From patchwork Wed May 29 16:23:05 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: John Levon X-Patchwork-Id: 13679204 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 367A0C25B75 for ; Wed, 29 May 2024 16:26:02 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sCM6x-00019b-TC; Wed, 29 May 2024 12:25:11 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sCM6s-00017P-Mn for qemu-devel@nongnu.org; Wed, 29 May 2024 12:25:07 -0400 Received: from ssh.movementarian.org ([139.162.205.133] helo=movementarian.org) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sCM6l-0006Kb-6u for qemu-devel@nongnu.org; Wed, 29 May 2024 12:25:06 -0400 Received: from movement by movementarian.org with local (Exim 4.95) (envelope-from ) id 1sCM6j-006CP6-80; Wed, 29 May 2024 17:24:57 +0100 From: John Levon To: qemu-devel@nongnu.org Cc: alex.williamson@redhat.com, clg@redhat.com, jag.raman@oracle.com, thanos.makatos@nutanix.com, John Johnson , Elena Ufimtseva , John Levon Subject: [PATCH 12/26] vfio-user: define socket receive functions Date: Wed, 29 May 2024 17:23:05 +0100 Message-Id: <20240529162319.1476680-13-levon@movementarian.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240529162319.1476680-1-levon@movementarian.org> References: <20240529162319.1476680-1-levon@movementarian.org> MIME-Version: 1.0 Received-SPF: pass client-ip=139.162.205.133; envelope-from=movement@movementarian.org; helo=movementarian.org X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Jagannathan Raman Add infrastructure needed to receive incoming messages Originally-by: John Johnson Signed-off-by: Elena Ufimtseva Signed-off-by: Jagannathan Raman Signed-off-by: John Levon --- hw/vfio/trace-events | 5 + hw/vfio/user-pci.c | 11 ++ hw/vfio/user-protocol.h | 54 ++++++ hw/vfio/user.c | 408 ++++++++++++++++++++++++++++++++++++++++ hw/vfio/user.h | 10 + 5 files changed, 488 insertions(+) create mode 100644 hw/vfio/user-protocol.h diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events index 64161bf6f4..a5a5a34198 100644 --- a/hw/vfio/trace-events +++ b/hw/vfio/trace-events @@ -176,3 +176,8 @@ iommufd_cdev_fail_attach_existing_container(const char *msg) " %s" iommufd_cdev_alloc_ioas(int iommufd, int ioas_id) " [iommufd=%d] new IOMMUFD container with ioasid=%d" iommufd_cdev_device_info(char *name, int devfd, int num_irqs, int num_regions, int flags) " %s (%d) num_irqs=%d num_regions=%d flags=%d" iommufd_cdev_pci_hot_reset_dep_devices(int domain, int bus, int slot, int function, int dev_id) "\t%04x:%02x:%02x.%x devid %d" + +# user.c +vfio_user_recv_hdr(const char *name, uint16_t id, uint16_t cmd, uint32_t size, uint32_t flags) " (%s) id 0x%x cmd 0x%x size 0x%x flags 0x%x" +vfio_user_recv_read(uint16_t id, int read) " id 0x%x read 0x%x" +vfio_user_recv_request(uint16_t cmd) " command 0x%x" diff --git a/hw/vfio/user-pci.c b/hw/vfio/user-pci.c index 8c66833118..350e957132 100644 --- a/hw/vfio/user-pci.c +++ b/hw/vfio/user-pci.c @@ -42,6 +42,16 @@ struct VFIOUserPCIDevice { char *sock_name; }; +/* + * Incoming request message callback. + * + * Runs off main loop, so BQL held. + */ +static void vfio_user_pci_process_req(void *opaque, VFIOUserMsg *msg) +{ + +} + /* * Emulated devices don't use host hot reset */ @@ -87,6 +97,7 @@ static void vfio_user_pci_realize(PCIDevice *pdev, Error **errp) return; } vbasedev->proxy = proxy; + vfio_user_set_handler(vbasedev, vfio_user_pci_process_req, vdev); vbasedev->name = g_strdup_printf("VFIO user <%s>", udev->sock_name); vbasedev->ops = &vfio_user_pci_ops; diff --git a/hw/vfio/user-protocol.h b/hw/vfio/user-protocol.h new file mode 100644 index 0000000000..d23877c958 --- /dev/null +++ b/hw/vfio/user-protocol.h @@ -0,0 +1,54 @@ +#ifndef VFIO_USER_PROTOCOL_H +#define VFIO_USER_PROTOCOL_H + +/* + * vfio protocol over a UNIX socket. + * + * Copyright © 2018, 2021 Oracle and/or its affiliates. + * + * This work is licensed under the terms of the GNU GPL, version 2. See + * the COPYING file in the top-level directory. + * + * Each message has a standard header that describes the command + * being sent, which is almost always a VFIO ioctl(). + * + * The header may be followed by command-specific data, such as the + * region and offset info for read and write commands. + */ + +typedef struct { + uint16_t id; + uint16_t command; + uint32_t size; + uint32_t flags; + uint32_t error_reply; +} VFIOUserHdr; + +/* VFIOUserHdr commands */ +enum vfio_user_command { + VFIO_USER_VERSION = 1, + VFIO_USER_DMA_MAP = 2, + VFIO_USER_DMA_UNMAP = 3, + VFIO_USER_DEVICE_GET_INFO = 4, + VFIO_USER_DEVICE_GET_REGION_INFO = 5, + VFIO_USER_DEVICE_GET_REGION_IO_FDS = 6, + VFIO_USER_DEVICE_GET_IRQ_INFO = 7, + VFIO_USER_DEVICE_SET_IRQS = 8, + VFIO_USER_REGION_READ = 9, + VFIO_USER_REGION_WRITE = 10, + VFIO_USER_DMA_READ = 11, + VFIO_USER_DMA_WRITE = 12, + VFIO_USER_DEVICE_RESET = 13, + VFIO_USER_DIRTY_PAGES = 14, + VFIO_USER_MAX, +}; + +/* VFIOUserHdr flags */ +#define VFIO_USER_REQUEST 0x0 +#define VFIO_USER_REPLY 0x1 +#define VFIO_USER_TYPE 0xF + +#define VFIO_USER_NO_REPLY 0x10 +#define VFIO_USER_ERROR 0x20 + +#endif /* VFIO_USER_PROTOCOL_H */ diff --git a/hw/vfio/user.c b/hw/vfio/user.c index 91501f625c..998816b97d 100644 --- a/hw/vfio/user.c +++ b/hw/vfio/user.c @@ -24,11 +24,27 @@ #include "io/channel-util.h" #include "sysemu/iothread.h" #include "user.h" +#include "trace.h" static IOThread *vfio_user_iothread; static void vfio_user_shutdown(VFIOUserProxy *proxy); +static VFIOUserMsg *vfio_user_getmsg(VFIOUserProxy *proxy, VFIOUserHdr *hdr, + VFIOUserFDs *fds); +static VFIOUserFDs *vfio_user_getfds(int numfds); +static void vfio_user_recycle(VFIOUserProxy *proxy, VFIOUserMsg *msg); +static void vfio_user_recv(void *opaque); +static int vfio_user_recv_one(VFIOUserProxy *proxy); +static void vfio_user_cb(void *opaque); + +static void vfio_user_request(void *opaque); + +static inline void vfio_user_set_error(VFIOUserHdr *hdr, uint32_t err) +{ + hdr->flags |= VFIO_USER_ERROR; + hdr->error_reply = err; +} /* * Functions called by main, CPU, or iothread threads @@ -41,10 +57,340 @@ static void vfio_user_shutdown(VFIOUserProxy *proxy) proxy->ctx, NULL, NULL); } +static VFIOUserMsg *vfio_user_getmsg(VFIOUserProxy *proxy, VFIOUserHdr *hdr, + VFIOUserFDs *fds) +{ + VFIOUserMsg *msg; + + msg = QTAILQ_FIRST(&proxy->free); + if (msg != NULL) { + QTAILQ_REMOVE(&proxy->free, msg, next); + } else { + msg = g_malloc0(sizeof(*msg)); + qemu_cond_init(&msg->cv); + } + + msg->hdr = hdr; + msg->fds = fds; + return msg; +} + +/* + * Recycle a message list entry to the free list. + */ +static void vfio_user_recycle(VFIOUserProxy *proxy, VFIOUserMsg *msg) +{ + if (msg->type == VFIO_MSG_NONE) { + error_printf("vfio_user_recycle - freeing free msg\n"); + return; + } + + /* free