From a110b7ebb9c674a2b591af2780dd512ad0198d50 Mon Sep 17 00:00:00 2001 From: George Zhang Date: Tue, 8 Jan 2013 15:53:15 -0800 Subject: [PATCH] VMCI: datagram implementation. VMCI datagram Implements datagrams to allow data to be sent between host and guest. Signed-off-by: George Zhang Acked-by: Andy king Acked-by: Dmitry Torokhov Signed-off-by: Greg Kroah-Hartman --- drivers/misc/vmw_vmci/vmci_datagram.c | 500 ++++++++++++++++++++++++++ drivers/misc/vmw_vmci/vmci_datagram.h | 52 +++ 2 files changed, 552 insertions(+) create mode 100644 drivers/misc/vmw_vmci/vmci_datagram.c create mode 100644 drivers/misc/vmw_vmci/vmci_datagram.h diff --git a/drivers/misc/vmw_vmci/vmci_datagram.c b/drivers/misc/vmw_vmci/vmci_datagram.c new file mode 100644 index 00000000000..ed5c433cd49 --- /dev/null +++ b/drivers/misc/vmw_vmci/vmci_datagram.c @@ -0,0 +1,500 @@ +/* + * VMware VMCI Driver + * + * Copyright (C) 2012 VMware, Inc. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation version 2 and no later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY + * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * for more details. + */ + +#include +#include +#include +#include +#include +#include + +#include "vmci_datagram.h" +#include "vmci_resource.h" +#include "vmci_context.h" +#include "vmci_driver.h" +#include "vmci_event.h" +#include "vmci_route.h" + +/* + * struct datagram_entry describes the datagram entity. It is used for datagram + * entities created only on the host. + */ +struct datagram_entry { + struct vmci_resource resource; + u32 flags; + bool run_delayed; + vmci_datagram_recv_cb recv_cb; + void *client_data; + u32 priv_flags; +}; + +struct delayed_datagram_info { + struct datagram_entry *entry; + struct vmci_datagram msg; + struct work_struct work; + bool in_dg_host_queue; +}; + +/* Number of in-flight host->host datagrams */ +static atomic_t delayed_dg_host_queue_size = ATOMIC_INIT(0); + +/* + * Create a datagram entry given a handle pointer. + */ +static int dg_create_handle(u32 resource_id, + u32 flags, + u32 priv_flags, + vmci_datagram_recv_cb recv_cb, + void *client_data, struct vmci_handle *out_handle) +{ + int result; + u32 context_id; + struct vmci_handle handle; + struct datagram_entry *entry; + + if ((flags & VMCI_FLAG_WELLKNOWN_DG_HND) != 0) + return VMCI_ERROR_INVALID_ARGS; + + if ((flags & VMCI_FLAG_ANYCID_DG_HND) != 0) { + context_id = VMCI_INVALID_ID; + } else { + context_id = vmci_get_context_id(); + if (context_id == VMCI_INVALID_ID) + return VMCI_ERROR_NO_RESOURCES; + } + + handle = vmci_make_handle(context_id, resource_id); + + entry = kmalloc(sizeof(*entry), GFP_KERNEL); + if (!entry) { + pr_warn("Failed allocating memory for datagram entry\n"); + return VMCI_ERROR_NO_MEM; + } + + entry->run_delayed = (flags & VMCI_FLAG_DG_DELAYED_CB) ? true : false; + entry->flags = flags; + entry->recv_cb = recv_cb; + entry->client_data = client_data; + entry->priv_flags = priv_flags; + + /* Make datagram resource live. */ + result = vmci_resource_add(&entry->resource, + VMCI_RESOURCE_TYPE_DATAGRAM, + handle); + if (result != VMCI_SUCCESS) { + pr_warn("Failed to add new resource (handle=0x%x:0x%x), error: %d\n", + handle.context, handle.resource, result); + kfree(entry); + return