xref: /freebsd/sys/amd64/vmm/intel/ept.c (revision 7426d572424bb2295c93022ac10e51abf9ae9d88)
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 "ept.h"
47 
48 #define	EPT_SUPPORTS_EXEC_ONLY(cap)	((cap) & (1UL << 0))
49 #define	EPT_PWL4(cap)			((cap) & (1UL << 6))
50 #define	EPT_MEMORY_TYPE_WB(cap)		((cap) & (1UL << 14))
51 #define	EPT_PDE_SUPERPAGE(cap)		((cap) & (1UL << 16))	/* 2MB pages */
52 #define	EPT_PDPTE_SUPERPAGE(cap)	((cap) & (1UL << 17))	/* 1GB pages */
53 #define	INVEPT_SUPPORTED(cap)		((cap) & (1UL << 20))
54 #define	AD_BITS_SUPPORTED(cap)		((cap) & (1UL << 21))
55 #define	INVVPID_SUPPORTED(cap)		((cap) & (1UL << 32))
56 
57 #define	INVVPID_ALL_TYPES_MASK		0xF0000000000UL
58 #define	INVVPID_ALL_TYPES_SUPPORTED(cap)	\
59 	(((cap) & INVVPID_ALL_TYPES_MASK) == INVVPID_ALL_TYPES_MASK)
60 
61 #define	INVEPT_ALL_TYPES_MASK		0x6000000UL
62 #define	INVEPT_ALL_TYPES_SUPPORTED(cap)		\
63 	(((cap) & INVEPT_ALL_TYPES_MASK) == INVEPT_ALL_TYPES_MASK)
64 
65 #define	EPT_PWLEVELS		4		/* page walk levels */
66 #define	EPT_ENABLE_AD_BITS	(1 << 6)
67 
68 SYSCTL_DECL(_hw_vmm);
69 SYSCTL_NODE(_hw_vmm, OID_AUTO, ept, CTLFLAG_RW, NULL, NULL);
70 
71 static int ept_enable_ad_bits;
72 
73 static int ept_pmap_flags;
74 SYSCTL_INT(_hw_vmm_ept, OID_AUTO, pmap_flags, CTLFLAG_RD,
75     &ept_pmap_flags, 0, NULL);
76 
77 int
78 ept_init(int ipinum)
79 {
80 	int use_hw_ad_bits, use_superpages, use_exec_only;
81 	uint64_t cap;
82 
83 	cap = rdmsr(MSR_VMX_EPT_VPID_CAP);
84 
85 	/*
86 	 * Verify that:
87 	 * - page walk length is 4 steps
88 	 * - extended page tables can be laid out in write-back memory
89 	 * - invvpid instruction with all possible types is supported
90 	 * - invept instruction with all possible types is supported
91 	 */
92 	if (!EPT_PWL4(cap) ||
93 	    !EPT_MEMORY_TYPE_WB(cap) ||
94 	    !INVVPID_SUPPORTED(cap) ||
95 	    !INVVPID_ALL_TYPES_SUPPORTED(cap) ||
96 	    !INVEPT_SUPPORTED(cap) ||
97 	    !INVEPT_ALL_TYPES_SUPPORTED(cap))
98 		return (EINVAL);
99 
100 	ept_pmap_flags = ipinum & PMAP_NESTED_IPIMASK;
101 
102 	use_superpages = 1;
103 	TUNABLE_INT_FETCH("hw.vmm.ept.use_superpages", &use_superpages);
104 	if (use_superpages && EPT_PDE_SUPERPAGE(cap))
105 		ept_pmap_flags |= PMAP_PDE_SUPERPAGE;	/* 2MB superpage */
106 
107 	use_hw_ad_bits = 1;
108 	TUNABLE_INT_FETCH("hw.vmm.ept.use_hw_ad_bits", &use_hw_ad_bits);
109 	if (use_hw_ad_bits && AD_BITS_SUPPORTED(cap))
110 		ept_enable_ad_bits = 1;
111 	else
112 		ept_pmap_flags |= PMAP_EMULATE_AD_BITS;
113 
114 	use_exec_only = 1;
115 	TUNABLE_INT_FETCH("hw.vmm.ept.use_exec_only", &use_exec_only);
116 	if (use_exec_only && EPT_SUPPORTS_EXEC_ONLY(cap))
117 		ept_pmap_flags |= PMAP_SUPPORTS_EXEC_ONLY;
118 
119 	return (0);
120 }
121 
122 #if 0
123 static void
124 ept_dump(uint64_t *ptp, int nlevels)
125 {
126 	int i, t, tabs;
127 	uint64_t *ptpnext, ptpval;
128 
129 	if (--nlevels < 0)
130 		return;
131 
132 	tabs = 3 - nlevels;
133 	for (t = 0; t < tabs; t++)
134 		printf("\t");
135 	printf("PTP = %p\n", ptp);
136 
137 	for (i = 0; i < 512; i++) {
138 		ptpval = ptp[i];
139 
140 		if (ptpval == 0)
141 			continue;
142 
143 		for (t = 0; t < tabs; t++)
144 			printf("\t");
145 		printf("%3d 0x%016lx\n", i, ptpval);
146 
147 		if (nlevels != 0 && (ptpval & EPT_PG_SUPERPAGE) == 0) {
148 			ptpnext = (uint64_t *)
149 				  PHYS_TO_DMAP(ptpval & EPT_ADDR_MASK);
150 			ept_dump(ptpnext, nlevels);
151 		}
152 	}
153 }
154 #endif
155 
156 static void
157 invept_single_context(void *arg)
158 {
159 	struct invept_desc desc = *(struct invept_desc *)arg;
160 
161 	invept(INVEPT_TYPE_SINGLE_CONTEXT, desc);
162 }
163 
164 void
165 ept_invalidate_mappings(u_long eptp)
166 {
167 	struct invept_desc invept_desc = { 0 };
168 
169 	invept_desc.eptp = eptp;
170 
171 	smp_rendezvous(NULL, invept_single_context, NULL, &invept_desc);
172 }
173 
174 static int
175 ept_pinit(pmap_t pmap)
176 {
177 
178 	return (pmap_pinit_type(pmap, PT_EPT, ept_pmap_flags));
179 }
180 
181 struct vmspace *
182 ept_vmspace_alloc(vm_offset_t min, vm_offset_t max)
183 {
184 
185 	return (vmspace_alloc(min, max, ept_pinit));
186 }
187 
188 void
189 ept_vmspace_free(struct vmspace *vmspace)
190 {
191 
192 	vmspace_free(vmspace);
193 }
194 
195 uint64_t
196 eptp(uint64_t pml4)
197 {
198 	uint64_t eptp_val;
199 
200 	eptp_val = pml4 | (EPT_PWLEVELS - 1) << 3 | PAT_WRITE_BACK;
201 	if (ept_enable_ad_bits)
202 		eptp_val |= EPT_ENABLE_AD_BITS;
203 
204 	return (eptp_val);
205 }
206