xref: /freebsd/sys/dev/hyperv/vmbus/x86/hyperv_x86.c (revision e0c4386e7e71d93b0edc0c8fa156263fc4a8b0b6)
1 /*- SPDX-License-Identifier: BSD-2-Clause
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 
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/kernel.h>
36 #include <sys/malloc.h>
37 #include <sys/timetc.h>
38 
39 #include <vm/vm.h>
40 #include <vm/pmap.h>
41 #include <vm/vm_extern.h>
42 #include <vm/vm_kern.h>
43 
44 #include <dev/hyperv/include/hyperv.h>
45 #include <dev/hyperv/include/hyperv_busdma.h>
46 #include <dev/hyperv/vmbus/hyperv_var.h>
47 #include <dev/hyperv/vmbus/x86/hyperv_machdep.h>
48 #include <dev/hyperv/vmbus/x86/hyperv_reg.h>
49 #include <dev/hyperv/vmbus/hyperv_common_reg.h>
50 
51 #define HYPERV_FREEBSD_BUILD 0ULL
52 #define HYPERV_FREEBSD_VERSION ((uint64_t)__FreeBSD_version)
53 #define HYPERV_FREEBSD_OSID 0ULL
54 
55 void hyperv_init_tc(void);
56 int hypercall_page_setup(vm_paddr_t);
57 void hypercall_disable(void);
58 bool hyperv_identify_features(void);
59 
60 u_int hyperv_ver_major;
61 u_int hyperv_features;
62 u_int hyperv_recommends;
63 
64 hyperv_tc64_t hyperv_tc64;
65 
66 static u_int hyperv_pm_features;
67 static u_int hyperv_features3;
68 static u_int hyperv_get_timecount(struct timecounter *);
69 
70 static struct timecounter hyperv_timecounter = {
71 	.tc_get_timecount = hyperv_get_timecount,
72 	.tc_poll_pps = NULL,
73 	.tc_counter_mask = 0xffffffff,
74 	.tc_frequency = HYPERV_TIMER_FREQ,
75 	.tc_name = "Hyper-V",
76 	.tc_quality = 2000,
77 	.tc_flags = 0,
78 	.tc_priv = NULL
79 };
80 
81 static u_int
82 hyperv_get_timecount(struct timecounter *tc __unused)
83 {
84 	return rdmsr(MSR_HV_TIME_REF_COUNT);
85 }
86 
87 static uint64_t
88 hyperv_tc64_rdmsr(void)
89 {
90 
91 	return (rdmsr(MSR_HV_TIME_REF_COUNT));
92 }
93 
94 void
95 hyperv_init_tc(void)
96 {
97 	if (hyperv_features & CPUID_HV_MSR_TIME_REFCNT) {
98 		/*
99 		 * Register Hyper-V timecounter.  This should be done as early
100 		 * as possible to let DELAY() work, since the 8254 PIT is not
101 		 * reliably emulated or even available.
102 		 */
103 		tc_init(&hyperv_timecounter);
104 
105 		/*
106 		 * Install 64 bits timecounter method for other modules
107 		 * to use.
108 		 */
109 		hyperv_tc64 = hyperv_tc64_rdmsr;
110 	}
111 }
112 
113 int
114 hypercall_page_setup(vm_paddr_t paddr)
115 {
116 	uint64_t hc, hc_orig;
117 	hc_orig = rdmsr(MSR_HV_HYPERCALL);
118 
119 	/*
120 	 * Setup the Hypercall page.
121 	 *
122 	 * NOTE: 'reserved' bits MUST be preserved.
123 	 */
124 	hc = ((paddr >> PAGE_SHIFT) << MSR_HV_HYPERCALL_PGSHIFT) |
125 	    (hc_orig & MSR_HV_HYPERCALL_RSVD_MASK) | MSR_HV_HYPERCALL_ENABLE;
126 	wrmsr(MSR_HV_HYPERCALL, hc);
127 
128 	/*
129 	 * Confirm that Hypercall page did get setup.
130 	 */
131 	hc = rdmsr(MSR_HV_HYPERCALL);
132 	if ((hc & MSR_HV_HYPERCALL_ENABLE) == 0) {
133 		printf("hyperv: Hypercall setup failed\n");
134 		/* Can't perform any Hyper-V specific actions */
135 		vm_guest = VM_GUEST_VM;
136 		return (-1);
137 	}
138 	return (0);
139 }
140 
141 void
142 hypercall_disable(void)
143 {
144 	uint64_t hc;
145 	/* Disable Hypercall */
146 	hc = rdmsr(MSR_HV_HYPERCALL);
147 	wrmsr(MSR_HV_HYPERCALL, (hc & MSR_HV_HYPERCALL_RSVD_MASK));
148 }
149 
150 bool
151 hyperv_identify_features(void)
152 {
153 	u_int regs[4];
154 	unsigned int maxleaf;
155 
156 	if (vm_guest != VM_GUEST_HV)
157 		return (false);
158 
159 	do_cpuid(CPUID_LEAF_HV_MAXLEAF, regs);
160 	maxleaf = regs[0];
161 	if (maxleaf < CPUID_LEAF_HV_LIMITS)
162 		return (false);
163 
164 	do_cpuid(CPUID_LEAF_HV_INTERFACE, regs);
165 	if (regs[0] != CPUID_HV_IFACE_HYPERV)
166 		return (false);
167 
168 	do_cpuid(CPUID_LEAF_HV_FEATURES, regs);
169 	if ((regs[0] & CPUID_HV_MSR_HYPERCALL) == 0) {
170 		/*
171 		 * Hyper-V w/o Hypercall is impossible; someone
172 		 * is faking Hyper-V.