result; + } + + *out_handle = vmci_resource_handle(&entry->resource); + return VMCI_SUCCESS; +} + +/* + * Internal utility function with the same purpose as + * vmci_datagram_get_priv_flags that also takes a context_id. + */ +static int vmci_datagram_get_priv_flags(u32 context_id, + struct vmci_handle handle, + u32 *priv_flags) +{ + if (context_id == VMCI_INVALID_ID) + return VMCI_ERROR_INVALID_ARGS; + + if (context_id == VMCI_HOST_CONTEXT_ID) { + struct datagram_entry *src_entry; + struct vmci_resource *resource; + + resource = vmci_resource_by_handle(handle, + VMCI_RESOURCE_TYPE_DATAGRAM); + if (!resource) + return VMCI_ERROR_INVALID_ARGS; + + src_entry = container_of(resource, struct datagram_entry, + resource); + *priv_flags = src_entry->priv_flags; + vmci_resource_put(resource); + } else if (context_id == VMCI_HYPERVISOR_CONTEXT_ID) + *priv_flags = VMCI_MAX_PRIVILEGE_FLAGS; + else + *priv_flags = vmci_context_get_priv_flags(context_id); + + return VMCI_SUCCESS; +} + +/* + * Calls the specified callback in a delayed context. + */ +static void dg_delayed_dispatch(struct work_struct *work) +{ + struct delayed_datagram_info *dg_info = + container_of(work, struct delayed_datagram_info, work); + + dg_info->entry->recv_cb(dg_info->entry->client_data, &dg_info->msg); + + vmci_resource_put(&dg_info->entry->resource); + + if (dg_info->in_dg_host_queue) + atomic_dec(&delayed_dg_host_queue_size); + + kfree(dg_info); +} + +/* + * Dispatch datagram as a host, to the host, or other vm context. This + * function cannot dispatch to hypervisor context handlers. This should + * have been handled before we get here by vmci_datagram_dispatch. + * Returns number of bytes sent on success, error code otherwise. + */ +static int dg_dispatch_as_host(u32 context_id, struct vmci_datagram *dg) +{ + int retval; + size_t dg_size; + u32 src_priv_flags; + + dg_size = VMCI_DG_SIZE(dg); + + /* Host cannot send to the hypervisor. */ + if (dg->dst.context == VMCI_HYPERVISOR_CONTEXT_ID) + return VMCI_ERROR_DST_UNREACHABLE; + + /* Check that source handle matches sending context. */ + if (dg->src.context != context_id) { + pr_devel("Sender context (ID=0x%x) is not owner of src datagram entry (handle=0x%x:0x%x)\n", + context_id, dg->src.context, dg->src.resource); + return VMCI_ERROR_NO_ACCESS; + } + + /* Get hold of privileges of sending endpoint. */ + retval = vmci_datagram_get_priv_flags(context_id, dg->src, + &src_priv_flags); + if (retval != VMCI_SUCCESS) { + pr_warn("Couldn't get privileges (handle=0x%x:0x%x)\n", + dg->src.context, dg->src.resource); + return retval; + } + + /* Determine if we should route to host or guest destination. */ + if (dg->dst.context == VMCI_HOST_CONTEXT_ID) { + /* Route to host datagram entry. */ + struct datagram_entry *dst_entry; + struct vmci_resource *resource; + + if (dg->src.context == VMCI_HYPERVISOR_CONTEXT_ID && + dg->dst.resource == VMCI_EVENT_HANDLER) { + return vmci_event_dispatch(dg); + } + + resource = vmci_resource_by_handle(dg->dst, + VMCI_RESOURCE_TYPE_DATAGRAM); + if (!resource) { + pr_devel("Sending to invalid destination (handle=0x%x:0x%x)\n", + dg->dst.context, dg->dst.resource); + return VMCI_ERROR_INVALID_RESOURCE; + } + dst_entry = container_of(resource, struct