xen-asm_64.S 3.4 KB
Newer Older
1
/* SPDX-License-Identifier: GPL-2.0 */
2
/*
3
 * Asm versions of Xen pv-ops, suitable for direct use.
4 5
 *
 * We only bother with direct forms (ie, vcpu in pda) of the
6
 * operations here; the indirect forms are better handled in C.
7 8
 */

9
#include <asm/errno.h>
10
#include <asm/percpu.h>
11 12
#include <asm/processor-flags.h>
#include <asm/segment.h>
13
#include <asm/asm-offsets.h>
14
#include <asm/thread_info.h>
15 16 17

#include <xen/interface/xen.h>

18
#include <linux/linkage.h>
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
.macro xen_pv_trap name
ENTRY(xen_\name)
	pop %rcx
	pop %r11
	jmp  \name
END(xen_\name)
.endm

xen_pv_trap divide_error
xen_pv_trap debug
xen_pv_trap xendebug
xen_pv_trap int3
xen_pv_trap xenint3
xen_pv_trap nmi
xen_pv_trap overflow
xen_pv_trap bounds
xen_pv_trap invalid_op
xen_pv_trap device_not_available
xen_pv_trap double_fault
xen_pv_trap coprocessor_segment_overrun
xen_pv_trap invalid_TSS
xen_pv_trap segment_not_present
xen_pv_trap stack_segment
xen_pv_trap general_protection
xen_pv_trap page_fault
xen_pv_trap spurious_interrupt_bug
xen_pv_trap coprocessor_error
xen_pv_trap alignment_check
#ifdef CONFIG_X86_MCE
xen_pv_trap machine_check
#endif /* CONFIG_X86_MCE */
xen_pv_trap simd_coprocessor_error
#ifdef CONFIG_IA32_EMULATION
xen_pv_trap entry_INT80_compat
#endif
xen_pv_trap hypervisor_callback
56

57 58
hypercall_iret = hypercall_page + __HYPERVISOR_iret * 32
/*
59 60 61 62 63 64 65 66 67 68 69 70 71
 * Xen64 iret frame:
 *
 *	ss
 *	rsp
 *	rflags
 *	cs
 *	rip		<-- standard iret frame
 *
 *	flags
 *
 *	rcx		}
 *	r11		}<-- pushed by hypercall page
 * rsp->rax		}
72
 */
73 74
ENTRY(xen_iret)
	pushq $0
75
	jmp hypercall_iret
76

77
ENTRY(xen_sysret64)
78 79 80 81
	/*
	 * We're already on the usermode stack at this point, but
	 * still with the kernel gs, so we can easily switch back
	 */
82
	movq %rsp, PER_CPU_VAR(rsp_scratch)
83
	movq PER_CPU_VAR(cpu_current_top_of_stack), %rsp
84 85

	pushq $__USER_DS
86
	pushq PER_CPU_VAR(rsp_scratch)
87 88 89 90 91
	pushq %r11
	pushq $__USER_CS
	pushq %rcx

	pushq $VGCF_in_syscall
92
	jmp hypercall_iret
93 94

/*
95 96 97 98 99 100 101 102 103 104 105 106
 * Xen handles syscall callbacks much like ordinary exceptions, which
 * means we have:
 * - kernel gs
 * - kernel rsp
 * - an iret-like stack frame on the stack (including rcx and r11):
 *	ss
 *	rsp
 *	rflags
 *	cs
 *	rip
 *	r11
 * rsp->rcx
107 108 109 110
 */

/* Normal 64-bit system call target */
ENTRY(xen_syscall_target)
111 112
	popq %rcx
	popq %r11
113 114 115 116 117 118 119 120 121

	/*
	 * Neither Xen nor the kernel really knows what the old SS and
	 * CS were.  The kernel expects __USER_DS and __USER_CS, so
	 * report those values even though Xen will guess its own values.
	 */
	movq $__USER_DS, 4*8(%rsp)
	movq $__USER_CS, 1*8(%rsp)

122
	jmp entry_SYSCALL_64_after_hwframe
123 124 125 126 127 128
ENDPROC(xen_syscall_target)

#ifdef CONFIG_IA32_EMULATION

/* 32-bit compat syscall target */
ENTRY(xen_syscall32_target)
129 130
	popq %rcx
	popq %r11
131 132 133 134 135 136 137 138 139

	/*
	 * Neither Xen nor the kernel really knows what the old SS and
	 * CS were.  The kernel expects __USER32_DS and __USER32_CS, so
	 * report those values even though Xen will guess its own values.
	 */
	movq $__USER32_DS, 4*8(%rsp)
	movq $__USER32_CS, 1*8(%rsp)

140
	jmp entry_SYSCALL_compat_after_hwframe
141 142 143 144
ENDPROC(xen_syscall32_target)

/* 32-bit compat sysenter target */
ENTRY(xen_sysenter_target)
145 146 147
	mov 0*8(%rsp), %rcx
	mov 1*8(%rsp), %r11
	mov 5*8(%rsp), %rsp
148
	jmp entry_SYSENTER_compat
149 150 151 152 153 154
ENDPROC(xen_sysenter_target)

#else /* !CONFIG_IA32_EMULATION */

ENTRY(xen_syscall32_target)
ENTRY(xen_sysenter_target)
155
	lea 16(%rsp), %rsp	/* strip %rcx, %r11 */
156
	mov $-ENOSYS, %rax
157
	pushq $0
158 159 160 161 162
	jmp hypercall_iret
ENDPROC(xen_syscall32_target)
ENDPROC(xen_sysenter_target)

#endif	/* CONFIG_IA32_EMULATION */