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Re: [Qemu-devel] [PATCH v2 01/22] contrib/rdmacm-mux: Add implementation
From: |
Shamir Rabinovitch |
Subject: |
Re: [Qemu-devel] [PATCH v2 01/22] contrib/rdmacm-mux: Add implementation of RDMA User MAD multiplexer |
Date: |
Sat, 10 Nov 2018 22:10:04 +0200 |
User-agent: |
Mutt/1.10.1 (2018-07-13) |
On Thu, Nov 08, 2018 at 06:07:57PM +0200, Yuval Shaia wrote:
> RDMA MAD kernel module (ibcm) disallow more than one MAD-agent for a
> given MAD class.
> This does not go hand-by-hand with qemu pvrdma device's requirements
> where each VM is MAD agent.
> Fix it by adding implementation of RDMA MAD multiplexer service which on
> one hand register as a sole MAD agent with the kernel module and on the
> other hand gives service to more than one VM.
>
> Design Overview:
> ----------------
> A server process is registered to UMAD framework (for this to work the
> rdma_cm kernel module needs to be unloaded) and creates a unix socket to
> listen to incoming request from clients.
> A client process (such as QEMU) connects to this unix socket and
> registers with its own GID.
>
> TX:
> ---
> When client needs to send rdma_cm MAD message it construct it the same
> way as without this multiplexer, i.e. creates a umad packet but this
> time it writes its content to the socket instead of calling umad_send().
> The server, upon receiving such a message fetch local_comm_id from it so
> a context for this session can be maintain and relay the message to UMAD
> layer by calling umad_send().
>
> RX:
> ---
> The server creates a worker thread to process incoming rdma_cm MAD
> messages. When an incoming message arrived (umad_recv()) the server,
> depending on the message type (attr_id) looks for target client by
> either searching in gid->fd table or in local_comm_id->fd table. With
> the extracted fd the server relays to incoming message to the client.
>
> Signed-off-by: Yuval Shaia <address@hidden>
> ---
> MAINTAINERS | 1 +
> Makefile | 3 +
> Makefile.objs | 1 +
> contrib/rdmacm-mux/Makefile.objs | 4 +
> contrib/rdmacm-mux/main.c | 770 +++++++++++++++++++++++++++++++
> contrib/rdmacm-mux/rdmacm-mux.h | 56 +++
> 6 files changed, 835 insertions(+)
> create mode 100644 contrib/rdmacm-mux/Makefile.objs
> create mode 100644 contrib/rdmacm-mux/main.c
> create mode 100644 contrib/rdmacm-mux/rdmacm-mux.h
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 98a1856afc..e087d58ac6 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -2231,6 +2231,7 @@ S: Maintained
> F: hw/rdma/*
> F: hw/rdma/vmw/*
> F: docs/pvrdma.txt
> +F: contrib/rdmacm-mux/*
>
> Build and test automation
> -------------------------
> diff --git a/Makefile b/Makefile
> index f2947186a4..94072776ff 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -418,6 +418,7 @@ dummy := $(call unnest-vars,, \
> elf2dmp-obj-y \
> ivshmem-client-obj-y \
> ivshmem-server-obj-y \
> + rdmacm-mux-obj-y \
> libvhost-user-obj-y \
> vhost-user-scsi-obj-y \
> vhost-user-blk-obj-y \
> @@ -725,6 +726,8 @@ vhost-user-scsi$(EXESUF): $(vhost-user-scsi-obj-y)
> libvhost-user.a
> $(call LINK, $^)
> vhost-user-blk$(EXESUF): $(vhost-user-blk-obj-y) libvhost-user.a
> $(call LINK, $^)
> +rdmacm-mux$(EXESUF): $(rdmacm-mux-obj-y) $(COMMON_LDADDS)
