arch/x86/xen/xen-head.S

   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 necessary 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
  39 ENTRY(startup_xen)
  40         cld
  41
  42         /* Clear .bss */
  43         xor %eax,%eax
  44         mov $__bss_start, %_ASM_DI
  45         mov $__bss_stop, %_ASM_CX
  46         sub %_ASM_DI, %_ASM_CX
  47         shr $__ASM_SEL(2, 3), %_ASM_CX
  48         rep __ASM_SIZE(stos)
  49
  50         mov %_ASM_SI, xen_start_info
  51         mov $init_thread_union+THREAD_SIZE, %_ASM_SP
  52
  53         jmp xen_start_kernel
  54
  55         __FINIT
  56
  57 #ifdef CONFIG_XEN_PVH
  58 /*
  59  * xen_pvh_early_cpu_init() - early PVH VCPU initialization
  60  * @cpu:   this cpu number (%rdi)
  61  * @entry: true if this is a secondary vcpu coming up on this entry
  62  *         point, false if this is the boot CPU being initialized for
  63  *         the first time (%rsi)
  64  *
  65  * Note: This is called as a function on the boot CPU, and is the entry point
  66  *       on the secondary CPU.
  67  */
  68 ENTRY(xen_pvh_early_cpu_init)
  69         mov     %rsi, %r11
  70
  71         /* Gather features to see if NX implemented. */
  72         mov     $0x80000001, %eax
  73         cpuid
  74         mov     %edx, %esi
  75
  76         mov     $MSR_EFER, %ecx
  77         rdmsr
  78         bts     $_EFER_SCE, %eax
  79
  80         bt      $20, %esi
  81         jnc     1f              /* No NX, skip setting it */
  82         bts     $_EFER_NX, %eax
  83 1:      wrmsr
  84 #ifdef CONFIG_SMP
  85         cmp     $0, %r11b
  86         jne     cpu_bringup_and_idle
  87 #endif
  88         ret
  89
  90 #endif /* CONFIG_XEN_PVH */
  91
  92 .pushsection .text
  93         .balign PAGE_SIZE
  94 ENTRY(hypercall_page)
  95         .skip PAGE_SIZE
  96
  97 #define HYPERCALL(n) \
  98         .equ xen_hypercall_##n, hypercall_page + __HYPERVISOR_##n * 32; \
  99         .type xen_hypercall_##n, @function; .size xen_hypercall_##n, 32
 100 #include <asm/xen-hypercalls.h>
 101 #undef HYPERCALL
 102
 103 .popsection
 104
 105         ELFNOTE(Xen, XEN_ELFNOTE_GUEST_OS,       .asciz "linux")
 106         ELFNOTE(Xen, XEN_ELFNOTE_GUEST_VERSION,  .asciz "2.6")
 107         ELFNOTE(Xen, XEN_ELFNOTE_XEN_VERSION,    .asciz "xen-3.0")
 108 #ifdef CONFIG_X86_32
 109         ELFNOTE(Xen, XEN_ELFNOTE_VIRT_BASE,      _ASM_PTR __PAGE_OFFSET)
 110 #else
 111         ELFNOTE(Xen, XEN_ELFNOTE_VIRT_BASE,      _ASM_PTR __START_KERNEL_map)
 112         /* Map the p2m table to a 512GB-aligned user address. */
 113         ELFNOTE(Xen, XEN_ELFNOTE_INIT_P2M,       .quad PGDIR_SIZE)
 114 #endif
 115         ELFNOTE(Xen, XEN_ELFNOTE_ENTRY,          _ASM_PTR startup_xen)
 116         ELFNOTE(Xen, XEN_ELFNOTE_HYPERCALL_PAGE, _ASM_PTR hypercall_page)
 117         ELFNOTE(Xen, XEN_ELFNOTE_FEATURES,       .ascii "!writable_page_tables|pae_pgdir_above_4gb"; .asciz PVH_FEATURES_STR)
 118         ELFNOTE(Xen, XEN_ELFNOTE_SUPPORTED_FEATURES, .long (PVH_FEATURES) |
 119                                                 (1 << XENFEAT_writable_page_tables) |
 120                                                 (1 << XENFEAT_dom0))
 121         ELFNOTE(Xen, XEN_ELFNOTE_PAE_MODE,       .asciz "yes")
 122         ELFNOTE(Xen, XEN_ELFNOTE_LOADER,         .asciz "generic")
 123         ELFNOTE(Xen, XEN_ELFNOTE_L1_MFN_VALID,
 124                 .quad _PAGE_PRESENT; .quad _PAGE_PRESENT)
 125         ELFNOTE(Xen, XEN_ELFNOTE_SUSPEND_CANCEL, .long 1)
 126         ELFNOTE(Xen, XEN_ELFNOTE_MOD_START_PFN,  .long 1)
 127         ELFNOTE(Xen, XEN_ELFNOTE_HV_START_LOW,   _ASM_PTR __HYPERVISOR_VIRT_START)
 128         ELFNOTE(Xen, XEN_ELFNOTE_PADDR_OFFSET,   _ASM_PTR 0)
 129
 130 #endif /*CONFIG_XEN */