static bool __init early_alloc_p2m(unsigned long pfn)
{
unsigned topidx = p2m_top_index(pfn);
unsigned long *mid_mfn_p;
unsigned long **mid;
mid = p2m_top[topidx];
mid_mfn_p = p2m_top_mfn_p[topidx];
if (mid == p2m_mid_missing) {
mid = extend_brk(PAGE_SIZE, PAGE_SIZE);
p2m_mid_init(mid);
p2m_top[topidx] = mid;
BUG_ON(mid_mfn_p != p2m_mid_missing_mfn);
}
/* And the save/restore P2M tables.. */
if (mid_mfn_p == p2m_mid_missing_mfn) {
mid_mfn_p = extend_brk(PAGE_SIZE, PAGE_SIZE);
p2m_mid_mfn_init(mid_mfn_p);
p2m_top_mfn_p[topidx] = mid_mfn_p;
p2m_top_mfn[topidx] = virt_to_mfn(mid_mfn_p);
/* Note: we don't set mid_mfn_p[midix] here,
* look in early_alloc_p2m_middle */
}
return true;
}
/*
* Build the parallel p2m_top_mfn and p2m_mid_mfn structures
*
* This is called both at boot time, and after resuming from suspend:
* - At boot time we're called rather early, and must use alloc_bootmem*()
* to allocate memory.
*
* - After resume we're called from within stop_machine, but the mfn
* tree should already be completely allocated.
*/
void __ref xen_build_mfn_list_list(void)
{
unsigned long pfn, mfn;
pte_t *ptep;
unsigned int level, topidx, mididx;
unsigned long *mid_mfn_p;
if (xen_feature(XENFEAT_auto_translated_physmap))
return;
/* Pre-initialize p2m_top_mfn to be completely missing */
if (p2m_top_mfn == NULL) {
p2m_mid_missing_mfn = alloc_p2m_page();
p2m_mid_mfn_init(p2m_mid_missing_mfn, p2m_missing);
p2m_top_mfn_p = alloc_p2m_page();
p2m_top_mfn_p_init(p2m_top_mfn_p);
p2m_top_mfn = alloc_p2m_page();
p2m_top_mfn_init(p2m_top_mfn);
} else {
/* Reinitialise, mfn's all change after migration */
p2m_mid_mfn_init(p2m_mid_missing_mfn, p2m_missing);
}
for (pfn = 0; pfn < xen_max_p2m_pfn && pfn < MAX_P2M_PFN;
pfn += P2M_PER_PAGE) {
topidx = p2m_top_index(pfn);
mididx = p2m_mid_index(pfn);
mid_mfn_p = p2m_top_mfn_p[topidx];
ptep = lookup_address((unsigned long)(xen_p2m_addr + pfn),
&level);
BUG_ON(!ptep || level != PG_LEVEL_4K);
mfn = pte_mfn(*ptep);
ptep = (pte_t *)((unsigned long)ptep & ~(PAGE_SIZE - 1));
/* Don't bother allocating any mfn mid levels if
* they're just missing, just update the stored mfn,
* since all could have changed over a migrate.
