1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
23 */
24
25 #include <sys/types.h>
26 #include <sys/archsystm.h>
27 #include <sys/machsystm.h>
28 #include <sys/sunndi.h>
29 #include <sys/sunddi.h>
30 #include <sys/ddi_subrdefs.h>
31 #include <sys/xpv_support.h>
32 #include <sys/xen_errno.h>
33 #include <sys/hypervisor.h>
34 #include <sys/gnttab.h>
35 #include <sys/xenbus_comms.h>
36 #include <sys/xenbus_impl.h>
37 #include <sys/sysmacros.h>
38 #include <sys/x86_archext.h>
39 #include <sys/mman.h>
40 #include <sys/stat.h>
41 #include <sys/conf.h>
42 #include <sys/devops.h>
43 #include <sys/pc_mmu.h>
44 #include <sys/cmn_err.h>
45 #include <sys/cpr.h>
46 #include <sys/ddi.h>
47 #include <vm/seg_kmem.h>
48 #include <vm/as.h>
49 #include <vm/hat_pte.h>
50 #include <vm/hat_i86.h>
51
52 static int xen_hvm_inited;
53
54 /*
55 * This structure is ordinarily constructed by Xen. In the HVM world, we
56 * manually fill in the few fields the PV drivers need.
57 */
58 static start_info_t __xen_info;
59 start_info_t *xen_info = NULL;
60
61 static int xen_bits = -1;
62 static int xen_major = -1, xen_minor = -1;
63
64 /*
65 * Feature bits; more bits will be added, like direct I/O, etc.
66 */
67 #define XEN_HVM_HYPERCALLS 0x0001
68 #define XEN_HVM_TLBFLUSH 0x0002
69 static uint64_t xen_hvm_features;
70
71 /* Metadata page shared between domain and Xen */
72 shared_info_t *HYPERVISOR_shared_info = NULL;
73 pfn_t xen_shared_info_frame;
74
75 /* Page containing code to issue hypercalls. */
76 extern caddr_t hypercall_page;
77 extern caddr_t hypercall_shared_info_page;
78
79 static int
80 hvm_get_param(int param_id, uint64_t *val)
81 {
82 struct xen_hvm_param xhp;
83
84 xhp.domid = DOMID_SELF;
85 xhp.index = param_id;
86 if ((HYPERVISOR_hvm_op(HVMOP_get_param, &xhp) < 0))
87 return (-1);
88 *val = xhp.value;
89 return (0);
90 }
91
92 void
93 xen_hvm_init(void)
94 {
95 struct cpuid_regs cp;
96 uint32_t xen_signature[4], base;
97 char *xen_str;
98 struct xen_add_to_physmap xatp;
99 xen_capabilities_info_t caps;
100 pfn_t pfn;
101 uint64_t msrval, val;
102
103 if (xen_hvm_inited != 0)
104 return;
105
106 xen_hvm_inited = 1;
107
108 /*
109 * Xen's pseudo-cpuid function returns a string representing
110 * the Xen signature in %ebx, %ecx, and %edx.
111 * Loop over the base values, since it may be different if
112 * the hypervisor has hyper-v emulation switched on.
113 *
114 * %eax contains the maximum supported cpuid function.
115 */
116 for (base = 0x40000000; base < 0x40010000; base += 0x100) {
117 cp.cp_eax = base;
118 (void) __cpuid_insn(&cp);
119 xen_signature[0] = cp.cp_ebx;
120 xen_signature[1] = cp.cp_ecx;
121 xen_signature[2] = cp.cp_edx;
122 xen_signature[3] = 0;
123 xen_str = (char *)xen_signature;
124 if (strcmp("XenVMMXenVMM", xen_str) == 0 &&
125 cp.cp_eax >= (base + 2))
126 break;
127 }
128 if (base >= 0x40010000)
129 return;
130
131 /*
132 * cpuid function at base + 1 returns the Xen version in %eax. The
133 * top 16 bits are the major version, the bottom 16 are the minor
134 * version.
135 */
136 cp.cp_eax = base + 1;
137 (void) __cpuid_insn(&cp);
138 xen_major = cp.cp_eax >> 16;
139 xen_minor = cp.cp_eax & 0xffff;
140
141 /*
142 * Below version 3.1 we can't do anything special as a HVM domain;
143 * the PV drivers don't work, many hypercalls are not available,
144 * etc.
