xref: /linux/drivers/hv/hv.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
1 /*
2  * Copyright (c) 2009, Microsoft Corporation.
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms and conditions of the GNU General Public License,
6  * version 2, as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope it will be useful, but WITHOUT
9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
11  * more details.
12  *
13  * You should have received a copy of the GNU General Public License along with
14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
15  * Place - Suite 330, Boston, MA 02111-1307 USA.
16  *
17  * Authors:
18  *   Haiyang Zhang <haiyangz@microsoft.com>
19  *   Hank Janssen  <hjanssen@microsoft.com>
20  *
21  */
22 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
23 
24 #include <linux/kernel.h>
25 #include <linux/mm.h>
26 #include <linux/slab.h>
27 #include <linux/vmalloc.h>
28 #include <linux/hyperv.h>
29 #include <linux/version.h>
30 #include <asm/hyperv.h>
31 #include "hyperv_vmbus.h"
32 
33 /* The one and only */
34 struct hv_context hv_context = {
35 	.synic_initialized	= false,
36 	.hypercall_page		= NULL,
37 	.signal_event_param	= NULL,
38 	.signal_event_buffer	= NULL,
39 };
40 
41 /*
42  * query_hypervisor_info - Get version info of the windows hypervisor
43  */
44 static int query_hypervisor_info(void)
45 {
46 	unsigned int eax;
47 	unsigned int ebx;
48 	unsigned int ecx;
49 	unsigned int edx;
50 	unsigned int max_leaf;
51 	unsigned int op;
52 
53 	/*
54 	* Its assumed that this is called after confirming that Viridian
55 	* is present. Query id and revision.
56 	*/
57 	eax = 0;
58 	ebx = 0;
59 	ecx = 0;
60 	edx = 0;
61 	op = HVCPUID_VENDOR_MAXFUNCTION;
62 	cpuid(op, &eax, &ebx, &ecx, &edx);
63 
64 	max_leaf = eax;
65 
66 	if (max_leaf >= HVCPUID_VERSION) {
67 		eax = 0;
68 		ebx = 0;
69 		ecx = 0;
70 		edx = 0;
71 		op = HVCPUID_VERSION;
72 		cpuid(op, &eax, &ebx, &ecx, &edx);
73 		pr_info("Hyper-V Host OS Build:%d-%d.%d-%d-%d.%d\n",
74 			    eax,
75 			    ebx >> 16,
76 			    ebx & 0xFFFF,
77 			    ecx,
78 			    edx >> 24,
79 			    edx & 0xFFFFFF);
80 	}
81 	return max_leaf;
82 }
83 
84 /*
85  * do_hypercall- Invoke the specified hypercall
86  */
87 static u64 do_hypercall(u64 control, void *input, void *output)
88 {
89 #ifdef CONFIG_X86_64
90 	u64 hv_status = 0;
91 	u64 input_address = (input) ? virt_to_phys(input) : 0;
92 	u64 output_address = (output) ? virt_to_phys(output) : 0;
93 	void *hypercall_page = hv_context.hypercall_page;
94 
95 	__asm__ __volatile__("mov %0, %%r8" : : "r" (output_address) : "r8");
96 	__asm__ __volatile__("call *%3" : "=a" (hv_status) :
97 			     "c" (control), "d" (input_address),
98 			     "m" (hypercall_page));
99 
100 	return hv_status;
101 
102 #else
103 
104 	u32 control_hi = control >> 32;
105 	u32 control_lo = control & 0xFFFFFFFF;
106 	u32 hv_status_hi = 1;
107 	u32 hv_status_lo = 1;
108 	u64 input_address = (input) ? virt_to_phys(input) : 0;
109 	u32 input_address_hi = input_address >> 32;
110 	u32 input_address_lo = input_address & 0xFFFFFFFF;
111 	u64 output_address = (output) ? virt_to_phys(output) : 0;
112 	u32 output_address_hi = output_address >> 32;
113 	u32 output_address_lo = output_address & 0xFFFFFFFF;
114 	void *hypercall_page = hv_context.hypercall_page;
115 
116 	__asm__ __volatile__ ("call *%8" : "=d"(hv_status_hi),
117 			      "=a"(hv_status_lo) : "d" (control_hi),
118 			      "a" (control_lo), "b" (input_address_hi),
119 			      "c" (input_address_lo), "D"(output_address_hi),
120 			      "S"(output_address_lo), "m" (hypercall_page));
121 
122 	return hv_status_lo | ((u64)hv_status_hi << 32);
123 #endif /* !x86_64 */
124 }
125 
126 /*
127  * hv_init - Main initialization routine.
