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ec83f8256276c6f99dfe13bb2b56d168c080f098
xen/xen/common/memory.c
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Paul Durrant ec83f82562 mm.h: add helper function to test-and-clear _PGC_allocated 
The _PGC_allocated flag is set on a page when it is assigned to a domain
along with an initial reference count of at least 1. To clear this
'allocation' reference it is necessary to test-and-clear _PGC_allocated and
then only drop the reference if the test-and-clear succeeds. This is open-
coded in many places. It is also unsafe to test-and-clear _PGC_allocated
unless the caller holds an additional reference.

This patch adds a helper function, put_page_alloc_ref(), to replace all the
open-coded test-and-clear/put_page occurrences. That helper function
incorporates a check that an additional page reference is held and will
BUG() if it is not.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
2019-07-16 09:10:36 +02:00

1738 lines
48 KiB
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/******************************************************************************
* memory.c
*
* Code to handle memory-related requests.
*
* Copyright (c) 2003-2004, B Dragovic
* Copyright (c) 2003-2005, K A Fraser
*/
#include <xen/domain_page.h>
#include <xen/types.h>
#include <xen/lib.h>
#include <xen/mm.h>
#include <xen/perfc.h>
#include <xen/sched.h>
#include <xen/event.h>
#include <xen/paging.h>
#include <xen/iocap.h>
#include <xen/guest_access.h>
#include <xen/hypercall.h>
#include <xen/errno.h>
#include <xen/numa.h>
#include <xen/mem_access.h>
#include <xen/trace.h>
#include <xen/grant_table.h>
#include <asm/current.h>
#include <asm/hardirq.h>
#include <asm/p2m.h>
#include <public/memory.h>
#include <xsm/xsm.h>
#ifdef CONFIG_X86
#include <asm/guest.h>
#endif
struct memop_args {
/* INPUT */
struct domain *domain; /* Domain to be affected. */
XEN_GUEST_HANDLE(xen_pfn_t) extent_list; /* List of extent base addrs. */
unsigned int nr_extents; /* Number of extents to allocate or free. */
unsigned int extent_order; /* Size of each extent. */
unsigned int memflags; /* Allocation flags. */
/* INPUT/OUTPUT */
unsigned int nr_done; /* Number of extents processed so far. */
int preempted; /* Was the hypercall preempted? */
};
#ifndef CONFIG_CTLDOM_MAX_ORDER
#define CONFIG_CTLDOM_MAX_ORDER CONFIG_PAGEALLOC_MAX_ORDER
#endif
#ifndef CONFIG_PTDOM_MAX_ORDER
#define CONFIG_PTDOM_MAX_ORDER CONFIG_HWDOM_MAX_ORDER
#endif
static unsigned int __read_mostly domu_max_order = CONFIG_DOMU_MAX_ORDER;
static unsigned int __read_mostly ctldom_max_order = CONFIG_CTLDOM_MAX_ORDER;
static unsigned int __read_mostly hwdom_max_order = CONFIG_HWDOM_MAX_ORDER;
#ifdef HAS_PASSTHROUGH
static unsigned int __read_mostly ptdom_max_order = CONFIG_PTDOM_MAX_ORDER;
#endif
static int __init parse_max_order(const char *s)
{
if ( *s != ',' )
domu_max_order = simple_strtoul(s, &s, 0);
if ( *s == ',' && *++s != ',' )
ctldom_max_order = simple_strtoul(s, &s, 0);
if ( *s == ',' && *++s != ',' )
hwdom_max_order = simple_strtoul(s, &s, 0);
#ifdef HAS_PASSTHROUGH
if ( *s == ',' && *++s != ',' )
ptdom_max_order = simple_strtoul(s, &s, 0);
#endif
return *s ? -EINVAL : 0;
}
custom_param("memop-max-order", parse_max_order);
static unsigned int max_order(const struct domain *d)
{
unsigned int order = domu_max_order;
#ifdef HAS_PASSTHROUGH
if ( cache_flush_permitted(d) && order < ptdom_max_order )
order = ptdom_max_order;
#endif
if ( is_control_domain(d) && order < ctldom_max_order )
order = ctldom_max_order;
if ( is_hardware_domain(d) && order < hwdom_max_order )
order = hwdom_max_order;
return min(order, MAX_ORDER + 0U);
}
/* Helper to copy a typesafe MFN to guest */
static inline
unsigned long __copy_mfn_to_guest_offset(XEN_GUEST_HANDLE(xen_pfn_t) hnd,
size_t off, mfn_t mfn)
{
xen_pfn_t mfn_ = mfn_x(mfn);
return __copy_to_guest_offset(hnd, off, &mfn_, 1);
}
static void increase_reservation(struct memop_args *a)
{
struct page_info *page;
unsigned long i;
struct domain *d = a->domain;
if ( !guest_handle_is_null(a->extent_list) &&
!guest_handle_subrange_okay(a->extent_list, a->nr_done,
a->nr_extents-1) )
return;
if ( a->extent_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;
}
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;
}
/* Inform the domain of the new page's machine address. */
if ( !paging_mode_translate(d) &&
!guest_handle_is_null(a->extent_list) )
{
mfn_t mfn = page_to_mfn(page);
if ( unlikely(__copy_mfn_to_guest_offset(a->extent_list, i, mfn)) )
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;
struct domain *d = a->domain, *curr_d = current->domain;
bool need_tlbflush = false;
uint32_t tlbflush_timestamp = 0;
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(curr_d)) )
return;
if ( unlikely(!d->creation_finished) )
{
/*
* With MEMF_no_tlbflush set, alloc_heap_pages() will ignore
* TLB-flushes. After VM creation, this is a security issue (it can
* make pages accessible to guest B, when guest A may still have a
* cached mapping to them). So we do this only during domain creation,
* when the domain itself has not yet been unpaused for the first
* time.
*/
a->memflags |= MEMF_no_tlbflush;
/*
* With MEMF_no_icache_flush, alloc_heap_pages() will skip
* performing icache flushes. We do it only before domain
* creation as once the domain is running there is a danger of
* executing instructions from stale caches if icache flush is
* delayed.
