summaryrefslogtreecommitdiffstats
path: root/arch/x86/xen/xen-head.S
blob: 7f8d8abf4c1ab8b1ea114fee0365f1505b81aeea (plain)
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
/* Xen-specific pieces of head.S, intended to be included in the right
	place in head.S */

#ifdef CONFIG_XEN

#include <linux/elfnote.h>
#include <linux/init.h>

#include <asm/boot.h>
#include <asm/asm.h>
#include <asm/page_types.h>

#include <xen/interface/elfnote.h>
#include <xen/interface/features.h>
#include <xen/interface/xen.h>
#include <xen/interface/xen-mca.h>
#include <asm/xen/interface.h>

#ifdef CONFIG_XEN_PVH
#define PVH_FEATURES_STR  "|writable_descriptor_tables|auto_translated_physmap|supervisor_mode_kernel"
/* Note the lack of 'hvm_callback_vector'. Older hypervisor will
 * balk at this being part of XEN_ELFNOTE_FEATURES, so we put it in
 * XEN_ELFNOTE_SUPPORTED_FEATURES which older hypervisors will ignore.
 */
#define PVH_FEATURES ((1 << XENFEAT_writable_page_tables) | \
		      (1 << XENFEAT_auto_translated_physmap) | \
		      (1 << XENFEAT_supervisor_mode_kernel) | \
		      (1 << XENFEAT_hvm_callback_vector))
/* The XENFEAT_writable_page_tables is not stricly necessary as we set that
 * up regardless whether this CONFIG option is enabled or not, but it
 * clarifies what the right flags need to be.
 */
#else
#define PVH_FEATURES_STR  ""
#define PVH_FEATURES (0)
#endif

	__INIT
ENTRY(startup_xen)
	cld

	/* Clear .bss */
	xor %eax,%eax
	mov $__bss_start, %_ASM_DI
	mov $__bss_stop, %_ASM_CX
	sub %_ASM_DI, %_ASM_CX
	shr $__ASM_SEL(2, 3), %_ASM_CX
	rep __ASM_SIZE(stos)

	mov %_ASM_SI, xen_start_info
	mov $init_thread_union+THREAD_SIZE, %_ASM_SP

	jmp xen_start_kernel

	__FINIT

#ifdef CONFIG_XEN_PVH
/*
 * xen_pvh_early_cpu_init() - early PVH VCPU initialization
 * @cpu:   this cpu number (%rdi)
 * @entry: true if this is a secondary vcpu coming up on this entry
 *         point, false if this is the boot CPU being initialized for
 *         the first time (%rsi)
 *
 * Note: This is called as a function on the boot CPU, and is the entry point
 *       on the secondary CPU.
 */
ENTRY(xen_pvh_early_cpu_init)
	mov     %rsi, %r11

	/* Gather features to see if NX implemented. */
	mov     $0x80000001, %eax
	cpuid
	mov     %edx, %esi

	mov     $MSR_EFER, %ecx
	rdmsr
	bts     $_EFER_SCE, %eax

	bt      $20, %esi
	jnc     1f      	/* No NX, skip setting it */
	bts     $_EFER_NX, %eax
1:	wrmsr
#ifdef CONFIG_SMP
	cmp     $0, %r11b
	jne     cpu_bringup_and_idle
#endif
	ret

#endif /* CONFIG_XEN_PVH */

.pushsection .text
	.balign PAGE_SIZE
ENTRY(hypercall_page)
	.skip PAGE_SIZE

#define HYPERCALL(n) \
	.equ xen_hypercall_##n, hypercall_page + __HYPERVISOR_##n * 32; \
	.type xen_hypercall_##n, @function; .size xen_hypercall_##n, 32
#include <asm/xen-hypercalls.h>
#undef HYPERCALL

.popsection

	ELFNOTE(Xen, XEN_ELFNOTE_GUEST_OS,       .asciz "linux")
	ELFNOTE(Xen, XEN_ELFNOTE_GUEST_VERSION,  .asciz "2.6")
	ELFNOTE(Xen, XEN_ELFNOTE_XEN_VERSION,    .asciz "xen-3.0")
#ifdef CONFIG_X86_32
	ELFNOTE(Xen, XEN_ELFNOTE_VIRT_BASE,      _ASM_PTR __PAGE_OFFSET)
#else
	ELFNOTE(Xen, XEN_ELFNOTE_VIRT_BASE,      _ASM_PTR __START_KERNEL_map)
	/* Map the p2m table to a 512GB-aligned user address. */
	ELFNOTE(Xen, XEN_ELFNOTE_INIT_P2M,       .quad PGDIR_SIZE)
#endif
	ELFNOTE(Xen, XEN_ELFNOTE_ENTRY,          _ASM_PTR startup_xen)
	ELFNOTE(Xen, XEN_ELFNOTE_HYPERCALL_PAGE, _ASM_PTR hypercall_page)
	ELFNOTE(Xen, XEN_ELFNOTE_FEATURES,       .ascii "!writable_page_tables|pae_pgdir_above_4gb"; .asciz PVH_FEATURES_STR)
	ELFNOTE(Xen, XEN_ELFNOTE_SUPPORTED_FEATURES, .long (PVH_FEATURES) |
						(1 << XENFEAT_writable_page_tables) |
						(1 << XENFEAT_dom0))
	ELFNOTE(Xen, XEN_ELFNOTE_PAE_MODE,       .asciz "yes")
	ELFNOTE(Xen, XEN_ELFNOTE_LOADER,         .asciz "generic")
	ELFNOTE(Xen, XEN_ELFNOTE_L1_MFN_VALID,
		.quad _PAGE_PRESENT; .quad _PAGE_PRESENT)
	ELFNOTE(Xen, XEN_ELFNOTE_SUSPEND_CANCEL, .long 1)
	ELFNOTE(Xen, XEN_ELFNOTE_MOD_START_PFN,  .long 1)
	ELFNOTE(Xen, XEN_ELFNOTE_HV_START_LOW,   _ASM_PTR __HYPERVISOR_VIRT_START)
	ELFNOTE(Xen, XEN_ELFNOTE_PADDR_OFFSET,   _ASM_PTR 0)

#endif /*CONFIG_XEN */