diff options
Diffstat (limited to 'arch/x86/xen/xen-asm_64.S')
| -rw-r--r-- | arch/x86/xen/xen-asm_64.S | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/arch/x86/xen/xen-asm_64.S b/arch/x86/xen/xen-asm_64.S new file mode 100644 index 000000000..a93d8a7ce --- /dev/null +++ b/arch/x86/xen/xen-asm_64.S @@ -0,0 +1,177 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Asm versions of Xen pv-ops, suitable for direct use. + * + * We only bother with direct forms (ie, vcpu in pda) of the + * operations here; the indirect forms are better handled in C. + */ + +#include <asm/errno.h> +#include <asm/percpu.h> +#include <asm/processor-flags.h> +#include <asm/segment.h> +#include <asm/asm-offsets.h> +#include <asm/thread_info.h> +#include <asm/asm.h> + +#include <xen/interface/xen.h> + +#include <linux/init.h> +#include <linux/linkage.h> + +.macro xen_pv_trap name +ENTRY(xen_\name) + pop %rcx + pop %r11 + jmp \name +END(xen_\name) +_ASM_NOKPROBE(xen_\name) +.endm + +xen_pv_trap divide_error +xen_pv_trap debug +xen_pv_trap xendebug +xen_pv_trap int3 +xen_pv_trap xennmi +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 + + __INIT +ENTRY(xen_early_idt_handler_array) + i = 0 + .rept NUM_EXCEPTION_VECTORS + pop %rcx + pop %r11 + jmp early_idt_handler_array + i*EARLY_IDT_HANDLER_SIZE + i = i + 1 + .fill xen_early_idt_handler_array + i*XEN_EARLY_IDT_HANDLER_SIZE - ., 1, 0xcc + .endr +END(xen_early_idt_handler_array) + __FINIT + +hypercall_iret = hypercall_page + __HYPERVISOR_iret * 32 +/* + * Xen64 iret frame: + * + * ss + * rsp + * rflags + * cs + * rip <-- standard iret frame + * + * flags + * + * rcx } + * r11 }<-- pushed by hypercall page + * rsp->rax } + */ +ENTRY(xen_iret) + pushq $0 + jmp hypercall_iret + +ENTRY(xen_sysret64) + /* + * We're already on the usermode stack at this point, but + * still with the kernel gs, so we can easily switch back + */ + movq %rsp, PER_CPU_VAR(rsp_scratch) + movq PER_CPU_VAR(cpu_current_top_of_stack), %rsp + + pushq $__USER_DS + pushq PER_CPU_VAR(rsp_scratch) + pushq %r11 + pushq $__USER_CS + pushq %rcx + + pushq $VGCF_in_syscall + jmp hypercall_iret + +/* + * 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 + */ + +/* Normal 64-bit system call target */ +ENTRY(xen_syscall_target) + popq %rcx + popq %r11 + + /* + * 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) + + jmp entry_SYSCALL_64_after_hwframe +ENDPROC(xen_syscall_target) + +#ifdef CONFIG_IA32_EMULATION + +/* 32-bit compat syscall target */ +ENTRY(xen_syscall32_target) + popq %rcx + popq %r11 + + /* + * 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) + + jmp entry_SYSCALL_compat_after_hwframe +ENDPROC(xen_syscall32_target) + +/* 32-bit compat sysenter target */ +ENTRY(xen_sysenter_target) + mov 0*8(%rsp), %rcx + mov 1*8(%rsp), %r11 + mov 5*8(%rsp), %rsp + jmp entry_SYSENTER_compat +ENDPROC(xen_sysenter_target) + +#else /* !CONFIG_IA32_EMULATION */ + +ENTRY(xen_syscall32_target) +ENTRY(xen_sysenter_target) + lea 16(%rsp), %rsp /* strip %rcx, %r11 */ + mov $-ENOSYS, %rax + pushq $0 + jmp hypercall_iret +ENDPROC(xen_syscall32_target) +ENDPROC(xen_sysenter_target) + +#endif /* CONFIG_IA32_EMULATION */ |