datagram_entry, + resource); + if (vmci_deny_interaction(src_priv_flags, + dst_entry->priv_flags)) { + vmci_resource_put(resource); + return VMCI_ERROR_NO_ACCESS; + } + + /* + * If a VMCI datagram destined for the host is also sent by the + * host, we always run it delayed. This ensures that no locks + * are held when the datagram callback runs. + */ + if (dst_entry->run_delayed || + dg->src.context == VMCI_HOST_CONTEXT_ID) { + struct delayed_datagram_info *dg_info; + + if (atomic_add_return(1, &delayed_dg_host_queue_size) + == VMCI_MAX_DELAYED_DG_HOST_QUEUE_SIZE) { + atomic_dec(&delayed_dg_host_queue_size); + vmci_resource_put(resource); + return VMCI_ERROR_NO_MEM; + } + + dg_info = kmalloc(sizeof(*dg_info) + + (size_t) dg->payload_size, GFP_ATOMIC); + if (!dg_info) { + atomic_dec(&delayed_dg_host_queue_size); + vmci_resource_put(resource); + return VMCI_ERROR_NO_MEM; + } + + dg_info->in_dg_host_queue = true; + dg_info->entry = dst_entry; + memcpy(&dg_info->msg, dg, dg_size); + + INIT_WORK(&dg_info->work, dg_delayed_dispatch); + schedule_work(&dg_info->work); + retval = VMCI_SUCCESS; + + } else { + retval = dst_entry->recv_cb(dst_entry->client_data, dg); + vmci_resource_put(resource); + if (retval < VMCI_SUCCESS) + return retval; + } + } else { + /* Route to destination VM context. */ + struct vmci_datagram *new_dg; + + if (context_id != dg->dst.context) { + if (vmci_deny_interaction(src_priv_flags, + vmci_context_get_priv_flags + (dg->dst.context))) { + return VMCI_ERROR_NO_ACCESS; + } else if (VMCI_CONTEXT_IS_VM(context_id)) { + /* + * If the sending context is a VM, it + * cannot reach another VM. + */ + + pr_devel("Datagram communication between VMs not supported (src=0x%x, dst=0x%x)\n", + context_id, dg->dst.context); + return VMCI_ERROR_DST_UNREACHABLE; + } + } + + /* We make a copy to enqueue. */ + new_dg = kmalloc(dg_size, GFP_KERNEL); + if (new_dg == NULL) + return VMCI_ERROR_NO_MEM; + + memcpy(new_dg, dg, dg_size); + retval = vmci_ctx_enqueue_datagram(dg->dst.context, new_dg); + if (retval < VMCI_SUCCESS) { + kfree(new_dg); + return retval; + } + } + + /* + * We currently truncate the size to signed 32 bits. This doesn't + * matter for this handler as it only support 4Kb messages. + */ + return (int)dg_size; +} + +/* + * Dispatch datagram as a guest, down through the VMX and potentially to + * the host. + * Returns number of bytes sent on success, error code otherwise. + */ +static int dg_dispatch_as_guest(struct vmci_datagram *dg) +{ + int retval; + struct vmci_resource *resource; + + resource = vmci_resource_by_handle(dg->src, + VMCI_RESOURCE_TYPE_DATAGRAM); + if (!resource) + return VMCI_ERROR_NO_HANDLE; + + retval = vmci_send_datagram(dg); + vmci_resource_put(resource); + return retval; +} + +/* + * Dispatch datagram. This will determine the routing for the datagram + * and dispatch it accordingly. + * Returns number of bytes sent on success, error code otherwise. + */ +int vmci_datagram_dispatch(u32 context_id, + struct vmci_datagram *dg, bool from_guest) +{ + int retval; + enum vmci_route route; + + BUILD_BUG_ON(sizeof(struct vmci_datagram) != 24); + + if (VMCI_DG_SIZE(dg) > VMCI_MAX_DG_SIZE) { + pr_devel("Payload (size=%llu bytes) too big to send\n", + (unsigned long