xref: /freebsd/sys/xen/xen_common.c (revision 19fae0f66023a97a9b464b3beeeabb2081f575b3)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright © 2008, 2013 Citrix Systems, Inc.
5  * Copyright © 2012 Spectra Logic Corporation
6  * Copyright © 2021 Elliott Mitchell
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 #include <sys/param.h> /* required by xen/xen-os.h */
35 
36 #include <vm/vm.h>
37 #include <vm/pmap.h>
38 
39 #include <machine/atomic.h> /* required by xen/xen-os.h */
40 
41 #include <xen/xen-os.h>
42 #include <xen/hvm.h>
43 
44 #include <contrib/xen/vcpu.h>
45 
46 /*-------------------------------- Global Data -------------------------------*/
47 enum xen_domain_type xen_domain_type = XEN_NATIVE;
48 
49 /**
50  * Start info flags. ATM this only used to store the initial domain flag for
51  * PVHv2, and it's always empty for HVM guests.
52  */
53 uint32_t hvm_start_flags;
54 
55 /*------------------ Hypervisor Access Shared Memory Regions -----------------*/
56 shared_info_t *HYPERVISOR_shared_info;
57 
58 /*------------------------------- Per-CPU Data -------------------------------*/
59 DPCPU_DEFINE(struct vcpu_info *, vcpu_info);
60 
61 void
62 xen_setup_vcpu_info(void)
63 {
64 	/* This isn't directly accessed outside this function */
65 	DPCPU_DEFINE_STATIC(vcpu_info_t, vcpu_local_info)
66 	    __attribute__((aligned(64)));
67 
68 	vcpu_info_t *vcpu_info = DPCPU_PTR(vcpu_local_info);
69 	vcpu_register_vcpu_info_t info = {
70 		.mfn = vtophys(vcpu_info) >> PAGE_SHIFT,
71 		.offset = vtophys(vcpu_info) & PAGE_MASK,
72 	};
73 	unsigned int cpu = XEN_VCPUID();
74 	int rc;
75 
76 	KASSERT(xen_domain(), ("%s(): invoked when not on Xen?", __func__));
77 
78 	_Static_assert(sizeof(struct vcpu_info) <= 64,
79 	    "struct vcpu_info is larger than supported limit of 64 bytes");
80 
81 	/*
82 	 * Set the vCPU info.
83 	 *
84 	 * NB: the vCPU info for some vCPUs can be fetched from the shared info
85 	 * page, but in order to make sure the mapping code is correct always
86 	 * attempt to map the vCPU info at a custom place.
87 	 */
88 	rc = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info);
89 	if (rc == 0)
90 		DPCPU_SET(vcpu_info, vcpu_info);
91 	else if (cpu < nitems(HYPERVISOR_shared_info->vcpu_info)) {
92 		static bool warned = false;
93 
94 		DPCPU_SET(vcpu_info, &HYPERVISOR_shared_info->vcpu_info[cpu]);
95 
96 		if (bootverbose && !warned) {
97 			warned = true;
98 			printf(
99 		"WARNING: Xen vCPU %u failed to setup vcpu_info rc = %d\n",
100 			    cpu, rc);
101 		}
102 	} else
103 		panic("Unable to register vCPU %u, rc=%d\n", cpu, rc);
104 }
105