*/
if (ptep == p2m_missing_pte || ptep == p2m_identity_pte) {
BUG_ON(mididx);
BUG_ON(mid_mfn_p != p2m_mid_missing_mfn);
p2m_top_mfn[topidx] = virt_to_mfn(p2m_mid_missing_mfn);
pfn += (P2M_MID_PER_PAGE - 1) * P2M_PER_PAGE;
continue;
}
if (mid_mfn_p == p2m_mid_missing_mfn) {
mid_mfn_p = alloc_p2m_page();
p2m_mid_mfn_init(mid_mfn_p, p2m_missing);
p2m_top_mfn_p[topidx] = mid_mfn_p;
}
p2m_top_mfn[topidx] = virt_to_mfn(mid_mfn_p);
mid_mfn_p[mididx] = mfn;
}
}
unsigned long __init set_phys_range_identity(unsigned long pfn_s,
unsigned long pfn_e)
{
unsigned long pfn;
if (unlikely(pfn_s >= MAX_P2M_PFN || pfn_e >= MAX_P2M_PFN))
return 0;
if (unlikely(xen_feature(XENFEAT_auto_translated_physmap)))
return pfn_e - pfn_s;
if (pfn_s > pfn_e)
return 0;
for (pfn = (pfn_s & ~(P2M_MID_PER_PAGE * P2M_PER_PAGE - 1));
pfn < ALIGN(pfn_e, (P2M_MID_PER_PAGE * P2M_PER_PAGE));
pfn += P2M_MID_PER_PAGE * P2M_PER_PAGE)
{
unsigned topidx = p2m_top_index(pfn);
unsigned long *mid_mfn_p;
unsigned long **mid;
mid = p2m_top[topidx];
mid_mfn_p = p2m_top_mfn_p[topidx];
if (mid == p2m_mid_missing) {
mid = extend_brk(PAGE_SIZE, PAGE_SIZE);
p2m_mid_init(mid);
p2m_top[topidx] = mid;
BUG_ON(mid_mfn_p != p2m_mid_missing_mfn);
}
if (mid_mfn_p == p2m_mid_missing_mfn) {
mid_mfn_p = extend_brk(PAGE_SIZE, PAGE_SIZE);
p2m_mid_mfn_init(mid_mfn_p);
p2m_top_mfn_p[topidx] = mid_mfn_p;
p2m_top_mfn[topidx] = virt_to_mfn(mid_mfn_p);
}
}
__early_alloc_p2m(pfn_s);
__early_alloc_p2m(pfn_e);
for (pfn = pfn_s; pfn < pfn_e; pfn++)
if (!__set_phys_to_machine(pfn, IDENTITY_FRAME(pfn)))
break;
if (!WARN((pfn - pfn_s) != (pfn_e - pfn_s),
"Identity mapping failed. We are %ld short of 1-1 mappings!\n",
(pfn_e - pfn_s) - (pfn - pfn_s)))
printk(KERN_DEBUG "1-1 mapping on %lx->%lx\n", pfn_s, pfn);
return pfn - pfn_s;
}
/*
* Build the parallel p2m_top_mfn and p2m_mid_mfn structures
*
* This is called both at boot time, and after resuming from suspend:
* - At boot time we're called very early, and must use extend_brk()
* to allocate memory.
*
* - After resume we're called from within stop_machine, but the mfn
* tree should alreay be completely allocated.
*/
void __ref xen_build_mfn_list_list(void)
{
unsigned long pfn;
/* Pre-initialize p2m_top_mfn to be completely missing */
if (p2m_top_mfn == NULL) {
p2m_mid_missing_mfn = extend_brk(PAGE_SIZE, PAGE_SIZE);
p2m_mid_mfn_init(p2m_mid_missing_mfn);
p2m_top_mfn_p = extend_brk(PAGE_SIZE, PAGE_SIZE);
p2m_top_mfn_p_init(p2m_top_mfn_p);
p2m_top_mfn = extend_brk(PAGE_SIZE, PAGE_SIZE);
p2m_top_mfn_init(p2m_top_mfn);
} else {
/* Reinitialise, mfn's all change after migration */
p2m_mid_mfn_init(p2m_mid_missing_mfn);
}
for (pfn = 0; pfn < xen_max_p2m_pfn; pfn += P2M_PER_PAGE) {
unsigned topidx = p2m_top_index(pfn);
unsigned mididx = p2m_mid_index(pfn);
unsigned long **mid;
unsigned long *mid_mfn_p;
mid = p2m_top[topidx];
mid_mfn_p = p2m_top_mfn_p[topidx];
/* Don't bother allocating any mfn mid levels if
* they're just missing, just update the stored mfn,
* since all could have changed over a migrate.
*/
if (mid == p2m_mid_missing) {
BUG_ON(mididx);
BUG_ON(mid_mfn_p != p2m_mid_missing_mfn);
p2m_top_mfn[topidx] = virt_to_mfn(p2m_mid_missing_mfn);
pfn += (P2M_MID_PER_PAGE - 1) * P2M_PER_PAGE;
continue;
}
if (mid_mfn_p == p2m_mid_missing_mfn) {
/*
* XXX boot-time only! We should never find
* missing parts of the mfn tree after
* runtime. extend_brk() will BUG if we call
* it too late.
