/*
* Set access type for a region of gfns.
* If gfn == INVALID_GFN, sets the default access type.
*/
long p2m_set_mem_access(struct domain *d, gfn_t gfn, uint32_t nr,
uint32_t start, uint32_t mask, xenmem_access_t access,
unsigned int altp2m_idx)
{
struct p2m_domain *p2m = p2m_get_hostp2m(d), *ap2m = NULL;
p2m_access_t a;
unsigned long gfn_l;
long rc = 0;
/* altp2m view 0 is treated as the hostp2m */
if ( altp2m_idx )
{
if ( altp2m_idx >= MAX_ALTP2M ||
d->arch.altp2m_eptp[altp2m_idx] == mfn_x(INVALID_MFN) )
return -EINVAL;
ap2m = d->arch.altp2m_p2m[altp2m_idx];
}
if ( !xenmem_access_to_p2m_access(p2m, access, &a) )
return -EINVAL;
/* If request to set default access. */
if ( gfn_eq(gfn, INVALID_GFN) )
{
p2m->default_access = a;
return 0;
}
p2m_lock(p2m);
if ( ap2m )
p2m_lock(ap2m);
for ( gfn_l = gfn_x(gfn) + start; nr > start; ++gfn_l )
{
rc = set_mem_access(d, p2m, ap2m, a, _gfn(gfn_l));
if ( rc )
break;
/* Check for continuation if it's not the last iteration. */
if ( nr > ++start && !(start & mask) && hypercall_preempt_check() )
{
rc = start;
break;
}
}
if ( ap2m )
p2m_unlock(ap2m);
p2m_unlock(p2m);
return rc;
}
/* Modify the p2m type of a range of gfns from ot to nt.
* Resets the access permissions. */
void p2m_change_type_range(struct domain *d,
unsigned long start, unsigned long end,
p2m_type_t ot, p2m_type_t nt)
{
p2m_access_t a;
p2m_type_t pt;
unsigned long gfn;
mfn_t mfn;
struct p2m_domain *p2m = p2m_get_hostp2m(d);
BUG_ON(p2m_is_grant(ot) || p2m_is_grant(nt));
p2m_lock(p2m);
p2m->defer_nested_flush = 1;
for ( gfn = start; gfn < end; gfn++ )
{
mfn = p2m->get_entry(p2m, gfn, &pt, &a, 0, NULL);
if ( pt == ot )
set_p2m_entry(p2m, gfn, mfn, PAGE_ORDER_4K, nt, p2m->default_access);
}
p2m->defer_nested_flush = 0;
if ( nestedhvm_enabled(d) )
p2m_flush_nestedp2m(d);
p2m_unlock(p2m);
}
void p2m_change_entry_type_global(struct domain *d,
p2m_type_t ot, p2m_type_t nt)
{
struct p2m_domain *p2m = p2m_get_hostp2m(d);
p2m_lock(p2m);
p2m->change_entry_type_global(p2m, ot, nt);
p2m_unlock(p2m);
}
// 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;
}
void p2m_teardown(struct p2m_domain *p2m)
/* Return all the p2m pages to Xen.
* We know we don't have any extra mappings to these pages */
{
struct page_info *pg;
struct domain *d;
if (p2m == NULL)
return;
d = p2m->domain;
p2m_lock(p2m);
ASSERT(atomic_read(&d->shr_pages) == 0);
p2m->phys_table = pagetable_null();
while ( (pg = page_list_remove_head(&p2m->pages)) )
d->arch.paging.free_page(d, pg);
p2m_unlock(p2m);
}
int
guest_physmap_add_entry(struct domain *d, unsigned long gfn,
unsigned long mfn, unsigned int page_order,
p2m_type_t t)
{
struct p2m_domain *p2m = p2m_get_hostp2m(d);
unsigned long i, ogfn;
p2m_type_t ot;
p2m_access_t a;
mfn_t omfn;
int pod_count = 0;
int rc = 0;
if ( !paging_mode_translate(d) )
{
if ( need_iommu(d) && t == p2m_ram_rw )
{
for ( i = 0; i < (1 << page_order); i++ )
{
rc = iommu_map_page(
d, mfn + i, mfn + i, IOMMUF_readable|IOMMUF_writable);
if ( rc != 0 )
{
while ( i-- > 0 )
iommu_unmap_page(d, mfn + i);
return rc;
}
}
}
return 0;
}
p2m_lock(p2m);
P2M_DEBUG("adding gfn=%#lx mfn=%#lx\n", gfn, mfn);
/* First, remove m->p mappings for existing p->m mappings */
for ( i = 0; i < (1UL << page_order); i++ )
{
omfn = p2m->get_entry(p2m, gfn + i, &ot, &a, 0, NULL);
if ( p2m_is_shared(ot) )
{
/* Do an unshare to cleanly take care of all corner
* cases. */
int rc;
rc = mem_sharing_unshare_page(p2m->domain, gfn + i, 0);
if ( rc )
{
p2m_unlock(p2m);
/* NOTE: Should a guest domain bring this upon itself,
* there is not a whole lot we can do. We are buried
* deep in locks from most code paths by now. So, fail
* the call and don't try to sleep on a wait queue
* while placing the mem event.