long)dg->payload_size); + return VMCI_ERROR_INVALID_ARGS; + } + + retval = vmci_route(&dg->src, &dg->dst, from_guest, &route); + if (retval < VMCI_SUCCESS) { + pr_devel("Failed to route datagram (src=0x%x, dst=0x%x, err=%d)\n", + dg->src.context, dg->dst.context, retval); + return retval; + } + + if (VMCI_ROUTE_AS_HOST == route) { + if (VMCI_INVALID_ID == context_id) + context_id = VMCI_HOST_CONTEXT_ID; + return dg_dispatch_as_host(context_id, dg); + } + + if (VMCI_ROUTE_AS_GUEST == route) + return dg_dispatch_as_guest(dg); + + pr_warn("Unknown route (%d) for datagram\n", route); + return VMCI_ERROR_DST_UNREACHABLE; +} + +/* + * Invoke the handler for the given datagram. This is intended to be + * called only when acting as a guest and receiving a datagram from the + * virtual device. + */ +int vmci_datagram_invoke_guest_handler(struct vmci_datagram *dg) +{ + struct vmci_resource *resource; + struct datagram_entry *dst_entry; + + resource = vmci_resource_by_handle(dg->dst, + VMCI_RESOURCE_TYPE_DATAGRAM); + if (!resource) { + pr_devel("destination (handle=0x%x:0x%x) doesn't exist\n", + dg->dst.context, dg->dst.resource); + return VMCI_ERROR_NO_HANDLE; + } + + dst_entry = container_of(resource, struct datagram_entry, resource); + if (dst_entry->run_delayed) { + struct delayed_datagram_info *dg_info; + + dg_info = kmalloc(sizeof(*dg_info) + (size_t)dg->payload_size, + GFP_ATOMIC); + if (!dg_info) { + vmci_resource_put(resource); + return VMCI_ERROR_NO_MEM; + } + + dg_info->in_dg_host_queue = false; + dg_info->entry = dst_entry; + memcpy(&dg_info->msg, dg, VMCI_DG_SIZE(dg)); + + INIT_WORK(&dg_info->work, dg_delayed_dispatch); + schedule_work(&dg_info->work); + } else { + dst_entry->recv_cb(dst_entry->client_data, dg); + vmci_resource_put(resource); + } + + return VMCI_SUCCESS; +} + +/* + * vmci_datagram_create_handle_priv() - Create host context datagram endpoint + * @resource_id: The resource ID. + * @flags: Datagram Flags. + * @priv_flags: Privilege Flags. + * @recv_cb: Callback when receiving datagrams. + * @client_data: Pointer for a datagram_entry struct + * @out_handle: vmci_handle that is populated as a result of this function. + * + * Creates a host context datagram endpoint and returns a handle to it. + */ +int vmci_datagram_create_handle_priv(u32 resource_id, + u32 flags, + u32 priv_flags, + vmci_datagram_recv_cb recv_cb, + void *client_data, + struct vmci_handle *out_handle) +{ + if (out_handle == NULL) + return VMCI_ERROR_INVALID_ARGS; + + if (recv_cb == NULL) { + pr_devel("Client callback needed when creating datagram\n"); + return VMCI_ERROR_INVALID_ARGS; + } + + if (priv_flags & ~VMCI_PRIVILEGE_ALL_FLAGS) + return VMCI_ERROR_INVALID_ARGS; + + return dg_create_handle(resource_id, flags, priv_flags, recv_cb, + client_data, out_handle); +} +EXPORT_SYMBOL_GPL(vmci_datagram_create_handle_priv); + +/* + * vmci_datagram_create_handle() - Create host context datagram endpoint + * @resource_id: Resource ID. + * @flags: Datagram Flags. + * @recv_cb: Callback when receiving datagrams. + * @client_ata: Pointer for a datagram_entry struct + * @out_handle: vmci_handle that is populated as a result of this function. + * + * Creates a host context datagram endpoint and returns a handle to + * it. Same