#include <linux/linkage.h>
#include <linux/lguest.h>
#include <asm/asm-offsets.h>
#include <asm/thread_info.h>
/* FIXME: Once asm/processor-flags.h goes in, include that */
#define X86_EFLAGS_IF 0x00000200
/*
* This is where we begin: we have a magic signature which the launcher looks
* for. The plan is that the Linux boot protocol will be extended with a
* "platform type" field which will guide us here from the normal entry point,
* but for the moment this suffices. We pass the virtual address of the boot
* info to lguest_init().
*
* We put it in .init.text will be discarded after boot.
*/
.section .init.text, "ax", @progbits
.ascii "GenuineLguest"
/* Set up initial stack. */
movl $(init_thread_union+THREAD_SIZE),%esp
movl %esi, %eax
addl $__PAGE_OFFSET, %eax
jmp lguest_init
/* The templates for inline patching. */
#define LGUEST_PATCH(name, insns...) \
lgstart_##name: insns; lgend_##name:; \
.globl lgstart_##name; .globl lgend_##name
LGUEST_PATCH(cli, movl $0, lguest_data+LGUEST_DATA_irq_enabled)
LGUEST_PATCH(sti, movl $X86_EFLAGS_IF, lguest_data+LGUEST_DATA_irq_enabled)
LGUEST_PATCH(popf, movl %eax, lguest_data+LGUEST_DATA_irq_enabled)
LGUEST_PATCH(pushf, movl lguest_data+LGUEST_DATA_irq_enabled, %eax)
.text
/* These demark the EIP range where host should never deliver interrupts. */
.global lguest_noirq_start
.global lguest_noirq_end
/*
* We move eflags word to lguest_data.irq_enabled to restore interrupt state.
* For page faults, gpfs and virtual interrupts, the hypervisor has saved
* eflags manually, otherwise it was delivered directly and so eflags reflects
* the real machine IF state, ie. interrupts on. Since the kernel always dies
* if it takes such a trap with interrupts disabled anyway, turning interrupts
* back on unconditionally here is OK.
*/
ENTRY(lguest_iret)
pushl %eax
movl 12(%esp), %eax
lguest_noirq_start:
movl %eax,%ss:lguest_data+LGUEST_DATA_irq_enabled
popl %eax
iret
lguest_noirq_end:
