1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2009, Microsoft Corporation.
4 *
5 * Authors:
6 * Haiyang Zhang <haiyangz@microsoft.com>
7 * Hank Janssen <hjanssen@microsoft.com>
8 */
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11 #include <linux/kernel.h>
12 #include <linux/mm.h>
13 #include <linux/slab.h>
14 #include <linux/vmalloc.h>
15 #include <linux/hyperv.h>
16 #include <linux/version.h>
17 #include <linux/random.h>
18 #include <linux/clockchips.h>
19 #include <clocksource/hyperv_timer.h>
20 #include <asm/mshyperv.h>
21 #include "hyperv_vmbus.h"
22
23 /* The one and only */
24 struct hv_context hv_context;
25
26 /*
27 * hv_init - Main initialization routine.
28 *
29 * This routine must be called before any other routines in here are called
30 */
hv_init(void)31 int hv_init(void)
32 {
33 hv_context.cpu_context = alloc_percpu(struct hv_per_cpu_context);
34 if (!hv_context.cpu_context)
35 return -ENOMEM;
36 return 0;
37 }
38
39 /*
40 * hv_post_message - Post a message using the hypervisor message IPC.
41 *
42 * This involves a hypercall.
43 */
hv_post_message(union hv_connection_id connection_id,enum hv_message_type message_type,void * payload,size_t payload_size)44 int hv_post_message(union hv_connection_id connection_id,
45 enum hv_message_type message_type,
46 void *payload, size_t payload_size)
47 {
48 struct hv_input_post_message *aligned_msg;
49 struct hv_per_cpu_context *hv_cpu;
50 u64 status;
51
52 if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT)
53 return -EMSGSIZE;
54
55 hv_cpu = get_cpu_ptr(hv_context.cpu_context);
56 aligned_msg = hv_cpu->post_msg_page;
57 aligned_msg->connectionid = connection_id;
58 aligned_msg->reserved = 0;
59 aligned_msg->message_type = message_type;
60 aligned_msg->payload_size = payload_size;
61 memcpy((void *)aligned_msg->payload, payload, payload_size);
62
63 status = hv_do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL);
64
65 /* Preemption must remain disabled until after the hypercall
66 * so some other thread can't get scheduled onto this cpu and
67 * corrupt the per-cpu post_msg_page
68 */
69 put_cpu_ptr(hv_cpu);
70
71 return status & 0xFFFF;
72 }
73
hv_synic_alloc(void)74 int hv_synic_alloc(void)
75 {
76 int cpu;
77 struct hv_per_cpu_context *hv_cpu;
78
79 /*
80 * First, zero all per-cpu memory areas so hv_synic_free() can
81 * detect what memory has been allocated and cleanup properly
82 * after any failures.
83 */
84 for_each_present_cpu(cpu) {
85 hv_cpu = per_cpu_ptr(hv_context.cpu_context, cpu);
86 memset(hv_cpu, 0, sizeof(*hv_cpu));
87 }
88
89 hv_context.hv_numa_map = kcalloc(nr_node_ids, sizeof(struct cpumask),
90 GFP_KERNEL);
91 if (hv_context.hv_numa_map == NULL) {
92 pr_err("Unable to allocate NUMA map\n");
93 goto err;
94 }
95
96 for_each_present_cpu(cpu) {
97 hv_cpu = per_cpu_ptr(hv_context.cpu_context, cpu);
98
99 tasklet_init(&hv_cpu->msg_dpc,
100 vmbus_on_msg_dpc, (unsigned long) hv_cpu);
101
102 hv_cpu->synic_message_page =
103 (void *)get_zeroed_page(GFP_ATOMIC);
104 if (hv_cpu->synic_message_page == NULL) {
105 pr_err("Unable to allocate SYNIC message page\n");
106 goto err;
107 }
108
109 hv_cpu->synic_event_page = (void *)get_zeroed_page(GFP_ATOMIC);
110 if (hv_cpu->synic_event_page == NULL) {
111 pr_err("Unable to allocate SYNIC event page\n");
112 goto err;
113 }
114
115 hv_cpu->post_msg_page = (void *)get_zeroed_page(GFP_ATOMIC);
116 if (hv_cpu->post_msg_page == NULL) {
117 pr_err("Unable to allocate post msg page\n");
118 goto err;
119 }
120 }
121
122 return 0;
123 err:
124 /*
125 * Any memory allocations that succeeded will be freed when
126 * the caller cleans up by calling hv_synic_free()
127 */
128 return -ENOMEM;
129 }
130
131
hv_synic_free(void)132 void hv_synic_free(void)
133 {
134 int cpu;
135
136 for_each_present_cpu(cpu) {
137 struct hv_per_cpu_context *hv_cpu
138 = per_cpu_ptr(hv_context.cpu_context, cpu);
139
140 free_page((unsigned long)hv_cpu->synic_event_page);
141 free_page((unsigned long)hv_cpu->synic_message_page);
142 free_page((unsigned long)hv_cpu->post_msg_page);
143 }
144
145 kfree(hv_context.hv_numa_map);
146 }
147
148 /*
149 * hv_synic_init - Initialize the Synthetic Interrupt Controller.