*/
a->memflags |= MEMF_no_icache_flush;
}
for ( i = a->nr_done; i < a->nr_extents; i++ )
{
mfn_t mfn;
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 )
{
/* Disallow populating PoD pages on oneself. */
if ( d == curr_d )
goto out;
if ( is_hvm_domain(d) &&
guest_physmap_mark_populate_on_demand(d, gpfn,
a->extent_order) < 0 )
goto out;
}
else
{
if ( is_domain_direct_mapped(d) )
{
mfn = _mfn(gpfn);
for ( j = 0; j < (1U << a->extent_order); j++,
mfn = mfn_add(mfn, 1) )
{
if ( !mfn_valid(mfn) )
{
gdprintk(XENLOG_INFO, "Invalid mfn %#"PRI_mfn"\n",
mfn_x(mfn));
goto out;
}
page = mfn_to_page(mfn);
if ( !get_page(page, d) )
{
gdprintk(XENLOG_INFO,
"mfn %#"PRI_mfn" doesn't belong to d%d\n",
mfn_x(mfn), d->domain_id);
goto out;
}
put_page(page);
}
mfn = _mfn(gpfn);
}
else
{
page = alloc_domheap_pages(d, a->extent_order, a->memflags);
if ( unlikely(!page) )
{
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;
}
if ( unlikely(a->memflags & MEMF_no_tlbflush) )
{
for ( j = 0; j < (1U << a->extent_order); j++ )
accumulate_tlbflush(&need_tlbflush, &page[j],
&tlbflush_timestamp);
}
mfn = page_to_mfn(page);
}
guest_physmap_add_page(d, _gfn(gpfn), mfn, a->extent_order);
if ( !paging_mode_translate(d) &&
/* Inform the domain of the new page's machine address. */
unlikely(__copy_mfn_to_guest_offset(a->extent_list, i, mfn)) )
goto out;
}
}
out:
if ( need_tlbflush )
filtered_flush_tlb_mask(tlbflush_timestamp);
if ( a->memflags & MEMF_no_icache_flush )
invalidate_icache();
a->nr_done = i;
}
int guest_remove_page(struct domain *d, unsigned long gmfn)
{
struct page_info *page;
#ifdef CONFIG_X86
p2m_type_t p2mt;
#endif
mfn_t mfn;
int rc;
#ifdef CONFIG_X86
mfn = get_gfn_query(d, gmfn, &p2mt);
if ( unlikely(p2mt == p2m_invalid) || unlikely(p2mt == p2m_mmio_dm) )
{
put_gfn(d, gmfn);
return -ENOENT;
}
if ( unlikely(p2m_is_paging(p2mt)) )
{
/*
* If the page hasn't yet been paged out, there is an
* actual page that needs to be released.
*/
if ( p2mt == p2m_ram_paging_out )
{
ASSERT(mfn_valid(mfn));
goto obtain_page;
}
rc = guest_physmap_remove_page(d, _gfn(gmfn), mfn, 0);
if ( rc )
goto out_put_gfn;
put_gfn(d, gmfn);
p2m_mem_paging_drop_page(d, gmfn, p2mt);
return 0;
}
if ( p2mt == p2m_mmio_direct )
{
rc = clear_mmio_p2m_entry(d, gmfn, mfn, PAGE_ORDER_4K);
goto out_put_gfn;
}
#else
mfn = gfn_to_mfn(d, _gfn(gmfn));
#endif
if ( unlikely(!mfn_valid(mfn)) )
{
#ifdef CONFIG_X86
put_gfn(d, gmfn);
#endif
gdprintk(XENLOG_INFO, "Domain %u page number %lx invalid\n",
d->domain_id, gmfn);
return -EINVAL;
}
#ifdef CONFIG_X86
if ( p2m_is_shared(p2mt) )
{
/*
* Unshare the page, bail out on error. We unshare because we
* might be the only one using this shared page, and we need to
* trigger proper cleanup. Once done, this is like any other page.
*/
rc = mem_sharing_unshare_page(d, gmfn, 0);
if ( rc )
{
mem_sharing_notify_enomem(d, gmfn, false);
goto out_put_gfn;
}
/* Maybe the mfn changed */
mfn = get_gfn_query_unlocked(d, gmfn, &p2mt);
ASSERT(!p2m_is_shared(p2mt));
}
#endif /* CONFIG_X86 */
obtain_page: __maybe_unused;
page = mfn_to_page(mfn);
if ( unlikely(!get_page(page, d)) )
{
#ifdef CONFIG_X86
put_gfn(d, gmfn);
if ( !p2m_is_paging(p2mt) )
#endif
gdprintk(XENLOG_INFO, "Bad page free for Dom%u GFN %lx\n",
d->domain_id, gmfn);
return -ENXIO;
}
rc = guest_physmap_remove_page(d, _gfn(gmfn), mfn, 0);
/*
* With the lack of an IOMMU on some platforms, domains with DMA-capable
* device must retrieve the same pfn when the hypercall populate_physmap
* is called.
*
* For this purpose (and to match populate_physmap() behavior), the page
* is kept allocated.
*/
if ( !rc && !is_domain_direct_mapped(d) )
put_page_alloc_ref(page);
put_page(page);
#ifdef CONFIG_X86
out_put_gfn:
put_gfn(d, gmfn);
#endif
/*
* Filter out -ENOENT return values that aren't a result of an empty p2m
* entry.
*/
return rc != -ENOENT ? rc : -EINVAL;
}
static void decrease_reservation(struct memop_args *a)
{
unsigned long i, j;
xen_pfn_t gmfn;
if ( !guest_handle_subrange_okay(a->extent_list, a->nr_done,
a->nr_extents-1) ||
a->extent_order > max_order(current->domain) )
return;
for ( i = a->nr_done; i < a->nr_extents; i++ )
{
unsigned long pod_done;
if ( i != a->nr_done && hypercall_preempt_check() )
{
a->preempted = 1;
goto out;
}
if ( unlikely(__copy_from_guest_offset(&gmfn, a->extent_list, i, 1)) )
goto out;
if ( tb_init_done )
{
struct {
u64 gfn;
int d:16,order:16;
} t;
t.gfn = gmfn;
t.d = a->domain->domain_id;
t.order = a->extent_order;
__trace_var(TRC_MEM_DECREASE_RESERVATION, 0, sizeof(t), &t);
}
/* See if populate-on-demand wants to handle this */
pod_done = is_hvm_domain(a->domain) ?
p2m_pod_decrease_reservation(a->domain, _gfn(gmfn),
a->extent_order) : 0;
/*
* Look for pages not handled by p2m_pod_decrease_reservation().
