diff options
Diffstat (limited to 'qemu/migration/rdma.c')
| -rw-r--r-- | qemu/migration/rdma.c | 3516 |
1 files changed, 0 insertions, 3516 deletions
diff --git a/qemu/migration/rdma.c b/qemu/migration/rdma.c deleted file mode 100644 index f6a9992b3..000000000 --- a/qemu/migration/rdma.c +++ /dev/null @@ -1,3516 +0,0 @@ -/* - * RDMA protocol and interfaces - * - * Copyright IBM, Corp. 2010-2013 - * - * Authors: - * Michael R. Hines <mrhines@us.ibm.com> - * Jiuxing Liu <jl@us.ibm.com> - * - * This work is licensed under the terms of the GNU GPL, version 2 or - * later. See the COPYING file in the top-level directory. - * - */ -#include "qemu/osdep.h" -#include "qapi/error.h" -#include "qemu-common.h" -#include "qemu/cutils.h" -#include "migration/migration.h" -#include "migration/qemu-file.h" -#include "exec/cpu-common.h" -#include "qemu/error-report.h" -#include "qemu/main-loop.h" -#include "qemu/sockets.h" -#include "qemu/bitmap.h" -#include "qemu/coroutine.h" -#include <sys/socket.h> -#include <netdb.h> -#include <arpa/inet.h> -#include <rdma/rdma_cma.h> -#include "trace.h" - -/* - * Print and error on both the Monitor and the Log file. - */ -#define ERROR(errp, fmt, ...) \ - do { \ - fprintf(stderr, "RDMA ERROR: " fmt "\n", ## __VA_ARGS__); \ - if (errp && (*(errp) == NULL)) { \ - error_setg(errp, "RDMA ERROR: " fmt, ## __VA_ARGS__); \ - } \ - } while (0) - -#define RDMA_RESOLVE_TIMEOUT_MS 10000 - -/* Do not merge data if larger than this. */ -#define RDMA_MERGE_MAX (2 * 1024 * 1024) -#define RDMA_SIGNALED_SEND_MAX (RDMA_MERGE_MAX / 4096) - -#define RDMA_REG_CHUNK_SHIFT 20 /* 1 MB */ - -/* - * This is only for non-live state being migrated. - * Instead of RDMA_WRITE messages, we use RDMA_SEND - * messages for that state, which requires a different - * delivery design than main memory. - */ -#define RDMA_SEND_INCREMENT 32768 - -/* - * Maximum size infiniband SEND message - */ -#define RDMA_CONTROL_MAX_BUFFER (512 * 1024) -#define RDMA_CONTROL_MAX_COMMANDS_PER_MESSAGE 4096 - -#define RDMA_CONTROL_VERSION_CURRENT 1 -/* - * Capabilities for negotiation. - */ -#define RDMA_CAPABILITY_PIN_ALL 0x01 - -/* - * Add the other flags above to this list of known capabilities - * as they are introduced. - */ -static uint32_t known_capabilities = RDMA_CAPABILITY_PIN_ALL; - -#define CHECK_ERROR_STATE() \ - do { \ - if (rdma->error_state) { \ - if (!rdma->error_reported) { \ - error_report("RDMA is in an error state waiting migration" \ - " to abort!"); \ - rdma->error_reported = 1; \ - } \ - return rdma->error_state; \ - } \ - } while (0); - -/* - * A work request ID is 64-bits and we split up these bits - * into 3 parts: - * - * bits 0-15 : type of control message, 2^16 - * bits 16-29: ram block index, 2^14 - * bits 30-63: ram block chunk number, 2^34 - * - * The last two bit ranges are only used for RDMA writes, - * in order to track their completion and potentially - * also track unregistration status of the message. - */ -#define RDMA_WRID_TYPE_SHIFT 0UL -#define RDMA_WRID_BLOCK_SHIFT 16UL -#define RDMA_WRID_CHUNK_SHIFT 30UL - -#define RDMA_WRID_TYPE_MASK \ - ((1UL << RDMA_WRID_BLOCK_SHIFT) - 1UL) - -#define RDMA_WRID_BLOCK_MASK \ - (~RDMA_WRID_TYPE_MASK & ((1UL << RDMA_WRID_CHUNK_SHIFT) - 1UL)) - -#define RDMA_WRID_CHUNK_MASK (~RDMA_WRID_BLOCK_MASK & ~RDMA_WRID_TYPE_MASK) - -/* - * RDMA migration protocol: - * 1. RDMA Writes (data messages, i.e. RAM) - * 2. IB Send/Recv (control channel messages) - */ -enum { - RDMA_WRID_NONE = 0, - RDMA_WRID_RDMA_WRITE = 1, - RDMA_WRID_SEND_CONTROL = 2000, - RDMA_WRID_RECV_CONTROL = 4000, -}; - -static const char *wrid_desc[] = { - [RDMA_WRID_NONE] = "NONE", - [RDMA_WRID_RDMA_WRITE] = "WRITE RDMA", - [RDMA_WRID_SEND_CONTROL] = "CONTROL SEND", - [RDMA_WRID_RECV_CONTROL] = "CONTROL RECV", -}; - -/* - * Work request IDs for IB SEND messages only (not RDMA writes). - * This is used by the migration protocol to transmit - * control messages (such as device state and registration commands) - * - * We could use more WRs, but we have enough for now. - */ -enum { - RDMA_WRID_READY = 0, - RDMA_WRID_DATA, - RDMA_WRID_CONTROL, - RDMA_WRID_MAX, -}; - -/* - * SEND/RECV IB Control Messages. - */ -enum { - RDMA_CONTROL_NONE = 0, - RDMA_CONTROL_ERROR, - RDMA_CONTROL_READY, /* ready to receive */ - RDMA_CONTROL_QEMU_FILE, /* QEMUFile-transmitted bytes */ - RDMA_CONTROL_RAM_BLOCKS_REQUEST, /* RAMBlock synchronization */ - RDMA_CONTROL_RAM_BLOCKS_RESULT, /* RAMBlock synchronization */ - RDMA_CONTROL_COMPRESS, /* page contains repeat values */ - RDMA_CONTROL_REGISTER_REQUEST, /* dynamic page registration */ - RDMA_CONTROL_REGISTER_RESULT, /* key to use after registration */ - RDMA_CONTROL_REGISTER_FINISHED, /* current iteration finished */ - RDMA_CONTROL_UNREGISTER_REQUEST, /* dynamic UN-registration */ - RDMA_CONTROL_UNREGISTER_FINISHED, /* unpinning finished */ -}; - -static const char *control_desc[] = { - [RDMA_CONTROL_NONE] = "NONE", - [RDMA_CONTROL_ERROR] = "ERROR", - [RDMA_CONTROL_READY] = "READY", - [RDMA_CONTROL_QEMU_FILE] = "QEMU FILE", - [RDMA_CONTROL_RAM_BLOCKS_REQUEST] = "RAM BLOCKS REQUEST", - [RDMA_CONTROL_RAM_BLOCKS_RESULT] = "RAM BLOCKS RESULT", - [RDMA_CONTROL_COMPRESS] = "COMPRESS", - [RDMA_CONTROL_REGISTER_REQUEST] = "REGISTER REQUEST", - [RDMA_CONTROL_REGISTER_RESULT] = "REGISTER RESULT", - [RDMA_CONTROL_REGISTER_FINISHED] = "REGISTER FINISHED", - [RDMA_CONTROL_UNREGISTER_REQUEST] = "UNREGISTER REQUEST", - [RDMA_CONTROL_UNREGISTER_FINISHED] = "UNREGISTER FINISHED", -}; - -/* - * Memory and MR structures used to represent an IB Send/Recv work request. - * This is *not* used for RDMA writes, only IB Send/Recv. - */ -typedef struct { - uint8_t control[RDMA_CONTROL_MAX_BUFFER]; /* actual buffer to register */ - struct ibv_mr *control_mr; /* registration metadata */ - size_t control_len; /* length of the message */ - uint8_t *control_curr; /* start of unconsumed bytes */ -} RDMAWorkRequestData; - -/* - * Negotiate RDMA capabilities during connection-setup time. - */ -typedef struct { - uint32_t version; - uint32_t flags; -} RDMACapabilities; - -static void caps_to_network(RDMACapabilities *cap) -{ - cap->version = htonl(cap->version); - cap->flags = htonl(cap->flags); -} - -static void network_to_caps(RDMACapabilities *cap) -{ - cap->version = ntohl(cap->version); - cap->flags = ntohl(cap->flags); -} - -/* - * Representation of a RAMBlock from an RDMA perspective. - * This is not transmitted, only local. - * This and subsequent structures cannot be linked lists - * because we're using a single IB message to transmit - * the information. It's small anyway, so a list is overkill. - */ -typedef struct RDMALocalBlock { - char *block_name; - uint8_t *local_host_addr; /* local virtual address */ - uint64_t remote_host_addr; /* remote virtual address */ - uint64_t offset; - uint64_t length; - struct ibv_mr **pmr; /* MRs for chunk-level registration */ - struct ibv_mr *mr; /* MR for non-chunk-level registration */ - uint32_t *remote_keys; /* rkeys for chunk-level registration */ - uint32_t remote_rkey; /* rkeys for non-chunk-level registration */ - int index; /* which block are we */ - unsigned int src_index; /* (Only used on dest) */ - bool is_ram_block; - int nb_chunks; - unsigned long *transit_bitmap; - unsigned long *unregister_bitmap; -} RDMALocalBlock; - -/* - * Also represents a RAMblock, but only on the dest. - * This gets transmitted by the dest during connection-time - * to the source VM and then is used to populate the - * corresponding RDMALocalBlock with - * the information needed to perform the actual RDMA. - */ -typedef struct QEMU_PACKED RDMADestBlock { - uint64_t remote_host_addr; - uint64_t offset; - uint64_t length; - uint32_t remote_rkey; - uint32_t padding; -} RDMADestBlock; - -static uint64_t htonll(uint64_t v) -{ - union { uint32_t lv[2]; uint64_t llv; } u; - u.lv[0] = htonl(v >> 32); - u.lv[1] = htonl(v & 0xFFFFFFFFULL); - return u.llv; -} - -static uint64_t ntohll(uint64_t v) { - union { uint32_t lv[2]; uint64_t llv; } u; - u.llv = v; - return ((uint64_t)ntohl(u.lv[0]) << 32) | (uint64_t) ntohl(u.lv[1]); -} - -static void dest_block_to_network(RDMADestBlock *db) -{ - db->remote_host_addr = htonll(db->remote_host_addr); - db->offset = htonll(db->offset); - db->length = htonll(db->length); - db->remote_rkey = htonl(db->remote_rkey); -} - -static void network_to_dest_block(RDMADestBlock *db) -{ - db->remote_host_addr = ntohll(db->remote_host_addr); - db->offset = ntohll(db->offset); - db->length = ntohll(db->length); - db->remote_rkey = ntohl(db->remote_rkey); -} - -/* - * Virtual address of the above structures used for transmitting - * the RAMBlock descriptions at connection-time. - * This structure is *not* transmitted. - */ -typedef struct RDMALocalBlocks { - int nb_blocks; - bool init; /* main memory init complete */ - RDMALocalBlock *block; -} RDMALocalBlocks; - -/* - * Main data structure for RDMA state. - * While there is only one copy of this structure being allocated right now, - * this is the place where one would start if you wanted to consider - * having more than one RDMA connection open at the same time. - */ -typedef struct RDMAContext { - char *host; - int port; - - RDMAWorkRequestData wr_data[RDMA_WRID_MAX]; - - /* - * This is used by *_exchange_send() to figure out whether or not - * the initial "READY" message has already been received or not. - * This is because other functions may potentially poll() and detect - * the READY message before send() does, in which case we need to - * know if it completed. - */ - int control_ready_expected; - - /* number of outstanding writes */ - int nb_sent; - - /* store info about current buffer so that we can - merge it with future sends */ - uint64_t current_addr; - uint64_t current_length; - /* index of ram block the current buffer belongs to */ - int current_index; - /* index of the chunk in the current ram block */ - int current_chunk; - - bool pin_all; - - /* - * infiniband-specific variables for opening the device - * and maintaining connection state and so forth. - * - * cm_id also has ibv_context, rdma_event_channel, and ibv_qp in - * cm_id->verbs, cm_id->channel, and cm_id->qp. - */ - struct rdma_cm_id *cm_id; /* connection manager ID */ - struct rdma_cm_id *listen_id; - bool connected; - - struct ibv_context *verbs; - struct rdma_event_channel *channel; - struct ibv_qp *qp; /* queue pair */ - struct ibv_comp_channel *comp_channel; /* completion channel */ - struct ibv_pd *pd; /* protection domain */ - struct ibv_cq *cq; /* completion queue */ - - /* - * If a previous write failed (perhaps because of a failed - * memory registration, then do not attempt any future work - * and remember the error state. - */ - int error_state; - int error_reported; - - /* - * Description of ram blocks used throughout the code. - */ - RDMALocalBlocks local_ram_blocks; - RDMADestBlock *dest_blocks; - - /* Index of the next RAMBlock received during block registration */ - unsigned int next_src_index; - - /* - * Migration on *destination* started. - * Then use coroutine yield function. - * Source runs in a thread, so we don't care. - */ - int migration_started_on_destination; - - int total_registrations; - int total_writes; - - int unregister_current, unregister_next; - uint64_t unregistrations[RDMA_SIGNALED_SEND_MAX]; - - GHashTable *blockmap; -} RDMAContext; - -/* - * Interface to the rest of the migration call stack. - */ -typedef struct QEMUFileRDMA { - RDMAContext *rdma; - size_t len; - void *file; -} QEMUFileRDMA; - -/* - * Main structure for IB Send/Recv control messages. - * This gets prepended at the beginning of every Send/Recv. - */ -typedef struct QEMU_PACKED { - uint32_t len; /* Total length of data portion */ - uint32_t type; /* which control command