145 */
146 if (xen_major < 3 || (xen_major == 3 && xen_minor < 1))
147 return;
148
149 /*
150 * cpuid function at base + 2 returns information about the
151 * hypercall page. %eax nominally contains the number of pages
152 * with hypercall code, but according to the Xen guys, "I'll
153 * guarantee that remains one forever more, so you can just
154 * allocate a single page and get quite upset if you ever see CPUID
155 * return more than one page." %ebx contains an MSR we use to ask
156 * Xen to remap each page at a specific pfn.
157 */
158 cp.cp_eax = base + 2;
159 (void) __cpuid_insn(&cp);
160
161 /*
162 * Let Xen know where we want the hypercall page mapped. We
163 * already have a page allocated in the .text section to simplify
164 * the wrapper code.
165 */
166 pfn = va_to_pfn(&hypercall_page);
167 msrval = mmu_ptob(pfn);
168 wrmsr(cp.cp_ebx, msrval);
169
170 /* Fill in the xen_info data */
171 xen_info = &__xen_info;
172 (void) sprintf(xen_info->magic, "xen-%d.%d", xen_major, xen_minor);
173
174 if (hvm_get_param(HVM_PARAM_STORE_PFN, &val) < 0)
175 return;
176 /*
177 * The first hypercall worked, so mark hypercalls as working.
178 */
179 xen_hvm_features |= XEN_HVM_HYPERCALLS;
180
181 xen_info->store_mfn = (mfn_t)val;
182 if (hvm_get_param(HVM_PARAM_STORE_EVTCHN, &val) < 0)
183 return;
184 xen_info->store_evtchn = (mfn_t)val;
185
186 /* Figure out whether the hypervisor is 32-bit or 64-bit. */
187 if ((HYPERVISOR_xen_version(XENVER_capabilities, &caps) == 0)) {
188 ((char *)(caps))[sizeof (caps) - 1] = '\0';
189 if (strstr(caps, "x86_64") != NULL)
190 xen_bits = 64;
191 else if (strstr(caps, "x86_32") != NULL)
192 xen_bits = 32;
193 }
194
195 if (xen_bits < 0)
196 return;
197 #ifdef __amd64
198 ASSERT(xen_bits == 64);
199 #endif
200
201 /*
202 * Allocate space for the shared_info page and tell Xen where it
203 * is.
204 */
205 xen_shared_info_frame = va_to_pfn(&hypercall_shared_info_page);
206 xatp.domid = DOMID_SELF;
207 xatp.idx = 0;
208 xatp.space = XENMAPSPACE_shared_info;
209 xatp.gpfn = xen_shared_info_frame;
210 if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp) != 0)
211 return;
212
213 HYPERVISOR_shared_info = (void *)&hypercall_shared_info_page;
214
215 /*
216 * A working HVM tlb flush hypercall was introduced in Xen 3.3.
217 */
218 if (xen_major > 3 || (xen_major == 3 && xen_minor >= 3))
219 xen_hvm_features |= XEN_HVM_TLBFLUSH;
220 }
221
222 /*
223 * Returns:
224 * -1 if a feature is not available
225 * 1 if a boolean feature is available
226 * > 0 if numeric feature is available
227 */
228 int
229 xpv_feature(int which)
230 {
231 switch (which) {
232 case XPVF_BITS:
233 return (xen_bits);
234 case XPVF_VERSION_MAJOR:
235 return (xen_major);
236 case XPVF_VERSION_MINOR:
237 return (xen_minor);
238 case XPVF_HYPERCALLS:
239 if (xen_hvm_features & XEN_HVM_HYPERCALLS)
240 return (1);
241 break;
242 case XPVF_SHARED_INFO:
243 if (HYPERVISOR_shared_info != NULL)
244 return (1);
245 break;
246 case XPVF_TLB_FLUSH:
247 if (xen_hvm_features & XEN_HVM_TLBFLUSH)
248 return (1);
249 break;
250 default:
251 break;
252 }
253
254 return (-1);
255 }