*
* guest_remove_page() will return -ENOENT for pages which have already
* been removed by p2m_pod_decrease_reservation(); so expect to see
* exactly pod_done failures. Any more means that there were invalid
* entries before p2m_pod_decrease_reservation() was called.
*/
for ( j = 0; j + pod_done < (1UL << a->extent_order); j++ )
{
switch ( guest_remove_page(a->domain, gmfn + j) )
{
case 0:
break;
case -ENOENT:
if ( !pod_done )
goto out;
--pod_done;
break;
default:
goto out;
}
}
}
out:
a->nr_done = i;
}
static bool propagate_node(unsigned int xmf, unsigned int *memflags)
{
const struct domain *currd = current->domain;
BUILD_BUG_ON(XENMEMF_get_node(0) != NUMA_NO_NODE);
BUILD_BUG_ON(MEMF_get_node(0) != NUMA_NO_NODE);
if ( XENMEMF_get_node(xmf) == NUMA_NO_NODE )
return true;
if ( is_hardware_domain(currd) || is_control_domain(currd) )
{
if ( XENMEMF_get_node(xmf) >= MAX_NUMNODES )
return false;
*memflags |= MEMF_node(XENMEMF_get_node(xmf));
if ( xmf & XENMEMF_exact_node_request )
*memflags |= MEMF_exact_node;
}
else if ( xmf & XENMEMF_exact_node_request )
return false;
return true;
}
static long memory_exchange(XEN_GUEST_HANDLE_PARAM(xen_memory_exchange_t) arg)
{
struct xen_memory_exchange exch;
PAGE_LIST_HEAD(in_chunk_list);
PAGE_LIST_HEAD(out_chunk_list);
unsigned long in_chunk_order, out_chunk_order;
xen_pfn_t gpfn, gmfn;
mfn_t mfn;
unsigned long i, j, k;
unsigned int memflags = 0;
long rc = 0;
struct domain *d;
struct page_info *page;
if ( copy_from_guest(&exch, arg, 1) )
return -EFAULT;
if ( max(exch.in.extent_order, exch.out.extent_order) >
max_order(current->domain) )
{
rc = -EPERM;
goto fail_early;
}
/* Various sanity checks. */
if ( (exch.nr_exchanged > exch.in.nr_extents) ||
/* Input and output domain identifiers match? */
(exch.in.domid != exch.out.domid) ||
/* Sizes of input and output lists do not overflow a long? */
((~0UL >> exch.in.extent_order) < exch.in.nr_extents) ||
((~0UL >> exch.out.extent_order) < exch.out.nr_extents) ||
/* Sizes of input and output lists match? */
((exch.in.nr_extents << exch.in.extent_order) !=
(exch.out.nr_extents << exch.out.extent_order)) )
{
rc = -EINVAL;
goto fail_early;
}
if ( exch.nr_exchanged == exch.in.nr_extents )
return 0;
if ( !guest_handle_subrange_okay(exch.in.extent_start, exch.nr_exchanged,
exch.in.nr_extents - 1) )
{
rc = -EFAULT;
goto fail_early;
}
if ( exch.in.extent_order <= exch.out.extent_order )
{
in_chunk_order = exch.out.extent_order - exch.in.extent_order;
out_chunk_order = 0;
if ( !guest_handle_subrange_okay(exch.out.extent_start,
exch.nr_exchanged >> in_chunk_order,
exch.out.nr_extents - 1) )
{
rc = -EFAULT;
goto fail_early;
}
}
else
{
in_chunk_order = 0;
out_chunk_order = exch.in.extent_order - exch.out.extent_order;
if ( !guest_handle_subrange_okay(exch.out.extent_start,
exch.nr_exchanged << out_chunk_order,
exch.out.nr_extents - 1) )
{
rc = -EFAULT;
goto fail_early;
}
}
if ( unlikely(!propagate_node(exch.out.mem_flags, &memflags)) )
{
rc = -EINVAL;
goto fail_early;
}
d = rcu_lock_domain_by_any_id(exch.in.domid);
if ( d == NULL )
{
rc = -ESRCH;
goto fail_early;
}
rc = xsm_memory_exchange(XSM_TARGET, d);
if ( rc )
{
rcu_unlock_domain(d);
goto fail_early;
}
memflags |= MEMF_bits(domain_clamp_alloc_bitsize(
d,
XENMEMF_get_address_bits(exch.out.mem_flags) ? :
(BITS_PER_LONG+PAGE_SHIFT)));
for ( i = (exch.nr_exchanged >> in_chunk_order);
i < (exch.in.nr_extents >> in_chunk_order);
i++ )
{
if ( i != (exch.nr_exchanged >> in_chunk_order) &&
hypercall_preempt_check() )
{
exch.nr_exchanged = i << in_chunk_order;
rcu_unlock_domain(d);
if ( __copy_field_to_guest(arg, &exch, nr_exchanged) )
return -EFAULT;
return hypercall_create_continuation(
__HYPERVISOR_memory_op, "lh", XENMEM_exchange, arg);
}
/* Steal a chunk's worth of input pages from the domain. */
for ( j = 0; j < (1UL << in_chunk_order); j++ )
{
if ( unlikely(__copy_from_guest_offset(
&gmfn, exch.in.extent_start, (i<<in_chunk_order)+j, 1)) )
{
rc = -EFAULT;
goto fail;
}
for ( k = 0; k < (1UL << exch.in.extent_order); k++ )
{
#ifdef CONFIG_X86
p2m_type_t p2mt;
/* Shared pages cannot be exchanged */
mfn = get_gfn_unshare(d, gmfn + k, &p2mt);
if ( p2m_is_shared(p2mt) )
{
put_gfn(d, gmfn + k);
rc = -ENOMEM;
goto fail;
}
#else /* !CONFIG_X86 */
mfn = gfn_to_mfn(d, _gfn(gmfn + k));
#endif
if ( unlikely(!mfn_valid(mfn)) )
{
#ifdef CONFIG_X86
put_gfn(d, gmfn + k);
#endif
rc = -EINVAL;
goto fail;
}
page = mfn_to_page(mfn);
rc = steal_page(d, page, MEMF_no_refcount);
if ( unlikely(rc) )
{
#ifdef CONFIG_X86
put_gfn(d, gmfn + k);
#endif
goto fail;
}
page_list_add(page, &in_chunk_list);
#ifdef CONFIG_X86
put_gfn(d, gmfn + k);
#endif
}
}
/* Allocate a chunk's worth of anonymous output pages. */
for ( j = 0; j < (1UL << out_chunk_order); j++ )
{
page = alloc_domheap_pages(d, exch.out.extent_order,
MEMF_no_owner | memflags);
if ( unlikely(page == NULL) )
{
rc = -ENOMEM;
goto fail;
}
page_list_add(page, &out_chunk_list);
}
/*
* Success! Beyond this point we cannot fail for this chunk.