to perform */ - uint32_t repeat; /* number of commands in data portion of same type */ - uint32_t padding; -} RDMAControlHeader; - -static void control_to_network(RDMAControlHeader *control) -{ - control->type = htonl(control->type); - control->len = htonl(control->len); - control->repeat = htonl(control->repeat); -} - -static void network_to_control(RDMAControlHeader *control) -{ - control->type = ntohl(control->type); - control->len = ntohl(control->len); - control->repeat = ntohl(control->repeat); -} - -/* - * Register a single Chunk. - * Information sent by the source VM to inform the dest - * to register an single chunk of memory before we can perform - * the actual RDMA operation. - */ -typedef struct QEMU_PACKED { - union QEMU_PACKED { - uint64_t current_addr; /* offset into the ram_addr_t space */ - uint64_t chunk; /* chunk to lookup if unregistering */ - } key; - uint32_t current_index; /* which ramblock the chunk belongs to */ - uint32_t padding; - uint64_t chunks; /* how many sequential chunks to register */ -} RDMARegister; - -static void register_to_network(RDMAContext *rdma, RDMARegister *reg) -{ - RDMALocalBlock *local_block; - local_block = &rdma->local_ram_blocks.block[reg->current_index]; - - if (local_block->is_ram_block) { - /* - * current_addr as passed in is an address in the local ram_addr_t - * space, we need to translate this for the destination - */ - reg->key.current_addr -= local_block->offset; - reg->key.current_addr += rdma->dest_blocks[reg->current_index].offset; - } - reg->key.current_addr = htonll(reg->key.current_addr); - reg->current_index = htonl(reg->current_index); - reg->chunks = htonll(reg->chunks); -} - -static void network_to_register(RDMARegister *reg) -{ - reg->key.current_addr = ntohll(reg->key.current_addr); - reg->current_index = ntohl(reg->current_index); - reg->chunks = ntohll(reg->chunks); -} - -typedef struct QEMU_PACKED { - uint32_t value; /* if zero, we will madvise() */ - uint32_t block_idx; /* which ram block index */ - uint64_t offset; /* Address in remote ram_addr_t space */ - uint64_t length; /* length of the chunk */ -} RDMACompress; - -static void compress_to_network(RDMAContext *rdma, RDMACompress *comp) -{ - comp->value = htonl(comp->value); - /* - * comp->offset as passed in is an address in the local ram_addr_t - * space, we need to translate this for the destination - */ - comp->offset -= rdma->local_ram_blocks.block[comp->block_idx].offset; - comp->offset += rdma->dest_blocks[comp->block_idx].offset; - comp->block_idx = htonl(comp->block_idx); - comp->offset = htonll(comp->offset); - comp->length = htonll(comp->length); -} - -static void network_to_compress(RDMACompress *comp) -{ - comp->value = ntohl(comp->value); - comp->block_idx = ntohl(comp->block_idx); - comp->offset = ntohll(comp->offset); - comp->length = ntohll(comp->length); -} - -/* - * The result of the dest's memory registration produces an "rkey" - * which the source VM must reference in order to perform - * the RDMA operation. - */ -typedef struct QEMU_PACKED { - uint32_t rkey; - uint32_t padding; - uint64_t host_addr; -} RDMARegisterResult; - -static void result_to_network(RDMARegisterResult *result) -{ - result->rkey = htonl(result->rkey); - result->host_addr = htonll(result->host_addr); -}; - -static void network_to_result(RDMARegisterResult *result) -{ - result->rkey = ntohl(result->rkey); - result->host_addr = ntohll(result->host_addr); -}; - -const char *print_wrid(int wrid); -static int qemu_rdma_exchange_send(RDMAContext *rdma, RDMAControlHeader *head, - uint8_t *data, RDMAControlHeader *resp, - int *resp_idx, - int (*callback)(RDMAContext *rdma)); - -static inline uint64_t ram_chunk_index(const uint8_t *start, - const uint8_t *host) -{ - return ((uintptr_t) host - (uintptr_t) start) >> RDMA_REG_CHUNK_SHIFT; -} - -static inline uint8_t *ram_chunk_start(const RDMALocalBlock *rdma_ram_block, - uint64_t i) -{ - return (uint8_t *)(uintptr_t)(rdma_ram_block->local_host_addr + - (i << RDMA_REG_CHUNK_SHIFT)); -} - -static inline uint8_t *ram_chunk_end(const RDMALocalBlock *rdma_ram_block, - uint64_t i) -{ - uint8_t *result = ram_chunk_start(rdma_ram_block, i) + - (1UL << RDMA_REG_CHUNK_SHIFT); - - if (result > (rdma_ram_block->local_host_addr + rdma_ram_block->length)) { - result = rdma_ram_block->local_host_addr + rdma_ram_block->length; - } - - return result; -} - -static int rdma_add_block(RDMAContext *rdma, const char *block_name, - void *host_addr, - ram_addr_t block_offset, uint64_t length) -{ - RDMALocalBlocks *local = &rdma->local_ram_blocks; - RDMALocalBlock *block; - RDMALocalBlock *old = local->block; - - local->block = g_new0(RDMALocalBlock, local->nb_blocks + 1); - - if (local->nb_blocks) { - int x; - - if (rdma->blockmap) { - for (x = 0; x < local->nb_blocks; x++) { - g_hash_table_remove(rdma->blockmap, - (void *)(uintptr_t)old[x].offset); - g_hash_table_insert(rdma->blockmap, - (void *)(uintptr_t)old[x].offset, - &local->block[x]); - } - } - memcpy(local->block, old, sizeof(RDMALocalBlock) * local->nb_blocks); - g_free(old); - } - - block = &local->block[local->nb_blocks]; - - block->block_name = g_strdup(block_name); - block->local_host_addr = host_addr; - block->offset = block_offset; - block->length = length; - block->index = local->nb_blocks; - block->src_index = ~0U; /* Filled in by the receipt of the block list */ - block->nb_chunks = ram_chunk_index(host_addr, host_addr + length) + 1UL; - block->transit_bitmap = bitmap_new(block->nb_chunks); - bitmap_clear(block->transit_bitmap, 0, block->nb_chunks); - block->unregister_bitmap = bitmap_new(block->nb_chunks); - bitmap_clear(block->unregister_bitmap, 0, block->nb_chunks); - block->remote_keys = g_new0(uint32_t, block->nb_chunks); - - block->is_ram_block = local->init ? false : true; - - if (rdma->blockmap) { - g_hash_table_insert(rdma->blockmap, (void *)(uintptr_t)block_offset, block); - } - - trace_rdma_add_block(block_name, local->nb_blocks, - (uintptr_t) block->local_host_addr, - block->offset, block->length, - (uintptr_t) (block->local_host_addr + block->length), - BITS_TO_LONGS(block->nb_chunks) * - sizeof(unsigned long) * 8, - block->nb_chunks); - - local->nb_blocks++; - - return 0; -} - -/* - * Memory regions need to be registered with the device and queue pairs setup - * in advanced before the migration starts. This tells us where the RAM blocks - * are so that we can register them individually. - */ -static int qemu_rdma_init_one_block(const char *block_name, void *host_addr, - ram_addr_t block_offset, ram_addr_t length, void *opaque) -{ - return rdma_add_block(opaque, block_name, host_addr, block_offset, length); -} - -/* - * Identify the RAMBlocks and their quantity. They will be references to - * identify chunk boundaries inside each RAMBlock and also be referenced - * during dynamic page registration. - */ -static int qemu_rdma_init_ram_blocks(RDMAContext *rdma) -{ - RDMALocalBlocks *local = &rdma->local_ram_blocks; - - assert(rdma->blockmap == NULL); - memset(local, 0, sizeof *local); - qemu_ram_foreach_block(qemu_rdma_init_one_block, rdma); - trace_qemu_rdma_init_ram_blocks(local->nb_blocks); - rdma->dest_blocks = g_new0(RDMADestBlock, - rdma->local_ram_blocks.nb_blocks); - local->init = true; - return 0; -} - -/* - * Note: If used outside of cleanup, the caller must ensure that the destination - * block structures are also updated - */ -static int rdma_delete_block(RDMAContext *rdma, RDMALocalBlock *block) -{ - RDMALocalBlocks *local = &rdma->local_ram_blocks; - RDMALocalBlock *old = local->block; - int x; - - if (rdma->blockmap) { - g_hash_table_remove(rdma->blockmap, (void *)(uintptr_t)block->offset); - } - if (block->pmr) { - int j; - - for (j = 0; j < block->nb_chunks; j++) { - if (!block->pmr[j]) { - continue; - } - ibv_dereg_mr(block->pmr[j]); - rdma->total_registrations--; - } - g_free(block->pmr); - block->pmr = NULL; - } - - if (block->mr) { - ibv_dereg_mr(block->mr); - rdma->total_registrations--; - block->mr = NULL; - } - - g_free(block->transit_bitmap); - block->transit_bitmap = NULL; - - g_free(block->unregister_bitmap); - block->unregister_bitmap = NULL; - - g_free(block->remote_keys); - block->remote_keys = NULL; - - g_free(block->block_name); - block->block_name = NULL; - - if (rdma->blockmap) { - for (x = 0; x < local->nb_blocks; x++) { - g_hash_table_remove(rdma->blockmap, - (void *)(uintptr_t)old[x].offset); - } - } - - if (local->nb_blocks > 1) { - - local->block = g_new0(RDMALocalBlock, local->nb_blocks - 1); - - if (block->index) { - memcpy(local->block, old, sizeof(RDMALocalBlock) * block->index); - } - - if (block->index < (local->nb_blocks - 1)) { - memcpy(local->block + block->index, old + (block->index + 1), - sizeof(RDMALocalBlock) * - (local->nb_blocks - (block->index + 1))); - } - } else { - assert(block == local->block); - local->block = NULL; - } - - trace_rdma_delete_block(block, (uintptr_t)block->local_host_addr, - block->offset, block->length, - (uintptr_t)(block->local_host_addr + block->length), - BITS_TO_LONGS(block->nb_chunks) * - sizeof(unsigned long) * 8, block->nb_chunks); - - g_free(old); - - local->nb_blocks--; - - if (local->nb_blocks && rdma->blockmap) { - for (x = 0; x < local->nb_blocks; x++) { - g_hash_table_insert(rdma->blockmap, - (void *)(uintptr_t)local->block[x].offset, - &local->block[x]); - } - } - - return 0; -} - -/* - * Put in the log file which RDMA device was opened and the details - * associated with that device. - */ -static void qemu_rdma_dump_id(const char *who, struct ibv_context *verbs) -{ - struct ibv_port_attr port; - - if (ibv_query_port(verbs, 1, &port)) { - error_report("Failed to query port information"); - return; - } - - printf("%s RDMA Device opened: kernel name %s " - "uverbs device name %s, " - "infiniband_verbs class device path %s, " - "infiniband class device path %s, " - "transport: (%d) %s\n", - who, - verbs->device->name, - verbs->device->dev_name, - verbs->device->dev_path, - verbs->device->ibdev_path, - port.link_layer, - (port.link_layer == IBV_LINK_LAYER_INFINIBAND) ? "Infiniband" : - ((port.link_layer == IBV_LINK_LAYER_ETHERNET) - ? "Ethernet" : "Unknown")); -} - -/* - * Put in the log file the RDMA gid addressing information, - * useful for folks who have trouble understanding the - * RDMA device hierarchy in the kernel. - */ -static void qemu_rdma_dump_gid(const char *who, struct rdma_cm_id *id) -{ - char sgid[33]; - char dgid[33]; - inet_ntop(AF_INET6, &id->route.addr.addr.ibaddr.sgid, sgid, sizeof sgid); - inet_ntop(AF_INET6, &id->route.addr.addr.ibaddr.dgid, dgid, sizeof dgid); - trace_qemu_rdma_dump_gid(who, sgid, dgid); -} - -/* - * As of now, IPv6 over RoCE / iWARP is not supported by linux. - * We will try the next addrinfo struct, and fail if there are - * no other valid addresses to bind against. - * - * If user is listening on '[::]', then we will not have a opened a device - * yet and have no way of verifying if the device is RoCE or not. - * - * In this case, the source VM will throw an error for ALL types of - * connections (both IPv4 and IPv6) if the destination machine does not have - * a regular infiniband network available for use. - * - * The only way to guarantee that an error is thrown for broken kernels is - * for the management software to choose a *specific* interface at bind time - * and validate what time of hardware it is. - * - * Unfortunately, this puts the user in a fix: - * - * If the source VM connects with an IPv4 address without knowing that the - * destination has bound to '[::]' the migration will unconditionally fail - * unless the management software is explicitly listening on the IPv4 - * address while using a RoCE-based device. - * - * If the source VM connects with an IPv6 address, then we're