> + $(call LINK, $^)
>
> module_block.h: $(SRC_PATH)/scripts/modules/module_block.py config-host.mak
> $(call quiet-command,$(PYTHON) $< $@ \
> diff --git a/Makefile.objs b/Makefile.objs
> index 1e1ff387d7..cc7df3ad80 100644
> --- a/Makefile.objs
> +++ b/Makefile.objs
> @@ -194,6 +194,7 @@ vhost-user-scsi.o-cflags := $(LIBISCSI_CFLAGS)
> vhost-user-scsi.o-libs := $(LIBISCSI_LIBS)
> vhost-user-scsi-obj-y = contrib/vhost-user-scsi/
> vhost-user-blk-obj-y = contrib/vhost-user-blk/
> +rdmacm-mux-obj-y = contrib/rdmacm-mux/
>
> ######################################################################
> trace-events-subdirs =
> diff --git a/contrib/rdmacm-mux/Makefile.objs
> b/contrib/rdmacm-mux/Makefile.objs
> new file mode 100644
> index 0000000000..be3eacb6f7
> --- /dev/null
> +++ b/contrib/rdmacm-mux/Makefile.objs
> @@ -0,0 +1,4 @@
> +ifdef CONFIG_PVRDMA
> +CFLAGS += -libumad -Wno-format-truncation
> +rdmacm-mux-obj-y = main.o
> +endif
> diff --git a/contrib/rdmacm-mux/main.c b/contrib/rdmacm-mux/main.c
> new file mode 100644
> index 0000000000..0308074b15
> --- /dev/null
> +++ b/contrib/rdmacm-mux/main.c
> @@ -0,0 +1,770 @@
> +/*
> + * QEMU paravirtual RDMA - rdmacm-mux implementation
> + *
> + * Copyright (C) 2018 Oracle
> + * Copyright (C) 2018 Red Hat Inc
> + *
> + * Authors:
> + * Yuval Shaia <address@hidden>
> + * Marcel Apfelbaum <address@hidden>
> + *
> + * 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 "sys/poll.h"
> +#include "sys/ioctl.h"
> +#include "pthread.h"
> +#include "syslog.h"
> +
> +#include "infiniband/verbs.h"
> +#include "infiniband/umad.h"
> +#include "infiniband/umad_types.h"
> +#include "infiniband/umad_sa.h"
> +#include "infiniband/umad_cm.h"
> +
> +#include "rdmacm-mux.h"
> +
> +#define SCALE_US 1000
> +#define COMMID_TTL 2 /* How many SCALE_US a context of MAD session is saved
> */
> +#define SLEEP_SECS 5 /* This is used both in poll() and thread */
> +#define SERVER_LISTEN_BACKLOG 10
> +#define MAX_CLIENTS 4096
> +#define MAD_RMPP_VERSION 0
> +#define MAD_METHOD_MASK0 0x8
> +
> +#define IB_USER_MAD_LONGS_PER_METHOD_MASK (128 / (8 * sizeof(long)))
> +
> +#define CM_REQ_DGID_POS 80
> +#define CM_SIDR_REQ_DGID_POS 44
> +
> +/* The below can be override by command line parameter */
> +#define UNIX_SOCKET_PATH "/var/run/rdmacm-mux"
> +#define RDMA_DEVICE "rxe0"
> +#define RDMA_PORT_NUM 1
> +
> +typedef struct RdmaCmServerArgs {
> + char unix_socket_path[PATH_MAX];
> + char rdma_dev_name[NAME_MAX];
> + int rdma_port_num;
> +} RdmaCMServerArgs;
> +
> +typedef struct CommId2FdEntry {
> + int fd;
> + int ttl; /* Initialized to 2, decrement each timeout, entry delete when
> 0 */
> + __be64 gid_ifid;
> +} CommId2FdEntry;
> +
> +typedef struct RdmaCmUMadAgent {
> + int port_id;
> + int agent_id;
> + GHashTable *gid2fd; /* Used to find fd of a given gid */
> + GHashTable *commid2fd; /* Used to find fd on of a given comm_id */
> +} RdmaCmUMadAgent;
> +
> +typedef struct RdmaCmServer {
> + bool run;
> + RdmaCMServerArgs args;
> + struct pollfd fds[MAX_CLIENTS];
> + int nfds;
> + RdmaCmUMadAgent umad_agent;
> + pthread_t umad_recv_thread;
> + pthread_rwlock_t lock;
> +} RdmaCMServer;
> +
> +RdmaCMServer server = {0};
Maybe static is better here ?
