diff options
Diffstat (limited to 'x86_64/xen_locore.S')
| -rw-r--r-- | x86_64/xen_locore.S | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/x86_64/xen_locore.S b/x86_64/xen_locore.S new file mode 100644 index 00000000..967c8904 --- /dev/null +++ b/x86_64/xen_locore.S @@ -0,0 +1,146 @@ +/* + * Copyright (C) 2006-2009 Free Software Foundation + * + * This program is free software ; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation ; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY ; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with the program ; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include <mach/machine/asm.h> + +#include <i386/i386/i386asm.h> +#include <i386/i386/cpu_number.h> +#include <i386/i386/xen.h> + + .data 2 +int_active: + .long 0 + + + .text + .globl hyp_callback, hyp_failsafe_callback + P2ALIGN(TEXT_ALIGN) +hyp_callback: + popq %rcx + popq %r11 + pushq %rax + jmp EXT(all_intrs) + +ENTRY(interrupt) + incl int_active /* currently handling interrupts */ + call EXT(hyp_c_callback) /* call generic interrupt routine */ + decl int_active /* stopped handling interrupts */ + sti + ret + +/* FIXME: if we're _very_ unlucky, we may be re-interrupted, filling stack + * + * Far from trivial, see mini-os. That said, maybe we could just, before poping + * everything (which is _not_ destructive), save sp into a known place and use + * it+jmp back? + * + * Mmm, there seems to be an iret hypcall that does exactly what we want: + * perform iret, and if IF is set, clear the interrupt mask. + */ + +/* Pfff, we have to check pending interrupts ourselves. Some other DomUs just make an hypercall for retriggering the irq. Not sure it's really easier/faster */ +ENTRY(hyp_sti) + pushq %rbp + movq %rsp, %rbp +_hyp_sti: + movb $0,hyp_shared_info+CPU_CLI /* Enable interrupts */ + cmpl $0,int_active /* Check whether we were already checking pending interrupts */ + jz 0f + popq %rbp + ret /* Already active, just return */ +0: + /* Not active, check pending interrupts by hand */ + /* no memory barrier needed on x86 */ + cmpb $0,hyp_shared_info+CPU_PENDING + jne 0f + popq %rbp + ret +0: + movb $0xff,hyp_shared_info+CPU_CLI +1: + pushq %rax + pushq %rcx + pushq %rdx + pushq %rdi + pushq %rsi + pushq %r8 + pushq %r9 + pushq %r10 + pushq %r11 + incl int_active /* currently handling interrupts */ + + xorq %rdi,%rdi + xorq %rsi,%rsi + call EXT(hyp_c_callback) + + popq %r11 + popq %r10 + popq %r9 + popq %r8 + popq %rsi + popq %rdi + popq %rdx + popq %rcx + popq %rax + decl int_active /* stopped handling interrupts */ + cmpb $0,hyp_shared_info+CPU_PENDING + jne 1b + jmp _hyp_sti + +/* Hypervisor failed to reload segments. Dump them. */ +hyp_failsafe_callback: +ud2 +#if 1 +/* TODO: FIXME */ + /* load sane segments */ + mov %ss, %ax +#if 0 + mov %ax, %ds + mov %ax, %es +#endif + mov %ax, %fs + mov %ax, %gs + movq %rsp, %rdi + call EXT(hyp_failsafe_c_callback) +#else + popq %rdx + movq %rdx,%ds + popq %rdx + movq %rdx,%es + popq %fs + popq %gs + +movq (%rsp),%rax +ud2 + iretq +#endif + +#undef iretq +ENTRY(hyp_iretq) + testb $2,1*8(%rsp) + jnz slow + /* There is no ring1 on x86_64, we have to force ring 3 */ + orb $3,1*8(%rsp) + orb $3,4*8(%rsp) + iretq + +slow: +/* There is no ring 1/2 on x86_64, so going back to user needs to go through + * hypervisor */ + pushq $0 + jmp __hyp_iret |