OK because we can - * throw an error on the source (and similarly on the destination). - * - * But in mixed environments, this will be broken for a while until it is fixed - * inside linux. - * - * We do provide a *tiny* bit of help in this function: We can list all of the - * devices in the system and check to see if all the devices are RoCE or - * Infiniband. - * - * If we detect that we have a *pure* RoCE environment, then we can safely - * thrown an error even if the management software has specified '[::]' as the - * bind address. - * - * However, if there is are multiple hetergeneous devices, then we cannot make - * this assumption and the user just has to be sure they know what they are - * doing. - * - * Patches are being reviewed on linux-rdma. - */ -static int qemu_rdma_broken_ipv6_kernel(Error **errp, struct ibv_context *verbs) -{ - struct ibv_port_attr port_attr; - - /* This bug only exists in linux, to our knowledge. */ -#ifdef CONFIG_LINUX - - /* - * Verbs are only NULL if management has bound to '[::]'. - * - * Let's iterate through all the devices and see if there any pure IB - * devices (non-ethernet). - * - * If not, then we can safely proceed with the migration. - * Otherwise, there are no guarantees until the bug is fixed in linux. - */ - if (!verbs) { - int num_devices, x; - struct ibv_device ** dev_list = ibv_get_device_list(&num_devices); - bool roce_found = false; - bool ib_found = false; - - for (x = 0; x < num_devices; x++) { - verbs = ibv_open_device(dev_list[x]); - if (!verbs) { - if (errno == EPERM) { - continue; - } else { - return -EINVAL; - } - } - - if (ibv_query_port(verbs, 1, &port_attr)) { - ibv_close_device(verbs); - ERROR(errp, "Could not query initial IB port"); - return -EINVAL; - } - - if (port_attr.link_layer == IBV_LINK_LAYER_INFINIBAND) { - ib_found = true; - } else if (port_attr.link_layer == IBV_LINK_LAYER_ETHERNET) { - roce_found = true; - } - - ibv_close_device(verbs); - - } - - if (roce_found) { - if (ib_found) { - fprintf(stderr, "WARN: migrations may fail:" - " IPv6 over RoCE / iWARP in linux" - " is broken. But since you appear to have a" - " mixed RoCE / IB environment, be sure to only" - " migrate over the IB fabric until the kernel " - " fixes the bug.\n"); - } else { - ERROR(errp, "You only have RoCE / iWARP devices in your systems" - " and your management software has specified '[::]'" - ", but IPv6 over RoCE / iWARP is not supported in Linux."); - return -ENONET; - } - } - - return 0; - } - - /* - * If we have a verbs context, that means that some other than '[::]' was - * used by the management software for binding. In which case we can - * actually warn the user about a potentially broken kernel. - */ - - /* IB ports start with 1, not 0 */ - if (ibv_query_port(verbs, 1, &port_attr)) { - ERROR(errp, "Could not query initial IB port"); - return -EINVAL; - } - - if (port_attr.link_layer == IBV_LINK_LAYER_ETHERNET) { - ERROR(errp, "Linux kernel's RoCE / iWARP does not support IPv6 " - "(but patches on linux-rdma in progress)"); - return -ENONET; - } - -#endif - - return 0; -} - -/* - * Figure out which RDMA device corresponds to the requested IP hostname - * Also create the initial connection manager identifiers for opening - * the connection. - */ -static int qemu_rdma_resolve_host(RDMAContext *rdma, Error **errp) -{ - int ret; - struct rdma_addrinfo *res; - char port_str[16]; - struct rdma_cm_event *cm_event; - char ip[40] = "unknown"; - struct rdma_addrinfo *e; - - if (rdma->host == NULL || !strcmp(rdma->host, "")) { - ERROR(errp, "RDMA hostname has not been set"); - return -EINVAL; - } - - /* create CM channel */ - rdma->channel = rdma_create_event_channel(); - if (!rdma->channel) { - ERROR(errp, "could not create CM channel"); - return -EINVAL; - } - - /* create CM id */ - ret = rdma_create_id(rdma->channel, &rdma->cm_id, NULL, RDMA_PS_TCP); - if (ret) { - ERROR(errp, "could not create channel id"); - goto err_resolve_create_id; - } - - snprintf(port_str, 16, "%d", rdma->port); - port_str[15] = '\0'; - - ret = rdma_getaddrinfo(rdma->host, port_str, NULL, &res); - if (ret < 0) { - ERROR(errp, "could not rdma_getaddrinfo address %s", rdma->host); - goto err_resolve_get_addr; - } - - for (e = res; e != NULL; e = e->ai_next) { - inet_ntop(e->ai_family, - &((struct sockaddr_in *) e->ai_dst_addr)->sin_addr, ip, sizeof ip); - trace_qemu_rdma_resolve_host_trying(rdma->host, ip); - - ret = rdma_resolve_addr(rdma->cm_id, NULL, e->ai_dst_addr, - RDMA_RESOLVE_TIMEOUT_MS); - if (!ret) { - if (e->ai_family == AF_INET6) { - ret = qemu_rdma_broken_ipv6_kernel(errp, rdma->cm_id->verbs); - if (ret) { - continue; - } - } - goto route; - } - } - - ERROR(errp, "could not resolve address %s", rdma->host); - goto err_resolve_get_addr; - -route: - qemu_rdma_dump_gid("source_resolve_addr", rdma->cm_id); - - ret = rdma_get_cm_event(rdma->channel, &cm_event); - if (ret) { - ERROR(errp, "could not perform event_addr_resolved"); - goto err_resolve_get_addr; - } - - if (cm_event->event != RDMA_CM_EVENT_ADDR_RESOLVED) { - ERROR(errp, "result not equal to event_addr_resolved %s", - rdma_event_str(cm_event->event)); - perror("rdma_resolve_addr"); - rdma_ack_cm_event(cm_event); - ret = -EINVAL; - goto err_resolve_get_addr; - } - rdma_ack_cm_event(cm_event); - - /* resolve route */ - ret = rdma_resolve_route(rdma->cm_id, RDMA_RESOLVE_TIMEOUT_MS); - if (ret) { - ERROR(errp, "could not resolve rdma route"); - goto err_resolve_get_addr; - } - - ret = rdma_get_cm_event(rdma->channel, &cm_event); - if (ret) { - ERROR(errp, "could not perform event_route_resolved"); - goto err_resolve_get_addr; - } - if (cm_event->event != RDMA_CM_EVENT_ROUTE_RESOLVED) { - ERROR(errp, "result not equal to event_route_resolved: %s", - rdma_event_str(cm_event->event)); - rdma_ack_cm_event(cm_event); - ret = -EINVAL; - goto err_resolve_get_addr; - } - rdma_ack_cm_event(cm_event); - rdma->verbs = rdma->cm_id->verbs; - qemu_rdma_dump_id("source_resolve_host", rdma->cm_id->verbs); - qemu_rdma_dump_gid("source_resolve_host", rdma->cm_id); - return 0; - -err_resolve_get_addr: - rdma_destroy_id(rdma->cm_id); - rdma->cm_id = NULL; -err_resolve_create_id: - rdma_destroy_event_channel(rdma->channel); - rdma->channel = NULL; - return ret; -} - -/* - * Create protection domain and completion queues - */ -static int qemu_rdma_alloc_pd_cq(RDMAContext *rdma) -{ - /* allocate pd */ - rdma->pd = ibv_alloc_pd(rdma->verbs); - if (!rdma->pd) { - error_report("failed to allocate protection domain"); - return -1; - } - - /* create completion channel */ - rdma->comp_channel = ibv_create_comp_channel(rdma->verbs); - if (!rdma->comp_channel) { - error_report("failed to allocate completion channel"); - goto err_alloc_pd_cq; - } - - /* - * Completion queue can be filled by both read and write work requests, - * so must reflect the sum of both possible queue sizes. - */ - rdma->cq = ibv_create_cq(rdma->verbs, (RDMA_SIGNALED_SEND_MAX * 3), - NULL, rdma->comp_channel, 0); - if (!rdma->cq) { - error_report("failed to allocate completion queue"); - goto err_alloc_pd_cq; - } - - return 0; - -err_alloc_pd_cq: - if (rdma->pd) { - ibv_dealloc_pd(rdma->pd); - } - if (rdma->comp_channel) { - ibv_destroy_comp_channel(rdma->comp_channel); - } - rdma->pd = NULL; - rdma->comp_channel = NULL; - return -1; - -} - -/* - * Create queue pairs. - */ -static int qemu_rdma_alloc_qp(RDMAContext *rdma) -{ - struct ibv_qp_init_attr attr = { 0 }; - int ret; - - attr.cap.max_send_wr = RDMA_SIGNALED_SEND_MAX; - attr.cap.max_recv_wr = 3; - attr.cap.max_send_sge = 1; - attr.cap.max_recv_sge = 1; - attr.send_cq = rdma->cq; - attr.recv_cq = rdma->cq; - attr.qp_type = IBV_QPT_RC; - - ret = rdma_create_qp(rdma->cm_id, rdma->pd, &attr); - if (ret) { - return -1; - } - - rdma->qp = rdma->cm_id->qp; - return 0; -} - -static int qemu_rdma_reg_whole_ram_blocks(RDMAContext *rdma) -{ - int i; - RDMALocalBlocks *local = &rdma->local_ram_blocks; - - for (i = 0; i < local->nb_blocks; i++) { - local->block[i].mr = - ibv_reg_mr(rdma->pd, - local->block[i].local_host_addr, - local->block[i].length, - IBV_ACCESS_LOCAL_WRITE | - IBV_ACCESS_REMOTE_WRITE - ); - if (!local->block[i].mr) { - perror("Failed to register local dest ram block!\n"); - break; - } - rdma->total_registrations++; - } - - if (i >= local->nb_blocks) { - return 0; - } - - for (i--; i >= 0; i--) { - ibv_dereg_mr(local->block[i].mr); - rdma->total_registrations--; - } - - return -1; - -} - -/* - * Find the ram block that corresponds to the page requested to be - * transmitted by QEMU. - * - * Once the block is found, also identify which 'chunk' within that - * block that the page belongs to. - * - * This search cannot fail or the migration will fail. - */ -static int qemu_rdma_search_ram_block(RDMAContext *rdma, - uintptr_t block_offset, - uint64_t offset, - uint64_t length, - uint64_t *block_index, - uint64_t *chunk_index) -{ - uint64_t current_addr = block_offset + offset; - RDMALocalBlock *block = g_hash_table_lookup(rdma->blockmap, - (void *) block_offset); - assert(block); - assert(current_addr >= block->offset); - assert((current_addr + length) <= (block->offset + block->length)); - - *block_index = block->index; - *chunk_index = ram_chunk_index(block->local_host_addr, - block->local_host_addr + (current_addr - block->offset)); - - return 0; -} - -/* - * Register a chunk with IB. If the chunk was already registered - * previously, then skip. - * - * Also return the keys associated with the registration needed - * to perform the actual RDMA operation. - */ -static int qemu_rdma_register_and_get_keys(RDMAContext *rdma, - RDMALocalBlock *block, uintptr_t host_addr, - uint32_t *lkey, uint32_t *rkey, int chunk, - uint8_t *chunk_start, uint8_t *chunk_end) -{ - if (block->mr) { - if (lkey) { - *lkey = block->mr->lkey; - } - if (rkey) { - *rkey = block->mr->rkey; - } - return 0; - } - - /* allocate memory to store chunk MRs */ - if (!block->pmr) { - block->pmr = g_new0(struct ibv_mr *, block->nb_chunks); - } - - /* - * If 'rkey', then we're the destination, so grant access to the source. - * - * If 'lkey', then we're the source VM, so grant access only to ourselves. - */ - if (!block->pmr[chunk]) { - uint64_t len = chunk_end - chunk_start; - - trace_qemu_rdma_register_and_get_keys(len, chunk_start); - - block->pmr[chunk] = ibv_reg_mr(rdma->pd, - chunk_start, len, - (rkey ? (IBV_ACCESS_LOCAL_WRITE | - IBV_ACCESS_REMOTE_WRITE) : 0)); - - if (!block->pmr[chunk]) { - perror("Failed to register chunk!"); - fprintf(stderr, "Chunk details: block: %d chunk index %d" - " start %" PRIuPTR " end %" PRIuPTR - " host %" PRIuPTR - " local %" PRIuPTR " registrations: %d\n", - block->index, chunk, (uintptr_t)chunk_start, - (uintptr_t)chunk_end, host_addr, - (uintptr_t)block->local_host_addr, - rdma->total_registrations); - return -1; - } - rdma->total_registrations++; - } - - if (lkey) { - *lkey = block->pmr[chunk]->lkey; - } - if (rkey) { - *rkey = block->pmr[chunk]->rkey; - } - return 0; -} - -/* - * Register (at connection time) the memory used for control - * channel messages. - */ -static int qemu_rdma_reg_control(RDMAContext *rdma, int idx) -{ - rdma->wr_data[idx].control_mr = ibv_reg_mr(rdma->pd, - rdma->wr_data[idx].control, RDMA_CONTROL_MAX_BUFFER, - IBV_ACCESS_LOCAL_WRITE | IBV_ACCESS_REMOTE_WRITE); - if (rdma->wr_data[idx].control_mr) { - rdma->total_registrations++; - return 0; - } - error_report("qemu_rdma_reg_control failed"); - return -1; -} - -const char *print_wrid(int wrid) -{ - if (wrid >= RDMA_WRID_RECV_CONTROL) { - return wrid_desc[RDMA_WRID_RECV_CONTROL]; - } - return wrid_desc[wrid]; -} - -/* - * RDMA requires memory registration (mlock/pinning), but this is not good for - * overcommitment. - * - * In preparation for the future where LRU