get_config_cb) (VuDev *dev, uint8_t *config, uint32_t len); typedef int (*vu_set_config_cb) (VuDev *dev, const uint8_t *data, uint32_t offset, uint32_t size, uint32_t flags); +typedef int (*vu_get_shared_object_cb) (VuDev *dev, const unsigned char *uuid); typedef struct VuDevIface { /* called by VHOST_USER_GET_FEATURES to get the features bitmask */ @@ -258,6 +271,8 @@ typedef struct VuDevIface { vu_get_config_cb get_config; /* set the config space of the device */ vu_set_config_cb set_config; + /* get virtio shared object from the underlying vhost implementation. */ + vu_get_shared_object_cb get_shared_object; } VuDevIface; typedef void (*vu_queue_handler_cb) (VuDev *dev, int qidx); @@ -541,6 +556,44 @@ void vu_set_queue_handler(VuDev *dev, VuVirtq *vq, bool vu_set_queue_host_notifier(VuDev *dev, VuVirtq *vq, int fd, int size, int offset); +/** + * vu_lookup_shared_object: + * @dev: a VuDev context + * @uuid: UUID of the shared object + * @dmabuf_fd: output dma-buf file descriptor + * + * Lookup for a virtio shared object (i.e., dma-buf fd) associated with the + * received UUID. Result, if found, is stored in the dmabuf_fd argument. + * + * Returns: whether the virtio object was found. + */ +bool vu_lookup_shared_object(VuDev *dev, unsigned char uuid[UUID_LEN], + int *dmabuf_fd); + +/** + * vu_add_shared_object: + * @dev: a VuDev context + * @uuid: UUID of the shared object + * + * Registers this back-end as the exporter for the object associated with + * the received UUID. + * + * Returns: TRUE on success, FALSE on failure. + */ +bool vu_add_shared_object(VuDev *dev, unsigned char uuid[UUID_LEN]); + +/** + * vu_rm_shared_object: + * @dev: a VuDev context + * @uuid: UUID of the shared object + * + * Removes a shared object entry (i.e., back-end entry) associated with the + * received UUID key from the hash table. + * + * Returns: TRUE on success, FALSE on failure. + */ +bool vu_rm_shared_object(VuDev *dev, unsigned char uuid[UUID_LEN]); + /** * vu_queue_set_notification: * @dev: a VuDev context