> +
> +static void usage(const char *progname)
> +{
> + printf("Usage: %s [OPTION]...\n"
> + "Start a RDMA-CM multiplexer\n"
> + "\n"
> + "\t-h Show this help\n"
> + "\t-s unix-socket-path Path to unix socket to listen on
> (default %s)\n"
> + "\t-d rdma-device-name Name of RDMA device to register with
> (default %s)\n"
> + "\t-p rdma-device-port Port number of RDMA device to register
> with (default %d)\n",
> + progname, UNIX_SOCKET_PATH, RDMA_DEVICE, RDMA_PORT_NUM);
> +}
> +
> +static void help(const char *progname)
> +{
> + fprintf(stderr, "Try '%s -h' for more information.\n", progname);
> +}
> +
> +static void parse_args(int argc, char *argv[])
> +{
> + int c;
> + char unix_socket_path[PATH_MAX];
> +
> + strcpy(unix_socket_path, UNIX_SOCKET_PATH);
> + strncpy(server.args.rdma_dev_name, RDMA_DEVICE, NAME_MAX - 1);
> + server.args.rdma_port_num = RDMA_PORT_NUM;
> +
> + while ((c = getopt(argc, argv, "hs:d:p:")) != -1) {
> + switch (c) {
> + case 'h':
> + usage(argv[0]);
> + exit(0);
> +
> + case 's':
> + /* This is temporary, final name will build below */
> + strncpy(unix_socket_path, optarg, PATH_MAX);
> + break;
> +
> + case 'd':
> + strncpy(server.args.rdma_dev_name, optarg, NAME_MAX - 1);
> + break;
> +
> + case 'p':
> + server.args.rdma_port_num = atoi(optarg);
> + break;
> +
> + default:
> + help(argv[0]);
> + exit(1);
> + }
> + }
> +
> + /* Build unique unix-socket file name */
> + snprintf(server.args.unix_socket_path, PATH_MAX, "%s-%s-%d",
> + unix_socket_path, server.args.rdma_dev_name,
> + server.args.rdma_port_num);
Please check for truncation:
"a return value of size or more means that the output was truncated"
> +
> + syslog(LOG_INFO, "unix_socket_path=%s", server.args.unix_socket_path);
> + syslog(LOG_INFO, "rdma-device-name=%s", server.args.rdma_dev_name);
> + syslog(LOG_INFO, "rdma-device-port=%d", server.args.rdma_port_num);
> +}
> +
> +static void hash_tbl_alloc(void)
> +{
> +
> + server.umad_agent.gid2fd = g_hash_table_new_full(g_int64_hash,
> + g_int64_equal,
> + g_free, g_free);
> + server.umad_agent.commid2fd = g_hash_table_new_full(g_int_hash,
> + g_int_equal,
> + g_free, g_free);
Any reason not to use 'g_hash_table_new' above ?
Can the above functions fail to create new hash table ? If yes, please
add return status from this function and check it in the caller...
> +}
> +
> +static void hash_tbl_free(void)
> +{
> + if (server.umad_agent.commid2fd) {
> + g_hash_table_destroy(server.umad_agent.commid2fd);
> + }
> + if (server.umad_agent.gid2fd) {
> + g_hash_table_destroy(server.umad_agent.gid2fd);
> + }
> +}
> +
> +
> +static int _hash_tbl_search_fd_by_ifid(__be64 *gid_ifid)
> +{
> + int *fd;
> +
> + fd = g_hash_table_lookup(server.umad_agent.gid2fd, gid_ifid);
> + if (!fd) {
> + /* Let's try IPv4 */
> + *gid_ifid |= 0x00000000ffff0000;
> + fd = g_hash_table_lookup(server.umad_agent.gid2fd, gid_ifid);
> + }
> +
> + return fd ? *fd : 0;
> +}
> +
> +static int hash_tbl_search_fd_by_ifid(int *fd, __be64 *gid_ifid)
> +{
> + pthread_rwlock_rdlock(&server.lock);
> + *fd = _hash_tbl_search_fd_by_ifid(gid_ifid);
> + pthread_rwlock_unlock(&server.lock);
> +
> + if (!fd) {
> + syslog(LOG_WARNING, "Can't find matching for ifid 0x%llx\n",
> *gid_ifid);
