/* This is called just after a mm has been created, but it has not
been used yet. We need to make sure that its pagetable is all
read-only, and can be pinned. */
void xen_pgd_pin(pgd_t *pgd)
{
struct multicall_space mcs;
struct mmuext_op *op;
xen_mc_batch();
if (pgd_walk(pgd, pin_page, TASK_SIZE)) {
/* re-enable interrupts for kmap_flush_unused */
xen_mc_issue(0);
kmap_flush_unused();
xen_mc_batch();
}
mcs = __xen_mc_entry(sizeof(*op));
op = mcs.args;
#ifdef CONFIG_X86_PAE
op->cmd = MMUEXT_PIN_L3_TABLE;
#else
op->cmd = MMUEXT_PIN_L2_TABLE;
#endif
op->arg1.mfn = pfn_to_mfn(PFN_DOWN(__pa(pgd)));
MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
xen_mc_issue(0);
}
/* Release a pagetables pages back as normal RW */
static void xen_pgd_unpin(pgd_t *pgd)
{
struct mmuext_op *op;
struct multicall_space mcs;
xen_mc_batch();
mcs = __xen_mc_entry(sizeof(*op));
op = mcs.args;
op->cmd = MMUEXT_UNPIN_TABLE;
op->arg1.mfn = pfn_to_mfn(PFN_DOWN(__pa(pgd)));
MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
pgd_walk(pgd, unpin_page, TASK_SIZE);
xen_mc_issue(0);
}
void __init xen_mark_init_mm_pinned(void)
{
pgd_walk(init_mm.pgd, mark_pinned, FIXADDR_TOP);
}
static void __pgd_unpin(pgd_t *pgd)
{
xen_pgd_unpin(__pa(pgd));
pgd_walk(pgd, PAGE_KERNEL);
clear_bit(PG_pinned, &virt_to_page(pgd)->flags);
}
static void __pgd_pin(pgd_t *pgd)
{
pgd_walk(pgd, PAGE_KERNEL_RO);
xen_pgd_pin(__pa(pgd));
set_bit(PG_pinned, &virt_to_page(pgd)->flags);
}
