https://github.com/torvalds/linux
Tip revision: 8005c49d9aea74d382f474ce11afbbc7d7130bec authored by Linus Torvalds on 16 November 2015, 01:00:27 UTC
Linux 4.4-rc1
Linux 4.4-rc1
Tip revision: 8005c49
xen-head.S
/* 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 neccessary 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
#ifdef CONFIG_X86_32
mov %esi,xen_start_info
mov $init_thread_union+THREAD_SIZE,%esp
#else
mov %rsi,xen_start_info
mov $init_thread_union+THREAD_SIZE,%rsp
#endif
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 */