xref: /freebsd/sys/amd64/vmm/intel/ept.c (revision 12babbf2199a73f505e929a35a13cf88d1b38022)
1 /*-
2  * Copyright (c) 2011 NetApp, Inc.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/kernel.h>
34 #include <sys/types.h>
35 #include <sys/systm.h>
36 #include <sys/smp.h>
37 #include <sys/sysctl.h>
38 
39 #include <vm/vm.h>
40 #include <vm/pmap.h>
41 #include <vm/vm_extern.h>
42 
43 #include <machine/vmm.h>
44 
45 #include "vmx_cpufunc.h"
46 #include "vmx_msr.h"
47 #include "ept.h"
48 
49 #define	EPT_SUPPORTS_EXEC_ONLY(cap)	((cap) & (1UL << 0))
50 #define	EPT_PWL4(cap)			((cap) & (1UL << 6))
51 #define	EPT_MEMORY_TYPE_WB(cap)		((cap) & (1UL << 14))
52 #define	EPT_PDE_SUPERPAGE(cap)		((cap) & (1UL << 16))	/* 2MB pages */
53 #define	EPT_PDPTE_SUPERPAGE(cap)	((cap) & (1UL << 17))	/* 1GB pages */
54 #define	INVEPT_SUPPORTED(cap)		((cap) & (1UL << 20))
55 #define	AD_BITS_SUPPORTED(cap)		((cap) & (1UL << 21))
56 #define	INVVPID_SUPPORTED(cap)		((cap) & (1UL << 32))
57 
58 #define	INVVPID_ALL_TYPES_MASK		0xF0000000000UL
59 #define	INVVPID_ALL_TYPES_SUPPORTED(cap)	\
60 	(((cap) & INVVPID_ALL_TYPES_MASK) == INVVPID_ALL_TYPES_MASK)
61 
62 #define	INVEPT_ALL_TYPES_MASK		0x6000000UL
63 #define	INVEPT_ALL_TYPES_SUPPORTED(cap)		\
64 	(((cap) & INVEPT_ALL_TYPES_MASK) == INVEPT_ALL_TYPES_MASK)
65 
66 #define	EPT_PWLEVELS		4		/* page walk levels */
67 #define	EPT_ENABLE_AD_BITS	(1 << 6)
68 
69 SYSCTL_DECL(_hw_vmm);
70 SYSCTL_NODE(_hw_vmm, OID_AUTO, ept, CTLFLAG_RW, NULL, NULL);
71 
72 static int ept_enable_ad_bits;
73 
74 static int ept_pmap_flags;
75 SYSCTL_INT(_hw_vmm_ept, OID_AUTO, pmap_flags, CTLFLAG_RD,
76     &ept_pmap_flags, 0, NULL);
77 
78 int
79 ept_init(void)
80 {
81 	int use_hw_ad_bits, use_superpages, use_exec_only;
82 	uint64_t cap;
83 
84 	cap = rdmsr(MSR_VMX_EPT_VPID_CAP);
85 
86 	/*
87 	 * Verify that:
88 	 * - page walk length is 4 steps
89 	 * - extended page tables can be laid out in write-back memory
90 	 * - invvpid instruction with all possible types is supported
91 	 * - invept instruction with all possible types is supported
92 	 */
93 	if (!EPT_PWL4(cap) ||
94 	    !EPT_MEMORY_TYPE_WB(cap) ||
95 	    !INVVPID_SUPPORTED(cap) ||
96 	    !INVVPID_ALL_TYPES_SUPPORTED(cap) ||
97 	    !INVEPT_SUPPORTED(cap) ||
98 	    !INVEPT_ALL_TYPES_SUPPORTED(cap))
99 		return (EINVAL);
100 
101 	use_superpages = 1;
102 	TUNABLE_INT_FETCH("hw.vmm.ept.use_superpages", &use_superpages);
103 	if (use_superpages && EPT_PDE_SUPERPAGE(cap))
104 		ept_pmap_flags |= PMAP_PDE_SUPERPAGE;	/* 2MB superpage */
105 
106 	use_hw_ad_bits = 1;
107 	TUNABLE_INT_FETCH("hw.vmm.ept.use_hw_ad_bits", &use_hw_ad_bits);
108 	if (use_hw_ad_bits && AD_BITS_SUPPORTED(cap))
109 		ept_enable_ad_bits = 1;
110 	else
111 		ept_pmap_flags |= PMAP_EMULATE_AD_BITS;
112 
113 	use_exec_only = 1;
114 	TUNABLE_INT_FETCH("hw.vmm.ept.use_exec_only", &use_exec_only);
115 	if (use_exec_only && EPT_SUPPORTS_EXEC_ONLY(cap))
116 		ept_pmap_flags |= PMAP_SUPPORTS_EXEC_ONLY;
117 
118 	return (0);
119 }
120 
121 #if 0
122 static void
123 ept_dump(uint64_t *ptp, int nlevels)
124 {
125 	int i, t, tabs;
126 	uint64_t *ptpnext, ptpval;
127 
128 	if (--nlevels < 0)
129 		return;
130 
131 	tabs = 3 - nlevels;
132 	for (t = 0; t < tabs; t++)
133 		printf("\t");
134 	printf("PTP = %p\n", ptp);
135 
136 	for (i = 0; i < 512; i++) {
137 		ptpval = ptp[i];
138 
139 		if (ptpval == 0)
140 			continue;
141 
142 		for (t = 0; t < tabs; t++)
143 			printf("\t");
144 		printf("%3d 0x%016lx\n", i, ptpval);
145 
146 		if (nlevels != 0 && (ptpval & EPT_PG_SUPERPAGE) == 0) {
147 			ptpnext = (uint64_t *)
148 				  PHYS_TO_DMAP(ptpval & EPT_ADDR_MASK);
149 			ept_dump(ptpnext, nlevels);
150 		}
151 	}
152 }
153 #endif
154 
155 static void
156 invept_single_context(void *arg)
157 {
158 	struct invept_desc desc = *(struct invept_desc *)arg;
159 
160 	invept(INVEPT_TYPE_SINGLE_CONTEXT, desc);
161 }
162 
163 void
164 ept_invalidate_mappings(u_long eptp)
165 {
166 	struct invept_desc invept_desc = { 0 };
167 
168 	invept_desc.eptp = eptp;
169 
170 	smp_rendezvous(NULL, invept_single_context, NULL, &invept_desc);
171 }
172 
173 static int
174 ept_pinit(pmap_t pmap)
175 {
176 
177 	return (pmap_pinit_type(pmap, PT_EPT, ept_pmap_flags));
178 }
179 
180 struct vmspace *
181 ept_vmspace_alloc(vm_offset_t min, vm_offset_t max)
182 {
183 
184 	return (vmspace_alloc(min, max, ept_pinit));
185 }
186 
187 void
188 ept_vmspace_free(struct vmspace *vmspace)
189 {
190 
191 	vmspace_free(vmspace);
192 }
193 
194 uint64_t
195 eptp(uint64_t pml4)
196 {
197 	uint64_t eptp_val;
198 
199 	eptp_val = pml4 | (EPT_PWLEVELS - 1) << 3 | PAT_WRITE_BACK;
200 	if (ept_enable_ad_bits)
201 		eptp_val |= EPT_ENABLE_AD_BITS;
202 
203 	return (eptp_val);
204 }
205