*/
mid_mfn_p = extend_brk(PAGE_SIZE, PAGE_SIZE);
p2m_mid_mfn_init(mid_mfn_p);
p2m_top_mfn_p[topidx] = mid_mfn_p;
}
p2m_top_mfn[topidx] = virt_to_mfn(mid_mfn_p);
mid_mfn_p[mididx] = virt_to_mfn(mid[mididx]);
}
}
unsigned long get_phys_to_machine(unsigned long pfn)
{
unsigned topidx, idx;
if (unlikely(pfn >= MAX_DOMAIN_PAGES))
return INVALID_P2M_ENTRY;
topidx = p2m_top_index(pfn);
idx = p2m_index(pfn);
return p2m_top[topidx][idx];
}
/* Set up p2m_top to point to the domain-builder provided p2m pages */
void __init xen_build_dynamic_phys_to_machine(void)
{
unsigned long *mfn_list = (unsigned long *)xen_start_info->mfn_list;
unsigned long max_pfn = min(MAX_DOMAIN_PAGES, xen_start_info->nr_pages);
unsigned long pfn;
xen_max_p2m_pfn = max_pfn;
p2m_missing = extend_brk(PAGE_SIZE, PAGE_SIZE);
p2m_init(p2m_missing);
p2m_mid_missing = extend_brk(PAGE_SIZE, PAGE_SIZE);
p2m_mid_init(p2m_mid_missing);
p2m_top = extend_brk(PAGE_SIZE, PAGE_SIZE);
p2m_top_init(p2m_top);
p2m_identity = extend_brk(PAGE_SIZE, PAGE_SIZE);
p2m_init(p2m_identity);
/*
* The domain builder gives us a pre-constructed p2m array in
* mfn_list for all the pages initially given to us, so we just
* need to graft that into our tree structure.
*/
for (pfn = 0; pfn < max_pfn; pfn += P2M_PER_PAGE) {
unsigned topidx = p2m_top_index(pfn);
unsigned mididx = p2m_mid_index(pfn);
if (p2m_top[topidx] == p2m_mid_missing) {
unsigned long **mid = extend_brk(PAGE_SIZE, PAGE_SIZE);
p2m_mid_init(mid);
p2m_top[topidx] = mid;
}
/*
* As long as the mfn_list has enough entries to completely
* fill a p2m page, pointing into the array is ok. But if
* not the entries beyond the last pfn will be undefined.
*/
if (unlikely(pfn + P2M_PER_PAGE > max_pfn)) {
unsigned long p2midx;
p2midx = max_pfn % P2M_PER_PAGE;
for ( ; p2midx < P2M_PER_PAGE; p2midx++)
mfn_list[pfn + p2midx] = INVALID_P2M_ENTRY;
}
p2m_top[topidx][mididx] = &mfn_list[pfn];
}
m2p_override_init();
}
/* Set up p2m_top to point to the domain-builder provided p2m pages */
void __init xen_build_dynamic_phys_to_machine(void)
{
unsigned long *mfn_list = (unsigned long *)xen_start_info->mfn_list;
unsigned long max_pfn = min(MAX_DOMAIN_PAGES, xen_start_info->nr_pages);
unsigned pfn;
for (pfn = 0; pfn < max_pfn; pfn += P2M_ENTRIES_PER_PAGE) {
unsigned topidx = p2m_top_index(pfn);
p2m_top[topidx] = &mfn_list[pfn];
}
xen_build_mfn_list_list();
}
/* Build the parallel p2m_top_mfn structures */
static void __init xen_build_mfn_list_list(void)
{
unsigned pfn, idx;
for (pfn = 0; pfn < MAX_DOMAIN_PAGES; pfn += P2M_ENTRIES_PER_PAGE) {
unsigned topidx = p2m_top_index(pfn);
p2m_top_mfn[topidx] = virt_to_mfn(p2m_top[topidx]);
}
for (idx = 0; idx < ARRAY_SIZE(p2m_top_mfn_list); idx++) {
unsigned topidx = idx * P2M_ENTRIES_PER_PAGE;
p2m_top_mfn_list[idx] = virt_to_mfn(&p2m_top_mfn[topidx]);
}
}
unsigned long get_phys_to_machine(unsigned long pfn)
{
unsigned topidx, mididx, idx;
if (unlikely(pfn >= MAX_P2M_PFN))
return INVALID_P2M_ENTRY;
topidx = p2m_top_index(pfn);
mididx = p2m_mid_index(pfn);
idx = p2m_index(pfn);
if (p2m_top[topidx][mididx] == p2m_identity)
return IDENTITY_FRAME(pfn);