msg buffer if no one is waiting to consume the reply */ + if (msg->type == VFIO_MSG_NOWAIT || msg->type == VFIO_MSG_ASYNC) { + g_free(msg->hdr); + if (msg->fds != NULL) { + g_free(msg->fds); + } + } + + msg->type = VFIO_MSG_NONE; + msg->hdr = NULL; + msg->fds = NULL; + msg->complete = false; + QTAILQ_INSERT_HEAD(&proxy->free, msg, next); +} + +static VFIOUserFDs *vfio_user_getfds(int numfds) +{ + VFIOUserFDs *fds = g_malloc0(sizeof(*fds) + (numfds * sizeof(int))); + + fds->fds = (int *)((char *)fds + sizeof(*fds)); + + return fds; +} + /* * Functions only called by iothread */ +/* + * Process a received message. + */ +static void vfio_user_process(VFIOUserProxy *proxy, VFIOUserMsg *msg, + bool isreply) +{ + + /* + * Replies signal a waiter, if none just check for errors + * and free the message buffer. + * + * Requests get queued for the BH. + */ + if (isreply) { + msg->complete = true; + if (msg->type == VFIO_MSG_WAIT) { + qemu_cond_signal(&msg->cv); + } else { + if (msg->hdr->flags & VFIO_USER_ERROR) { + error_printf("vfio_user_process: error reply on async "); + error_printf("request command %x error %s\n", + msg->hdr->command, + strerror(msg->hdr->error_reply)); + } + /* youngest nowait msg has been ack'd */ + if (proxy->last_nowait == msg) { + proxy->last_nowait = NULL; + } + vfio_user_recycle(proxy, msg); + } + } else { + QTAILQ_INSERT_TAIL(&proxy->incoming, msg, next); + qemu_bh_schedule(proxy->req_bh); + } +} + +/* + * Complete a partial message read + */ +static int vfio_user_complete(VFIOUserProxy *proxy, Error **errp) +{ + VFIOUserMsg *msg = proxy->part_recv; + size_t msgleft = proxy->recv_left; + bool isreply; + char *data; + int ret; + + data = (char *)msg->hdr + (msg->hdr->size - msgleft); + while (msgleft > 0) { + ret = qio_channel_read(proxy->ioc, data, msgleft, errp); + + /* error or would block */ + if (ret <= 0) { + /* try for rest on next iternation */ + if (ret == QIO_CHANNEL_ERR_BLOCK) { + proxy->recv_left = msgleft; + } + return ret; + } + trace_vfio_user_recv_read(msg->hdr->id, ret); + + msgleft -= ret; + data += ret; + } + + /* + * Read complete message, process it. + */ + proxy->part_recv = NULL; + proxy->recv_left = 0; + isreply = (msg->hdr->flags & VFIO_USER_TYPE) == VFIO_USER_REPLY; + vfio_user_process(proxy, msg, isreply); + + /* return positive value */ + return 1; +} + +static void vfio_user_recv(void *opaque) +{ + VFIOUserProxy *proxy = opaque; + + QEMU_LOCK_GUARD(&proxy->lock); + + if (proxy->state == VFIO_PROXY_CONNECTED) { + while (vfio_user_recv_one(proxy) == 0) { + ; + } + } +} + +/* + * Receive and process one incoming message. + * + * For replies, find matching outgoing request and wake any waiters. + * For requests, queue in incoming list and run request BH. + */ +static int vfio_user_recv_one(VFIOUserProxy *proxy) +{ + VFIOUserMsg *msg = NULL; + g_autofree int *fdp = NULL; + VFIOUserFDs *reqfds; + VFIOUserHdr hdr; + struct iovec iov = { + .iov_base = &hdr, + .iov_len = sizeof(hdr), + }; + bool isreply = false; + int i, ret; + size_t msgleft, numfds = 0; + char *data = NULL; + char *buf = NULL; + Error *local_err = NULL; + + /* + * Complete any partial reads + */ + if (proxy->part_recv != NULL) { + ret = vfio_user_complete(proxy, &local_err); + + /* still not complete, try later */ + if (ret == QIO_CHANNEL_ERR_BLOCK) { + return ret; + } + + if (ret <= 0) { + goto