xref: /freebsd/sys/dev/hyperv/vmbus/x86/hyperv_x86.c (revision 3c4ba5f55438f7afd4f4b0b56f88f2bb505fd6a6)
1 /*- SPDX-License-Identifier: BSD-2-Clause-FreeBSD
2  * Copyright (c) 2009-2012,2016-2017, 2022 Microsoft Corp.
3  * Copyright (c) 2012 NetApp Inc.
4  * Copyright (c) 2012 Citrix Inc.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice unmodified, this list of conditions, and the following
12  *    disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 /**
30  * Implements low-level interactions with Hyper-V/Azure
31  */
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/kernel.h>
38 #include <sys/malloc.h>
39 #include <sys/timetc.h>
40 
41 #include <vm/vm.h>
42 #include <vm/pmap.h>
43 #include <vm/vm_extern.h>
44 #include <vm/vm_kern.h>
45 
46 #include <dev/hyperv/include/hyperv.h>
47 #include <dev/hyperv/include/hyperv_busdma.h>
48 #include <dev/hyperv/vmbus/hyperv_var.h>
49 #include <dev/hyperv/vmbus/x86/hyperv_machdep.h>
50 #include <dev/hyperv/vmbus/x86/hyperv_reg.h>
51 #include <dev/hyperv/vmbus/hyperv_common_reg.h>
52 
53 #define HYPERV_FREEBSD_BUILD 0ULL
54 #define HYPERV_FREEBSD_VERSION ((uint64_t)__FreeBSD_version)
55 #define HYPERV_FREEBSD_OSID 0ULL
56 
57 void hyperv_init_tc(void);
58 int hypercall_page_setup(vm_paddr_t);
59 void hypercall_disable(void);
60 bool hyperv_identify_features(void);
61 
62 u_int hyperv_ver_major;
63 u_int hyperv_features;
64 u_int hyperv_recommends;
65 
66 hyperv_tc64_t hyperv_tc64;
67 
68 static u_int hyperv_pm_features;
69 static u_int hyperv_features3;
70 static u_int hyperv_get_timecount(struct timecounter *);
71 
72 static struct timecounter hyperv_timecounter = {
73 	.tc_get_timecount = hyperv_get_timecount,
74 	.tc_poll_pps = NULL,
75 	.tc_counter_mask = 0xffffffff,
76 	.tc_frequency = HYPERV_TIMER_FREQ,
77 	.tc_name = "Hyper-V",
78 	.tc_quality = 2000,
79 	.tc_flags = 0,
80 	.tc_priv = NULL
81 };
82 
83 static u_int
84 hyperv_get_timecount(struct timecounter *tc __unused)
85 {
86 	return rdmsr(MSR_HV_TIME_REF_COUNT);
87 }
88 
89 static uint64_t
90 hyperv_tc64_rdmsr(void)
91 {
92 
93 	return (rdmsr(MSR_HV_TIME_REF_COUNT));
94 }
95 
96 void
97 hyperv_init_tc(void)
98 {
99 	if (hyperv_features & CPUID_HV_MSR_TIME_REFCNT) {
100 		/*
101 		 * Register Hyper-V timecounter.  This should be done as early
102 		 * as possible to let DELAY() work, since the 8254 PIT is not
103 		 * reliably emulated or even available.
104 		 */
105 		tc_init(&hyperv_timecounter);
106 
107 		/*
108 		 * Install 64 bits timecounter method for other modules
109 		 * to use.
110 		 */
111 		hyperv_tc64 = hyperv_tc64_rdmsr;
112 	}
113 }
114 
115 int
116 hypercall_page_setup(vm_paddr_t paddr)
117 {
118 	uint64_t hc, hc_orig;
119 	hc_orig = rdmsr(MSR_HV_HYPERCALL);
120 
121 	/*
122 	 * Setup the Hypercall page.
123 	 *
124 	 * NOTE: 'reserved' bits MUST be preserved.
125 	 */
126 	hc = ((paddr >> PAGE_SHIFT) << MSR_HV_HYPERCALL_PGSHIFT) |
127 	    (hc_orig & MSR_HV_HYPERCALL_RSVD_MASK) | MSR_HV_HYPERCALL_ENABLE;
128 	wrmsr(MSR_HV_HYPERCALL, hc);
129 
130 	/*
131 	 * Confirm that Hypercall page did get setup.