information or workload-specific - * writable writable working set memory access behavior is available to QEMU - * it would be nice to have in place the ability to UN-register/UN-pin - * particular memory regions from the RDMA hardware when it is determine that - * those regions of memory will likely not be accessed again in the near future. - * - * While we do not yet have such information right now, the following - * compile-time option allows us to perform a non-optimized version of this - * behavior. - * - * By uncommenting this option, you will cause *all* RDMA transfers to be - * unregistered immediately after the transfer completes on both sides of the - * connection. This has no effect in 'rdma-pin-all' mode, only regular mode. - * - * This will have a terrible impact on migration performance, so until future - * workload information or LRU information is available, do not attempt to use - * this feature except for basic testing. - */ -//#define RDMA_UNREGISTRATION_EXAMPLE - -/* - * Perform a non-optimized memory unregistration after every transfer - * for demonstration purposes, only if pin-all is not requested. - * - * Potential optimizations: - * 1. Start a new thread to run this function continuously - - for bit clearing - - and for receipt of unregister messages - * 2. Use an LRU. - * 3. Use workload hints. - */ -static int qemu_rdma_unregister_waiting(RDMAContext *rdma) -{ - while (rdma->unregistrations[rdma->unregister_current]) { - int ret; - uint64_t wr_id = rdma->unregistrations[rdma->unregister_current]; - uint64_t chunk = - (wr_id & RDMA_WRID_CHUNK_MASK) >> RDMA_WRID_CHUNK_SHIFT; - uint64_t index = - (wr_id & RDMA_WRID_BLOCK_MASK) >> RDMA_WRID_BLOCK_SHIFT; - RDMALocalBlock *block = - &(rdma->local_ram_blocks.block[index]); - RDMARegister reg = { .current_index = index }; - RDMAControlHeader resp = { .type = RDMA_CONTROL_UNREGISTER_FINISHED, - }; - RDMAControlHeader head = { .len = sizeof(RDMARegister), - .type = RDMA_CONTROL_UNREGISTER_REQUEST, - .repeat = 1, - }; - - trace_qemu_rdma_unregister_waiting_proc(chunk, - rdma->unregister_current); - - rdma->unregistrations[rdma->unregister_current] = 0; - rdma->unregister_current++; - - if (rdma->unregister_current == RDMA_SIGNALED_SEND_MAX) { - rdma->unregister_current = 0; - } - - - /* - * Unregistration is speculative (because migration is single-threaded - * and we cannot break the protocol's inifinband message ordering). - * Thus, if the memory is currently being used for transmission, - * then abort the attempt to unregister and try again - * later the next time a completion is received for this memory. - */ - clear_bit(chunk, block->unregister_bitmap); - - if (test_bit(chunk, block->transit_bitmap)) { - trace_qemu_rdma_unregister_waiting_inflight(chunk); - continue; - } - - trace_qemu_rdma_unregister_waiting_send(chunk); - - ret = ibv_dereg_mr(block->pmr[chunk]); - block->pmr[chunk] = NULL; - block->remote_keys[chunk] = 0; - - if (ret != 0) { - perror("unregistration chunk failed"); - return -ret; - } - rdma->total_registrations--; - - reg.key.chunk = chunk; - register_to_network(rdma, ®); - ret = qemu_rdma_exchange_send(rdma, &head, (uint8_t *) ®, - &resp, NULL, NULL); - if (ret < 0) { - return ret; - } - - trace_qemu_rdma_unregister_waiting_complete(chunk); - } - - return 0; -} - -static uint64_t qemu_rdma_make_wrid(uint64_t wr_id, uint64_t index, - uint64_t chunk) -{ - uint64_t result = wr_id & RDMA_WRID_TYPE_MASK; - - result |= (index << RDMA_WRID_BLOCK_SHIFT); - result |= (chunk << RDMA_WRID_CHUNK_SHIFT); - - return result; -} - -/* - * Set bit for unregistration in the next iteration. - * We cannot transmit right here, but will unpin later. - */ -static void qemu_rdma_signal_unregister(RDMAContext *rdma, uint64_t index, - uint64_t chunk, uint64_t wr_id) -{ - if (rdma->unregistrations[rdma->unregister_next] != 0) { - error_report("rdma migration: queue is full"); - } else { - RDMALocalBlock *block = &(rdma->local_ram_blocks.block[index]); - - if (!test_and_set_bit(chunk, block->unregister_bitmap)) { - trace_qemu_rdma_signal_unregister_append(chunk, - rdma->unregister_next); - - rdma->unregistrations[rdma->unregister_next++] = - qemu_rdma_make_wrid(wr_id, index, chunk); - - if (rdma->unregister_next == RDMA_SIGNALED_SEND_MAX) { - rdma->unregister_next = 0; - } - } else { - trace_qemu_rdma_signal_unregister_already(chunk); - } - } -} - -/* - * Consult the connection manager to see a work request - * (of any kind) has completed. - * Return the work request ID that completed. - */ -static uint64_t qemu_rdma_poll(RDMAContext *rdma, uint64_t *wr_id_out, - uint32_t *byte_len) -{ - int ret; - struct ibv_wc wc; - uint64_t wr_id; - - ret = ibv_poll_cq(rdma->cq, 1, &wc); - - if (!ret) { - *wr_id_out = RDMA_WRID_NONE; - return 0; - } - - if (ret < 0) { - error_report("ibv_poll_cq return %d", ret); - return ret; - } - - wr_id = wc.wr_id & RDMA_WRID_TYPE_MASK; - - if (wc.status != IBV_WC_SUCCESS) { - fprintf(stderr, "ibv_poll_cq wc.status=%d %s!\n", - wc.status, ibv_wc_status_str(wc.status)); - fprintf(stderr, "ibv_poll_cq wrid=%s!\n", wrid_desc[wr_id]); - - return -1; - } - - if (rdma->control_ready_expected && - (wr_id >= RDMA_WRID_RECV_CONTROL)) { - trace_qemu_rdma_poll_recv(wrid_desc[RDMA_WRID_RECV_CONTROL], - wr_id - RDMA_WRID_RECV_CONTROL, wr_id, rdma->nb_sent); - rdma->control_ready_expected = 0; - } - - if (wr_id == RDMA_WRID_RDMA_WRITE) { - uint64_t chunk = - (wc.wr_id & RDMA_WRID_CHUNK_MASK) >> RDMA_WRID_CHUNK_SHIFT; - uint64_t index = - (wc.wr_id & RDMA_WRID_BLOCK_MASK) >> RDMA_WRID_BLOCK_SHIFT; - RDMALocalBlock *block = &(rdma->local_ram_blocks.block[index]); - - trace_qemu_rdma_poll_write(print_wrid(wr_id), wr_id, rdma->nb_sent, - index, chunk, block->local_host_addr, - (void *)(uintptr_t)block->remote_host_addr); - - clear_bit(chunk, block->transit_bitmap); - - if (rdma->nb_sent > 0) { - rdma->nb_sent--; - } - - if (!rdma->pin_all) { - /* - * FYI: If one wanted to signal a specific chunk to be unregistered - * using LRU or workload-specific information, this is the function - * you would call to do so. That chunk would then get asynchronously - * unregistered later. - */ -#ifdef RDMA_UNREGISTRATION_EXAMPLE - qemu_rdma_signal_unregister(rdma, index, chunk, wc.wr_id); -#endif - } - } else { - trace_qemu_rdma_poll_other(print_wrid(wr_id), wr_id, rdma->nb_sent); - } - - *wr_id_out = wc.wr_id; - if (byte_len) { - *byte_len = wc.byte_len; - } - - return 0; -} - -/* - * Block until the next work request has completed. - * - * First poll to see if a work request has already completed, - * otherwise block. - * - * If we encounter completed work requests for IDs other than - * the one we're interested in, then that's generally an error. - * - * The only exception is actual RDMA Write completions. These - * completions only need to be recorded, but do not actually - * need further processing. - */ -static int qemu_rdma_block_for_wrid(RDMAContext *rdma, int wrid_requested, - uint32_t *byte_len) -{ - int num_cq_events = 0, ret = 0; - struct ibv_cq *cq; - void *cq_ctx; - uint64_t wr_id = RDMA_WRID_NONE, wr_id_in; - - if (ibv_req_notify_cq(rdma->cq, 0)) { - return -1; - } - /* poll cq first */ - while (wr_id != wrid_requested) { - ret = qemu_rdma_poll(rdma, &wr_id_in, byte_len); - if (ret < 0) { - return ret; - } - - wr_id = wr_id_in & RDMA_WRID_TYPE_MASK; - - if (wr_id == RDMA_WRID_NONE) { - break; - } - if (wr_id != wrid_requested) { - trace_qemu_rdma_block_for_wrid_miss(print_wrid(wrid_requested), - wrid_requested, print_wrid(wr_id), wr_id); - } - } - - if (wr_id == wrid_requested) { - return 0; - } - - while (1) { - /* - * Coroutine doesn't start until process_incoming_migration() - * so don't yield unless we know we're running inside of a coroutine. - */ - if (rdma->migration_started_on_destination) { - yield_until_fd_readable(rdma->comp_channel->fd); - } - - if (ibv_get_cq_event(rdma->comp_channel, &cq, &cq_ctx)) { - perror("ibv_get_cq_event"); - goto err_block_for_wrid; - } - - num_cq_events++; - - if (ibv_req_notify_cq(cq, 0)) { - goto err_block_for_wrid; - } - - while (wr_id != wrid_requested) { - ret = qemu_rdma_poll(rdma, &wr_id_in, byte_len); - if (ret < 0) { - goto err_block_for_wrid; - } - - wr_id = wr_id_in & RDMA_WRID_TYPE_MASK; - - if (wr_id == RDMA_WRID_NONE) { - break; - } - if (wr_id != wrid_requested) { - trace_qemu_rdma_block_for_wrid_miss(print_wrid(wrid_requested), - wrid_requested, print_wrid(wr_id), wr_id); - } - } - - if (wr_id == wrid_requested) { - goto success_block_for_wrid; - } - } - -success_block_for_wrid: - if (num_cq_events) { - ibv_ack_cq_events(cq, num_cq_events); - } - return 0; - -err_block_for_wrid: - if (num_cq_events) { - ibv_ack_cq_events(cq, num_cq_events); - } - return ret; -} - -/* - * Post a SEND message work request for the control channel - * containing some data and block until the post completes. - */ -static int qemu_rdma_post_send_control(RDMAContext *rdma, uint8_t *buf, - RDMAControlHeader *head) -{ - int ret = 0; - RDMAWorkRequestData *wr = &rdma->wr_data[RDMA_WRID_CONTROL]; - struct ibv_send_wr *bad_wr; - struct ibv_sge sge = { - .addr = (uintptr_t)(wr->control), - .length = head->len + sizeof(RDMAControlHeader), - .lkey = wr->control_mr->lkey, - }; - struct ibv_send_wr send_wr = { - .wr_id = RDMA_WRID_SEND_CONTROL, - .opcode = IBV_WR_SEND, - .send_flags = IBV_SEND_SIGNALED, - .sg_list = &sge, - .num_sge = 1, - }; - - trace_qemu_rdma_post_send_control(control_desc[head->type]); - - /* - * We don't actually need to do a memcpy() in here if we used - * the "sge" properly, but since we're only sending control messages - * (not RAM in a performance-critical path), then its OK for now. - * - * The copy makes the RDMAControlHeader simpler to manipulate - * for the time being. - */ - assert(head->len <= RDMA_CONTROL_MAX_BUFFER - sizeof(*head)); - memcpy(wr->control, head, sizeof(RDMAControlHeader)); - control_to_network((void *) wr->control); - - if (buf) { - memcpy(wr->control + sizeof(RDMAControlHeader), buf, head->len); - } - - - ret = ibv_post_send(rdma->qp, &send_wr, &bad_wr); - - if (ret > 0) { - error_report("Failed to use post IB SEND for control"); - return -ret; - } - - ret = qemu_rdma_block_for_wrid(rdma, RDMA_WRID_SEND_CONTROL, NULL); - if (ret < 0) { - error_report("rdma migration: send polling control error"); - } - - return ret; -} - -/* - * Post a RECV work request in anticipation of some future receipt - * of data on the control channel. - */ -static int qemu_rdma_post_recv_control(RDMAContext *rdma, int idx) -{ - struct ibv_recv_wr *bad_wr; - struct ibv_sge sge = { - .addr = (uintptr_t)(rdma->wr_data[idx].control), - .length = RDMA_CONTROL_MAX_BUFFER, - .lkey = rdma->wr_data[idx].control_mr->lkey, - }; - - struct ibv_recv_wr recv_wr = { - .wr_id = RDMA_WRID_RECV_CONTROL + idx, - .sg_list = &sge, - .num_sge = 1, - }; - - - if (ibv_post_recv(rdma->qp, &recv_wr, &bad_wr)) { - return -1; - } - - return 0; -} - -/* - * Block and wait for a RECV control channel message to arrive. - */ -static int qemu_rdma_exchange_get_response(RDMAContext *rdma, - RDMAControlHeader *head, int expecting, int idx) -{ - uint32_t byte_len; - int ret = qemu_rdma_block_for_wrid(rdma, RDMA_WRID_RECV_CONTROL + idx, - &byte_len); - - if (ret < 0) { - error_report("rdma migration: recv polling control error!"); - return ret; - } - - network_to_control((void *) rdma->wr_data[idx].control); - memcpy(head, rdma->wr_data[idx].control, sizeof(RDMAControlHeader)); - - trace_qemu_rdma_exchange_get_response_start(control_desc[expecting]); - - if (expecting == RDMA_CONTROL_NONE) { - trace_qemu_rdma_exchange_get_response_none(control_desc[head->type], - head->type); - } else if (head->type != expecting || head->type == RDMA_CONTROL_ERROR) { - error_report("Was