*/
/*
* These pages have already had owner and reference cleared.
* Do the final two steps: Remove from the physmap, and free
* them.
*/
while ( (page = page_list_remove_head(&in_chunk_list)) )
{
unsigned long gfn;
mfn = page_to_mfn(page);
gfn = mfn_to_gmfn(d, mfn_x(mfn));
/* Pages were unshared above */
BUG_ON(SHARED_M2P(gfn));
if ( guest_physmap_remove_page(d, _gfn(gfn), mfn, 0) )
domain_crash(d);
free_domheap_page(page);
}
/* Assign each output page to the domain. */
for ( j = 0; (page = page_list_remove_head(&out_chunk_list)); ++j )
{
if ( assign_pages(d, page, exch.out.extent_order,
MEMF_no_refcount) )
{
unsigned long dec_count;
bool_t drop_dom_ref;
/*
* Pages in in_chunk_list is stolen without
* decreasing the tot_pages. If the domain is dying when
* assign pages, we need decrease the count. For those pages
* that has been assigned, it should be covered by
* domain_relinquish_resources().
*/
dec_count = (((1UL << exch.in.extent_order) *
(1UL << in_chunk_order)) -
(j * (1UL << exch.out.extent_order)));
spin_lock(&d->page_alloc_lock);
drop_dom_ref = (dec_count &&
!domain_adjust_tot_pages(d, -dec_count));
spin_unlock(&d->page_alloc_lock);
if ( drop_dom_ref )
put_domain(d);
free_domheap_pages(page, exch.out.extent_order);
goto dying;
}
if ( __copy_from_guest_offset(&gpfn, exch.out.extent_start,
(i << out_chunk_order) + j, 1) )
{
rc = -EFAULT;
continue;
}
mfn = page_to_mfn(page);
guest_physmap_add_page(d, _gfn(gpfn), mfn,
exch.out.extent_order);
if ( !paging_mode_translate(d) &&
__copy_mfn_to_guest_offset(exch.out.extent_start,
(i << out_chunk_order) + j,
mfn) )
rc = -EFAULT;
}
BUG_ON( !(d->is_dying) && (j != (1UL << out_chunk_order)) );
if ( rc )
goto fail;
}
exch.nr_exchanged = exch.in.nr_extents;
if ( __copy_field_to_guest(arg, &exch, nr_exchanged) )
rc = -EFAULT;
rcu_unlock_domain(d);
return rc;
/*
* Failed a chunk! Free any partial chunk work. Tell caller how many
* chunks succeeded.
*/
fail:
/*
* Reassign any input pages we managed to steal. NB that if the assign
* fails again, we're on the hook for freeing the page, since we've already
* cleared PGC_allocated.
*/
while ( (page = page_list_remove_head(&in_chunk_list)) )
if ( assign_pages(d, page, 0, MEMF_no_refcount) )
{
BUG_ON(!d->is_dying);
free_domheap_page(page);
}
dying:
rcu_unlock_domain(d);
/* Free any output pages we managed to allocate. */
while ( (page = page_list_remove_head(&out_chunk_list)) )
free_domheap_pages(page, exch.out.extent_order);
exch.nr_exchanged = i << in_chunk_order;
fail_early:
if ( __copy_field_to_guest(arg, &exch, nr_exchanged) )
rc = -EFAULT;
return rc;
}
int xenmem_add_to_physmap(struct domain *d, struct xen_add_to_physmap *xatp,
unsigned int start)
{
unsigned int done = 0;
long rc = 0;
union xen_add_to_physmap_batch_extra extra;
ASSERT(paging_mode_translate(d));
if ( xatp->space != XENMAPSPACE_gmfn_foreign )
extra.res0 = 0;
else
extra.foreign_domid = DOMID_INVALID;
if ( xatp->space != XENMAPSPACE_gmfn_range )
return xenmem_add_to_physmap_one(d, xatp->space, extra,
xatp->idx, _gfn(xatp->gpfn));
if ( xatp->size < start )
return -EILSEQ;
xatp->idx += start;
xatp->gpfn += start;
xatp->size -= start;
if ( has_iommu_pt(d) )
this_cpu(iommu_dont_flush_iotlb) = 1;
while ( xatp->size > done )
{
rc = xenmem_add_to_physmap_one(d, XENMAPSPACE_gmfn, extra,
xatp->idx, _gfn(xatp->gpfn));
if ( rc < 0 )
break;
xatp->idx++;
xatp->gpfn++;
/* Check for continuation if it's not the last iteration. */
if ( xatp->size > ++done && hypercall_preempt_check() )
{
rc = start + done;
break;
}
}
if ( has_iommu_pt(d) )
{
int ret;
this_cpu(iommu_dont_flush_iotlb) = 0;
ret = iommu_iotlb_flush(d, _dfn(xatp->idx - done), done,
IOMMU_FLUSHF_added | IOMMU_FLUSHF_modified);
if ( unlikely(ret) && rc >= 0 )
rc = ret;
ret = iommu_iotlb_flush(d, _dfn(xatp->gpfn - done), done,
IOMMU_FLUSHF_added | IOMMU_FLUSHF_modified);
if ( unlikely(ret) && rc >= 0 )
rc = ret;
}
return rc;
}
static int xenmem_add_to_physmap_batch(struct domain *d,
struct xen_add_to_physmap_batch *xatpb,
unsigned int extent)
{
if ( unlikely(xatpb->size < extent) )
