// 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;
}
mfn_t __get_gfn_type_access(struct p2m_domain *p2m, unsigned long gfn,
p2m_type_t *t, p2m_access_t *a, p2m_query_t q,
unsigned int *page_order, bool_t locked)
{
mfn_t mfn;
/* Unshare makes no sense withuot populate. */
if ( q & P2M_UNSHARE )
q |= P2M_ALLOC;
if ( !p2m || !paging_mode_translate(p2m->domain) )
{
/* Not necessarily true, but for non-translated guests, we claim
* it's the most generic kind of memory */
*t = p2m_ram_rw;
return _mfn(gfn);
}
if ( locked )
/* Grab the lock here, don't release until put_gfn */
gfn_lock(p2m, gfn, 0);
mfn = p2m->get_entry(p2m, gfn, t, a, q, page_order);
if ( (q & P2M_UNSHARE) && p2m_is_shared(*t) )
{
ASSERT(!p2m_is_nestedp2m(p2m));
/* Try to unshare. If we fail, communicate ENOMEM without
* sleeping. */
if ( mem_sharing_unshare_page(p2m->domain, gfn, 0) < 0 )
(void)mem_sharing_notify_enomem(p2m->domain, gfn, 0);
mfn = p2m->get_entry(p2m, gfn, t, a, q, page_order);
}
if (unlikely((p2m_is_broken(*t))))
{
/* Return invalid_mfn to avoid caller's access */
mfn = _mfn(INVALID_MFN);
if ( q & P2M_ALLOC )
domain_crash(p2m->domain);
}
return mfn;
}
unsigned long hap_p2m_ga_to_gfn(GUEST_PAGING_LEVELS)(
struct vcpu *v, struct p2m_domain *p2m, unsigned long cr3,
paddr_t ga, uint32_t *pfec, unsigned int *page_order)
{
uint32_t missing;
mfn_t top_mfn;
void *top_map;
p2m_type_t p2mt;
walk_t gw;
unsigned long top_gfn;
struct page_info *top_page;
/* Get the top-level table's MFN */
top_gfn = cr3 >> PAGE_SHIFT;
top_page = get_page_from_gfn_p2m(p2m->domain, p2m, top_gfn,
&p2mt, NULL, P2M_ALLOC | P2M_UNSHARE);
if ( p2m_is_paging(p2mt) )
{
ASSERT(!p2m_is_nestedp2m(p2m));
pfec[0] = PFEC_page_paged;
if ( top_page )
put_page(top_page);
p2m_mem_paging_populate(p2m->domain, cr3 >> PAGE_SHIFT);
return INVALID_GFN;
}
if ( p2m_is_shared(p2mt) )
{
pfec[0] = PFEC_page_shared;
if ( top_page )
put_page(top_page);
return INVALID_GFN;
}
if ( !top_page )
{
pfec[0] &= ~PFEC_page_present;
return INVALID_GFN;
}
top_mfn = _mfn(page_to_mfn(top_page));
/* Map the top-level table and call the tree-walker */
ASSERT(mfn_valid(mfn_x(top_mfn)));
top_map = map_domain_page(mfn_x(top_mfn));
#if GUEST_PAGING_LEVELS == 3
top_map += (cr3 & ~(PAGE_MASK | 31));
#endif
missing = guest_walk_tables(v, p2m, ga, &gw, pfec[0], top_mfn, top_map);
unmap_domain_page(top_map);
put_page(top_page);
/* Interpret the answer */
if ( missing == 0 )
{
gfn_t gfn = guest_l1e_get_gfn(gw.l1e);
struct page_info *page;
page = get_page_from_gfn_p2m(p2m->domain, p2m, gfn_x(gfn), &p2mt,
NULL, P2M_ALLOC | P2M_UNSHARE);
if ( page )
put_page(page);
if ( p2m_is_paging(p2mt) )
{
ASSERT(!p2m_is_nestedp2m(p2m));
pfec[0] = PFEC_page_paged;
p2m_mem_paging_populate(p2m->domain, gfn_x(gfn));
return INVALID_GFN;
}
if ( p2m_is_shared(p2mt) )
{
pfec[0] = PFEC_page_shared;
return INVALID_GFN;
}
if ( page_order )
*page_order = guest_walk_to_page_order(&gw);
return gfn_x(gfn);
}
if ( missing & _PAGE_PRESENT )
pfec[0] &= ~PFEC_page_present;
if ( missing & _PAGE_INVALID_BITS )
pfec[0] |= PFEC_reserved_bit;
if ( missing & _PAGE_PAGED )
pfec[0] = PFEC_page_paged;
if ( missing & _PAGE_SHARED )
pfec[0] = PFEC_page_shared;
return INVALID_GFN;
}