128  *
129  * This routine must be called before any other routines in here are called
130  */
131 int hv_init(void)
132 {
133 	int max_leaf;
134 	union hv_x64_msr_hypercall_contents hypercall_msr;
135 	void *virtaddr = NULL;
136 
137 	memset(hv_context.synic_event_page, 0, sizeof(void *) * NR_CPUS);
138 	memset(hv_context.synic_message_page, 0,
139 	       sizeof(void *) * NR_CPUS);
140 
141 	max_leaf = query_hypervisor_info();
142 
143 	/*
144 	 * Write our OS ID.
145 	 */
146 	hv_context.guestid = generate_guest_id(0, LINUX_VERSION_CODE, 0);
147 	wrmsrl(HV_X64_MSR_GUEST_OS_ID, hv_context.guestid);
148 
149 	/* See if the hypercall page is already set */
150 	rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
151 
152 	virtaddr = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL_EXEC);
153 
154 	if (!virtaddr)
155 		goto cleanup;
156 
157 	hypercall_msr.enable = 1;
158 
159 	hypercall_msr.guest_physical_address = vmalloc_to_pfn(virtaddr);
160 	wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
161 
162 	/* Confirm that hypercall page did get setup. */
163 	hypercall_msr.as_uint64 = 0;
164 	rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
165 
166 	if (!hypercall_msr.enable)
167 		goto cleanup;
168 
169 	hv_context.hypercall_page = virtaddr;
170 
171 	/* Setup the global signal event param for the signal event hypercall */
172 	hv_context.signal_event_buffer =
173 			kmalloc(sizeof(struct hv_input_signal_event_buffer),
174 				GFP_KERNEL);
175 	if (!hv_context.signal_event_buffer)
176 		goto cleanup;
177 
178 	hv_context.signal_event_param =
179 		(struct hv_input_signal_event *)
180 			(ALIGN((unsigned long)
181 				  hv_context.signal_event_buffer,
182 				  HV_HYPERCALL_PARAM_ALIGN));
183 	hv_context.signal_event_param->connectionid.asu32 = 0;
184 	hv_context.signal_event_param->connectionid.u.id =
185 						VMBUS_EVENT_CONNECTION_ID;
186 	hv_context.signal_event_param->flag_number = 0;
187 	hv_context.signal_event_param->rsvdz = 0;
188 
189 	return 0;
190 
191 cleanup:
192 	if (virtaddr) {
193 		if (hypercall_msr.enable) {
194 			hypercall_msr.as_uint64 = 0;
195 			wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
196 		}
197 
198 		vfree(virtaddr);
199 	}
200 
201 	return -ENOTSUPP;
202 }
203 
204 /*
205  * hv_cleanup - Cleanup routine.
206  *
207  * This routine is called normally during driver unloading or exiting.
208  */
209 void hv_cleanup(void)
210 {
211 	union hv_x64_msr_hypercall_contents hypercall_msr;
212 
213 	/* Reset our OS id */
214 	wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
215 
216 	kfree(hv_context.signal_event_buffer);
217 	hv_context.signal_event_buffer = NULL;
218 	hv_context.signal_event_param = NULL;
219 
220 	if (hv_context.hypercall_page) {
221 		hypercall_msr.as_uint64 = 0;
222 		wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
223 		vfree(hv_context.hypercall_page);
224 		hv_context.hypercall_page = NULL;
225 	}
226 }
227 
228 /*
229  * hv_post_message - Post a message using the hypervisor message IPC.
230  *
231  * This involves a hypercall.
232  */
233 int hv_post_message(union hv_connection_id connection_id,
234 		  enum hv_message_type message_type,
235 		  void *payload, size_t payload_size)
236 {
237 	struct aligned_input {
238 		u64 alignment8;
239 		struct hv_input_post_message msg;
240 	};
241 
242 	struct hv_input_post_message *aligned_msg;
243 	u16 status;
244 	unsigned long addr;
245 
246 	if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT)
247 		return -EMSGSIZE;
248 
249 	addr = (unsigned long)kmalloc(sizeof(struct aligned_input), GFP_ATOMIC);
250 	if (!addr)
251 		return -ENOMEM;
252 
253 	aligned_msg = (struct hv_input_post_message *)
254 			(ALIGN(addr, HV_HYPERCALL_PARAM_ALIGN));
255 
256 	aligned_msg->connectionid = connection_id;
257 	aligned_msg->message_type = message_type;
258 	aligned_msg->payload_size = payload_size;
259 	memcpy((void *)aligned_msg->payload, payload, payload_size);
260 
261 	status = do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL)
262 		& 0xFFFF;
263 
264 	kfree((void *)addr);
265 
266 	return status;
267 }
268 
269 
270 /*
271  * hv_signal_event -
272  * Signal an event on the specified connection using the hypervisor event IPC.