173 		 */
174 		return (false);
175 	}
176 	hyperv_features = regs[0];
177 	hyperv_pm_features = regs[2];
178 	hyperv_features3 = regs[3];
179 	do_cpuid(CPUID_LEAF_HV_IDENTITY, regs);
180 	hyperv_ver_major = regs[1] >> 16;
181 	printf("Hyper-V Version: %d.%d.%d [SP%d]\n", hyperv_ver_major,
182 	    regs[1] & 0xffff, regs[0], regs[2]);
183 
184 	printf("  Features=0x%b\n", hyperv_features,
185 	    "\020"
186 	    "\001VPRUNTIME" /* MSR_HV_VP_RUNTIME */
187 	    "\002TMREFCNT"  /* MSR_HV_TIME_REF_COUNT */
188 	    "\003SYNIC"	    /* MSRs for SynIC */
189 	    "\004SYNTM"	    /* MSRs for SynTimer */
190 	    "\005APIC"	    /* MSR_HV_{EOI,ICR,TPR} */
191 	    "\006HYPERCALL" /* MSR_HV_{GUEST_OS_ID,HYPERCALL} */
192 	    "\007VPINDEX"   /* MSR_HV_VP_INDEX */
193 	    "\010RESET"	    /* MSR_HV_RESET */
194 	    "\011STATS"	    /* MSR_HV_STATS_ */
195 	    "\012REFTSC"    /* MSR_HV_REFERENCE_TSC */
196 	    "\013IDLE"	    /* MSR_HV_GUEST_IDLE */
197 	    "\014TMFREQ"    /* MSR_HV_{TSC,APIC}_FREQUENCY */
198 	    "\015DEBUG");   /* MSR_HV_SYNTH_DEBUG_ */
199 	printf("  PM Features=0x%b [C%u]\n",
200 	    (hyperv_pm_features & ~CPUPM_HV_CSTATE_MASK),
201 	    "\020"
202 	    "\005C3HPET", /* HPET is required for C3 state */
203 	    CPUPM_HV_CSTATE(hyperv_pm_features));
204 	printf("  Features3=0x%b\n", hyperv_features3,
205 	    "\020"
206 	    "\001MWAIT"	   /* MWAIT */
207 	    "\002DEBUG"	   /* guest debug support */
208 	    "\003PERFMON"  /* performance monitor */
209 	    "\004PCPUDPE"  /* physical CPU dynamic partition event */
210 	    "\005XMMHC"	   /* hypercall input through XMM regs */
211 	    "\006IDLE"	   /* guest idle support */
212 	    "\007SLEEP"	   /* hypervisor sleep support */
213 	    "\010NUMA"	   /* NUMA distance query support */
214 	    "\011TMFREQ"   /* timer frequency query (TSC, LAPIC) */
215 	    "\012SYNCMC"   /* inject synthetic machine checks */
216 	    "\013CRASH"	   /* MSRs for guest crash */
217 	    "\014DEBUGMSR" /* MSRs for guest debug */
218 	    "\015NPIEP"	   /* NPIEP */
219 	    "\016HVDIS");  /* disabling hypervisor */
220 
221 	do_cpuid(CPUID_LEAF_HV_RECOMMENDS, regs);
222 	hyperv_recommends = regs[0];
223 	if (bootverbose)
224 		printf("  Recommends: %08x %08x\n", regs[0], regs[1]);
225 
226 	do_cpuid(CPUID_LEAF_HV_LIMITS, regs);
227 	if (bootverbose) {
228 		printf("  Limits: Vcpu:%d Lcpu:%d Int:%d\n", regs[0], regs[1],
229 		    regs[2]);
230 	}
231 
232 	if (maxleaf >= CPUID_LEAF_HV_HWFEATURES) {
233 		do_cpuid(CPUID_LEAF_HV_HWFEATURES, regs);
234 		if (bootverbose) {
235 			printf("  HW Features: %08x, AMD: %08x\n", regs[0],
236 			    regs[3]);
237 		}
238 	}
239 	return (true);
240 }
241