fatal; + } + /* else fall into reading another msg */ + } + + /* + * Read header + */ + ret = qio_channel_readv_full(proxy->ioc, &iov, 1, &fdp, &numfds, 0, + &local_err); + if (ret == QIO_CHANNEL_ERR_BLOCK) { + return ret; + } + + /* read error or other side closed connection */ + if (ret <= 0) { + goto fatal; + } + + if (ret < sizeof(msg)) { + error_setg(&local_err, "short read of header"); + goto fatal; + } + + /* + * Validate header + */ + if (hdr.size < sizeof(VFIOUserHdr)) { + error_setg(&local_err, "bad header size"); + goto fatal; + } + switch (hdr.flags & VFIO_USER_TYPE) { + case VFIO_USER_REQUEST: + isreply = false; + break; + case VFIO_USER_REPLY: + isreply = true; + break; + default: + error_setg(&local_err, "unknown message type"); + goto fatal; + } + trace_vfio_user_recv_hdr(proxy->sockname, hdr.id, hdr.command, hdr.size, + hdr.flags); + + /* + * For replies, find the matching pending request. + * For requests, reap incoming FDs. + */ + if (isreply) { + QTAILQ_FOREACH(msg, &proxy->pending, next) { + if (hdr.id == msg->id) { + break; + } + } + if (msg == NULL) { + error_setg(&local_err, "unexpected reply"); + goto err; + } + QTAILQ_REMOVE(&proxy->pending, msg, next); + + /* + * Process any received FDs + */ + if (numfds != 0) { + if (msg->fds == NULL || msg->fds->recv_fds < numfds) { + error_setg(&local_err, "unexpected FDs"); + goto err; + } + msg->fds->recv_fds = numfds; + memcpy(msg->fds->fds, fdp, numfds * sizeof(int)); + } + } else { + if (numfds != 0) { + reqfds = vfio_user_getfds(numfds); + memcpy(reqfds->fds, fdp, numfds * sizeof(int)); + } else { + reqfds = NULL; + } + } + + /* + * Put the whole message into a single buffer. + */ + if (isreply) { + if (hdr.size > msg->rsize) { + error_setg(&local_err, "reply larger than recv buffer"); + goto err; + } + *msg->hdr = hdr; + data = (char *)msg->hdr + sizeof(hdr); + } else { + buf = g_malloc0(hdr.size); + memcpy(buf, &hdr, sizeof(hdr)); + data = buf + sizeof(hdr); + msg = vfio_user_getmsg(proxy, (VFIOUserHdr *)buf, reqfds); + msg->type = VFIO_MSG_REQ; + } + + /* + * Read rest of message. + */ + msgleft = hdr.size - sizeof(hdr); + while (msgleft > 0) { + ret = qio_channel_read(proxy->ioc, data, msgleft, &local_err); + + /* prepare to complete read on next iternation */ + if (ret == QIO_CHANNEL_ERR_BLOCK) { + proxy->part_recv = msg; + proxy->recv_left = msgleft; + return ret; + } + + if (ret <= 0) { + goto fatal; + } + trace_vfio_user_recv_read(hdr.id, ret); + + msgleft -= ret; + data += ret; + } + + vfio_user_process(proxy, msg, isreply); + return 0; + + /* + * fatal means the other side closed or we don't trust the stream + * err means this message is corrupt + */ +fatal: + vfio_user_shutdown(proxy); + proxy->state = VFIO_PROXY_ERROR; + + /* set error if server side closed */ + if (ret == 0) { + error_setg(&local_err, "server closed socket"); + } + +err: + for (i = 0; i < numfds; i++) { + close(fdp[i]); + } + if (isreply && msg != NULL) { + /* force an error to keep sending thread from hanging */ + vfio_user_set_error(msg->hdr, EINVAL); + msg->complete = true; + qemu_cond_signal(&msg->cv); + } + error_prepend(&local_err, "vfio_user_recv_one: "); + error_report_err(local_err); + return -1; +} + static void vfio_user_cb(void *opaque) { VFIOUserProxy *proxy = opaque; @@ -60,6 +406,53 @@ static void vfio_user_cb(void *opaque) * Functions called by main or CPU