return p2m_top[topidx][mididx][idx];
}
void __ref xen_build_mfn_list_list(void)
{
unsigned long pfn;
if (p2m_top_mfn == NULL) {
p2m_mid_missing_mfn = extend_brk(PAGE_SIZE, PAGE_SIZE);
p2m_mid_mfn_init(p2m_mid_missing_mfn);
p2m_top_mfn_p = extend_brk(PAGE_SIZE, PAGE_SIZE);
p2m_top_mfn_p_init(p2m_top_mfn_p);
p2m_top_mfn = extend_brk(PAGE_SIZE, PAGE_SIZE);
p2m_top_mfn_init(p2m_top_mfn);
} else {
p2m_mid_mfn_init(p2m_mid_missing_mfn);
}
for (pfn = 0; pfn < xen_max_p2m_pfn; pfn += P2M_PER_PAGE) {
unsigned topidx = p2m_top_index(pfn);
unsigned mididx = p2m_mid_index(pfn);
unsigned long **mid;
unsigned long *mid_mfn_p;
mid = p2m_top[topidx];
mid_mfn_p = p2m_top_mfn_p[topidx];
if (mid == p2m_mid_missing) {
BUG_ON(mididx);
BUG_ON(mid_mfn_p != p2m_mid_missing_mfn);
p2m_top_mfn[topidx] = virt_to_mfn(p2m_mid_missing_mfn);
pfn += (P2M_MID_PER_PAGE - 1) * P2M_PER_PAGE;
continue;
}
if (mid_mfn_p == p2m_mid_missing_mfn) {
mid_mfn_p = extend_brk(PAGE_SIZE, PAGE_SIZE);
p2m_mid_mfn_init(mid_mfn_p);
p2m_top_mfn_p[topidx] = mid_mfn_p;
}
p2m_top_mfn[topidx] = virt_to_mfn(mid_mfn_p);
mid_mfn_p[mididx] = virt_to_mfn(mid[mididx]);
}
}
void __init xen_build_dynamic_phys_to_machine(void)
{
unsigned long *mfn_list = (unsigned long *)xen_start_info->mfn_list;
unsigned long max_pfn = min(MAX_DOMAIN_PAGES, xen_start_info->nr_pages);
unsigned long pfn;
xen_max_p2m_pfn = max_pfn;
p2m_missing = extend_brk(PAGE_SIZE, PAGE_SIZE);
p2m_init(p2m_missing);
p2m_mid_missing = extend_brk(PAGE_SIZE, PAGE_SIZE);
p2m_mid_init(p2m_mid_missing);
p2m_top = extend_brk(PAGE_SIZE, PAGE_SIZE);
p2m_top_init(p2m_top);
p2m_identity = extend_brk(PAGE_SIZE, PAGE_SIZE);
p2m_init(p2m_identity);
for (pfn = 0; pfn < max_pfn; pfn += P2M_PER_PAGE) {
unsigned topidx = p2m_top_index(pfn);
unsigned mididx = p2m_mid_index(pfn);
if (p2m_top[topidx] == p2m_mid_missing) {
unsigned long **mid = extend_brk(PAGE_SIZE, PAGE_SIZE);
p2m_mid_init(mid);
p2m_top[topidx] = mid;
}
if (unlikely(pfn + P2M_PER_PAGE > max_pfn)) {
unsigned long p2midx;
p2midx = max_pfn % P2M_PER_PAGE;
for ( ; p2midx < P2M_PER_PAGE; p2midx++)
mfn_list[pfn + p2midx] = INVALID_P2M_ENTRY;
}
p2m_top[topidx][mididx] = &mfn_list[pfn];
}
m2p_override_init();
}
/* install a new p2m_top page */
bool install_p2mtop_page(unsigned long pfn, unsigned long *p)
{
unsigned topidx = p2m_top_index(pfn);
unsigned long **pfnp, *mfnp;
unsigned i;
pfnp = &p2m_top[topidx];
mfnp = &p2m_top_mfn[topidx];
for (i = 0; i < P2M_ENTRIES_PER_PAGE; i++)
p[i] = INVALID_P2M_ENTRY;
if (cmpxchg(pfnp, p2m_missing, p) == p2m_missing) {
*mfnp = virt_to_mfn(p);
return true;
}
return false;
}
static bool __init early_alloc_p2m_middle(unsigned long pfn, bool check_boundary)
{
unsigned topidx, mididx, idx;
unsigned long *p2m;
unsigned long *mid_mfn_p;
topidx = p2m_top_index(pfn);
mididx = p2m_mid_index(pfn);
idx = p2m_index(pfn);
/* Pfff.. No boundary cross-over, lets get out. */
if (!idx && check_boundary)
return false;
WARN(p2m_top[topidx][mididx] == p2m_identity,
"P2M[%d][%d] == IDENTITY, should be MISSING (or alloced)!\n",
topidx, mididx);
/*
* Could be done by xen_build_dynamic_phys_to_machine..