> + return -ENOENT;
> + }
> +
> + return 0;
> +}
> +
> +static int hash_tbl_search_fd_by_comm_id(uint32_t comm_id, int *fd,
> + __be64 *gid_idid)
> +{
> + CommId2FdEntry *fde;
> +
> + pthread_rwlock_rdlock(&server.lock);
> + fde = g_hash_table_lookup(server.umad_agent.commid2fd, &comm_id);
> + pthread_rwlock_unlock(&server.lock);
> +
> + if (!fde) {
> + syslog(LOG_WARNING, "Can't find matching for comm_id 0x%x\n",
> comm_id);
> + return -ENOENT;
> + }
> +
> + *fd = fde->fd;
> + *gid_idid = fde->gid_ifid;
> +
> + return 0;
> +}
> +
> +static RdmaCmMuxErrCode add_fd_ifid_pair(int fd, __be64 gid_ifid)
> +{
> + int fd1;
> +
> + pthread_rwlock_wrlock(&server.lock);
> +
> + fd1 = _hash_tbl_search_fd_by_ifid(&gid_ifid);
> + if (fd1) { /* record already exist - an error */
> + pthread_rwlock_unlock(&server.lock);
> + return fd == fd1 ? RDMACM_MUX_ERR_CODE_EEXIST :
> + RDMACM_MUX_ERR_CODE_EACCES;
> + }
> +
> + g_hash_table_insert(server.umad_agent.gid2fd, g_memdup(&gid_ifid,
> + sizeof(gid_ifid)), g_memdup(&fd, sizeof(fd)));
> +
> + pthread_rwlock_unlock(&server.lock);
> +
> + syslog(LOG_INFO, "0x%lx registered on socket %d", (uint64_t)gid_ifid,
> fd);
> +
> + return RDMACM_MUX_ERR_CODE_OK;
> +}
> +
> +static RdmaCmMuxErrCode delete_fd_ifid_pair(int fd, __be64 gid_ifid)
> +{
> + int fd1;
> +
> + pthread_rwlock_wrlock(&server.lock);
> +
> + fd1 = _hash_tbl_search_fd_by_ifid(&gid_ifid);
> + if (!fd1) { /* record not exist - an error */
> + pthread_rwlock_unlock(&server.lock);
> + return RDMACM_MUX_ERR_CODE_ENOTFOUND;
> + }
> +
> + g_hash_table_remove(server.umad_agent.gid2fd, g_memdup(&gid_ifid,
> + sizeof(gid_ifid)));
> + pthread_rwlock_unlock(&server.lock);
> +
> + syslog(LOG_INFO, "0x%lx unregistered on socket %d", (uint64_t)gid_ifid,
> fd);
> +
> + return RDMACM_MUX_ERR_CODE_OK;
> +}
> +
> +static void hash_tbl_save_fd_comm_id_pair(int fd, uint32_t comm_id,
> + uint64_t gid_ifid)
> +{
> + CommId2FdEntry fde = {fd, COMMID_TTL, gid_ifid};
> +
> + pthread_rwlock_wrlock(&server.lock);
> + g_hash_table_insert(server.umad_agent.commid2fd,
> + g_memdup(&comm_id, sizeof(comm_id)),
> + g_memdup(&fde, sizeof(fde)));
> + pthread_rwlock_unlock(&server.lock);
> +}
> +
> +static gboolean remove_old_comm_ids(gpointer key, gpointer value,
> + gpointer user_data)
> +{
> + CommId2FdEntry *fde = (CommId2FdEntry *)value;
> +
> + return !fde->ttl--;
> +}
> +
> +static gboolean remove_entry_from_gid2fd(gpointer key, gpointer value,
> + gpointer user_data)
> +{
> + if (*(int *)value == *(int *)user_data) {
> + syslog(LOG_INFO, "0x%lx unregistered on socket %d", *(uint64_t *)key,
> + *(int *)value);
> + return true;
> + }
> +
> + return false;
> +}
> +
> +static void hash_tbl_remove_fd_ifid_pair(int fd)
> +{
> + pthread_rwlock_wrlock(&server.lock);
> + g_hash_table_foreach_remove(server.umad_agent.gid2fd,
> + remove_entry_from_gid2fd, (gpointer)&fd);
> + pthread_rwlock_unlock(&server.lock);
> +}
> +
> +static int get_fd(const char *mad, int *fd, __be64 *gid_ifid)
> +{
> + struct umad_hdr *hdr = (struct umad_hdr *)mad;
> + char *data = (char *)hdr + sizeof(*hdr);
> + int32_t comm_id;
> + uint16_t attr_id = be16toh(hdr->attr_id);
> + int rc = 0;
> +
> + switch (attr_id) {
> + case UMAD_CM_ATTR_REQ:
