// Allocate a new p2m table for a domain.
//
// The structure of the p2m table is that of a pagetable for xen (i.e. it is
// controlled by CONFIG_PAGING_LEVELS).
//
// Returns 0 for success or -errno.
//
int p2m_alloc_table(struct p2m_domain *p2m)
{
struct page_info *p2m_top;
struct domain *d = p2m->domain;
p2m_lock(p2m);
if ( !p2m_is_nestedp2m(p2m)
&& !page_list_empty(&d->page_list) )
{
P2M_ERROR("dom %d already has memory allocated\n", d->domain_id);
p2m_unlock(p2m);
return -EINVAL;
}
if ( pagetable_get_pfn(p2m_get_pagetable(p2m)) != 0 )
{
P2M_ERROR("p2m already allocated for this domain\n");
p2m_unlock(p2m);
return -EINVAL;
}
P2M_PRINTK("allocating p2m table\n");
p2m_top = p2m_alloc_ptp(p2m, PGT_l4_page_table);
if ( p2m_top == NULL )
{
p2m_unlock(p2m);
return -ENOMEM;
}
p2m->phys_table = pagetable_from_mfn(page_to_mfn(p2m_top));
if ( hap_enabled(d) )
iommu_share_p2m_table(d);
P2M_PRINTK("populating p2m table\n");
/* Initialise physmap tables for slot zero. Other code assumes this. */
p2m->defer_nested_flush = 1;
if ( !set_p2m_entry(p2m, 0, _mfn(INVALID_MFN), PAGE_ORDER_4K,
p2m_invalid, p2m->default_access) )
goto error;
p2m->defer_nested_flush = 0;
P2M_PRINTK("p2m table initialised (%u pages)\n", page_count);
p2m_unlock(p2m);
return 0;
spin_unlock(&p2m->domain->page_alloc_lock);
error:
P2M_PRINTK("failed to initialize p2m table, gfn=%05lx, mfn=%"
PRI_mfn "\n", gfn, mfn_x(mfn));
p2m_unlock(p2m);
return -ENOMEM;
}
/* Returns: 0 for success, -errno for failure */
static int
p2m_next_level(struct p2m_domain *p2m, void **table,
unsigned long *gfn_remainder, unsigned long gfn, u32 shift,
u32 max, unsigned long type, bool_t unmap)
{
l1_pgentry_t *l1_entry;
l1_pgentry_t *p2m_entry;
l1_pgentry_t new_entry;
void *next;
int i;
if ( !(p2m_entry = p2m_find_entry(*table, gfn_remainder, gfn,
shift, max)) )
return -ENOENT;
/* PoD/paging: Not present doesn't imply empty. */
if ( !l1e_get_flags(*p2m_entry) )
{
struct page_info *pg;
pg = p2m_alloc_ptp(p2m, type);
if ( pg == NULL )
return -ENOMEM;
new_entry = l1e_from_pfn(mfn_x(page_to_mfn(pg)),
P2M_BASE_FLAGS | _PAGE_RW);
switch ( type ) {
case PGT_l3_page_table:
p2m_add_iommu_flags(&new_entry, 3, IOMMUF_readable|IOMMUF_writable);
p2m->write_p2m_entry(p2m, gfn, p2m_entry, new_entry, 4);
break;
case PGT_l2_page_table:
p2m_add_iommu_flags(&new_entry, 2, IOMMUF_readable|IOMMUF_writable);
p2m->write_p2m_entry(p2m, gfn, p2m_entry, new_entry, 3);
break;
case PGT_l1_page_table:
p2m_add_iommu_flags(&new_entry, 1, IOMMUF_readable|IOMMUF_writable);
p2m->write_p2m_entry(p2m, gfn, p2m_entry, new_entry, 2);
break;
default:
BUG();
break;
}
}
ASSERT(l1e_get_flags(*p2m_entry) & (_PAGE_PRESENT|_PAGE_PSE));
/* split 1GB pages into 2MB pages */
if ( type == PGT_l2_page_table && (l1e_get_flags(*p2m_entry) & _PAGE_PSE) )
{
unsigned long flags, pfn;
struct page_info *pg;
pg = p2m_alloc_ptp(p2m, PGT_l2_page_table);
if ( pg == NULL )
return -ENOMEM;
flags = l1e_get_flags(*p2m_entry);
pfn = l1e_get_pfn(*p2m_entry);
l1_entry = __map_domain_page(pg);
for ( i = 0; i < L2_PAGETABLE_ENTRIES; i++ )
{
new_entry = l1e_from_pfn(pfn + (i * L1_PAGETABLE_ENTRIES), flags);
p2m_add_iommu_flags(&new_entry, 1, IOMMUF_readable|IOMMUF_writable);
p2m->write_p2m_entry(p2m, gfn, l1_entry + i, new_entry, 2);
}
unmap_domain_page(l1_entry);
new_entry = l1e_from_pfn(mfn_x(page_to_mfn(pg)),
P2M_BASE_FLAGS | _PAGE_RW); /* disable PSE */
p2m_add_iommu_flags(&new_entry, 2, IOMMUF_readable|IOMMUF_writable);
p2m->write_p2m_entry(p2m, gfn, p2m_entry, new_entry, 3);
}
/* split single 2MB large page into 4KB page in P2M table */
if ( type == PGT_l1_page_table && (l1e_get_flags(*p2m_entry) & _PAGE_PSE) )
{
unsigned long flags, pfn;
struct page_info *pg;
pg = p2m_alloc_ptp(p2m, PGT_l1_page_table);
if ( pg == NULL )
return -ENOMEM;
/* New splintered mappings inherit the flags of the old superpage,
* with a little reorganisation for the _PAGE_PSE_PAT bit. */
flags = l1e_get_flags(*p2m_entry);
pfn = l1e_get_pfn(*p2m_entry);
if ( pfn & 1 ) /* ==> _PAGE_PSE_PAT was set */
pfn -= 1; /* Clear it; _PAGE_PSE becomes _PAGE_PAT */
else
flags &= ~_PAGE_PSE; /* Clear _PAGE_PSE (== _PAGE_PAT) */
l1_entry = __map_domain_page(pg);
for ( i = 0; i < L1_PAGETABLE_ENTRIES; i++ )
{
new_entry = l1e_from_pfn(pfn + i, flags);
p2m_add_iommu_flags(&new_entry, 0, 0);
p2m->write_p2m_entry(p2m, gfn, l1_entry + i, new_entry, 1);
}
unmap_domain_page(l1_entry);
new_entry = l1e_from_pfn(mfn_x(page_to_mfn(pg)),
P2M_BASE_FLAGS | _PAGE_RW);
p2m_add_iommu_flags(&new_entry, 1, IOMMUF_readable|IOMMUF_writable);
p2m->write_p2m_entry(p2m, gfn, p2m_entry, new_entry, 2);
}
next = map_domain_page(_mfn(l1e_get_pfn(*p2m_entry)));
if ( unmap )
unmap_domain_page(*table);
*table = next;
return 0;
}