static void copy_in_guest_info(struct lg_cpu *cpu, struct lguest_pages *pages)
{
if (__this_cpu_read(lg_last_cpu) != cpu || cpu->last_pages != pages) {
__this_cpu_write(lg_last_cpu, cpu);
cpu->last_pages = pages;
cpu->changed = CHANGED_ALL;
}
pages->state.host_cr3 = __pa(current->mm->pgd);
map_switcher_in_guest(cpu, pages);
pages->state.guest_tss.sp1 = cpu->esp1;
pages->state.guest_tss.ss1 = cpu->ss1;
if (cpu->changed & CHANGED_IDT)
copy_traps(cpu, pages->state.guest_idt, default_idt_entries);
if (cpu->changed & CHANGED_GDT)
copy_gdt(cpu, pages->state.guest_gdt);
else if (cpu->changed & CHANGED_GDT_TLS)
copy_gdt_tls(cpu, pages->state.guest_gdt);
cpu->changed = 0;
}
/*S:010
* We approach the Switcher.
*
* Remember that each CPU has two pages which are visible to the Guest when it
* runs on that CPU. This has to contain the state for that Guest: we copy the
* state in just before we run the Guest.
*
* Each Guest has "changed" flags which indicate what has changed in the Guest
* since it last ran. We saw this set in interrupts_and_traps.c and
* segments.c.
*/
static void copy_in_guest_info(struct lg_cpu *cpu, struct lguest_pages *pages)
{
/*
* Copying all this data can be quite expensive. We usually run the
* same Guest we ran last time (and that Guest hasn't run anywhere else
* meanwhile). If that's not the case, we pretend everything in the
* Guest has changed.
*/
if (__this_cpu_read(lg_last_cpu) != cpu || cpu->last_pages != pages) {
__this_cpu_write(lg_last_cpu, cpu);
cpu->last_pages = pages;
cpu->changed = CHANGED_ALL;
}
/*
* These copies are pretty cheap, so we do them unconditionally: */
/* Save the current Host top-level page directory.
*/
#ifdef CONFIG_PAX_PER_CPU_PGD
pages->state.host_cr3 = read_cr3();
#else
pages->state.host_cr3 = __pa(current->mm->pgd);
#endif
/*
* Set up the Guest's page tables to see this CPU's pages (and no
* other CPU's pages).
*/
map_switcher_in_guest(cpu, pages);
/*
* Set up the two "TSS" members which tell the CPU what stack to use
* for traps which do directly into the Guest (ie. traps at privilege
* level 1).
*/
pages->state.guest_tss.sp1 = cpu->esp1;
pages->state.guest_tss.ss1 = cpu->ss1;
/* Copy direct-to-Guest trap entries. */
if (cpu->changed & CHANGED_IDT)
copy_traps(cpu, pages->state.guest_idt, default_idt_entries);
/* Copy all GDT entries which the Guest can change. */
if (cpu->changed & CHANGED_GDT)
copy_gdt(cpu, pages->state.guest_gdt);
/* If only the TLS entries have changed, copy them. */
else if (cpu->changed & CHANGED_GDT_TLS)
copy_gdt_tls(cpu, pages->state.guest_gdt);
/* Mark the Guest as unchanged for next time. */
cpu->changed = 0;
}