return -EILSEQ;
if ( unlikely(xatpb->size == extent) )
return extent ? -EILSEQ : 0;
if ( !guest_handle_subrange_okay(xatpb->idxs, extent, xatpb->size - 1) ||
!guest_handle_subrange_okay(xatpb->gpfns, extent, xatpb->size - 1) ||
!guest_handle_subrange_okay(xatpb->errs, extent, xatpb->size - 1) )
return -EFAULT;
while ( xatpb->size > extent )
{
xen_ulong_t idx;
xen_pfn_t gpfn;
int rc;
if ( unlikely(__copy_from_guest_offset(&idx, xatpb->idxs,
extent, 1)) ||
unlikely(__copy_from_guest_offset(&gpfn, xatpb->gpfns,
extent, 1)) )
return -EFAULT;
rc = xenmem_add_to_physmap_one(d, xatpb->space,
xatpb->u,
idx, _gfn(gpfn));
if ( unlikely(__copy_to_guest_offset(xatpb->errs, extent, &rc, 1)) )
return -EFAULT;
/* Check for continuation if it's not the last iteration. */
if ( xatpb->size > ++extent && hypercall_preempt_check() )
return extent;
}
return 0;
}
static int construct_memop_from_reservation(
const struct xen_memory_reservation *r,
struct memop_args *a)
{
unsigned int address_bits;
a->extent_list = r->extent_start;
a->nr_extents = r->nr_extents;
a->extent_order = r->extent_order;
a->memflags = 0;
address_bits = XENMEMF_get_address_bits(r->mem_flags);
if ( (address_bits != 0) &&
(address_bits < (get_order_from_pages(max_page) + PAGE_SHIFT)) )
{
if ( address_bits <= PAGE_SHIFT )
return -EINVAL;
a->memflags = MEMF_bits(address_bits);
}
if ( r->mem_flags & XENMEMF_vnode )
{
nodeid_t vnode, pnode;
struct domain *d = a->domain;
read_lock(&d->vnuma_rwlock);
if ( d->vnuma )
{
vnode = XENMEMF_get_node(r->mem_flags);
if ( vnode >= d->vnuma->nr_vnodes )
{
read_unlock(&d->vnuma_rwlock);
return -EINVAL;
}
pnode = d->vnuma->vnode_to_pnode[vnode];
if ( pnode != NUMA_NO_NODE )
{
a->memflags |= MEMF_node(pnode);
if ( r->mem_flags & XENMEMF_exact_node_request )
a->memflags |= MEMF_exact_node;
}
}
read_unlock(&d->vnuma_rwlock);
}
else if ( unlikely(!propagate_node(r->mem_flags, &a->memflags)) )
return -EINVAL;
return 0;
}
#ifdef CONFIG_HAS_PASSTHROUGH
struct get_reserved_device_memory {
struct xen_reserved_device_memory_map map;
unsigned int used_entries;
};
static int get_reserved_device_memory(xen_pfn_t start, xen_ulong_t nr,
u32 id, void *ctxt)
{
struct get_reserved_device_memory *grdm = ctxt;
uint32_t sbdf = PCI_SBDF3(grdm->map.dev.pci.seg, grdm->map.dev.pci.bus,
grdm->map.dev.pci.devfn).sbdf;
if ( !(grdm->map.flags & XENMEM_RDM_ALL) && (sbdf != id) )
return 0;
if ( grdm->used_entries < grdm->map.nr_entries )
{
struct xen_reserved_device_memory rdm = {
.start_pfn = start, .nr_pages = nr
};
if ( __copy_to_guest_offset(grdm->map.buffer, grdm->used_entries,
&rdm, 1) )
return -EFAULT;
}
++grdm->used_entries;
return 1;
}
#endif
static long xatp_permission_check(struct domain *d, unsigned int space)
{
if ( !paging_mode_translate(d) )
return -EACCES;
/*
* XENMAPSPACE_dev_mmio mapping is only supported for hardware Domain
* to map this kind of space to itself.
*/
if ( (space == XENMAPSPACE_dev_mmio) &&
(!is_hardware_domain(d) || (d != current->domain)) )
return -EACCES;
return xsm_add_to_physmap(XSM_TARGET, current->domain, d);
}
static int acquire_grant_table(struct domain *d, unsigned int id,
unsigned long frame,
unsigned int nr_frames,
xen_pfn_t mfn_list[])
{
unsigned int i = nr_frames;
/* Iterate backwards in case table needs to grow */
while ( i-- != 0 )
{
mfn_t mfn = INVALID_MFN;
int rc;
switch ( id )
{
case XENMEM_resource_grant_table_id_shared:
rc = gnttab_get_shared_frame(d, frame + i, &mfn);
break;
case XENMEM_resource_grant_table_id_status:
rc = gnttab_get_status_frame(d, frame + i, &mfn);
break;
default:
rc = -EINVAL;
break;
}
if ( rc )
return rc;
ASSERT(!mfn_eq(mfn, INVALID_MFN));
mfn_list[i] = mfn_x(mfn);
}
return 0;
}
static int acquire_resource(
XEN_GUEST_HANDLE_PARAM(xen_mem_acquire_resource_t) arg)
{
struct domain *d, *currd = current->domain;
xen_mem_acquire_resource_t xmar;
/*
* The mfn_list and gfn_list (below) arrays are ok on stack for the
* moment since they are small, but if they need to grow in future
* use-cases then per-CPU arrays or heap allocations may be required.
