xref: /linux/drivers/misc/vmw_vmci/vmci_queue_pair.h (revision d0034a7a4ac7fae708146ac0059b9c47a1543f0d)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * VMware VMCI Driver
4  *
5  * Copyright (C) 2012 VMware, Inc. All rights reserved.
6  */
7 
8 #ifndef _VMCI_QUEUE_PAIR_H_
9 #define _VMCI_QUEUE_PAIR_H_
10 
11 #include <linux/vmw_vmci_defs.h>
12 #include <linux/types.h>
13 
14 #include "vmci_context.h"
15 
16 /* Callback needed for correctly waiting on events. */
17 typedef int (*vmci_event_release_cb) (void *client_data);
18 
19 /* Guest device port I/O. */
20 struct ppn_set {
21 	u64 num_produce_pages;
22 	u64 num_consume_pages;
23 	u64 *produce_ppns;
24 	u64 *consume_ppns;
25 	bool initialized;
26 };
27 
28 /* VMCIqueue_pairAllocInfo */
29 struct vmci_qp_alloc_info {
30 	struct vmci_handle handle;
31 	u32 peer;
32 	u32 flags;
33 	u64 produce_size;
34 	u64 consume_size;
35 	u64 ppn_va;	/* Start VA of queue pair PPNs. */
36 	u64 num_ppns;
37 	s32 result;
38 	u32 version;
39 };
40 
41 /* VMCIqueue_pairSetVAInfo */
42 struct vmci_qp_set_va_info {
43 	struct vmci_handle handle;
44 	u64 va;		/* Start VA of queue pair PPNs. */
45 	u64 num_ppns;
46 	u32 version;
47 	s32 result;
48 };
49 
50 /*
51  * For backwards compatibility, here is a version of the
52  * VMCIqueue_pairPageFileInfo before host support end-points was added.
53  * Note that the current version of that structure requires VMX to
54  * pass down the VA of the mapped file.  Before host support was added
55  * there was nothing of the sort.  So, when the driver sees the ioctl
56  * with a parameter that is the sizeof
57  * VMCIqueue_pairPageFileInfo_NoHostQP then it can infer that the version
58  * of VMX running can't attach to host end points because it doesn't
59  * provide the VA of the mapped files.
60  *
61  * The Linux driver doesn't get an indication of the size of the
62  * structure passed down from user space.  So, to fix a long standing
63  * but unfiled bug, the _pad field has been renamed to version.
64  * Existing versions of VMX always initialize the PageFileInfo
65  * structure so that _pad, er, version is set to 0.
66  *
67  * A version value of 1 indicates that the size of the structure has
68  * been increased to include two UVA's: produce_uva and consume_uva.
69  * These UVA's are of the mmap()'d queue contents backing files.
70  *
71  * In addition, if when VMX is sending down the
72  * VMCIqueue_pairPageFileInfo structure it gets an error then it will
73  * try again with the _NoHostQP version of the file to see if an older
74  * VMCI kernel module is running.
75  */
76 
77 /* VMCIqueue_pairPageFileInfo */
78 struct vmci_qp_page_file_info {
79 	struct vmci_handle handle;
80 	u64 produce_page_file;	  /* User VA. */
81 	u64 consume_page_file;	  /* User VA. */
82 	u64 produce_page_file_size;  /* Size of the file name array. */
83 	u64 consume_page_file_size;  /* Size of the file name array. */
84 	s32 result;
85 	u32 version;	/* Was _pad. */
86 	u64 produce_va;	/* User VA of the mapped file. */
87 	u64 consume_va;	/* User VA of the mapped file. */
88 };
89 
90 /* vmci queuepair detach info */
91 struct vmci_qp_dtch_info {
92 	struct vmci_handle handle;
93 	s32 result;
94 	u32 _pad;
95 };
96 
97 /*
98  * struct vmci_qp_page_store describes how the memory of a given queue pair
99  * is backed. When the queue pair is between the host and a guest, the
100  * page store consists of references to the guest pages. On vmkernel,
101  * this is a list of PPNs, and on hosted, it is a user VA where the
102  * queue pair is mapped into the VMX address space.
103  */
104 struct vmci_qp_page_store {
105 	/* Reference to pages backing the queue pair. */
106 	u64 pages;
107 	/* Length of pageList/virtual address range (in pages). */
108 	u32 len;
109 };
110 
111 /*
112  * This data type contains the information about a queue.
113  * There are two queues (hence, queue pairs) per transaction model between a
114  * pair of end points, A & B.  One queue is used by end point A to transmit
115  * commands and responses to B.  The other queue is used by B to transmit
116  * commands and responses.
117  *
118  * struct vmci_queue_kern_if is a per-OS defined Queue structure.  It contains
119  * either a direct pointer to the linear address of the buffer contents or a
120  * pointer to structures which help the OS locate those data pages.  See
121  * vmciKernelIf.c for each platform for its definition.
122  */
123 struct vmci_queue {
124 	struct vmci_queue_header *q_header;
125 	struct vmci_queue_header *saved_header;
126 	struct vmci_queue_kern_if *kernel_if;
127 };
128 
129 /*
130  * Utility function that checks whether the fields of the page
131  * store contain valid values.
132  * Result:
133  * true if the page store is wellformed. false otherwise.
134  */
135 static inline bool
VMCI_QP_PAGESTORE_IS_WELLFORMED(struct vmci_qp_page_store * page_store)136 VMCI_QP_PAGESTORE_IS_WELLFORMED(struct vmci_qp_page_store *page_store)
137 {
138 	return page_store->len >= 2;
139 }
140 
141 void vmci_qp_broker_exit(void);
142 int vmci_qp_broker_alloc(struct vmci_handle handle, u32 peer,
143 			 u32 flags, u32 priv_flags,
144 			 u64 produce_size, u64 consume_size,
145 			 struct vmci_qp_page_store *page_store,
146 			 struct vmci_ctx *context);
147 int vmci_qp_broker_set_page_store(struct vmci_handle handle,
148 				  u64 produce_uva, u64 consume_uva,
149 				  struct vmci_ctx *context);
150 int vmci_qp_broker_detach(struct vmci_handle handle, struct vmci_ctx *context);
151 
152 void vmci_qp_guest_endpoints_exit(void);
153 
154 int vmci_qp_alloc(struct vmci_handle *handle,
155 		  struct vmci_queue **produce_q, u64 produce_size,
156 		  struct vmci_queue **consume_q, u64 consume_size,
157 		  u32 peer, u32 flags, u32 priv_flags,
158 		  bool guest_endpoint, vmci_event_release_cb wakeup_cb,
159 		  void *client_data);
160 int vmci_qp_broker_map(struct vmci_handle handle,
161 		       struct vmci_ctx *context, u64 guest_mem);
162 int vmci_qp_broker_unmap(struct vmci_handle handle,
163 			 struct vmci_ctx *context, u32 gid);
164 
165 #endif /* _VMCI_QUEUE_PAIR_H_ */
166