/*L:030 lguest_arch_setup_regs()
*
* Most of the Guest's registers are left alone: we used get_zeroed_page() to
* allocate the structure, so they will be 0. */
void lguest_arch_setup_regs(struct lg_cpu *cpu, unsigned long start)
{
struct lguest_regs *regs = cpu->regs;
/* There are four "segment" registers which the Guest needs to boot:
* The "code segment" register (cs) refers to the kernel code segment
* __KERNEL_CS, and the "data", "extra" and "stack" segment registers
* refer to the kernel data segment __KERNEL_DS.
*
* The privilege level is packed into the lower bits. The Guest runs
* at privilege level 1 (GUEST_PL).*/
regs->ds = regs->es = regs->ss = __KERNEL_DS|GUEST_PL;
regs->cs = __KERNEL_CS|GUEST_PL;
/* The "eflags" register contains miscellaneous flags. Bit 1 (0x002)
* is supposed to always be "1". Bit 9 (0x200) controls whether
* interrupts are enabled. We always leave interrupts enabled while
* running the Guest. */
regs->eflags = X86_EFLAGS_IF | 0x2;
/* The "Extended Instruction Pointer" register says where the Guest is
* running. */
regs->eip = start;
/* %esi points to our boot information, at physical address 0, so don't
* touch it. */
/* There are a couple of GDT entries the Guest expects when first
* booting. */
setup_guest_gdt(cpu);
}
void lguest_arch_setup_regs(struct lg_cpu *cpu, unsigned long start)
{
struct lguest_regs *regs = cpu->regs;
regs->ds = regs->es = regs->ss = __KERNEL_DS|GUEST_PL;
regs->cs = __KERNEL_CS|GUEST_PL;
regs->eflags = X86_EFLAGS_IF | X86_EFLAGS_BIT1;
regs->eip = start;
setup_guest_gdt(cpu);
}