expecting a %s (%d) control message" - ", but got: %s (%d), length: %d", - control_desc[expecting], expecting, - control_desc[head->type], head->type, head->len); - return -EIO; - } - if (head->len > RDMA_CONTROL_MAX_BUFFER - sizeof(*head)) { - error_report("too long length: %d", head->len); - return -EINVAL; - } - if (sizeof(*head) + head->len != byte_len) { - error_report("Malformed length: %d byte_len %d", head->len, byte_len); - return -EINVAL; - } - - return 0; -} - -/* - * When a RECV work request has completed, the work request's - * buffer is pointed at the header. - * - * This will advance the pointer to the data portion - * of the control message of the work request's buffer that - * was populated after the work request finished. - */ -static void qemu_rdma_move_header(RDMAContext *rdma, int idx, - RDMAControlHeader *head) -{ - rdma->wr_data[idx].control_len = head->len; - rdma->wr_data[idx].control_curr = - rdma->wr_data[idx].control + sizeof(RDMAControlHeader); -} - -/* - * This is an 'atomic' high-level operation to deliver a single, unified - * control-channel message. - * - * Additionally, if the user is expecting some kind of reply to this message, - * they can request a 'resp' response message be filled in by posting an - * additional work request on behalf of the user and waiting for an additional - * completion. - * - * The extra (optional) response is used during registration to us from having - * to perform an *additional* exchange of message just to provide a response by - * instead piggy-backing on the acknowledgement. - */ -static int qemu_rdma_exchange_send(RDMAContext *rdma, RDMAControlHeader *head, - uint8_t *data, RDMAControlHeader *resp, - int *resp_idx, - int (*callback)(RDMAContext *rdma)) -{ - int ret = 0; - - /* - * Wait until the dest is ready before attempting to deliver the message - * by waiting for a READY message. - */ - if (rdma->control_ready_expected) { - RDMAControlHeader resp; - ret = qemu_rdma_exchange_get_response(rdma, - &resp, RDMA_CONTROL_READY, RDMA_WRID_READY); - if (ret < 0) { - return ret; - } - } - - /* - * If the user is expecting a response, post a WR in anticipation of it. - */ - if (resp) { - ret = qemu_rdma_post_recv_control(rdma, RDMA_WRID_DATA); - if (ret) { - error_report("rdma migration: error posting" - " extra control recv for anticipated result!"); - return ret; - } - } - - /* - * Post a WR to replace the one we just consumed for the READY message. - */ - ret = qemu_rdma_post_recv_control(rdma, RDMA_WRID_READY); - if (ret) { - error_report("rdma migration: error posting first control recv!"); - return ret; - } - - /* - * Deliver the control message that was requested. - */ - ret = qemu_rdma_post_send_control(rdma, data, head); - - if (ret < 0) { - error_report("Failed to send control buffer!"); - return ret; - } - - /* - * If we're expecting a response, block and wait for it. - */ - if (resp) { - if (callback) { - trace_qemu_rdma_exchange_send_issue_callback(); - ret = callback(rdma); - if (ret < 0) { - return ret; - } - } - - trace_qemu_rdma_exchange_send_waiting(control_desc[resp->type]); - ret = qemu_rdma_exchange_get_response(rdma, resp, - resp->type, RDMA_WRID_DATA); - - if (ret < 0) { - return ret; - } - - qemu_rdma_move_header(rdma, RDMA_WRID_DATA, resp); - if (resp_idx) { - *resp_idx = RDMA_WRID_DATA; - } - trace_qemu_rdma_exchange_send_received(control_desc[resp->type]); - } - - rdma->control_ready_expected = 1; - - return 0; -} - -/* - * This is an 'atomic' high-level operation to receive a single, unified - * control-channel message. - */ -static int qemu_rdma_exchange_recv(RDMAContext *rdma, RDMAControlHeader *head, - int expecting) -{ - RDMAControlHeader ready = { - .len = 0, - .type = RDMA_CONTROL_READY, - .repeat = 1, - }; - int ret; - - /* - * Inform the source that we're ready to receive a message. - */ - ret = qemu_rdma_post_send_control(rdma, NULL, &ready); - - if (ret < 0) { - error_report("Failed to send control buffer!"); - return ret; - } - - /* - * Block and wait for the message. - */ - ret = qemu_rdma_exchange_get_response(rdma, head, - expecting, RDMA_WRID_READY); - - if (ret < 0) { - return ret; - } - - qemu_rdma_move_header(rdma, RDMA_WRID_READY, head); - - /* - * Post a new RECV work request to replace the one we just consumed. - */ - ret = qemu_rdma_post_recv_control(rdma, RDMA_WRID_READY); - if (ret) { - error_report("rdma migration: error posting second control recv!"); - return ret; - } - - return 0; -} - -/* - * Write an actual chunk of memory using RDMA. - * - * If we're using dynamic registration on the dest-side, we have to - * send a registration command first. - */ -static int qemu_rdma_write_one(QEMUFile *f, RDMAContext *rdma, - int current_index, uint64_t current_addr, - uint64_t length) -{ - struct ibv_sge sge; - struct ibv_send_wr send_wr = { 0 }; - struct ibv_send_wr *bad_wr; - int reg_result_idx, ret, count = 0; - uint64_t chunk, chunks; - uint8_t *chunk_start, *chunk_end; - RDMALocalBlock *block = &(rdma->local_ram_blocks.block[current_index]); - RDMARegister reg; - RDMARegisterResult *reg_result; - RDMAControlHeader resp = { .type = RDMA_CONTROL_REGISTER_RESULT }; - RDMAControlHeader head = { .len = sizeof(RDMARegister), - .type = RDMA_CONTROL_REGISTER_REQUEST, - .repeat = 1, - }; - -retry: - sge.addr = (uintptr_t)(block->local_host_addr + - (current_addr - block->offset)); - sge.length = length; - - chunk = ram_chunk_index(block->local_host_addr, - (uint8_t *)(uintptr_t)sge.addr); - chunk_start = ram_chunk_start(block, chunk); - - if (block->is_ram_block) { - chunks = length / (1UL << RDMA_REG_CHUNK_SHIFT); - - if (chunks && ((length % (1UL << RDMA_REG_CHUNK_SHIFT)) == 0)) { - chunks--; - } - } else { - chunks = block->length / (1UL << RDMA_REG_CHUNK_SHIFT); - - if (chunks && ((block->length % (1UL << RDMA_REG_CHUNK_SHIFT)) == 0)) { - chunks--; - } - } - - trace_qemu_rdma_write_one_top(chunks + 1, - (chunks + 1) * - (1UL << RDMA_REG_CHUNK_SHIFT) / 1024 / 1024); - - chunk_end = ram_chunk_end(block, chunk + chunks); - - if (!rdma->pin_all) { -#ifdef RDMA_UNREGISTRATION_EXAMPLE - qemu_rdma_unregister_waiting(rdma); -#endif - } - - while (test_bit(chunk, block->transit_bitmap)) { - (void)count; - trace_qemu_rdma_write_one_block(count++, current_index, chunk, - sge.addr, length, rdma->nb_sent, block->nb_chunks); - - ret = qemu_rdma_block_for_wrid(rdma, RDMA_WRID_RDMA_WRITE, NULL); - - if (ret < 0) { - error_report("Failed to Wait for previous write to complete " - "block %d chunk %" PRIu64 - " current %" PRIu64 " len %" PRIu64 " %d", - current_index, chunk, sge.addr, length, rdma->nb_sent); - return ret; - } - } - - if (!rdma->pin_all || !block->is_ram_block) { - if (!block->remote_keys[chunk]) { - /* - * This chunk has not yet been registered, so first check to see - * if the entire chunk is zero. If so, tell the other size to - * memset() + madvise() the entire chunk without RDMA. - */ - - if (can_use_buffer_find_nonzero_offset((void *)(uintptr_t)sge.addr, - length) - && buffer_find_nonzero_offset((void *)(uintptr_t)sge.addr, - length) == length) { - RDMACompress comp = { - .offset = current_addr, - .value = 0, - .block_idx = current_index, - .length = length, - }; - - head.len = sizeof(comp); - head.type = RDMA_CONTROL_COMPRESS; - - trace_qemu_rdma_write_one_zero(chunk, sge.length, - current_index, current_addr); - - compress_to_network(rdma, &comp); - ret = qemu_rdma_exchange_send(rdma, &head, - (uint8_t *) &comp, NULL, NULL, NULL); - - if (ret < 0) { - return -EIO; - } - - acct_update_position(f, sge.length, true); - - return 1; - } - - /* - * Otherwise, tell other side to register. - */ - reg.current_index = current_index; - if (block->is_ram_block) { - reg.key.current_addr = current_addr; - } else { - reg.key.chunk = chunk; - } - reg.chunks = chunks; - - trace_qemu_rdma_write_one_sendreg(chunk, sge.length, current_index, - current_addr); - - register_to_network(rdma, ®); - ret = qemu_rdma_exchange_send(rdma, &head, (uint8_t *) ®, - &resp, ®_result_idx, NULL); - if (ret < 0) { - return ret; - } - - /* try to overlap this single registration with the one we sent. */ - if (qemu_rdma_register_and_get_keys(rdma, block, sge.addr, - &sge.lkey, NULL, chunk, - chunk_start, chunk_end)) { - error_report("cannot get lkey"); - return -EINVAL; - } - - reg_result = (RDMARegisterResult *) - rdma->wr_data[reg_result_idx].control_curr; - - network_to_result(reg_result); - - trace_qemu_rdma_write_one_recvregres(block->remote_keys[chunk], - reg_result->rkey, chunk); - - block->remote_keys[chunk] = reg_result->rkey; - block->remote_host_addr = reg_result->host_addr; - } else { - /* already registered before */ - if (qemu_rdma_register_and_get_keys(rdma, block, sge.addr, - &sge.lkey, NULL, chunk, - chunk_start, chunk_end)) { - error_report("cannot get lkey!"); - return -EINVAL; - } - } - - send_wr.wr.rdma.rkey = block->remote_keys[chunk]; - } else { - send_wr.wr.rdma.rkey = block->remote_rkey; - - if (qemu_rdma_register_and_get_keys(rdma, block, sge.addr, - &sge.lkey, NULL, chunk, - chunk_start, chunk_end)) { - error_report("cannot get lkey!"); - return -EINVAL; - } - } - - /* - * Encode the ram block index and chunk within this wrid. - * We will use this information at the time of completion - * to figure out which bitmap to check against and then which - * chunk in the bitmap to look for. - */ - send_wr.wr_id = qemu_rdma_make_wrid(RDMA_WRID_RDMA_WRITE, - current_index, chunk); - - send_wr.opcode = IBV_WR_RDMA_WRITE; - send_wr.send_flags = IBV_SEND_SIGNALED; - send_wr.sg_list = &sge; - send_wr.num_sge = 1; - send_wr.wr.rdma.remote_addr = block->remote_host_addr + - (current_addr - block->offset); - - trace_qemu_rdma_write_one_post(chunk, sge.addr, send_wr.wr.rdma.remote_addr, - sge.length); - - /* - * ibv_post_send() does not return negative error numbers, - * per the specification they are positive - no idea why. - */ - ret = ibv_post_send(rdma->qp, &send_wr, &bad_wr); - - if (ret == ENOMEM) { - trace_qemu_rdma_write_one_queue_full(); - ret = qemu_rdma_block_for_wrid(rdma, RDMA_WRID_RDMA_WRITE, NULL); - if (ret < 0) { - error_report("rdma migration: failed to make " - "room in full send queue! %d", ret); - return ret; - } - - goto retry; - - } else if (ret > 0) { - perror("rdma migration: post rdma write failed"); - return -ret; - } - - set_bit(chunk, block->transit_bitmap); - acct_update_position(f, sge.length, false); - rdma->total_writes++; - - return 0; -} - -/* - * Push out any unwritten RDMA operations. - * - * We support sending out multiple chunks at the same time. - * Not all of them need to get signaled in the completion queue. - */ -static int qemu_rdma_write_flush(QEMUFile *f, RDMAContext *rdma) -{ - int ret; - - if (!rdma->current_length) { - return 0; - } - - ret = qemu_rdma_write_one(f, rdma, - rdma->current_index, rdma->current_addr, rdma->current_length); - - if (ret < 0) { - return ret; - } - - if (ret == 0) { - rdma->nb_sent++; - trace_qemu_rdma_write_flush(rdma->nb_sent); - } - - rdma->current_length = 0; - rdma->current_addr = 0; - - return 0; -} - -static inline int qemu_rdma_buffer_mergable(RDMAContext *rdma, - uint64_t offset, uint64_t len) -{ - RDMALocalBlock *block; - uint8_t *host_addr; - uint8_t *chunk_end; - - if (rdma->current_index < 0) { - return 0; - } - - if (rdma->current_chunk < 0) { - return 0; - } - - block = &(rdma->local_ram_blocks.block[rdma->current_index]); - host_addr = block->local_host_addr + (offset - block->offset); - chunk_end = ram_chunk_end(block, rdma->current_chunk); - - if (rdma->current_length == 0) { - return 0; - } - - /* - * Only merge into chunk sequentially. - */ - if (offset != (rdma->current_addr + rdma->current_length)) { - return 0; - } - - if (offset < block->offset) { - return 