xref: /openbmc/linux/arch/x86/xen/xen-head.S (revision 19c233b7)
1/* Xen-specific pieces of head.S, intended to be included in the right
2	place in head.S */
3
4#ifdef CONFIG_XEN
5
6#include <linux/elfnote.h>
7#include <linux/init.h>
8
9#include <asm/boot.h>
10#include <asm/asm.h>
11#include <asm/page_types.h>
12
13#include <xen/interface/elfnote.h>
14#include <xen/interface/features.h>
15#include <xen/interface/xen.h>
16#include <xen/interface/xen-mca.h>
17#include <asm/xen/interface.h>
18
19#ifdef CONFIG_XEN_PVH
20#define PVH_FEATURES_STR  "|writable_descriptor_tables|auto_translated_physmap|supervisor_mode_kernel"
21/* Note the lack of 'hvm_callback_vector'. Older hypervisor will
22 * balk at this being part of XEN_ELFNOTE_FEATURES, so we put it in
23 * XEN_ELFNOTE_SUPPORTED_FEATURES which older hypervisors will ignore.
24 */
25#define PVH_FEATURES ((1 << XENFEAT_writable_page_tables) | \
26		      (1 << XENFEAT_auto_translated_physmap) | \
27		      (1 << XENFEAT_supervisor_mode_kernel) | \
28		      (1 << XENFEAT_hvm_callback_vector))
29/* The XENFEAT_writable_page_tables is not stricly neccessary as we set that
30 * up regardless whether this CONFIG option is enabled or not, but it
31 * clarifies what the right flags need to be.
32 */
33#else
34#define PVH_FEATURES_STR  ""
35#define PVH_FEATURES (0)
36#endif
37
38	__INIT
39ENTRY(startup_xen)
40	cld
41#ifdef CONFIG_X86_32
42	mov %esi,xen_start_info
43	mov $init_thread_union+THREAD_SIZE,%esp
44#else
45	mov %rsi,xen_start_info
46	mov $init_thread_union+THREAD_SIZE,%rsp
47#endif
48	jmp xen_start_kernel
49
50	__FINIT
51
52#ifdef CONFIG_XEN_PVH
53/*
54 * xen_pvh_early_cpu_init() - early PVH VCPU initialization
55 * @cpu:   this cpu number (%rdi)
56 * @entry: true if this is a secondary vcpu coming up on this entry
57 *         point, false if this is the boot CPU being initialized for
58 *         the first time (%rsi)
59 *
60 * Note: This is called as a function on the boot CPU, and is the entry point
61 *       on the secondary CPU.
62 */
63ENTRY(xen_pvh_early_cpu_init)
64	mov     %rsi, %r11
65
66	/* Gather features to see if NX implemented. */
67	mov     $0x80000001, %eax
68	cpuid
69	mov     %edx, %esi
70
71	mov     $MSR_EFER, %ecx
72	rdmsr
73	bts     $_EFER_SCE, %eax
74
75	bt      $20, %esi
76	jnc     1f      	/* No NX, skip setting it */
77	bts     $_EFER_NX, %eax
781:	wrmsr
79#ifdef CONFIG_SMP
80	cmp     $0, %r11b
81	jne     cpu_bringup_and_idle
82#endif
83	ret
84
85#endif /* CONFIG_XEN_PVH */
86
87.pushsection .text
88	.balign PAGE_SIZE
89ENTRY(hypercall_page)
90	.skip PAGE_SIZE
91
92#define HYPERCALL(n) \
93	.equ xen_hypercall_##n, hypercall_page + __HYPERVISOR_##n * 32; \
94	.type xen_hypercall_##n, @function; .size xen_hypercall_##n, 32
95#include <asm/xen-hypercalls.h>
96#undef HYPERCALL
97
98.popsection
99
100	ELFNOTE(Xen, XEN_ELFNOTE_GUEST_OS,       .asciz "linux")
101	ELFNOTE(Xen, XEN_ELFNOTE_GUEST_VERSION,  .asciz "2.6")
102	ELFNOTE(Xen, XEN_ELFNOTE_XEN_VERSION,    .asciz "xen-3.0")
103#ifdef CONFIG_X86_32
104	ELFNOTE(Xen, XEN_ELFNOTE_VIRT_BASE,      _ASM_PTR __PAGE_OFFSET)
105#else
106	ELFNOTE(Xen, XEN_ELFNOTE_VIRT_BASE,      _ASM_PTR __START_KERNEL_map)
107#endif
108	ELFNOTE(Xen, XEN_ELFNOTE_ENTRY,          _ASM_PTR startup_xen)
109	ELFNOTE(Xen, XEN_ELFNOTE_HYPERCALL_PAGE, _ASM_PTR hypercall_page)
110	ELFNOTE(Xen, XEN_ELFNOTE_FEATURES,       .ascii "!writable_page_tables|pae_pgdir_above_4gb"; .asciz PVH_FEATURES_STR)
111	ELFNOTE(Xen, XEN_ELFNOTE_SUPPORTED_FEATURES, .long (PVH_FEATURES) |
112						(1 << XENFEAT_writable_page_tables) |
113						(1 << XENFEAT_dom0))
114	ELFNOTE(Xen, XEN_ELFNOTE_PAE_MODE,       .asciz "yes")
115	ELFNOTE(Xen, XEN_ELFNOTE_LOADER,         .asciz "generic")
116	ELFNOTE(Xen, XEN_ELFNOTE_L1_MFN_VALID,
117		.quad _PAGE_PRESENT; .quad _PAGE_PRESENT)
118	ELFNOTE(Xen, XEN_ELFNOTE_SUSPEND_CANCEL, .long 1)
119	ELFNOTE(Xen, XEN_ELFNOTE_MOD_START_PFN,  .long 1)
120	ELFNOTE(Xen, XEN_ELFNOTE_HV_START_LOW,   _ASM_PTR __HYPERVISOR_VIRT_START)
121	ELFNOTE(Xen, XEN_ELFNOTE_PADDR_OFFSET,   _ASM_PTR 0)
122
123#endif /*CONFIG_XEN */
124