273  *
274  * This involves a hypercall.
275  */
276 u16 hv_signal_event(void)
277 {
278 	u16 status;
279 
280 	status = do_hypercall(HVCALL_SIGNAL_EVENT,
281 			       hv_context.signal_event_param,
282 			       NULL) & 0xFFFF;
283 	return status;
284 }
285 
286 /*
287  * hv_synic_init - Initialize the Synthethic Interrupt Controller.
288  *
289  * If it is already initialized by another entity (ie x2v shim), we need to
290  * retrieve the initialized message and event pages.  Otherwise, we create and
291  * initialize the message and event pages.
292  */
293 void hv_synic_init(void *irqarg)
294 {
295 	u64 version;
296 	union hv_synic_simp simp;
297 	union hv_synic_siefp siefp;
298 	union hv_synic_sint shared_sint;
299 	union hv_synic_scontrol sctrl;
300 
301 	u32 irq_vector = *((u32 *)(irqarg));
302 	int cpu = smp_processor_id();
303 
304 	if (!hv_context.hypercall_page)
305 		return;
306 
307 	/* Check the version */
308 	rdmsrl(HV_X64_MSR_SVERSION, version);
309 
310 	hv_context.synic_message_page[cpu] =
311 		(void *)get_zeroed_page(GFP_ATOMIC);
312 
313 	if (hv_context.synic_message_page[cpu] == NULL) {
314 		pr_err("Unable to allocate SYNIC message page\n");
315 		goto cleanup;
316 	}
317 
318 	hv_context.synic_event_page[cpu] =
319 		(void *)get_zeroed_page(GFP_ATOMIC);
320 
321 	if (hv_context.synic_event_page[cpu] == NULL) {
322 		pr_err("Unable to allocate SYNIC event page\n");
323 		goto cleanup;
324 	}
325 
326 	/* Setup the Synic's message page */
327 	rdmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
328 	simp.simp_enabled = 1;
329 	simp.base_simp_gpa = virt_to_phys(hv_context.synic_message_page[cpu])
330 		>> PAGE_SHIFT;
331 
332 	wrmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
333 
334 	/* Setup the Synic's event page */
335 	rdmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
336 	siefp.siefp_enabled = 1;
337 	siefp.base_siefp_gpa = virt_to_phys(hv_context.synic_event_page[cpu])
338 		>> PAGE_SHIFT;
339 
340 	wrmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
341 
342 	/* Setup the shared SINT. */
343 	rdmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
344 
345 	shared_sint.as_uint64 = 0;
346 	shared_sint.vector = irq_vector; /* HV_SHARED_SINT_IDT_VECTOR + 0x20; */
347 	shared_sint.masked = false;
348 	shared_sint.auto_eoi = false;
349 
350 	wrmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
351 
352 	/* Enable the global synic bit */
353 	rdmsrl(HV_X64_MSR_SCONTROL, sctrl.as_uint64);
354 	sctrl.enable = 1;
355 
356 	wrmsrl(HV_X64_MSR_SCONTROL, sctrl.as_uint64);
357 
358 	hv_context.synic_initialized = true;
359 	return;
360 
361 cleanup:
362 	if (hv_context.synic_event_page[cpu])
363 		free_page((unsigned long)hv_context.synic_event_page[cpu]);
364 
365 	if (hv_context.synic_message_page[cpu])
366 		free_page((unsigned long)hv_context.synic_message_page[cpu]);
367 	return;
368 }
369 
370 /*
371  * hv_synic_cleanup - Cleanup routine for hv_synic_init().
372  */
373 void hv_synic_cleanup(void *arg)
374 {
375 	union hv_synic_sint shared_sint;
376 	union hv_synic_simp simp;
377 	union hv_synic_siefp siefp;
378 	int cpu = smp_processor_id();
379 
380 	if (!hv_context.synic_initialized)
381 		return;
382 
383 	rdmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
384 
385 	shared_sint.masked = 1;
386 
387 	/* Need to correctly cleanup in the case of SMP!!! */
388 	/* Disable the interrupt */
389 	wrmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
390 
391 	rdmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
392 	simp.simp_enabled = 0;
393 	simp.base_simp_gpa = 0;
394 
395 	wrmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
396 
397 	rdmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
398 	siefp.siefp_enabled = 0;
399 	siefp.base_siefp_gpa = 0;
400 
401 	wrmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
402 
403 	free_page((unsigned long)hv_context.synic_message_page[cpu]);
404 	free_page((unsigned long)hv_context.synic_event_page[cpu]);
405 }
406