*/
xen_pfn_t mfn_list[32];
int rc;
if ( copy_from_guest(&xmar, arg, 1) )
return -EFAULT;
if ( xmar.flags != 0 )
return -EINVAL;
if ( guest_handle_is_null(xmar.frame_list) )
{
if ( xmar.nr_frames )
return -EINVAL;
xmar.nr_frames = ARRAY_SIZE(mfn_list);
if ( __copy_field_to_guest(arg, &xmar, nr_frames) )
return -EFAULT;
return 0;
}
if ( xmar.nr_frames > ARRAY_SIZE(mfn_list) )
return -E2BIG;
rc = rcu_lock_remote_domain_by_id(xmar.domid, &d);
if ( rc )
return rc;
rc = xsm_domain_resource_map(XSM_DM_PRIV, d);
if ( rc )
goto out;
switch ( xmar.type )
{
case XENMEM_resource_grant_table:
rc = acquire_grant_table(d, xmar.id, xmar.frame, xmar.nr_frames,
mfn_list);
break;
default:
rc = arch_acquire_resource(d, xmar.type, xmar.id, xmar.frame,
xmar.nr_frames, mfn_list, &xmar.flags);
break;
}
if ( rc )
goto out;
if ( !paging_mode_translate(currd) )
{
if ( copy_to_guest(xmar.frame_list, mfn_list, xmar.nr_frames) )
rc = -EFAULT;
}
else
{
xen_pfn_t gfn_list[ARRAY_SIZE(mfn_list)];
unsigned int i;
/*
* FIXME: Until foreign pages inserted into the P2M are properly
* reference counted, it is unsafe to allow mapping of
* non-caller-owned resource pages unless the caller is
* the hardware domain.
*/
if ( !(xmar.flags & XENMEM_rsrc_acq_caller_owned) &&
!is_hardware_domain(currd) )
return -EACCES;
if ( copy_from_guest(gfn_list, xmar.frame_list, xmar.nr_frames) )
rc = -EFAULT;
for ( i = 0; !rc && i < xmar.nr_frames; i++ )
{
rc = set_foreign_p2m_entry(currd, gfn_list[i],
_mfn(mfn_list[i]));
/* rc should be -EIO for any iteration other than the first */
if ( rc && i )
rc = -EIO;
}
}
if ( xmar.flags != 0 &&
__copy_field_to_guest(arg, &xmar, flags) )
rc = -EFAULT;
out:
rcu_unlock_domain(d);
return rc;
}
long do_memory_op(unsigned long cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
{
struct domain *d, *curr_d = current->domain;
long rc;
struct xen_memory_reservation reservation;
struct memop_args args;
domid_t domid;
unsigned long start_extent = cmd >> MEMOP_EXTENT_SHIFT;
int op = cmd & MEMOP_CMD_MASK;
switch ( op )
{
case XENMEM_increase_reservation:
case XENMEM_decrease_reservation:
case XENMEM_populate_physmap:
if ( copy_from_guest(&reservation, arg, 1) )
return start_extent;
/* Is size too large for us to encode a continuation? */
if ( reservation.nr_extents > (UINT_MAX >> MEMOP_EXTENT_SHIFT) )
return start_extent;
if ( unlikely(start_extent >= reservation.nr_extents) )
return start_extent;
d = rcu_lock_domain_by_any_id(reservation.domid);
if ( d == NULL )
return start_extent;
args.domain = d;
if ( construct_memop_from_reservation(&reservation, &args) )
{
rcu_unlock_domain(d);
return start_extent;
}
args.nr_done = start_extent;
args.preempted = 0;
if ( op == XENMEM_populate_physmap
&& (reservation.mem_flags & XENMEMF_populate_on_demand) )
args.memflags |= MEMF_populate_on_demand;
if ( xsm_memory_adjust_reservation(XSM_TARGET, curr_d, d) )
{
rcu_unlock_domain(d);
return start_extent;
}
#ifdef CONFIG_X86
if ( pv_shim && op != XENMEM_decrease_reservation && !args.preempted )
/* Avoid calling pv_shim_online_memory when preempted. */
pv_shim_online_memory(args.nr_extents, args.extent_order);
#endif
switch ( op )
{
case XENMEM_increase_reservation:
increase_reservation(&args);
break;
case XENMEM_decrease_reservation:
decrease_reservation(&args);
break;
default: /* XENMEM_populate_physmap */
populate_physmap(&args);
break;
}
rcu_unlock_domain(d);
rc = args.nr_done;
if ( args.preempted )
return hypercall_create_continuation(
__HYPERVISOR_memory_op, "lh",
op | (rc << MEMOP_EXTENT_SHIFT), arg);
#ifdef CONFIG_X86
if ( pv_shim && op == XENMEM_decrease_reservation )
/*
* Only call pv_shim_offline_memory when the hypercall has
* finished. Note that nr_done is used to cope in case the
* hypercall has failed and only part of the extents where
* processed.