0; - } - - if ((offset + len) > (block->offset + block->length)) { - return 0; - } - - if ((host_addr + len) > chunk_end) { - return 0; - } - - return 1; -} - -/* - * We're not actually writing here, but doing three things: - * - * 1. Identify the chunk the buffer belongs to. - * 2. If the chunk is full or the buffer doesn't belong to the current - * chunk, then start a new chunk and flush() the old chunk. - * 3. To keep the hardware busy, we also group chunks into batches - * and only require that a batch gets acknowledged in the completion - * qeueue instead of each individual chunk. - */ -static int qemu_rdma_write(QEMUFile *f, RDMAContext *rdma, - uint64_t block_offset, uint64_t offset, - uint64_t len) -{ - uint64_t current_addr = block_offset + offset; - uint64_t index = rdma->current_index; - uint64_t chunk = rdma->current_chunk; - int ret; - - /* If we cannot merge it, we flush the current buffer first. */ - if (!qemu_rdma_buffer_mergable(rdma, current_addr, len)) { - ret = qemu_rdma_write_flush(f, rdma); - if (ret) { - return ret; - } - rdma->current_length = 0; - rdma->current_addr = current_addr; - - ret = qemu_rdma_search_ram_block(rdma, block_offset, - offset, len, &index, &chunk); - if (ret) { - error_report("ram block search failed"); - return ret; - } - rdma->current_index = index; - rdma->current_chunk = chunk; - } - - /* merge it */ - rdma->current_length += len; - - /* flush it if buffer is too large */ - if (rdma->current_length >= RDMA_MERGE_MAX) { - return qemu_rdma_write_flush(f, rdma); - } - - return 0; -} - -static void qemu_rdma_cleanup(RDMAContext *rdma) -{ - struct rdma_cm_event *cm_event; - int ret, idx; - - if (rdma->cm_id && rdma->connected) { - if (rdma->error_state) { - RDMAControlHeader head = { .len = 0, - .type = RDMA_CONTROL_ERROR, - .repeat = 1, - }; - error_report("Early error. Sending error."); - qemu_rdma_post_send_control(rdma, NULL, &head); - } - - ret = rdma_disconnect(rdma->cm_id); - if (!ret) { - trace_qemu_rdma_cleanup_waiting_for_disconnect(); - ret = rdma_get_cm_event(rdma->channel, &cm_event); - if (!ret) { - rdma_ack_cm_event(cm_event); - } - } - trace_qemu_rdma_cleanup_disconnect(); - rdma->connected = false; - } - - g_free(rdma->dest_blocks); - rdma->dest_blocks = NULL; - - for (idx = 0; idx < RDMA_WRID_MAX; idx++) { - if (rdma->wr_data[idx].control_mr) { - rdma->total_registrations--; - ibv_dereg_mr(rdma->wr_data[idx].control_mr); - } - rdma->wr_data[idx].control_mr = NULL; - } - - if (rdma->local_ram_blocks.block) { - while (rdma->local_ram_blocks.nb_blocks) { - rdma_delete_block(rdma, &rdma->local_ram_blocks.block[0]); - } - } - - if (rdma->qp) { - rdma_destroy_qp(rdma->cm_id); - rdma->qp = NULL; - } - if (rdma->cq) { - ibv_destroy_cq(rdma->cq); - rdma->cq = NULL; - } - if (rdma->comp_channel) { - ibv_destroy_comp_channel(rdma->comp_channel); - rdma->comp_channel = NULL; - } - if (rdma->pd) { - ibv_dealloc_pd(rdma->pd); - rdma->pd = NULL; - } - if (rdma->cm_id) { - rdma_destroy_id(rdma->cm_id); - rdma->cm_id = NULL; - } - if (rdma->listen_id) { - rdma_destroy_id(rdma->listen_id); - rdma->listen_id = NULL; - } - if (rdma->channel) { - rdma_destroy_event_channel(rdma->channel); - rdma->channel = NULL; - } - g_free(rdma->host); - rdma->host = NULL; -} - - -static int qemu_rdma_source_init(RDMAContext *rdma, Error **errp, bool pin_all) -{ - int ret, idx; - Error *local_err = NULL, **temp = &local_err; - - /* - * Will be validated against destination's actual capabilities - * after the connect() completes. - */ - rdma->pin_all = pin_all; - - ret = qemu_rdma_resolve_host(rdma, temp); - if (ret) { - goto err_rdma_source_init; - } - - ret = qemu_rdma_alloc_pd_cq(rdma); - if (ret) { - ERROR(temp, "rdma migration: error allocating pd and cq! Your mlock()" - " limits may be too low. Please check $ ulimit -a # and " - "search for 'ulimit -l' in the output"); - goto err_rdma_source_init; - } - - ret = qemu_rdma_alloc_qp(rdma); - if (ret) { - ERROR(temp, "rdma migration: error allocating qp!"); - goto err_rdma_source_init; - } - - ret = qemu_rdma_init_ram_blocks(rdma); - if (ret) { - ERROR(temp, "rdma migration: error initializing ram blocks!"); - goto err_rdma_source_init; - } - - /* Build the hash that maps from offset to RAMBlock */ - rdma->blockmap = g_hash_table_new(g_direct_hash, g_direct_equal); - for (idx = 0; idx < rdma->local_ram_blocks.nb_blocks; idx++) { - g_hash_table_insert(rdma->blockmap, - (void *)(uintptr_t)rdma->local_ram_blocks.block[idx].offset, - &rdma->local_ram_blocks.block[idx]); - } - - for (idx = 0; idx < RDMA_WRID_MAX; idx++) { - ret = qemu_rdma_reg_control(rdma, idx); - if (ret) { - ERROR(temp, "rdma migration: error registering %d control!", - idx); - goto err_rdma_source_init; - } - } - - return 0; - -err_rdma_source_init: - error_propagate(errp, local_err); - qemu_rdma_cleanup(rdma); - return -1; -} - -static int qemu_rdma_connect(RDMAContext *rdma, Error **errp) -{ - RDMACapabilities cap = { - .version = RDMA_CONTROL_VERSION_CURRENT, - .flags = 0, - }; - struct rdma_conn_param conn_param = { .initiator_depth = 2, - .retry_count = 5, - .private_data = &cap, - .private_data_len = sizeof(cap), - }; - struct rdma_cm_event *cm_event; - int ret; - - /* - * Only negotiate the capability with destination if the user - * on the source first requested the capability. - */ - if (rdma->pin_all) { - trace_qemu_rdma_connect_pin_all_requested(); - cap.flags |= RDMA_CAPABILITY_PIN_ALL; - } - - caps_to_network(&cap); - - ret = rdma_connect(rdma->cm_id, &conn_param); - if (ret) { - perror("rdma_connect"); - ERROR(errp, "connecting to destination!"); - goto err_rdma_source_connect; - } - - ret = rdma_get_cm_event(rdma->channel, &cm_event); - if (ret) { - perror("rdma_get_cm_event after rdma_connect"); - ERROR(errp, "connecting to destination!"); - rdma_ack_cm_event(cm_event); - goto err_rdma_source_connect; - } - - if (cm_event->event != RDMA_CM_EVENT_ESTABLISHED) { - perror("rdma_get_cm_event != EVENT_ESTABLISHED after rdma_connect"); - ERROR(errp, "connecting to destination!"); - rdma_ack_cm_event(cm_event); - goto err_rdma_source_connect; - } - rdma->connected = true; - - memcpy(&cap, cm_event->param.conn.private_data, sizeof(cap)); - network_to_caps(&cap); - - /* - * Verify that the *requested* capabilities are supported by the destination - * and disable them otherwise. - */ - if (rdma->pin_all && !(cap.flags & RDMA_CAPABILITY_PIN_ALL)) { - ERROR(errp, "Server cannot support pinning all memory. " - "Will register memory dynamically."); - rdma->pin_all = false; - } - - trace_qemu_rdma_connect_pin_all_outcome(rdma->pin_all); - - rdma_ack_cm_event(cm_event); - - ret = qemu_rdma_post_recv_control(rdma, RDMA_WRID_READY); - if (ret) { - ERROR(errp, "posting second control recv!"); - goto err_rdma_source_connect; - } - - rdma->control_ready_expected = 1; - rdma->nb_sent = 0; - return 0; - -err_rdma_source_connect: - qemu_rdma_cleanup(rdma); - return -1; -} - -static int qemu_rdma_dest_init(RDMAContext *rdma, Error **errp) -{ - int ret, idx; - struct rdma_cm_id *listen_id; - char ip[40] = "unknown"; - struct rdma_addrinfo *res, *e; - char port_str[16]; - - for (idx = 0; idx < RDMA_WRID_MAX; idx++) { - rdma->wr_data[idx].control_len = 0; - rdma->wr_data[idx].control_curr = NULL; - } - - if (!rdma->host || !rdma->host[0]) { - ERROR(errp, "RDMA host is not set!"); - rdma->error_state = -EINVAL; - return -1; - } - /* create CM channel */ - rdma->channel = rdma_create_event_channel(); - if (!rdma->channel) { - ERROR(errp, "could not create rdma event channel"); - rdma->error_state = -EINVAL; - return -1; - } - - /* create CM id */ - ret = rdma_create_id(rdma->channel, &listen_id, NULL, RDMA_PS_TCP); - if (ret) { - ERROR(errp, "could not create cm_id!"); - goto err_dest_init_create_listen_id; - } - - snprintf(port_str, 16, "%d", rdma->port); - port_str[15] = '\0'; - - ret = rdma_getaddrinfo(rdma->host, port_str, NULL, &res); - if (ret < 0) { - ERROR(errp, "could not rdma_getaddrinfo address %s", rdma->host); - goto err_dest_init_bind_addr; - } - - for (e = res; e != NULL; e = e->ai_next) { - inet_ntop(e->ai_family, - &((struct sockaddr_in *) e->ai_dst_addr)->sin_addr, ip, sizeof ip); - trace_qemu_rdma_dest_init_trying(rdma->host, ip); - ret = rdma_bind_addr(listen_id, e->ai_dst_addr); - if (ret) { - continue; - } - if (e->ai_family == AF_INET6) { - ret = qemu_rdma_broken_ipv6_kernel(errp, listen_id->verbs); - if (ret) { - continue; - } - } - break; - } - - if (!e) { - ERROR(errp, "Error: could not rdma_bind_addr!"); - goto err_dest_init_bind_addr; - } - - rdma->listen_id = listen_id; - qemu_rdma_dump_gid("dest_init", listen_id); - return 0; - -err_dest_init_bind_addr: - rdma_destroy_id(listen_id); -err_dest_init_create_listen_id: - rdma_destroy_event_channel(rdma->channel); - rdma->channel = NULL; - rdma->error_state = ret; - return ret; - -} - -static void *qemu_rdma_data_init(const char *host_port, Error **errp) -{ - RDMAContext *rdma = NULL; - InetSocketAddress *addr; - - if (host_port) { - rdma = g_new0(RDMAContext, 1); - rdma->current_index = -1; - rdma->current_chunk = -1; - - addr = inet_parse(host_port, NULL); - if (addr != NULL) { - rdma->port = atoi(addr->port); - rdma->host = g_strdup(addr->host); - } else { - ERROR(errp, "bad RDMA migration address '%s'", host_port); - g_free(rdma); - rdma = NULL; - } - - qapi_free_InetSocketAddress(addr); - } - - return rdma; -} - -/* - * QEMUFile interface to the control channel. - * SEND messages for control only. - * VM's ram is handled with regular RDMA messages. - */ -static ssize_t qemu_rdma_put_buffer(void *opaque, const uint8_t *buf, - int64_t pos, size_t size) -{ - QEMUFileRDMA *r = opaque; - QEMUFile *f = r->file; - RDMAContext *rdma = r->rdma; - size_t remaining = size; - uint8_t * data = (void *) buf; - int ret; - - CHECK_ERROR_STATE(); - - /* - * Push out any writes that - * we're queued up for VM's ram. - */ - ret = qemu_rdma_write_flush(f, rdma); - if (ret < 0) { - rdma->error_state = ret; - return ret; - } - - while (remaining) { - RDMAControlHeader head; - - r->len = MIN(remaining, RDMA_SEND_INCREMENT); - remaining -= r->len; - - /* Guaranteed to fit due to RDMA_SEND_INCREMENT MIN above */ - head.len = (uint32_t)r->len; - head.type = RDMA_CONTROL_QEMU_FILE; - - ret = qemu_rdma_exchange_send(rdma, &head, data, NULL, NULL, NULL); - - if (ret < 0) { - rdma->error_state = ret; - return ret; - } - - data += r->len; - } - - return size; -} - -static size_t qemu_rdma_fill(RDMAContext *rdma, uint8_t *buf, - size_t size, int idx) -{ - size_t len = 0; - - if (rdma->wr_data[idx].control_len) { - trace_qemu_rdma_fill(rdma->wr_data[idx].control_len, size); - - len = MIN(size, rdma->wr_data[idx].control_len); - memcpy(buf, rdma->wr_data[idx].control_curr, len); - rdma->wr_data[idx].control_curr += len; - rdma->wr_data[idx].control_len -= len; - } - - return len; -} - -/* - * QEMUFile interface to the control channel. - * RDMA links don't use bytestreams, so we have to - * return bytes to QEMUFile opportunistically. - */ -static ssize_t qemu_rdma_get_buffer(void *opaque, uint8_t *buf, - int64_t pos, size_t size) -{ - QEMUFileRDMA *r = opaque; - RDMAContext *rdma = r->rdma; - RDMAControlHeader head; - int ret = 0; - - CHECK_ERROR_STATE(); - - /* - * First, we hold on to the last SEND message we - * were given and dish out the bytes until we run - * out of bytes. - */ - r->len = qemu_rdma_fill(r->rdma, buf, size, 0); - if (r->len) { - return r->len; - } - - /* - * Once we run out, we block and wait for another - * SEND message to arrive. - */ - ret = qemu_rdma_exchange_recv(rdma, &head, RDMA_CONTROL_QEMU_FILE); - - if (ret < 0) { - rdma->error_state = ret; - return ret; - } - - /* - * SEND was received with new bytes, now try again. - */ - return qemu_rdma_fill(r->rdma, buf, size, 0); -} - -/* - * Block until all the outstanding chunks have been delivered by the hardware. - */ -static int qemu_rdma_drain_cq(QEMUFile *f, RDMAContext *rdma) -{ - int ret; - - if (qemu_rdma_write_flush(f, rdma) < 0) { - return -EIO; - } - - while (rdma->nb_sent) { - ret = qemu_rdma_block_for_wrid(rdma, RDMA_WRID_RDMA_WRITE, NULL); - if (ret < 0) { - error_report("rdma migration: complete polling error!"); - return -EIO; - } - } - - qemu_rdma_unregister_waiting(rdma); - - return 0; -} - -static int qemu_rdma_close(void *opaque) -{ - trace_qemu_rdma_close(); - QEMUFileRDMA *r = opaque; - if (r->rdma) { - qemu_rdma_cleanup(r->rdma); - g_free(r->rdma); - } - g_free(r); - return 0; -} - -/* - * Parameters: - * @offset == 0 : - * This means that 'block_offset' is a full virtual address that does not - * belong to a RAMBlock of the virtual machine and instead - * represents a private malloc'd memory area that the caller wishes to - * transfer. - * - * @offset != 0 : - * Offset is an offset to be added to block_offset and used - * to also lookup the corresponding RAMBlock. - * - * @size > 0 : - * Initiate an transfer this size. - * - * @size == 0 : - * A 'hint' or 'advice' that means that we wish to speculatively - * and asynchronously unregister this memory. In this case, there is no - * guarantee that the unregister will actually happen, for example, - * if the memory is being actively transmitted. Additionally, the memory - * may be re-registered at any future time if a write within the same - * chunk was requested again, even if you attempted to unregister it - * here. - * - * @size < 0 : TODO, not yet supported - * Unregister the memory NOW. This means that the caller does not - * expect there to be any future RDMA transfers and we just want to clean - * things up. This is used in case the upper layer owns the memory and - * cannot wait for qemu_fclose() to occur. - * - * @bytes_sent : User-specificed pointer to indicate how many bytes were - * sent. Usually, this will not be more than a few bytes of - * the protocol because most transfers are sent asynchronously. - */ -static size_t qemu_rdma_save_page(QEMUFile *f, void *opaque, - ram_addr_t block_offset, ram_addr_t offset, - size_t size, uint64_t *bytes_sent) -{ - QEMUFileRDMA *rfile = opaque; - RDMAContext *rdma = rfile->rdma; - int ret; - - CHECK_ERROR_STATE(); - - qemu_fflush(f); - - if (size > 0) { - /* - * Add this page to the current 'chunk'. If the chunk - * is full, or the page doen't belong to the current chunk, - * an actual RDMA write will occur and a new chunk will be formed. - */ - ret = qemu_rdma_write(f, rdma, block_offset, offset, size); - if (ret < 0) { - error_report("rdma migration: write error! %d", ret); - goto err; - } - - /* - * We always return 1 bytes because the RDMA - * protocol is completely asynchronous. We do not yet know - * whether an identified chunk is zero or not because we're - * waiting for other pages to potentially be merged with - * the current chunk. So, we have to call qemu_update_position() - * later on when the actual write occurs. - */ - if (bytes_sent) { - *bytes_sent = 1; - } - } else { - uint64_t index, chunk; - - /* TODO: Change QEMUFileOps prototype to be signed: size_t => long - if (size < 0) { - ret = qemu_rdma_drain_cq(f, rdma); - if (ret < 0) { - fprintf(stderr, "rdma: failed to synchronously drain" - " completion queue before unregistration.\n"); - goto err; - } - } - */ - - ret = qemu_rdma_search_ram_block(rdma, block_offset, - offset, size, &index, &chunk); - - if (ret) { - error_report("ram block search failed"); - goto err; - } - - qemu_rdma_signal_unregister(rdma, index, chunk, 0); - - /* - * TODO: Synchronous, guaranteed unregistration (should not occur during - * fast-path). Otherwise, unregisters will process on the next call to - * qemu_rdma_drain_cq() - if (size < 0) { - qemu_rdma_unregister_waiting(rdma); - } - */ - } - - /* - * Drain the Completion Queue if possible, but do not block, - * just poll. - * - * If nothing to poll, the end of the iteration will do this - * again to make sure we don't overflow the request queue. - */ - while (1) { - uint64_t wr_id, wr_id_in; - int ret = qemu_rdma_poll(rdma, &wr_id_in, NULL); - if (ret < 0) { - error_report("rdma migration: polling error! %d", ret); - goto err; - } - - wr_id = wr_id_in & RDMA_WRID_TYPE_MASK; - - if (wr_id == RDMA_WRID_NONE) { - break; - } - } - - return RAM_SAVE_CONTROL_DELAYED; -err: - rdma->error_state = ret; - return ret; -} - -static int qemu_rdma_accept(RDMAContext *rdma) -{ - RDMACapabilities cap; - struct rdma_conn_param conn_param = { - .responder_resources = 2, - .private_data = &cap, - .private_data_len = sizeof(cap), - }; - struct rdma_cm_event *cm_event; - struct ibv_context *verbs; - int ret = -EINVAL; - int idx; - - ret = rdma_get_cm_event(rdma->channel, &cm_event); - if (ret) { - goto err_rdma_dest_wait; - } - - if (cm_event->event != RDMA_CM_EVENT_CONNECT_REQUEST) { - rdma_ack_cm_event(cm_event); - goto err_rdma_dest_wait; - } - - memcpy(&cap, cm_event->param.conn.private_data, sizeof(cap)); - - network_to_caps(&cap); - - if (cap.version < 1 || cap.version > RDMA_CONTROL_VERSION_CURRENT) { - error_report("Unknown source RDMA version: %d, bailing...", - cap.version); - rdma_ack_cm_event(cm_event); - goto err_rdma_dest_wait; - } - - /* - * Respond with only the capabilities this version of QEMU knows about. - */ - cap.flags &= known_capabilities; - - /* - * Enable the ones that we do know about. - * Add other checks here as new ones are introduced. - */ - if (cap.flags & RDMA_CAPABILITY_PIN_ALL) { - rdma->pin_all = true; - } - - rdma->cm_id = cm_event->id; - verbs = cm_event->id->verbs; - - rdma_ack_cm_event(cm_event); - - trace_qemu_rdma_accept_pin_state(rdma->pin_all); - - caps_to_network(&cap); - - trace_qemu_rdma_accept_pin_verbsc(verbs); - - if (!rdma->verbs) { - rdma->verbs = verbs; - } else if (rdma->verbs != verbs) { - error_report("ibv context not matching %p, %p!", rdma->verbs, - verbs); - goto err_rdma_dest_wait; - } - - qemu_rdma_dump_id("dest_init", verbs); - - ret = qemu_rdma_alloc_pd_cq(rdma); - if (ret) { - error_report("rdma migration: error allocating pd and cq!"); - goto err_rdma_dest_wait; - } - - ret = qemu_rdma_alloc_qp(rdma); - if (ret) { - error_report("rdma migration: error allocating qp!"); - goto err_rdma_dest_wait; - } - - ret = qemu_rdma_init_ram_blocks(rdma); - if (ret) { - error_report("rdma migration: error initializing ram blocks!"); - goto err_rdma_dest_wait; - } - - for (idx = 0; idx < RDMA_WRID_MAX; idx++) { - ret = qemu_rdma_reg_control(rdma, idx); - if (ret) { - error_report("rdma: error registering %d control", idx); - goto err_rdma_dest_wait; - } - } - - qemu_set_fd_handler(rdma->channel->fd, NULL, NULL, NULL); - - ret = rdma_accept(rdma->cm_id, &conn_param); - if (ret) { - error_report("rdma_accept returns %d", ret); - goto err_rdma_dest_wait; - } - - ret = rdma_get_cm_event(rdma->channel, &cm_event); - if (ret) { - error_report("rdma_accept get_cm_event failed %d", ret); - goto err_rdma_dest_wait; - } - - if (cm_event->event != RDMA_CM_EVENT_ESTABLISHED) { - error_report("rdma_accept not event established"); - rdma_ack_cm_event(cm_event); - goto err_rdma_dest_wait; - } - - rdma_ack_cm_event(cm_event); - rdma->connected = true; - - ret = qemu_rdma_post_recv_control(rdma, RDMA_WRID_READY); - if (ret) { - error_report("rdma migration: error posting second control recv"); - goto err_rdma_dest_wait; - } - - qemu_rdma_dump_gid("dest_connect", rdma->cm_id); - - return 0; - -err_rdma_dest_wait: - rdma->error_state = ret; - qemu_rdma_cleanup(rdma); - return ret; -} - -static int dest_ram_sort_func(const void *a, const void *b) -{ - unsigned int a_index = ((const RDMALocalBlock *)a)->src_index; - unsigned int b_index = ((const RDMALocalBlock *)b)->src_index; - - return (a_index < b_index) ? -1 : (a_index != b_index); -} - -/* - * During each iteration of the migration, we listen for instructions - * by the source VM to perform dynamic page registrations before they - * can perform RDMA operations. - * - * We respond with the 'rkey'. - * - * Keep doing this until the source tells us to stop. - */ -static int qemu_rdma_registration_handle(QEMUFile *f, void *opaque) -{ - RDMAControlHeader reg_resp = { .len = sizeof(RDMARegisterResult), - .type = RDMA_CONTROL_REGISTER_RESULT, - .repeat = 0, - }; - RDMAControlHeader unreg_resp = { .len = 0, - .type = RDMA_CONTROL_UNREGISTER_FINISHED, - .repeat = 0, - }; - RDMAControlHeader blocks = { .type = RDMA_CONTROL_RAM_BLOCKS_RESULT, - .repeat = 1 }; - QEMUFileRDMA *rfile = opaque; - RDMAContext *rdma = rfile->rdma; - RDMALocalBlocks *local = &rdma->local_ram_blocks; - RDMAControlHeader head; - RDMARegister *reg, *registers; - RDMACompress *comp; - RDMARegisterResult *reg_result; - static RDMARegisterResult results[RDMA_CONTROL_MAX_COMMANDS_PER_MESSAGE]; - RDMALocalBlock *block; - void *host_addr; - int ret = 0; - int idx = 0; - int count = 0; - int i = 0; - - CHECK_ERROR_STATE(); - - do { - trace_qemu_rdma_registration_handle_wait(); - - ret = qemu_rdma_exchange_recv(rdma, &head, RDMA_CONTROL_NONE); - - if (ret < 0) { - break; - } - - if (head.repeat > RDMA_CONTROL_MAX_COMMANDS_PER_MESSAGE) { - error_report("rdma: Too many requests in this message (%d)." - "Bailing.", head.repeat); - ret = -EIO; - break; - } - - switch (head.type) { - case RDMA_CONTROL_COMPRESS: - comp = (RDMACompress *) rdma->wr_data[idx].control_curr; - network_to_compress(comp); - - trace_qemu_rdma_registration_handle_compress(comp->length, - comp->block_idx, - comp->offset); - if (comp->block_idx >= rdma->local_ram_blocks.nb_blocks) { - error_report("rdma: 'compress' bad block index %u (vs %d)", - (unsigned int)comp->block_idx, - rdma->local_ram_blocks.nb_blocks); - ret = -EIO; - goto out; - } - block = &(rdma->local_ram_blocks.block[comp->block_idx]); - - host_addr = block->local_host_addr + - (comp->offset - block->offset); - - ram_handle_compressed(host_addr, comp->value, comp->length); - break; - - case RDMA_CONTROL_REGISTER_FINISHED: - trace_qemu_rdma_registration_handle_finished(); - goto out; - - case RDMA_CONTROL_RAM_BLOCKS_REQUEST: - trace_qemu_rdma_registration_handle_ram_blocks(); - - /* Sort our local RAM Block list so it's the same as the source, - * we can do this since we've filled in a src_index in the list - * as we received the RAMBlock list earlier. - */ - qsort(rdma->local_ram_blocks.block, - rdma->local_ram_blocks.nb_blocks, - sizeof(RDMALocalBlock), dest_ram_sort_func); - if (rdma->pin_all) { - ret = qemu_rdma_reg_whole_ram_blocks(rdma); - if (ret) { - error_report("rdma migration: error dest " - "registering ram blocks"); - goto out; - } - } - - /* - * Dest uses this to prepare to transmit the RAMBlock descriptions - * to the source VM after connection setup. - * Both sides use the "remote" structure to communicate and update - * their "local" descriptions with what was sent. - */ - for (i = 0; i < local->nb_blocks; i++) { - rdma->dest_blocks[i].remote_host_addr = - (uintptr_t)(local->block[i].local_host_addr); - - if (rdma->pin_all) { - rdma->dest_blocks[i].remote_rkey = local->block[i].mr->rkey; - } - - rdma->dest_blocks[i].offset = local->block[i].offset; - rdma->dest_blocks[i].length = local->block[i].length; - - dest_block_to_network(&rdma->dest_blocks[i]); - trace_qemu_rdma_registration_handle_ram_blocks_loop( - local->block[i].block_name, - local->block[i].offset, - local->block[i].length, - local->block[i].local_host_addr, - local->block[i].src_index); - } - - blocks.len = rdma->local_ram_blocks.nb_blocks - * sizeof(RDMADestBlock); - - - ret = qemu_rdma_post_send_control(rdma, - (uint8_t *) rdma->dest_blocks, &blocks); - - if (ret < 