1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
|
// SPDX-License-Identifier: GPL-2.0
#include <linux/acpi.h>
#include <linux/export.h>
#include <linux/mm.h>
#include <xen/hvc-console.h>
#include <asm/bootparam.h>
#include <asm/io_apic.h>
#include <asm/hypervisor.h>
#include <asm/e820/api.h>
#include <xen/xen.h>
#include <asm/xen/interface.h>
#include <asm/xen/hypercall.h>
#include <xen/interface/memory.h>
#include "xen-ops.h"
/*
* PVH variables.
*
* The variable xen_pvh needs to live in a data segment since it is used
* after startup_{32|64} is invoked, which will clear the .bss segment.
*/
bool __ro_after_init xen_pvh;
EXPORT_SYMBOL_GPL(xen_pvh);
void __init xen_pvh_init(struct boot_params *boot_params)
{
u32 msr;
u64 pfn;
xen_pvh = 1;
xen_domain_type = XEN_HVM_DOMAIN;
xen_start_flags = pvh_start_info.flags;
msr = cpuid_ebx(xen_cpuid_base() + 2);
pfn = __pa(hypercall_page);
wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32));
if (xen_initial_domain())
x86_init.oem.arch_setup = xen_add_preferred_consoles;
x86_init.oem.banner = xen_banner;
xen_efi_init(boot_params);
if (xen_initial_domain()) {
struct xen_platform_op op = {
.cmd = XENPF_get_dom0_console,
};
int ret = HYPERVISOR_platform_op(&op);
if (ret > 0)
xen_init_vga(&op.u.dom0_console,
min(ret * sizeof(char),
sizeof(op.u.dom0_console)),
&boot_params->screen_info);
}
}
void __init mem_map_via_hcall(struct boot_params *boot_params_p)
{
struct xen_memory_map memmap;
int rc;
memmap.nr_entries = ARRAY_SIZE(boot_params_p->e820_table);
set_xen_guest_handle(memmap.buffer, boot_params_p->e820_table);
rc = HYPERVISOR_memory_op(XENMEM_memory_map, &memmap);
if (rc) {
xen_raw_printk("XENMEM_memory_map failed (%d)\n", rc);
BUG();
}
boot_params_p->e820_entries = memmap.nr_entries;
}
/*
* Reserve e820 UNUSABLE regions to inflate the memory balloon.
*
* On PVH dom0 the host memory map is used, RAM regions available to dom0 are
* located as the same place as in the native memory map, but since dom0 gets
* less memory than the total amount of host RAM the ranges that can't be
* populated are converted from RAM -> UNUSABLE. Use such regions (up to the
* ratio signaled in EXTRA_MEM_RATIO) in order to inflate the balloon driver at
* boot. Doing so prevents the guest (even if just temporary) from using holes
* in the memory map in order to map grants or foreign addresses, and
* hopefully limits the risk of a clash with a device MMIO region. Ideally the
* hypervisor should notify us which memory ranges are suitable for creating
* foreign mappings, but that's not yet implemented.
*/
void __init xen_reserve_extra_memory(struct boot_params *bootp)
{
unsigned int i, ram_pages = 0, extra_pages;
for (i = 0; i < bootp->e820_entries; i++) {
struct boot_e820_entry *e = &bootp->e820_table[i];
if (e->type != E820_TYPE_RAM)
continue;
ram_pages += PFN_DOWN(e->addr + e->size) - PFN_UP(e->addr);
}
/* Max amount of extra memory. */
extra_pages = EXTRA_MEM_RATIO * ram_pages;
/*
* Convert UNUSABLE ranges to RAM and reserve them for foreign mapping
* purposes.
*/
for (i = 0; i < bootp->e820_entries && extra_pages; i++) {
struct boot_e820_entry *e = &bootp->e820_table[i];
unsigned long pages;
if (e->type != E820_TYPE_UNUSABLE)
continue;
pages = min(extra_pages,
PFN_DOWN(e->addr + e->size) - PFN_UP(e->addr));
if (pages != (PFN_DOWN(e->addr + e->size) - PFN_UP(e->addr))) {
struct boot_e820_entry *next;
if (bootp->e820_entries ==
ARRAY_SIZE(bootp->e820_table))
/* No space left to split - skip region. */
continue;
/* Split entry. */
next = e + 1;
memmove(next, e,
(bootp->e820_entries - i) * sizeof(*e));
bootp->e820_entries++;
next->addr = PAGE_ALIGN(e->addr) + PFN_PHYS(pages);
e->size = next->addr - e->addr;
next->size -= e->size;
}
e->type = E820_TYPE_RAM;
extra_pages -= pages;
xen_add_extra_mem(PFN_UP(e->addr), pages);
}
}
|