> + memcpy(gid_ifid, data + CM_REQ_DGID_POS, sizeof(*gid_ifid));
> + rc = hash_tbl_search_fd_by_ifid(fd, gid_ifid);
> + break;
> +
> + case UMAD_CM_ATTR_SIDR_REQ:
> + memcpy(gid_ifid, data + CM_SIDR_REQ_DGID_POS, sizeof(*gid_ifid));
> + rc = hash_tbl_search_fd_by_ifid(fd, gid_ifid);
> + break;
> +
> + case UMAD_CM_ATTR_REP:
> + /* Fall through */
> + case UMAD_CM_ATTR_REJ:
> + /* Fall through */
> + case UMAD_CM_ATTR_DREQ:
> + /* Fall through */
> + case UMAD_CM_ATTR_DREP:
> + /* Fall through */
> + case UMAD_CM_ATTR_RTU:
> + data += sizeof(comm_id);
> + /* Fall through */
> + case UMAD_CM_ATTR_SIDR_REP:
> + memcpy(&comm_id, data, sizeof(comm_id));
> + if (comm_id) {
> + rc = hash_tbl_search_fd_by_comm_id(comm_id, fd, gid_ifid);
> + }
> + break;
> +
> + default:
> + rc = -EINVAL;
> + syslog(LOG_WARNING, "Unsupported attr_id 0x%x\n", attr_id);
> + }
> +
> + return rc;
> +}
> +
> +static void *umad_recv_thread_func(void *args)
> +{
> + int rc;
> + RdmaCmMuxMsg msg = {0};
> + int fd = -2;
> +
> + while (server.run) {
> + do {
> + msg.umad_len = sizeof(msg.umad.mad);
> + rc = umad_recv(server.umad_agent.port_id, &msg.umad,
> &msg.umad_len,
> + SLEEP_SECS * SCALE_US);
> + if ((rc == -EIO) || (rc == -EINVAL)) {
> + syslog(LOG_CRIT, "Fatal error while trying to read MAD");
> + }
> +
> + if (rc == -ETIMEDOUT) {
> + g_hash_table_foreach_remove(server.umad_agent.commid2fd,
> + remove_old_comm_ids, NULL);
> + }
> + } while (rc && server.run);
> +
> + if (server.run) {
> + rc = get_fd(msg.umad.mad, &fd,
> &msg.hdr.sgid.global.interface_id);
> + if (rc) {
> + continue;
> + }
> +
> + send(fd, &msg, sizeof(msg), 0);
> + }
> + }
> +
> + return NULL;
> +}
> +
> +static int read_and_process(int fd)
> +{
> + int rc;
> + RdmaCmMuxMsg msg = {0};
> + struct umad_hdr *hdr;
> + uint32_t *comm_id;
> + uint16_t attr_id;
> +
> + rc = recv(fd, &msg, sizeof(msg), 0);
> +
> + if (rc < 0 && errno != EWOULDBLOCK) {
> + return -EIO;
> + }
> +
> + if (!rc) {
> + return -EPIPE;
> + }
> +
> + switch (msg.hdr.msg_type) {
> + case RDMACM_MUX_MSG_TYPE_REG:
> + rc = add_fd_ifid_pair(fd, msg.hdr.sgid.global.interface_id);
> + break;
> +
> + case RDMACM_MUX_MSG_TYPE_UNREG:
> + rc = delete_fd_ifid_pair(fd, msg.hdr.sgid.global.interface_id);
> + break;
> +
> + case RDMACM_MUX_MSG_TYPE_MAD:
> + /* If this is REQ or REP then store the pair comm_id,fd to be later
> + * used for other messages where gid is unknown */
> + hdr = (struct umad_hdr *)msg.umad.mad;
> + attr_id = be16toh(hdr->attr_id);
> + if ((attr_id == UMAD_CM_ATTR_REQ) || (attr_id == UMAD_CM_ATTR_DREQ)
> ||
> + (attr_id == UMAD_CM_ATTR_SIDR_REQ) ||
> + (attr_id == UMAD_CM_ATTR_REP) || (attr_id == UMAD_CM_ATTR_DREP))
> {
> + comm_id = (uint32_t *)(msg.umad.mad + sizeof(*hdr));
> + hash_tbl_save_fd_comm_id_pair(fd, *comm_id,
> + msg.hdr.sgid.global.interface_id);
> + }
> +
> + rc = umad_send(server.umad_agent.port_id, server.umad_agent.agent_id,
> + &msg.umad, msg.umad_len, 1, 0);
> + if (rc) {
> + syslog(LOG_WARNING, "Fail to send MAD message, err=%d", rc);
> + }
> + break;
> +
> + default:
> + syslog(LOG_WARNING, "Got invalid message (%d) from %d",
> + msg.hdr.msg_type, fd);
> + rc = RDMACM_MUX_ERR_CODE_EINVAL;
> + }
> +
> + msg.hdr.msg_type = RDMACM_MUX_MSG_TYPE_RESP;