as vmci_datagram_create_handle_priv without the priviledge + * flags argument. + */ +int vmci_datagram_create_handle(u32 resource_id, + u32 flags, + vmci_datagram_recv_cb recv_cb, + void *client_data, + struct vmci_handle *out_handle) +{ + return vmci_datagram_create_handle_priv( + resource_id, flags, + VMCI_DEFAULT_PROC_PRIVILEGE_FLAGS, + recv_cb, client_data, + out_handle); +} +EXPORT_SYMBOL_GPL(vmci_datagram_create_handle); + +/* + * vmci_datagram_destroy_handle() - Destroys datagram handle + * @handle: vmci_handle to be destroyed and reaped. + * + * Use this function to destroy any datagram handles created by + * vmci_datagram_create_handle{,Priv} functions. + */ +int vmci_datagram_destroy_handle(struct vmci_handle handle) +{ + struct datagram_entry *entry; + struct vmci_resource *resource; + + resource = vmci_resource_by_handle(handle, VMCI_RESOURCE_TYPE_DATAGRAM); + if (!resource) { + pr_devel("Failed to destroy datagram (handle=0x%x:0x%x)\n", + handle.context, handle.resource); + return VMCI_ERROR_NOT_FOUND; + } + + entry = container_of(resource, struct datagram_entry, resource); + + vmci_resource_put(&entry->resource); + vmci_resource_remove(&entry->resource); + kfree(entry); + + return VMCI_SUCCESS; +} +EXPORT_SYMBOL_GPL(vmci_datagram_destroy_handle); + +/* + * vmci_datagram_send() - Send a datagram + * @msg: The datagram to send. + * + * Sends the provided datagram on its merry way. + */ +int vmci_datagram_send(struct vmci_datagram *msg) +{ + if (msg == NULL) + return VMCI_ERROR_INVALID_ARGS; + + return vmci_datagram_dispatch(VMCI_INVALID_ID, msg, false); +} +EXPORT_SYMBOL_GPL(vmci_datagram_send); diff --git a/drivers/misc/vmw_vmci/vmci_datagram.h b/drivers/misc/vmw_vmci/vmci_datagram.h new file mode 100644 index 00000000000..eb4aab7f64e --- /dev/null +++ b/drivers/misc/vmw_vmci/vmci_datagram.h @@ -0,0 +1,52 @@ +/* + * VMware VMCI Driver + * + * Copyright (C) 2012 VMware, Inc. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation version 2 and no later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY + * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * for more details. + */ + +#ifndef _VMCI_DATAGRAM_H_ +#define _VMCI_DATAGRAM_H_ + +#include +#include + +#include "vmci_context.h" + +#define VMCI_MAX_DELAYED_DG_HOST_QUEUE_SIZE 256 + +/* + * The struct vmci_datagram_queue_entry is a queue header for the in-kernel VMCI + * datagram queues. It is allocated in non-paged memory, as the + * content is accessed while holding a spinlock. The pending datagram + * itself may be allocated from paged memory. We shadow the size of + * the datagram in the non-paged queue entry as this size is used + * while holding the same spinlock as above. + */ +struct vmci_datagram_queue_entry { + struct list_head list_item; /* For queuing. */ + size_t dg_size; /* Size of datagram. */ + struct vmci_datagram *dg; /* Pending datagram. */ +}; + +/* VMCIDatagramSendRecvInfo */ +struct vmci_datagram_snd_rcv_info { + u64 addr; + u32 len; + s32 result; +}; + +/* Datagram API for non-public use. */ +int vmci_datagram_dispatch(u32 context_id, struct vmci_datagram *dg, + bool from_guest); +int vmci_datagram_invoke_guest_handler(struct vmci_datagram *dg); + +#endif /* _VMCI_DATAGRAM_H_ */ -- 2.20.1