threads */ +/* + * Process incoming requests. + * + * The bus-specific callback has the form: + * request(opaque, msg) + * where 'opaque' was specified in vfio_user_set_handler + * and 'msg' is the inbound message. + * + * The callback is responsible for disposing of the message buffer, + * usually by re-using it when calling vfio_send_reply or vfio_send_error, + * both of which free their message buffer when the reply is sent. + * + * If the callback uses a new buffer, it needs to free the old one. + */ +static void vfio_user_request(void *opaque) +{ + VFIOUserProxy *proxy = opaque; + VFIOUserMsgQ new, free; + VFIOUserMsg *msg, *m1; + + /* reap all incoming */ + QTAILQ_INIT(&new); + WITH_QEMU_LOCK_GUARD(&proxy->lock) { + QTAILQ_FOREACH_SAFE(msg, &proxy->incoming, next, m1) { + QTAILQ_REMOVE(&proxy->incoming, msg, next); + QTAILQ_INSERT_TAIL(&new, msg, next); + } + } + + /* process list */ + QTAILQ_INIT(&free); + QTAILQ_FOREACH_SAFE(msg, &new, next, m1) { + QTAILQ_REMOVE(&new, msg, next); + trace_vfio_user_recv_request(msg->hdr->command); + proxy->request(proxy->req_arg, msg); + QTAILQ_INSERT_HEAD(&free, msg, next); + } + + /* free list */ + WITH_QEMU_LOCK_GUARD(&proxy->lock) { + QTAILQ_FOREACH_SAFE(msg, &free, next, m1) { + vfio_user_recycle(proxy, msg); + } + } +} + + static QLIST_HEAD(, VFIOUserProxy) vfio_user_sockets = QLIST_HEAD_INITIALIZER(vfio_user_sockets); @@ -98,6 +491,7 @@ VFIOUserProxy *vfio_user_connect_dev(SocketAddress *addr, Error **errp) } proxy->ctx = iothread_get_aio_context(vfio_user_iothread); + proxy->req_bh = qemu_bh_new(vfio_user_request, proxy); QTAILQ_INIT(&proxy->outgoing); QTAILQ_INIT(&proxy->incoming); @@ -108,6 +502,18 @@ VFIOUserProxy *vfio_user_connect_dev(SocketAddress *addr, Error **errp) return proxy; } +void vfio_user_set_handler(VFIODevice *vbasedev, + void (*handler)(void *opaque, VFIOUserMsg *msg), + void *req_arg) +{ + VFIOUserProxy *proxy = vbasedev->proxy; + + proxy->request = handler; + proxy->req_arg = req_arg; + qio_channel_set_aio_fd_handler(proxy->ioc, proxy->ctx, + vfio_user_recv, NULL, NULL, proxy); +} + void vfio_user_disconnect(VFIOUserProxy *proxy) { VFIOUserMsg *r1, *r2; @@ -123,6 +529,8 @@ void vfio_user_disconnect(VFIOUserProxy *proxy) } object_unref(OBJECT(proxy->ioc)); proxy->ioc = NULL; + qemu_bh_delete(proxy->req_bh); + proxy->req_bh = NULL; proxy->state = VFIO_PROXY_CLOSING; QTAILQ_FOREACH_SAFE(r1, &proxy->outgoing, next, r2) { diff --git a/hw/vfio/user.h b/hw/vfio/user.h index ac7d15dfa8..30cf35d3e4 100644 --- a/hw/vfio/user.h +++ b/hw/vfio/user.h @@ -11,6 +11,8 @@ * */ +#include "user-protocol.h" + typedef struct { int send_fds; int recv_fds; @@ -27,6 +29,7 @@ enum msg_type { typedef struct VFIOUserMsg { QTAILQ_ENTRY(VFIOUserMsg) next; + VFIOUserHdr *hdr; VFIOUserFDs *fds; uint32_t rsize; uint32_t id; @@ -66,13 +69,20 @@ typedef struct VFIOUserProxy { VFIOUserMsgQ incoming; VFIOUserMsgQ outgoing; VFIOUserMsg *last_nowait; + VFIOUserMsg *part_recv; + size_t recv_left; enum proxy_state state; } VFIOUserProxy; /* VFIOProxy flags */ #define VFIO_PROXY_CLIENT 0x1 +typedef struct VFIODevice VFIODevice; + VFIOUserProxy *vfio_user_connect_dev(SocketAddress *addr, Error **errp); void vfio_user_disconnect(VFIOUserProxy *proxy); +void vfio_user_set_handler(VFIODevice *vbasedev, + void (*handler)(void *opaque, VFIOUserMsg *msg), + void *reqarg); #endif /* VFIO_USER_H */