> + msg.hdr.err_code = rc;
> + rc = send(fd, &msg, sizeof(msg), 0);
> +
> + return rc == sizeof(msg) ? 0 : -EPIPE;
> +}
> +
> +static int accept_all(void)
> +{
> + int fd, rc = 0;;
> +
> + pthread_rwlock_wrlock(&server.lock);
> +
> + do {
> + if ((server.nfds + 1) > MAX_CLIENTS) {
> + syslog(LOG_WARNING, "Too many clients (%d)", server.nfds);
> + rc = -EIO;
> + goto out;
> + }
> +
> + fd = accept(server.fds[0].fd, NULL, NULL);
> + if (fd < 0) {
> + if (errno != EWOULDBLOCK) {
> + syslog(LOG_WARNING, "accept() failed");
> + rc = -EIO;
> + goto out;
> + }
> + break;
> + }
> +
> + syslog(LOG_INFO, "Client connected on socket %d\n", fd);
> + server.fds[server.nfds].fd = fd;
> + server.fds[server.nfds].events = POLLIN;
> + server.nfds++;
> + } while (fd != -1);
> +
> +out:
> + pthread_rwlock_unlock(&server.lock);
> + return rc;
> +}
> +
> +static void compress_fds(void)
> +{
> + int i, j;
> + int closed = 0;
> +
> + pthread_rwlock_wrlock(&server.lock);
> +
> + for (i = 1; i < server.nfds; i++) {
> + if (!server.fds[i].fd) {
> + closed++;
> + for (j = i; j < server.nfds; j++) {
> + server.fds[j].fd = server.fds[j + 1].fd;
> + }
> + }
> + }
> +
> + server.nfds -= closed;
> +
> + pthread_rwlock_unlock(&server.lock);
> +}
> +
> +static void close_fd(int idx)
> +{
> + close(server.fds[idx].fd);
> + syslog(LOG_INFO, "Socket %d closed\n", server.fds[idx].fd);
> + hash_tbl_remove_fd_ifid_pair(server.fds[idx].fd);
> + server.fds[idx].fd = 0;
> +}
> +
> +static void run(void)
> +{
> + int rc, nfds, i;
> + bool compress = false;
> +
> + syslog(LOG_INFO, "Service started");
> +
> + while (server.run) {
> + rc = poll(server.fds, server.nfds, SLEEP_SECS * SCALE_US);
> + if (rc < 0) {
> + if (errno != EINTR) {
> + syslog(LOG_WARNING, "poll() failed");
> + }
> + continue;
> + }
> +
> + if (rc == 0) {
> + continue;
> + }
> +
> + nfds = server.nfds;
> + for (i = 0; i < nfds; i++) {
> + if (server.fds[i].revents == 0) {
> + continue;
> + }
> +
> + if (server.fds[i].revents != POLLIN) {
> + if (i == 0) {
> + syslog(LOG_NOTICE, "Unexpected poll() event (0x%x)\n",
> + server.fds[i].revents);
> + } else {
> + close_fd(i);
> + compress = true;
> + }
> + continue;
> + }
> +
> + if (i == 0) {
> + rc = accept_all();
> + if (rc) {
> + continue;
> + }
> + } else {
> + rc = read_and_process(server.fds[i].fd);
> + if (rc) {
> + close_fd(i);
> + compress = true;
> + }
> + }
> + }
> +
> + if (compress) {
> + compress = false;
> + compress_fds();
> + }
> + }
> +}
> +
> +static void fini_listener(void)
> +{
> + int i;
> +
> + if (server.fds[0].fd <= 0) {
> + return;
> + }
> +
> + for (i = server.nfds - 1; i >= 0; i--) {
> + if (server.fds[i].fd) {
> + close(server.fds[i].fd);
> + }
> + }
> +
> + unlink(server.args.unix_socket_path);
> +}
> +
> +static void fini_umad(void)
> +{
> + if (server.umad_agent.agent_id) {
> + umad_unregister(server.umad_agent.port_id,
> server.umad_agent.agent_id);
> + }
> +
> + if (server.umad_agent.port_id) {
> + umad_close_port(server.umad_agent.port_id);
> + }
> +
> + hash_tbl_free();
> +}
> +
> +static void fini(void)
> +{
> + if (server.umad_recv_thread) {
> + pthread_join(server.umad_recv_thread, NULL);
Can pthread_join be called (raced) from signal handler & main ?
