xref: /netbsd/sys/arch/xen/x86/pvh_consinit.c (revision 469135ad)
1 /* $NetBSD: pvh_consinit.c,v 1.4 2023/07/22 19:13:17 mrg Exp $ */
2 
3 /*
4  * Copyright (c) 2020 Manuel Bouyer.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  *
26  */
27 
28 #include <sys/cdefs.h>
29 __KERNEL_RCSID(0, "$NetBSD: pvh_consinit.c,v 1.4 2023/07/22 19:13:17 mrg Exp $");
30 
31 #include "xencons.h"
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/device.h>
35 #include <uvm/uvm_extern.h>
36 #include <uvm/uvm_prot.h>
37 
38 #include <dev/cons.h>
39 #include <xen/xen.h>
40 #include <xen/hypervisor.h>
41 #include <xen/include/public/hvm/hvm_op.h>
42 #include <xen/include/public/hvm/params.h>
43 
44 #include "xen_def_cons.h"
45 
46 static int pvh_xenconscn_getc(dev_t);
47 static void pvh_xenconscn_putc(dev_t, int);
48 static void pvh_xenconscn_pollc(dev_t, int);
49 
50 static struct consdev pvh_xencons = {
51         NULL, NULL, pvh_xenconscn_getc, pvh_xenconscn_putc, pvh_xenconscn_pollc,
52 	NULL, NULL, NULL, NODEV, CN_NORMAL
53 };
54 
55 
56 int
xen_pvh_consinit(void)57 xen_pvh_consinit(void)
58 {
59 	/*
60 	 * hugly hack because we're called multiple times at different
61 	 * boot stage.
62 	 */
63 	static int initted = 0;
64 	if (xendomain_is_dom0()) {
65 		union xen_cmdline_parseinfo xcp;
66 		xen_parse_cmdline(XEN_PARSE_CONSOLE, &xcp);
67 #ifdef CONS_OVERRIDE
68                 if (strcmp(default_consinfo.devname, "tty0") == 0 ||
69 		    strcmp(default_consinfo.devname, "pc") == 0) {
70 #else
71 		if (strcmp(xcp.xcp_console, "tty0") == 0 || /* linux name */
72 		    strcmp(xcp.xcp_console, "pc") == 0) { /* NetBSD name */
73 #endif /* CONS_OVERRIDE */
74 			return 0; /* native console code will do it */
75 		}
76 	}
77 	if (initted == 0 && !xendomain_is_dom0()) {
78 		/* pmap not up yet, fall back to printk() */
79 		cn_tab = &pvh_xencons;
80 		initted++;
81 		return 1;
82 	} else if (initted > 1) {
83 		return 1;
84 	}
85 	initted++;
86 	if (xendomain_is_dom0()) {
87 		/* we know we're using Xen's console at this point */
88 		xenconscn_attach(); /* no ring in this case */
89 		initted++; /* don't init console twice */
90 		return 1;
91 	}
92 
93 #if NXENCONS > 0
94 	/* we can now map the xencons rings. */
95 	struct xen_hvm_param xen_hvm_param;
96 
97 
98 	xen_hvm_param.domid = DOMID_SELF;
99 	xen_hvm_param.index = HVM_PARAM_CONSOLE_PFN;
100 
101 	if ( HYPERVISOR_hvm_op(HVMOP_get_param, &xen_hvm_param) < 0)
102 		panic("xen_pvh_consinit: can't get console PFN");
103 
104 	xen_start_info.console.domU.mfn = xen_hvm_param.value;
105 	pmap_kenter_pa((vaddr_t) xencons_interface, ptoa(xen_hvm_param.value),
106 	    VM_PROT_READ|VM_PROT_WRITE, 0);
107 
108 	xen_hvm_param.domid = DOMID_SELF;
109 	xen_hvm_param.index = HVM_PARAM_CONSOLE_EVTCHN;
110 
111 	if ( HYPERVISOR_hvm_op(HVMOP_get_param, &xen_hvm_param) < 0)
112 		panic("xen_pvh_consinit: can't get console event");
113 
114 	xen_start_info.console.domU.evtchn = xen_hvm_param.value;
115 	xenconscn_attach();
116 #endif
117 	return 1;
118 }
119 
120 static int
121 pvh_xenconscn_getc(dev_t dev)
122 {
123 	while(1)
124 		;
125 	return -1;
126 }
127 
128 static void
129 pvh_xenconscn_putc(dev_t dev, int c)
130 {
131 	printk("%c", c);
132 }
133 
134 static void
135 pvh_xenconscn_pollc(dev_t dev, int on)
136 {
137 	return;
138 }
139