0) { - error_report("rdma migration: error sending remote info"); - goto out; - } - - break; - case RDMA_CONTROL_REGISTER_REQUEST: - trace_qemu_rdma_registration_handle_register(head.repeat); - - reg_resp.repeat = head.repeat; - registers = (RDMARegister *) rdma->wr_data[idx].control_curr; - - for (count = 0; count < head.repeat; count++) { - uint64_t chunk; - uint8_t *chunk_start, *chunk_end; - - reg = ®isters[count]; - network_to_register(reg); - - reg_result = &results[count]; - - trace_qemu_rdma_registration_handle_register_loop(count, - reg->current_index, reg->key.current_addr, reg->chunks); - - if (reg->current_index >= rdma->local_ram_blocks.nb_blocks) { - error_report("rdma: 'register' bad block index %u (vs %d)", - (unsigned int)reg->current_index, - rdma->local_ram_blocks.nb_blocks); - ret = -ENOENT; - goto out; - } - block = &(rdma->local_ram_blocks.block[reg->current_index]); - if (block->is_ram_block) { - if (block->offset > reg->key.current_addr) { - error_report("rdma: bad register address for block %s" - " offset: %" PRIx64 " current_addr: %" PRIx64, - block->block_name, block->offset, - reg->key.current_addr); - ret = -ERANGE; - goto out; - } - host_addr = (block->local_host_addr + - (reg->key.current_addr - block->offset)); - chunk = ram_chunk_index(block->local_host_addr, - (uint8_t *) host_addr); - } else { - chunk = reg->key.chunk; - host_addr = block->local_host_addr + - (reg->key.chunk * (1UL << RDMA_REG_CHUNK_SHIFT)); - /* Check for particularly bad chunk value */ - if (host_addr < (void *)block->local_host_addr) { - error_report("rdma: bad chunk for block %s" - " chunk: %" PRIx64, - block->block_name, reg->key.chunk); - ret = -ERANGE; - goto out; - } - } - chunk_start = ram_chunk_start(block, chunk); - chunk_end = ram_chunk_end(block, chunk + reg->chunks); - if (qemu_rdma_register_and_get_keys(rdma, block, - (uintptr_t)host_addr, NULL, ®_result->rkey, - chunk, chunk_start, chunk_end)) { - error_report("cannot get rkey"); - ret = -EINVAL; - goto out; - } - - reg_result->host_addr = (uintptr_t)block->local_host_addr; - - trace_qemu_rdma_registration_handle_register_rkey( - reg_result->rkey); - - result_to_network(reg_result); - } - - ret = qemu_rdma_post_send_control(rdma, - (uint8_t *) results, ®_resp); - - if (ret < 0) { - error_report("Failed to send control buffer"); - goto out; - } - break; - case RDMA_CONTROL_UNREGISTER_REQUEST: - trace_qemu_rdma_registration_handle_unregister(head.repeat); - unreg_resp.repeat = head.repeat; - registers = (RDMARegister *) rdma->wr_data[idx].control_curr; - - for (count = 0; count < head.repeat; count++) { - reg = ®isters[count]; - network_to_register(reg); - - trace_qemu_rdma_registration_handle_unregister_loop(count, - reg->current_index, reg->key.chunk); - - block = &(rdma->local_ram_blocks.block[reg->current_index]); - - ret = ibv_dereg_mr(block->pmr[reg->key.chunk]); - block->pmr[reg->key.chunk] = NULL; - - if (ret != 0) { - perror("rdma unregistration chunk failed"); - ret = -ret; - goto out; - } - - rdma->total_registrations--; - - trace_qemu_rdma_registration_handle_unregister_success( - reg->key.chunk); - } - - ret = qemu_rdma_post_send_control(rdma, NULL, &unreg_resp); - - if (ret < 0) { - error_report("Failed to send control buffer"); - goto out; - } - break; - case RDMA_CONTROL_REGISTER_RESULT: - error_report("Invalid RESULT message at dest."); - ret = -EIO; - goto out; - default: - error_report("Unknown control message %s", control_desc[head.type]); - ret = -EIO; - goto out; - } - } while (1); -out: - if (ret < 0) { - rdma->error_state = ret; - } - return ret; -} - -/* Destination: - * Called via a ram_control_load_hook during the initial RAM load section which - * lists the RAMBlocks by name. This lets us know the order of the RAMBlocks - * on the source. - * We've already built our local RAMBlock list, but not yet sent the list to - * the source. - */ -static int rdma_block_notification_handle(QEMUFileRDMA *rfile, const char *name) -{ - RDMAContext *rdma = rfile->rdma; - int curr; - int found = -1; - - /* Find the matching RAMBlock in our local list */ - for (curr = 0; curr < rdma->local_ram_blocks.nb_blocks; curr++) { - if (!strcmp(rdma->local_ram_blocks.block[curr].block_name, name)) { - found = curr; - break; - } - } - - if (found == -1) { - error_report("RAMBlock '%s' not found on destination", name); - return -ENOENT; - } - - rdma->local_ram_blocks.block[curr].src_index = rdma->next_src_index; - trace_rdma_block_notification_handle(name, rdma->next_src_index); - rdma->next_src_index++; - - return 0; -} - -static int rdma_load_hook(QEMUFile *f, void *opaque, uint64_t flags, void *data) -{ - switch (flags) { - case RAM_CONTROL_BLOCK_REG: - return rdma_block_notification_handle(opaque, data); - - case RAM_CONTROL_HOOK: - return qemu_rdma_registration_handle(f, opaque); - - default: - /* Shouldn't be called with any other values */ - abort(); - } -} - -static int qemu_rdma_registration_start(QEMUFile *f, void *opaque, - uint64_t flags, void *data) -{ - QEMUFileRDMA *rfile = opaque; - RDMAContext *rdma = rfile->rdma; - - CHECK_ERROR_STATE(); - - trace_qemu_rdma_registration_start(flags); - qemu_put_be64(f, RAM_SAVE_FLAG_HOOK); - qemu_fflush(f); - - return 0; -} - -/* - * Inform dest that dynamic registrations are done for now. - * First, flush writes, if any. - */ -static int qemu_rdma_registration_stop(QEMUFile *f, void *opaque, - uint64_t flags, void *data) -{ - Error *local_err = NULL, **errp = &local_err; - QEMUFileRDMA *rfile = opaque; - RDMAContext *rdma = rfile->rdma; - RDMAControlHeader head = { .len = 0, .repeat = 1 }; - int ret = 0; - - CHECK_ERROR_STATE(); - - qemu_fflush(f); - ret = qemu_rdma_drain_cq(f, rdma); - - if (ret < 0) { - goto err; - } - - if (flags == RAM_CONTROL_SETUP) { - RDMAControlHeader resp = {.type = RDMA_CONTROL_RAM_BLOCKS_RESULT }; - RDMALocalBlocks *local = &rdma->local_ram_blocks; - int reg_result_idx, i, nb_dest_blocks; - - head.type = RDMA_CONTROL_RAM_BLOCKS_REQUEST; - trace_qemu_rdma_registration_stop_ram(); - - /* - * Make sure that we parallelize the pinning on both sides. - * For very large guests, doing this serially takes a really - * long time, so we have to 'interleave' the pinning locally - * with the control messages by performing the pinning on this - * side before we receive the control response from the other - * side that the pinning has completed. - */ - ret = qemu_rdma_exchange_send(rdma, &head, NULL, &resp, - ®_result_idx, rdma->pin_all ? - qemu_rdma_reg_whole_ram_blocks : NULL); - if (ret < 0) { - ERROR(errp, "receiving remote info!"); - return ret; - } - - nb_dest_blocks = resp.len / sizeof(RDMADestBlock); - - /* - * The protocol uses two different sets of rkeys (mutually exclusive): - * 1. One key to represent the virtual address of the entire ram block. - * (dynamic chunk registration disabled - pin everything with one rkey.) - * 2. One to represent individual chunks within a ram block. - * (dynamic chunk registration enabled - pin individual chunks.) - * - * Once the capability is successfully negotiated, the destination transmits - * the keys to use (or sends them later) including the virtual addresses - * and then propagates the remote ram block descriptions to his local copy. - */ - - if (local->nb_blocks != nb_dest_blocks) { - ERROR(errp, "ram blocks mismatch (Number of blocks %d vs %d) " - "Your QEMU command line parameters are probably " - "not identical on both the source and destination.", - local->nb_blocks, nb_dest_blocks); - rdma->error_state = -EINVAL; - return -EINVAL; - } - - qemu_rdma_move_header(rdma, reg_result_idx, &resp); - memcpy(rdma->dest_blocks, - rdma->wr_data[reg_result_idx].control_curr, resp.len); - for (i = 0; i < nb_dest_blocks; i++) { - network_to_dest_block(&rdma->dest_blocks[i]); - - /* We require that the blocks are in the same order */ - if (rdma->dest_blocks[i].length != local->block[i].length) { - ERROR(errp, "Block %s/%d has a different length %" PRIu64 - "vs %" PRIu64, local->block[i].block_name, i, - local->block[i].length, - rdma->dest_blocks[i].length); - rdma->error_state = -EINVAL; - return -EINVAL; - } - local->block[i].remote_host_addr = - rdma->dest_blocks[i].remote_host_addr; - local->block[i].remote_rkey = rdma->dest_blocks[i].remote_rkey; - } - } - - trace_qemu_rdma_registration_stop(flags); - - head.type = RDMA_CONTROL_REGISTER_FINISHED; - ret = qemu_rdma_exchange_send(rdma, &head, NULL, NULL, NULL, NULL); - - if (ret < 0) { - goto err; - } - - return 0; -err: - rdma->error_state = ret; - return ret; -} - -static int qemu_rdma_get_fd(void *opaque) -{ - QEMUFileRDMA *rfile = opaque; - RDMAContext *rdma = rfile->rdma; - - return rdma->comp_channel->fd; -} - -static const QEMUFileOps rdma_read_ops = { - .get_buffer = qemu_rdma_get_buffer, - .get_fd = qemu_rdma_get_fd, - .close = qemu_rdma_close, - .hook_ram_load = rdma_load_hook, -}; - -static const QEMUFileOps rdma_write_ops = { - .put_buffer = qemu_rdma_put_buffer, - .close = qemu_rdma_close, - .before_ram_iterate = qemu_rdma_registration_start, - .after_ram_iterate = qemu_rdma_registration_stop, - .save_page = qemu_rdma_save_page, -}; - -static void *qemu_fopen_rdma(RDMAContext *rdma, const char *mode) -{ - QEMUFileRDMA *r; - - if (qemu_file_mode_is_not_valid(mode)) { - return NULL; - } - - r = g_new0(QEMUFileRDMA, 1); - r->rdma = rdma; - - if (mode[0] == 'w') { - r->file = qemu_fopen_ops(r, &rdma_write_ops); - } else { - r->file = qemu_fopen_ops(r, &rdma_read_ops); - } - - return r->file; -} - -static void rdma_accept_incoming_migration(void *opaque) -{ - RDMAContext *rdma = opaque; - int ret; - QEMUFile *f; - Error *local_err = NULL, **errp = &local_err; - - trace_qemu_rdma_accept_incoming_migration(); - ret = qemu_rdma_accept(rdma); - - if (ret) { - ERROR(errp, "RDMA Migration initialization failed!"); - return; - } - - trace_qemu_rdma_accept_incoming_migration_accepted(); - - f = qemu_fopen_rdma(rdma, "rb"); - if (f == NULL) { - ERROR(errp, "could not qemu_fopen_rdma!"); - qemu_rdma_cleanup(rdma); - return; - } - - rdma->migration_started_on_destination = 1; - process_incoming_migration(f); -} - -void rdma_start_incoming_migration(const char *host_port, Error **errp) -{ - int ret; - RDMAContext *rdma; - Error *local_err = NULL; - - trace_rdma_start_incoming_migration(); - rdma = qemu_rdma_data_init(host_port, &local_err); - - if (rdma == NULL) { - goto err; - } - - ret = qemu_rdma_dest_init(rdma, &local_err); - - if (ret) { - goto err; - } - - trace_rdma_start_incoming_migration_after_dest_init(); - - ret = rdma_listen(rdma->listen_id, 5); - - if (ret) { - ERROR(errp, "listening on socket!"); - goto err; - } - - trace_rdma_start_incoming_migration_after_rdma_listen(); - - qemu_set_fd_handler(rdma->channel->fd, rdma_accept_incoming_migration, - NULL, (void *)(intptr_t)rdma); - return; -err: - error_propagate(errp, local_err); - g_free(rdma); -} - -void rdma_start_outgoing_migration(void *opaque, - const char *host_port, Error **errp) -{ - MigrationState *s = opaque; - Error *local_err = NULL, **temp = &local_err; - RDMAContext *rdma = qemu_rdma_data_init(host_port, &local_err); - int ret = 0; - - if (rdma == NULL) { - ERROR(temp, "Failed to initialize RDMA data structures! %d", ret); - goto err; - } - - ret = qemu_rdma_source_init(rdma, &local_err, - s->enabled_capabilities[MIGRATION_CAPABILITY_RDMA_PIN_ALL]); - - if (ret) { - goto err; - } - - trace_rdma_start_outgoing_migration_after_rdma_source_init(); - ret = qemu_rdma_connect(rdma, &local_err); - - if (ret) { - goto err; - } - - trace_rdma_start_outgoing_migration_after_rdma_connect(); - - s->to_dst_file = qemu_fopen_rdma(rdma, "wb"); - migrate_fd_connect(s); - return; -err: - error_propagate(errp, local_err); - g_free(rdma); - migrate_fd_error(s); -} |