void share_xen_page_with_guest(
struct page_info *page, struct domain *d, int readonly)
{
if ( page_get_owner(page) == d )
return;
/* this causes us to leak pages in the Domain and reuslts in
* Zombie domains, I think we are missing a piece, until we find
* it we disable the following code */
set_gpfn_from_mfn(page_to_mfn(page), INVALID_M2P_ENTRY);
spin_lock(&d->page_alloc_lock);
/* The incremented type count pins as writable or read-only. */
page->u.inuse.type_info = (readonly ? PGT_none : PGT_writable_page);
page->u.inuse.type_info |= PGT_validated | 1;
page_set_owner(page, d);
wmb(); /* install valid domain ptr before updating refcnt. */
ASSERT(page->count_info == 0);
/* Only add to the allocation list if the domain isn't dying. */
if ( !d->is_dying )
{
page->count_info |= PGC_allocated | 1;
if ( unlikely(d->xenheap_pages++ == 0) )
get_knownalive_domain(d);
list_add_tail(&page->list, &d->xenpage_list);
}
spin_unlock(&d->page_alloc_lock);
}
int
set_shared_p2m_entry(struct domain *d, unsigned long gfn, mfn_t mfn)
{
struct p2m_domain *p2m = p2m_get_hostp2m(d);
int rc = 0;
p2m_access_t a;
p2m_type_t ot;
mfn_t omfn;
unsigned long pg_type;
if ( !paging_mode_translate(p2m->domain) )
return 0;
gfn_lock(p2m, gfn, 0);
omfn = p2m->get_entry(p2m, gfn, &ot, &a, 0, NULL);
/* At the moment we only allow p2m change if gfn has already been made
* sharable first */
ASSERT(p2m_is_shared(ot));
ASSERT(mfn_valid(omfn));
/* Set the m2p entry to invalid only if there are no further type
* refs to this page as shared */
pg_type = read_atomic(&(mfn_to_page(omfn)->u.inuse.type_info));
if ( (pg_type & PGT_count_mask) == 0
|| (pg_type & PGT_type_mask) != PGT_shared_page )
set_gpfn_from_mfn(mfn_x(omfn), INVALID_M2P_ENTRY);
P2M_DEBUG("set shared %lx %lx\n", gfn, mfn_x(mfn));
rc = set_p2m_entry(p2m, gfn, mfn, PAGE_ORDER_4K, p2m_ram_shared, p2m->default_access);
gfn_unlock(p2m, gfn, 0);
if ( 0 == rc )
gdprintk(XENLOG_ERR,
"set_shared_p2m_entry: set_p2m_entry failed! mfn=%08lx\n",
mfn_x(get_gfn_query_unlocked(p2m->domain, gfn, &ot)));
return rc;
}
int
set_mmio_p2m_entry(struct domain *d, unsigned long gfn, mfn_t mfn)
{
int rc = 0;
p2m_access_t a;
p2m_type_t ot;
mfn_t omfn;
struct p2m_domain *p2m = p2m_get_hostp2m(d);
if ( !paging_mode_translate(d) )
return 0;
gfn_lock(p2m, gfn, 0);
omfn = p2m->get_entry(p2m, gfn, &ot, &a, 0, NULL);
if ( p2m_is_grant(ot) )
{
p2m_unlock(p2m);
domain_crash(d);
return 0;
}
else if ( p2m_is_ram(ot) )
{
ASSERT(mfn_valid(omfn));
set_gpfn_from_mfn(mfn_x(omfn), INVALID_M2P_ENTRY);
}
P2M_DEBUG("set mmio %lx %lx\n", gfn, mfn_x(mfn));
rc = set_p2m_entry(p2m, gfn, mfn, PAGE_ORDER_4K, p2m_mmio_direct, p2m->default_access);
gfn_unlock(p2m, gfn, 0);
if ( 0 == rc )
gdprintk(XENLOG_ERR,
"set_mmio_p2m_entry: set_p2m_entry failed! mfn=%08lx\n",
mfn_x(get_gfn_query_unlocked(p2m->domain, gfn, &ot)));
return rc;
}
static void
p2m_remove_page(struct p2m_domain *p2m, unsigned long gfn, unsigned long mfn,
unsigned int page_order)
{
unsigned long i;
mfn_t mfn_return;
p2m_type_t t;
p2m_access_t a;
if ( !paging_mode_translate(p2m->domain) )
{
if ( need_iommu(p2m->domain) )
for ( i = 0; i < (1 << page_order); i++ )
iommu_unmap_page(p2m->domain, mfn + i);
return;
}
ASSERT(gfn_locked_by_me(p2m, gfn));
P2M_DEBUG("removing gfn=%#lx mfn=%#lx\n", gfn, mfn);
if ( mfn_valid(_mfn(mfn)) )
{