The man say this:
"If multiple threads simultaneously try to join with the same thread,
the results are undefined."
What ensure that above will not happen ?
> + server.umad_recv_thread = 0;
> + }
> + fini_umad();
> + fini_listener();
> + pthread_rwlock_destroy(&server.lock);
Same above question goes to here.
The man say this:
"Results are undefined if a read-write lock is used without first being
initialized."
> +
> + syslog(LOG_INFO, "Service going down");
> +}
> +
> +static int init_listener(void)
> +{
> + struct sockaddr_un sun;
> + int rc, on = 1;
> +
> + server.fds[0].fd = socket(AF_UNIX, SOCK_STREAM, 0);
> + if (server.fds[0].fd < 0) {
> + syslog(LOG_ALERT, "socket() failed");
> + return -EIO;
> + }
Since you work with full mad messages, won't it be better to use
SOCK_DGRAM ? Is there any use for partial mad message ?
>From the man:
"SOCK_DGRAM, for a datagram-oriented socket that preserves message boundaries"
> +
> + rc = setsockopt(server.fds[0].fd, SOL_SOCKET, SO_REUSEADDR, (char *)&on,
> + sizeof(on));
> + if (rc < 0) {
> + syslog(LOG_ALERT, "setsockopt() failed");
> + rc = -EIO;
> + goto err;
> + }
> +
> + rc = ioctl(server.fds[0].fd, FIONBIO, (char *)&on);
> + if (rc < 0) {
> + syslog(LOG_ALERT, "ioctl() failed");
> + rc = -EIO;
> + goto err;
> + }
> +
> + if (strlen(server.args.unix_socket_path) >= sizeof(sun.sun_path)) {
> + syslog(LOG_ALERT,
> + "Invalid unix_socket_path, size must be less than %ld\n",
> + sizeof(sun.sun_path));
> + rc = -EINVAL;
> + goto err;
> + }
> +
> + sun.sun_family = AF_UNIX;
> + rc = snprintf(sun.sun_path, sizeof(sun.sun_path), "%s",
> + server.args.unix_socket_path);
> + if (rc < 0 || rc >= sizeof(sun.sun_path)) {
> + syslog(LOG_ALERT, "Could not copy unix socket path\n");
> + rc = -EINVAL;
> + goto err;
> + }
> +
> + rc = bind(server.fds[0].fd, (struct sockaddr *)&sun, sizeof(sun));
> + if (rc < 0) {
> + syslog(LOG_ALERT, "bind() failed");
> + rc = -EIO;
> + goto err;
> + }
> +
> + rc = listen(server.fds[0].fd, SERVER_LISTEN_BACKLOG);
> + if (rc < 0) {
> + syslog(LOG_ALERT, "listen() failed");
> + rc = -EIO;
> + goto err;
> + }
> +
> + server.fds[0].events = POLLIN;
> + server.nfds = 1;
> + server.run = true;
> +
> + return 0;
> +
> +err:
> + close(server.fds[0].fd);
> + return rc;
> +}
> +
> +static int init_umad(void)
> +{
> + long method_mask[IB_USER_MAD_LONGS_PER_METHOD_MASK];
> +
> + server.umad_agent.port_id = umad_open_port(server.args.rdma_dev_name,
> + server.args.rdma_port_num);
> +
> + if (server.umad_agent.port_id < 0) {
> + syslog(LOG_WARNING, "umad_open_port() failed");
> + return -EIO;
> + }
> +
> + memset(&method_mask, 0, sizeof(method_mask));
> + method_mask[0] = MAD_METHOD_MASK0;
> + server.umad_agent.agent_id = umad_register(server.umad_agent.port_id,
> + UMAD_CLASS_CM,
> + UMAD_SA_CLASS_VERSION,
> + MAD_RMPP_VERSION,
> method_mask);
> + if (server.umad_agent.agent_id < 0) {
> + syslog(LOG_WARNING, "umad_register() failed");
> + return -EIO;
> + }
> +
> + hash_tbl_alloc();