*/
pv_shim_offline_memory(args.nr_extents, args.nr_done);
#endif
break;
case XENMEM_exchange:
if ( unlikely(start_extent) )
return -EINVAL;
rc = memory_exchange(guest_handle_cast(arg, xen_memory_exchange_t));
break;
case XENMEM_maximum_ram_page:
if ( unlikely(start_extent) )
return -EINVAL;
rc = max_page;
break;
case XENMEM_current_reservation:
case XENMEM_maximum_reservation:
case XENMEM_maximum_gpfn:
if ( unlikely(start_extent) )
return -EINVAL;
if ( copy_from_guest(&domid, arg, 1) )
return -EFAULT;
d = rcu_lock_domain_by_any_id(domid);
if ( d == NULL )
return -ESRCH;
rc = xsm_memory_stat_reservation(XSM_TARGET, curr_d, d);
if ( rc )
{
rcu_unlock_domain(d);
return rc;
}
switch ( op )
{
case XENMEM_current_reservation:
rc = d->tot_pages;
break;
case XENMEM_maximum_reservation:
rc = d->max_pages;
break;
default:
ASSERT(op == XENMEM_maximum_gpfn);
rc = domain_get_maximum_gpfn(d);
break;
}
rcu_unlock_domain(d);
break;
case XENMEM_add_to_physmap:
{
struct xen_add_to_physmap xatp;
BUILD_BUG_ON((typeof(xatp.size))-1 > (UINT_MAX >> MEMOP_EXTENT_SHIFT));
/* Check for malicious or buggy input. */
if ( start_extent != (typeof(xatp.size))start_extent )
return -EDOM;
if ( copy_from_guest(&xatp, arg, 1) )
return -EFAULT;
/* Foreign mapping is only possible via add_to_physmap_batch. */
if ( xatp.space == XENMAPSPACE_gmfn_foreign )
return -ENOSYS;
d = rcu_lock_domain_by_any_id(xatp.domid);
if ( d == NULL )
return -ESRCH;
rc = xatp_permission_check(d, xatp.space);
if ( rc )
{
rcu_unlock_domain(d);
return rc;
}
rc = xenmem_add_to_physmap(d, &xatp, start_extent);
rcu_unlock_domain(d);
if ( xatp.space == XENMAPSPACE_gmfn_range && rc > 0 )
rc = hypercall_create_continuation(
__HYPERVISOR_memory_op, "lh",
op | (rc << MEMOP_EXTENT_SHIFT), arg);
return rc;
}
case XENMEM_add_to_physmap_batch:
{
struct xen_add_to_physmap_batch xatpb;
BUILD_BUG_ON((typeof(xatpb.size))-1 >
(UINT_MAX >> MEMOP_EXTENT_SHIFT));
/* Check for malicious or buggy input. */
if ( start_extent != (typeof(xatpb.size))start_extent )
return -EDOM;
if ( copy_from_guest(&xatpb, arg, 1) )
return -EFAULT;
/* This mapspace is unsupported for this hypercall. */
if ( xatpb.space == XENMAPSPACE_gmfn_range )
return -EOPNOTSUPP;
d = rcu_lock_domain_by_any_id(xatpb.domid);
if ( d == NULL )
return -ESRCH;
rc = xatp_permission_check(d, xatpb.space);
if ( rc )
{
rcu_unlock_domain(d);
return rc;
}
rc = xenmem_add_to_physmap_batch(d, &xatpb, start_extent);
rcu_unlock_domain(d);
if ( rc > 0 )
rc = hypercall_create_continuation(
__HYPERVISOR_memory_op, "lh",
op | (rc << MEMOP_EXTENT_SHIFT), arg);
return rc;
}
case XENMEM_remove_from_physmap:
{
struct xen_remove_from_physmap xrfp;
struct page_info *page;
if ( unlikely(start_extent) )
return -EINVAL;
if ( copy_from_guest(&xrfp, arg, 1) )
return -EFAULT;
d = rcu_lock_domain_by_any_id(xrfp.domid);
if ( d == NULL )
return -ESRCH;
rc = paging_mode_translate(d)
? xsm_remove_from_physmap(XSM_TARGET, curr_d, d)
: -EACCES;
if ( rc )
{
rcu_unlock_domain(d);
return rc;
}
page = get_page_from_gfn(d, xrfp.gpfn, NULL, P2M_ALLOC);
if ( page )
{
rc = guest_physmap_remove_page(d, _gfn(xrfp.gpfn),
page_to_mfn(page), 0);
put_page(page);
}
else
rc = -ENOENT;
rcu_unlock_domain(d);
break;
}
case XENMEM_access_op:
rc = mem_access_memop(cmd, guest_handle_cast(arg, xen_mem_access_op_t));
break;
case XENMEM_claim_pages:
if ( unlikely(start_extent) )
return -EINVAL;
if ( copy_from_guest(&reservation, arg, 1) )
return -EFAULT;
if ( !guest_handle_is_null(reservation.extent_start) )
return -EINVAL;
if ( reservation.extent_order != 0 )
return -EINVAL;
if ( reservation.mem_flags != 0 )
return -EINVAL;
d = rcu_lock_domain_by_id(reservation.domid);
if ( d == NULL )
return -EINVAL;
rc = xsm_claim_pages(XSM_PRIV, d);
if ( !rc )
rc = domain_set_outstanding_pages(d, reservation.nr_extents);
rcu_unlock_domain(d);
break;
case XENMEM_get_vnumainfo:
{
struct xen_vnuma_topology_info topology;
unsigned int dom_vnodes, dom_vranges, dom_vcpus;
struct vnuma_info tmp;
if ( unlikely(start_extent) )
return -EINVAL;
/*
* Guest passes nr_vnodes, number of regions and nr_vcpus thus
* we know how much memory guest has allocated.
*/
if ( copy_from_guest(&topology, arg, 1 ))
return -EFAULT;
if ( topology.pad != 0 )
return -EINVAL;
if ( (d = rcu_lock_domain_by_any_id(topology.domid)) == NULL )
return -ESRCH;
rc = xsm_get_vnumainfo(XSM_TARGET, d);
if ( rc )
{
rcu_unlock_domain(d);
return rc;
}
read_lock(&d->vnuma_rwlock);
if ( d->vnuma == NULL )
{
read_unlock(&d->vnuma_rwlock);
rcu_unlock_domain(d);
return -EOPNOTSUPP;
}
dom_vnodes = d->vnuma->nr_vnodes;
dom_vranges = d->vnuma->nr_vmemranges;
dom_vcpus = d->max_vcpus;
/*
* Copied from guest values may differ from domain vnuma config.
* Check here guest parameters make sure we dont overflow.
* Additionaly check padding.
*/
if ( topology.nr_vnodes < dom_vnodes ||
topology.nr_vcpus < dom_vcpus ||
topology.nr_vmemranges < dom_vranges )
{
read_unlock(&d->vnuma_rwlock);
rcu_unlock_domain(d);
topology.nr_vnodes = dom_vnodes;
topology.nr_vcpus = dom_vcpus;
topology.nr_vmemranges = dom_vranges;
/* Copy back needed values. */
return __copy_to_guest(arg, &topology, 1) ? -EFAULT : -ENOBUFS;
}
read_unlock(&d->vnuma_rwlock);
tmp.vdistance = xmalloc_array(unsigned int, dom_vnodes * dom_vnodes);
tmp.vmemrange = xmalloc_array(xen_vmemrange_t, dom_vranges);
tmp.vcpu_to_vnode = xmalloc_array(unsigned int, dom_vcpus);
if ( tmp.vdistance == NULL ||
tmp.vmemrange == NULL ||
tmp.vcpu_to_vnode == NULL )
{
rc = -ENOMEM;
goto vnumainfo_out;
}
/*
* Check if vnuma info has changed and if the allocated arrays
* are not big enough.