132 	 */
133 	hc = rdmsr(MSR_HV_HYPERCALL);
134 	if ((hc & MSR_HV_HYPERCALL_ENABLE) == 0) {
135 		printf("hyperv: Hypercall setup failed\n");
136 		/* Can't perform any Hyper-V specific actions */
137 		vm_guest = VM_GUEST_VM;
138 		return (-1);
139 	}
140 	return (0);
141 }
142 
143 void
144 hypercall_disable(void)
145 {
146 	uint64_t hc;
147 	/* Disable Hypercall */
148 	hc = rdmsr(MSR_HV_HYPERCALL);
149 	wrmsr(MSR_HV_HYPERCALL, (hc & MSR_HV_HYPERCALL_RSVD_MASK));
150 }
151 
152 bool
153 hyperv_identify_features(void)
154 {
155 	u_int regs[4];
156 	unsigned int maxleaf;
157 
158 	if (vm_guest != VM_GUEST_HV)
159 		return (false);
160 
161 	do_cpuid(CPUID_LEAF_HV_MAXLEAF, regs);
162 	maxleaf = regs[0];
163 	if (maxleaf < CPUID_LEAF_HV_LIMITS)
164 		return (false);
165 
166 	do_cpuid(CPUID_LEAF_HV_INTERFACE, regs);
167 	if (regs[0] != CPUID_HV_IFACE_HYPERV)
168 		return (false);
169 
170 	do_cpuid(CPUID_LEAF_HV_FEATURES, regs);
171 	if ((regs[0] & CPUID_HV_MSR_HYPERCALL) == 0) {
172 		/*
173 		 * Hyper-V w/o Hypercall is impossible; someone
174 		 * is faking Hyper-V.
175 		 */
176 		return (false);
177 	}
178 	hyperv_features = regs[0];
179 	hyperv_pm_features = regs[2];
180 	hyperv_features3 = regs[3];
181 	do_cpuid(CPUID_LEAF_HV_IDENTITY, regs);
182 	hyperv_ver_major = regs[1] >> 16;
183 	printf("Hyper-V Version: %d.%d.%d [SP%d]\n", hyperv_ver_major,
184 	    regs[1] & 0xffff, regs[0], regs[2]);
185 
186 	printf("  Features=0x%b\n", hyperv_features,
187 	    "\020"
188 	    "\001VPRUNTIME" /* MSR_HV_VP_RUNTIME */
189 	    "\002TMREFCNT"  /* MSR_HV_TIME_REF_COUNT */
190 	    "\003SYNIC"	    /* MSRs for SynIC */
191 	    "\004SYNTM"	    /* MSRs for SynTimer */
192 	    "\005APIC"	    /* MSR_HV_{EOI,ICR,TPR} */
193 	    "\006HYPERCALL" /* MSR_HV_{GUEST_OS_ID,HYPERCALL} */
194 	    "\007VPINDEX"   /* MSR_HV_VP_INDEX */
195 	    "\010RESET"	    /* MSR_HV_RESET */
196 	    "\011STATS"	    /* MSR_HV_STATS_ */
197 	    "\012REFTSC"    /* MSR_HV_REFERENCE_TSC */
198 	    "\013IDLE"	    /* MSR_HV_GUEST_IDLE */
199 	    "\014TMFREQ"    /* MSR_HV_{TSC,APIC}_FREQUENCY */
200 	    "\015DEBUG");   /* MSR_HV_SYNTH_DEBUG_ */
201 	printf("  PM Features=0x%b [C%u]\n",
202 	    (hyperv_pm_features & ~CPUPM_HV_CSTATE_MASK),
203 	    "\020"
204 	    "\005C3HPET", /* HPET is required for C3 state */
205 	    CPUPM_HV_CSTATE(hyperv_pm_features));
206 	printf("  Features3=0x%b\n", hyperv_features3,
207 	    "\020"
208 	    "\001MWAIT"	   /* MWAIT */
209 	    "\002DEBUG"	   /* guest debug support */
210 	    "\003PERFMON"  /* performance monitor */
211 	    "\004PCPUDPE"  /* physical CPU dynamic partition event */
212 	    "\005XMMHC"	   /* hypercall input through XMM regs */
213 	    "\006IDLE"	   /* guest idle support */
214 	    "\007SLEEP"	   /* hypervisor sleep support */
215 	    "\010NUMA"	   /* NUMA distance query support */
216 	    "\011TMFREQ"   /* timer frequency query (TSC, LAPIC) */
217 	    "\012SYNCMC"   /* inject synthetic machine checks */
218 	    "\013CRASH"	   /* MSRs for guest crash */
219 	    "\014DEBUGMSR" /* MSRs for guest debug */
220 	    "\015NPIEP"	   /* NPIEP */
221 	    "\016HVDIS");  /* disabling hypervisor */
222 
223 	do_cpuid(CPUID_LEAF_HV_RECOMMENDS, regs);
224 	hyperv_recommends = regs[0];
225 	if (bootverbose)
226 		printf("  Recommends: %08x %08x\n", regs[0], regs[1]);
227 
228 	do_cpuid(CPUID_LEAF_HV_LIMITS, regs);
229 	if (bootverbose) {
230 		printf("  Limits: Vcpu:%d Lcpu:%d Int:%d\n", regs[0], regs[1],
231 		    regs[2]);
232 	}
233 
234 	if (maxleaf >= CPUID_LEAF_HV_HWFEATURES) {
235 		do_cpuid(CPUID_LEAF_HV_HWFEATURES, regs);
236 		if (bootverbose) {
237 			printf("  HW Features: %08x, AMD: %08x\n", regs[0],
238 			    regs[3]);
239 		}
240 	}
241 	return (true);
242 }
243