xref: /linux/arch/x86/xen/enlighten_pvh.c (revision 59dbb9d81adfe07a6f8483269146b407cf9d44d7)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/acpi.h>
3 #include <linux/export.h>
4 #include <linux/mm.h>
5 
6 #include <xen/hvc-console.h>
7 #include <xen/acpi.h>
8 
9 #include <asm/bootparam.h>
10 #include <asm/io_apic.h>
11 #include <asm/hypervisor.h>
12 #include <asm/e820/api.h>
13 #include <asm/setup.h>
14 
15 #include <xen/xen.h>
16 #include <asm/xen/interface.h>
17 #include <asm/xen/hypercall.h>
18 
19 #include <xen/interface/memory.h>
20 
21 #include "xen-ops.h"
22 
23 /*
24  * PVH variables.
25  *
26  * The variable xen_pvh needs to live in a data segment since it is used
27  * after startup_{32|64} is invoked, which will clear the .bss segment.
28  */
29 bool __ro_after_init xen_pvh;
30 EXPORT_SYMBOL_GPL(xen_pvh);
31 
32 #ifdef CONFIG_XEN_DOM0
xen_pvh_setup_gsi(int gsi,int trigger,int polarity)33 int xen_pvh_setup_gsi(int gsi, int trigger, int polarity)
34 {
35 	int ret;
36 	struct physdev_setup_gsi setup_gsi;
37 
38 	setup_gsi.gsi = gsi;
39 	setup_gsi.triggering = (trigger == ACPI_EDGE_SENSITIVE ? 0 : 1);
40 	setup_gsi.polarity = (polarity == ACPI_ACTIVE_HIGH ? 0 : 1);
41 
42 	ret = HYPERVISOR_physdev_op(PHYSDEVOP_setup_gsi, &setup_gsi);
43 	if (ret == -EEXIST) {
44 		xen_raw_printk("Already setup the GSI :%d\n", gsi);
45 		ret = 0;
46 	} else if (ret)
47 		xen_raw_printk("Fail to setup GSI (%d)!\n", gsi);
48 
49 	return ret;
50 }
51 EXPORT_SYMBOL_GPL(xen_pvh_setup_gsi);
52 #endif
53 
54 /*
55  * Reserve e820 UNUSABLE regions to inflate the memory balloon.
56  *
57  * On PVH dom0 the host memory map is used, RAM regions available to dom0 are
58  * located as the same place as in the native memory map, but since dom0 gets
59  * less memory than the total amount of host RAM the ranges that can't be
60  * populated are converted from RAM -> UNUSABLE.  Use such regions (up to the
61  * ratio signaled in EXTRA_MEM_RATIO) in order to inflate the balloon driver at
62  * boot.  Doing so prevents the guest (even if just temporary) from using holes
63  * in the memory map in order to map grants or foreign addresses, and
64  * hopefully limits the risk of a clash with a device MMIO region.  Ideally the
65  * hypervisor should notify us which memory ranges are suitable for creating
66  * foreign mappings, but that's not yet implemented.
67  */
pvh_reserve_extra_memory(void)68 static void __init pvh_reserve_extra_memory(void)
69 {
70 	struct boot_params *bootp = &boot_params;
71 	unsigned int i, ram_pages = 0, extra_pages;
72 
73 	for (i = 0; i < bootp->e820_entries; i++) {
74 		struct boot_e820_entry *e = &bootp->e820_table[i];
75 
76 		if (e->type != E820_TYPE_RAM)
77 			continue;
78 		ram_pages += PFN_DOWN(e->addr + e->size) - PFN_UP(e->addr);
79 	}
80 
81 	/* Max amount of extra memory. */
82 	extra_pages = EXTRA_MEM_RATIO * ram_pages;
83 
84 	/*
85 	 * Convert UNUSABLE ranges to RAM and reserve them for foreign mapping
86 	 * purposes.
87 	 */
88 	for (i = 0; i < bootp->e820_entries && extra_pages; i++) {
89 		struct boot_e820_entry *e = &bootp->e820_table[i];
90 		unsigned long pages;
91 
92 		if (e->type != E820_TYPE_UNUSABLE)
93 			continue;
94 
95 		pages = min(extra_pages,
96 			PFN_DOWN(e->addr + e->size) - PFN_UP(e->addr));
97 
98 		if (pages != (PFN_DOWN(e->addr + e->size) - PFN_UP(e->addr))) {
99 			struct boot_e820_entry *next;
100 
101 			if (bootp->e820_entries ==
102 			    ARRAY_SIZE(bootp->e820_table))
103 				/* No space left to split - skip region. */
104 				continue;
105 
106 			/* Split entry. */
107 			next = e + 1;
108 			memmove(next, e,
109 				(bootp->e820_entries - i) * sizeof(*e));
110 			bootp->e820_entries++;
111 			next->addr = PAGE_ALIGN(e->addr) + PFN_PHYS(pages);
112 			e->size = next->addr - e->addr;
113 			next->size -= e->size;
114 		}
115 		e->type = E820_TYPE_RAM;
116 		extra_pages -= pages;
117 
118 		xen_add_extra_mem(PFN_UP(e->addr), pages);
119 	}
120 }
121 
pvh_arch_setup(void)122 static void __init pvh_arch_setup(void)
123 {
124 	pvh_reserve_extra_memory();
125 
126 	if (xen_initial_domain())
127 		xen_add_preferred_consoles();
128 }
129 
xen_pvh_init(struct boot_params * boot_params)130 void __init xen_pvh_init(struct boot_params *boot_params)
131 {
132 	xen_pvh = 1;
133 	xen_domain_type = XEN_HVM_DOMAIN;
134 	xen_start_flags = pvh_start_info.flags;
135 
136 	x86_init.oem.arch_setup = pvh_arch_setup;
137 	x86_init.oem.banner = xen_banner;
138 
139 	xen_efi_init(boot_params);
140 
141 	if (xen_initial_domain()) {
142 		struct xen_platform_op op = {
143 			.cmd = XENPF_get_dom0_console,
144 		};
145 		int ret = HYPERVISOR_platform_op(&op);
146 
147 		if (ret > 0)
148 			xen_init_vga(&op.u.dom0_console,
149 				     min(ret * sizeof(char),
150 					 sizeof(op.u.dom0_console)),
151 				     &boot_params->screen_info);
152 	}
153 }
154 
mem_map_via_hcall(struct boot_params * boot_params_p)155 void __init mem_map_via_hcall(struct boot_params *boot_params_p)
156 {
157 	struct xen_memory_map memmap;
158 	int rc;
159 
160 	memmap.nr_entries = ARRAY_SIZE(boot_params_p->e820_table);
161 	set_xen_guest_handle(memmap.buffer, boot_params_p->e820_table);
162 	rc = HYPERVISOR_memory_op(XENMEM_memory_map, &memmap);
163 	if (rc) {
164 		xen_raw_printk("XENMEM_memory_map failed (%d)\n", rc);
165 		BUG();
166 	}
167 	boot_params_p->e820_entries = memmap.nr_entries;
168 }
169