for ( i = 0; i < (1UL << page_order); i++ )
{
mfn_return = p2m->get_entry(p2m, gfn + i, &t, &a, 0, NULL);
if ( !p2m_is_grant(t) && !p2m_is_shared(t) )
set_gpfn_from_mfn(mfn+i, INVALID_M2P_ENTRY);
ASSERT( !p2m_is_valid(t) || mfn + i == mfn_x(mfn_return) );
}
}
set_p2m_entry(p2m, gfn, _mfn(INVALID_MFN), page_order, p2m_invalid, p2m->default_access);
}
static void populate_physmap(struct memop_args *a)
{
struct page_info *page;
unsigned long i, j;
xen_pfn_t gpfn, mfn;
struct domain *d = a->domain;
if ( !guest_handle_subrange_okay(a->extent_list, a->nr_done,
a->nr_extents-1) )
return;
if ( (a->extent_order != 0) &&
!multipage_allocation_permitted(current->domain) )
return;
for ( i = a->nr_done; i < a->nr_extents; i++ )
{
if ( hypercall_preempt_check() )
{
a->preempted = 1;
goto out;
}
if ( unlikely(__copy_from_guest_offset(&gpfn, a->extent_list, i, 1)) )
goto out;
page = alloc_domheap_pages(d, a->extent_order, a->memflags);
if ( unlikely(page == NULL) )
{
gdprintk(XENLOG_INFO, "Could not allocate order=%d extent: "
"id=%d memflags=%x (%ld of %d)\n",
a->extent_order, d->domain_id, a->memflags,
i, a->nr_extents);
goto out;
}
mfn = page_to_mfn(page);
guest_physmap_add_page(d, gpfn, mfn, a->extent_order);
if ( !paging_mode_translate(d) )
{
for ( j = 0; j < (1 << a->extent_order); j++ )
set_gpfn_from_mfn(mfn + j, gpfn + j);
/* Inform the domain of the new page's machine address. */
if ( unlikely(__copy_to_guest_offset(a->extent_list, i, &mfn, 1)) )
goto out;
}
}
out:
a->nr_done = i;
}
static void populate_physmap(struct memop_args *a)
{
struct page_info *page;
unsigned int i, j;
xen_pfn_t gpfn, mfn;
struct domain *d = a->domain;
if ( !guest_handle_subrange_okay(a->extent_list, a->nr_done,
a->nr_extents-1) )
return;
if ( a->extent_order > (a->memflags & MEMF_populate_on_demand ? MAX_ORDER :
max_order(current->domain)) )
return;
for ( i = a->nr_done; i < a->nr_extents; i++ )
{
if ( i != a->nr_done && hypercall_preempt_check() )
{
a->preempted = 1;
goto out;
}
if ( unlikely(__copy_from_guest_offset(&gpfn, a->extent_list, i, 1)) )
goto out;
if ( a->memflags & MEMF_populate_on_demand )
{
if ( guest_physmap_mark_populate_on_demand(d, gpfn,
a->extent_order) < 0 )
goto out;
}
else
{
if ( is_domain_direct_mapped(d) )
{
mfn = gpfn;
for ( j = 0; j < (1U << a->extent_order); j++, mfn++ )
{
if ( !mfn_valid(mfn) )
{
gdprintk(XENLOG_INFO, "Invalid mfn %#"PRI_xen_pfn"\n",
mfn);
goto out;
}
page = mfn_to_page(mfn);
if ( !get_page(page, d) )
{
gdprintk(XENLOG_INFO,
"mfn %#"PRI_xen_pfn" doesn't belong to d%d\n",
mfn, d->domain_id);
goto out;
}
put_page(page);
}
mfn = gpfn;
page = mfn_to_page(mfn);
}
else
{
page = alloc_domheap_pages(d, a->extent_order, a->memflags);
if ( unlikely(!page) )
{
if ( !opt_tmem || a->extent_order )
gdprintk(XENLOG_INFO,
"Could not allocate order=%u extent: id=%d memflags=%#x (%u of %u)\n",
a->extent_order, d->domain_id, a->memflags,
i, a->nr_extents);
goto out;
}
mfn = page_to_mfn(page);
}
guest_physmap_add_page(d, gpfn, mfn, a->extent_order);
if ( !paging_mode_translate(d) )
{
for ( j = 0; j < (1U << a->extent_order); j++ )
set_gpfn_from_mfn(mfn + j, gpfn + j);
/* Inform the domain of the new page's machine address. */
if ( unlikely(__copy_to_guest_offset(a->extent_list, i, &mfn, 1)) )
goto out;
}
}
}
out:
a->nr_done = i;
}
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;
}