*/
read_lock(&d->vnuma_rwlock);
if ( dom_vnodes < d->vnuma->nr_vnodes ||
dom_vranges < d->vnuma->nr_vmemranges ||
dom_vcpus < d->max_vcpus )
{
read_unlock(&d->vnuma_rwlock);
rc = -EAGAIN;
goto vnumainfo_out;
}
dom_vnodes = d->vnuma->nr_vnodes;
dom_vranges = d->vnuma->nr_vmemranges;
dom_vcpus = d->max_vcpus;
memcpy(tmp.vmemrange, d->vnuma->vmemrange,
sizeof(*d->vnuma->vmemrange) * dom_vranges);
memcpy(tmp.vdistance, d->vnuma->vdistance,
sizeof(*d->vnuma->vdistance) * dom_vnodes * dom_vnodes);
memcpy(tmp.vcpu_to_vnode, d->vnuma->vcpu_to_vnode,
sizeof(*d->vnuma->vcpu_to_vnode) * dom_vcpus);
read_unlock(&d->vnuma_rwlock);
rc = -EFAULT;
if ( copy_to_guest(topology.vmemrange.h, tmp.vmemrange,
dom_vranges) != 0 )
goto vnumainfo_out;
if ( copy_to_guest(topology.vdistance.h, tmp.vdistance,
dom_vnodes * dom_vnodes) != 0 )
goto vnumainfo_out;
if ( copy_to_guest(topology.vcpu_to_vnode.h, tmp.vcpu_to_vnode,
dom_vcpus) != 0 )
goto vnumainfo_out;
topology.nr_vnodes = dom_vnodes;
topology.nr_vcpus = dom_vcpus;
topology.nr_vmemranges = dom_vranges;
rc = __copy_to_guest(arg, &topology, 1) ? -EFAULT : 0;
vnumainfo_out:
rcu_unlock_domain(d);
xfree(tmp.vdistance);
xfree(tmp.vmemrange);
xfree(tmp.vcpu_to_vnode);
break;
}
#ifdef CONFIG_HAS_PASSTHROUGH
case XENMEM_reserved_device_memory_map:
{
struct get_reserved_device_memory grdm;
if ( unlikely(start_extent) )
return -EINVAL;
if ( copy_from_guest(&grdm.map, arg, 1) ||
!guest_handle_okay(grdm.map.buffer, grdm.map.nr_entries) )
return -EFAULT;
if ( grdm.map.flags & ~XENMEM_RDM_ALL )
return -EINVAL;
grdm.used_entries = 0;
rc = iommu_get_reserved_device_memory(get_reserved_device_memory,
&grdm);
if ( !rc && grdm.map.nr_entries < grdm.used_entries )
rc = -ENOBUFS;
grdm.map.nr_entries = grdm.used_entries;
if ( __copy_to_guest(arg, &grdm.map, 1) )
rc = -EFAULT;
break;
}
#endif
case XENMEM_acquire_resource:
rc = acquire_resource(
guest_handle_cast(arg, xen_mem_acquire_resource_t));
break;
default:
rc = arch_memory_op(cmd, arg);
break;
}
return rc;
}
void clear_domain_page(mfn_t mfn)
{
void *ptr = map_domain_page(mfn);
clear_page(ptr);
unmap_domain_page(ptr);
}
void copy_domain_page(mfn_t dest, mfn_t source)
{
const void *src = map_domain_page(source);
void *dst = map_domain_page(dest);
copy_page(dst, src);
unmap_domain_page(dst);
unmap_domain_page(src);
}
void destroy_ring_for_helper(
void **_va, struct page_info *page)
{
void *va = *_va;
if ( va != NULL )
{
unmap_domain_page_global(va);
put_page_and_type(page);
*_va = NULL;
}
}
/*
* Acquire a pointer to struct page_info for a specified domain and GFN,
* checking whether the page has been paged out, or needs unsharing.
* If the function succeeds then zero is returned, page_p is written
* with a pointer to the struct page_info with a reference taken, and
* p2mt_p it is written with the P2M type of the page. The caller is
* responsible for dropping the reference.
* If the function fails then an appropriate errno is returned and the
* values referenced by page_p and p2mt_p are undefined.
*/
int check_get_page_from_gfn(struct domain *d, gfn_t gfn, bool readonly,
p2m_type_t *p2mt_p, struct page_info **page_p)
{
p2m_query_t q = readonly ? P2M_ALLOC : P2M_UNSHARE;
p2m_type_t p2mt;
struct page_info *page;
page = get_page_from_gfn(d, gfn_x(gfn), &p2mt, q);
#ifdef CONFIG_HAS_MEM_PAGING
if ( p2m_is_paging(p2mt) )
{
if ( page )
put_page(page);
p2m_mem_paging_populate(d, gfn_x(gfn));
return -EAGAIN;
}
#endif
#ifdef CONFIG_HAS_MEM_SHARING
if ( (q & P2M_UNSHARE) && p2m_is_shared(p2mt) )
{
if ( page )
put_page(page);
return -EAGAIN;
}
#endif
if ( !page )
return -EINVAL;
*p2mt_p = p2mt;
*page_p = page;
return 0;
}
int prepare_ring_for_helper(
struct domain *d, unsigned long gmfn, struct page_info **_page,
void **_va)
{
p2m_type_t p2mt;
struct page_info *page;
void *va;
int rc;
rc = check_get_page_from_gfn(d, _gfn(gmfn), false, &p2mt, &page);
if ( rc )
return (rc == -EAGAIN) ? -ENOENT : rc;
if ( !get_page_type(page, PGT_writable_page) )
{
put_page(page);
return -EINVAL;
}
va = __map_domain_page_global(page);
if ( va == NULL )
{
put_page_and_type(page);
return -ENOMEM;
}
*_va = va;
*_page = page;
return 0;
}
/*
* Local variables:
* mode: C
* c-file-style: "BSD"
* c-basic-offset: 4
* tab-width: 4
* indent-tabs-mode: nil
* End:
*/
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