150 *
151 * If it is already initialized by another entity (ie x2v shim), we need to
152 * retrieve the initialized message and event pages. Otherwise, we create and
153 * initialize the message and event pages.
154 */
hv_synic_enable_regs(unsigned int cpu)155 void hv_synic_enable_regs(unsigned int cpu)
156 {
157 struct hv_per_cpu_context *hv_cpu
158 = per_cpu_ptr(hv_context.cpu_context, cpu);
159 union hv_synic_simp simp;
160 union hv_synic_siefp siefp;
161 union hv_synic_sint shared_sint;
162 union hv_synic_scontrol sctrl;
163
164 /* Setup the Synic's message page */
165 hv_get_simp(simp.as_uint64);
166 simp.simp_enabled = 1;
167 simp.base_simp_gpa = virt_to_phys(hv_cpu->synic_message_page)
168 >> HV_HYP_PAGE_SHIFT;
169
170 hv_set_simp(simp.as_uint64);
171
172 /* Setup the Synic's event page */
173 hv_get_siefp(siefp.as_uint64);
174 siefp.siefp_enabled = 1;
175 siefp.base_siefp_gpa = virt_to_phys(hv_cpu->synic_event_page)
176 >> HV_HYP_PAGE_SHIFT;
177
178 hv_set_siefp(siefp.as_uint64);
179
180 /* Setup the shared SINT. */
181 hv_get_synint_state(VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
182
183 shared_sint.vector = hv_get_vector();
184 shared_sint.masked = false;
185 shared_sint.auto_eoi = hv_recommend_using_aeoi();
186 hv_set_synint_state(VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
187
188 /* Enable the global synic bit */
189 hv_get_synic_state(sctrl.as_uint64);
190 sctrl.enable = 1;
191
192 hv_set_synic_state(sctrl.as_uint64);
193 }
194
hv_synic_init(unsigned int cpu)195 int hv_synic_init(unsigned int cpu)
196 {
197 hv_synic_enable_regs(cpu);
198
199 hv_stimer_legacy_init(cpu, VMBUS_MESSAGE_SINT);
200
201 return 0;
202 }
203
204 /*
205 * hv_synic_cleanup - Cleanup routine for hv_synic_init().
206 */
hv_synic_disable_regs(unsigned int cpu)207 void hv_synic_disable_regs(unsigned int cpu)
208 {
209 union hv_synic_sint shared_sint;
210 union hv_synic_simp simp;
211 union hv_synic_siefp siefp;
212 union hv_synic_scontrol sctrl;
213
214 hv_get_synint_state(VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
215
216 shared_sint.masked = 1;
217
218 /* Need to correctly cleanup in the case of SMP!!! */
219 /* Disable the interrupt */
220 hv_set_synint_state(VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
221
222 hv_get_simp(simp.as_uint64);
223 simp.simp_enabled = 0;
224 simp.base_simp_gpa = 0;
225
226 hv_set_simp(simp.as_uint64);
227
228 hv_get_siefp(siefp.as_uint64);
229 siefp.siefp_enabled = 0;
230 siefp.base_siefp_gpa = 0;
231
232 hv_set_siefp(siefp.as_uint64);
233
234 /* Disable the global synic bit */
235 hv_get_synic_state(sctrl.as_uint64);
236 sctrl.enable = 0;
237 hv_set_synic_state(sctrl.as_uint64);
238 }
239
hv_synic_cleanup(unsigned int cpu)240 int hv_synic_cleanup(unsigned int cpu)
241 {
242 struct vmbus_channel *channel, *sc;
243 bool channel_found = false;
244
245 /*
246 * Hyper-V does not provide a way to change the connect CPU once
247 * it is set; we must prevent the connect CPU from going offline
248 * while the VM is running normally. But in the panic or kexec()
249 * path where the vmbus is already disconnected, the CPU must be
250 * allowed to shut down.
251 */
252 if (cpu == VMBUS_CONNECT_CPU &&
253 vmbus_connection.conn_state == CONNECTED)
254 return -EBUSY;
255
256 /*
257 * Search for channels which are bound to the CPU we're about to
258 * cleanup. In case we find one and vmbus is still connected, we
259 * fail; this will effectively prevent CPU offlining.
260 *
261 * TODO: Re-bind the channels to different CPUs.
262 */
263 mutex_lock(&vmbus_connection.channel_mutex);
264 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
265 if (channel->target_cpu == cpu) {
266 channel_found = true;
267 break;
268 }
269 list_for_each_entry(sc, &channel->sc_list, sc_list) {
270 if (sc->target_cpu == cpu) {
271 channel_found = true;
272 break;
273 }
274 }
275 if (channel_found)
276 break;
277 }
278 mutex_unlock(&vmbus_connection.channel_mutex);
279
280 if (channel_found && vmbus_connection.conn_state == CONNECTED)
281 return -EBUSY;
282
283 hv_stimer_legacy_cleanup(cpu);
284
285 hv_synic_disable_regs(cpu);
286
287 return 0;
288 }
289