> +
> + return 0;
> +}
> +
> +static void signal_handler(int sig, siginfo_t *siginfo, void *context)
> +{
> + static bool warned;
> +
> + /* Prevent stop if clients are connected */
> + if (server.nfds != 1) {
> + if (!warned) {
> + syslog(LOG_WARNING,
> + "Can't stop while active client exist, resend SIGINT to
> overid");
> + warned = true;
> + return;
> + }
> + }
> +
> + if (sig == SIGINT) {
> + server.run = false;
> + fini();
> + }
> +
> + exit(0);
> +}
> +
> +static int init(void)
> +{
> + int rc;
> +
> + rc = init_listener();
> + if (rc) {
> + return rc;
> + }
> +
> + rc = init_umad();
> + if (rc) {
> + return rc;
> + }
> +
> + pthread_rwlock_init(&server.lock, 0);
> +
> + rc = pthread_create(&server.umad_recv_thread, NULL,
> umad_recv_thread_func,
> + NULL);
> + if (!rc) {
> + return rc;
> + }
> +
> + return 0;
> +}
> +
> +int main(int argc, char *argv[])
> +{
> + int rc;
> + struct sigaction sig = {0};
> +
> + sig.sa_sigaction = &signal_handler;
> + sig.sa_flags = SA_SIGINFO;
> +
> + if (sigaction(SIGINT, &sig, NULL) < 0) {
> + syslog(LOG_ERR, "Fail to install SIGINT handler\n");
> + return -EAGAIN;
> + }
> +
> + memset(&server, 0, sizeof(server));
> +
> + parse_args(argc, argv);
> +
> + rc = init();
> + if (rc) {
> + syslog(LOG_ERR, "Fail to initialize server (%d)\n", rc);
> + rc = -EAGAIN;
> + goto out;
> + }
> +
> + run();
> +
> +out:
> + fini();
> +
> + return rc;
> +}
> diff --git a/contrib/rdmacm-mux/rdmacm-mux.h b/contrib/rdmacm-mux/rdmacm-mux.h
> new file mode 100644
> index 0000000000..03508d52b2
> --- /dev/null
> +++ b/contrib/rdmacm-mux/rdmacm-mux.h
> @@ -0,0 +1,56 @@
> +/*
> + * QEMU paravirtual RDMA - rdmacm-mux declarations
> + *
> + * Copyright (C) 2018 Oracle
> + * Copyright (C) 2018 Red Hat Inc
> + *
> + * Authors:
> + * Yuval Shaia <address@hidden>
> + * Marcel Apfelbaum <address@hidden>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
> + * See the COPYING file in the top-level directory.
> + *
> + */
> +
> +#ifndef RDMACM_MUX_H
> +#define RDMACM_MUX_H
> +
> +#include "linux/if.h"
> +#include "infiniband/verbs.h"
> +#include "infiniband/umad.h"
> +#include "rdma/rdma_user_cm.h"
> +
> +typedef enum RdmaCmMuxMsgType {
> + RDMACM_MUX_MSG_TYPE_REG = 0,
> + RDMACM_MUX_MSG_TYPE_UNREG = 1,
> + RDMACM_MUX_MSG_TYPE_MAD = 2,
> + RDMACM_MUX_MSG_TYPE_RESP = 3,
> +} RdmaCmMuxMsgType;
> +
> +typedef enum RdmaCmMuxErrCode {
> + RDMACM_MUX_ERR_CODE_OK = 0,
> + RDMACM_MUX_ERR_CODE_EINVAL = 1,
> + RDMACM_MUX_ERR_CODE_EEXIST = 2,
> + RDMACM_MUX_ERR_CODE_EACCES = 3,
> + RDMACM_MUX_ERR_CODE_ENOTFOUND = 4,
> +} RdmaCmMuxErrCode;
> +
> +typedef struct RdmaCmMuxHdr {
> + RdmaCmMuxMsgType msg_type;
> + union ibv_gid sgid;
> + RdmaCmMuxErrCode err_code;
> +} RdmaCmUHdr;
> +
> +typedef struct RdmaCmUMad {
> + struct ib_user_mad hdr;
> + char mad[RDMA_MAX_PRIVATE_DATA];
> +} RdmaCmUMad;
> +
> +typedef struct RdmaCmMuxMsg {
> + RdmaCmUHdr hdr;
> + int umad_len;
> + RdmaCmUMad umad;
> +} RdmaCmMuxMsg;
> +
> +#endif
> --
> 2.17.2
>