*
* However, all current (changeset 3432abcf9380) code
* paths avoid this unsavoury situation. For now.
*
* Foreign domains are okay to place an event as they
* won't go to sleep. */
(void)mem_sharing_notify_enomem(p2m->domain, gfn + i, 0);
return rc;
}
omfn = p2m->get_entry(p2m, gfn + i, &ot, &a, 0, NULL);
ASSERT(!p2m_is_shared(ot));
}
if ( p2m_is_grant(ot) )
{
/* Really shouldn't be unmapping grant maps this way */
domain_crash(d);
p2m_unlock(p2m);
return -EINVAL;
}
else if ( p2m_is_ram(ot) && !p2m_is_paged(ot) )
{
ASSERT(mfn_valid(omfn));
set_gpfn_from_mfn(mfn_x(omfn), INVALID_M2P_ENTRY);
}
else if ( ot == p2m_populate_on_demand )
{
/* Count how man PoD entries we'll be replacing if successful */
pod_count++;
}
else if ( p2m_is_paging(ot) && (ot != p2m_ram_paging_out) )
{
/* We're plugging a hole in the physmap where a paged out page was */
atomic_dec(&d->paged_pages);
}
}
/* Then, look for m->p mappings for this range and deal with them */
for ( i = 0; i < (1UL << page_order); i++ )
{
if ( page_get_owner(mfn_to_page(_mfn(mfn + i))) == dom_cow )
{
/* This is no way to add a shared page to your physmap! */
gdprintk(XENLOG_ERR, "Adding shared mfn %lx directly to dom %hu "
"physmap not allowed.\n", mfn+i, d->domain_id);
p2m_unlock(p2m);
return -EINVAL;
}
if ( page_get_owner(mfn_to_page(_mfn(mfn + i))) != d )
continue;
ogfn = mfn_to_gfn(d, _mfn(mfn+i));
if ( (ogfn != INVALID_M2P_ENTRY) && (ogfn != gfn + i) )
{
/* This machine frame is already mapped at another physical
* address */
P2M_DEBUG("aliased! mfn=%#lx, old gfn=%#lx, new gfn=%#lx\n",
mfn + i, ogfn, gfn + i);
omfn = p2m->get_entry(p2m, ogfn, &ot, &a, 0, NULL);
if ( p2m_is_ram(ot) && !p2m_is_paged(ot) )
{
ASSERT(mfn_valid(omfn));
P2M_DEBUG("old gfn=%#lx -> mfn %#lx\n",
ogfn , mfn_x(omfn));
if ( mfn_x(omfn) == (mfn + i) )
p2m_remove_page(p2m, ogfn, mfn + i, 0);
}
}
}
/* Now, actually do the two-way mapping */
if ( mfn_valid(_mfn(mfn)) )
{
if ( !set_p2m_entry(p2m, gfn, _mfn(mfn), page_order, t, p2m->default_access) )
{
rc = -EINVAL;
goto out; /* Failed to update p2m, bail without updating m2p. */
}
if ( !p2m_is_grant(t) )
{
for ( i = 0; i < (1UL << page_order); i++ )
set_gpfn_from_mfn(mfn+i, gfn+i);
}
}
else
{
gdprintk(XENLOG_WARNING, "Adding bad mfn to p2m map (%#lx -> %#lx)\n",
gfn, mfn);
if ( !set_p2m_entry(p2m, gfn, _mfn(INVALID_MFN), page_order,
p2m_invalid, p2m->default_access) )
rc = -EINVAL;
else
{
pod_lock(p2m);
p2m->pod.entry_count -= pod_count;
BUG_ON(p2m->pod.entry_count < 0);
pod_unlock(p2m);
}
}
out:
p2m_unlock(p2m);
return rc;
}