*/
if (p2m_top[topidx][mididx] != p2m_missing)
return false;
/* Boundary cross-over for the edges: */
p2m = extend_brk(PAGE_SIZE, PAGE_SIZE);
p2m_init(p2m);
p2m_top[topidx][mididx] = p2m;
/* For save/restore we need to MFN of the P2M saved */
mid_mfn_p = p2m_top_mfn_p[topidx];
WARN(mid_mfn_p[mididx] != virt_to_mfn(p2m_missing),
"P2M_TOP_P[%d][%d] != MFN of p2m_missing!\n",
topidx, mididx);
mid_mfn_p[mididx] = virt_to_mfn(p2m);
return true;
}
/* Try to install p2m mapping; fail if intermediate bits missing */
bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn)
{
unsigned topidx, idx;
if (unlikely(pfn >= MAX_DOMAIN_PAGES)) {
BUG_ON(mfn != INVALID_P2M_ENTRY);
return true;
}
topidx = p2m_top_index(pfn);
if (p2m_top[topidx] == p2m_missing) {
if (mfn == INVALID_P2M_ENTRY)
return true;
return false;
}
idx = p2m_index(pfn);
p2m_top[topidx][idx] = mfn;
return true;
}
unsigned long get_phys_to_machine(unsigned long pfn)
{
unsigned topidx, mididx, idx;
if (unlikely(pfn >= MAX_P2M_PFN))
return INVALID_P2M_ENTRY;
topidx = p2m_top_index(pfn);
mididx = p2m_mid_index(pfn);
idx = p2m_index(pfn);
/*
* The INVALID_P2M_ENTRY is filled in both p2m_*identity
* and in p2m_*missing, so returning the INVALID_P2M_ENTRY
* would be wrong.
*/
if (p2m_top[topidx][mididx] == p2m_identity)
return IDENTITY_FRAME(pfn);
return p2m_top[topidx][mididx][idx];
}
static bool __init __early_alloc_p2m(unsigned long pfn)
{
unsigned topidx, mididx, idx;
topidx = p2m_top_index(pfn);
mididx = p2m_mid_index(pfn);
idx = p2m_index(pfn);
if (!idx)
return false;
WARN(p2m_top[topidx][mididx] == p2m_identity,
"P2M[%d][%d] == IDENTITY, should be MISSING (or alloced)!\n",
topidx, mididx);
if (p2m_top[topidx][mididx] != p2m_missing)
return false;
if (idx) {
unsigned long *p2m = extend_brk(PAGE_SIZE, PAGE_SIZE);
unsigned long *mid_mfn_p;
p2m_init(p2m);
p2m_top[topidx][mididx] = p2m;
mid_mfn_p = p2m_top_mfn_p[topidx];
WARN(mid_mfn_p[mididx] != virt_to_mfn(p2m_missing),
"P2M_TOP_P[%d][%d] != MFN of p2m_missing!\n",
topidx, mididx);
mid_mfn_p[mididx] = virt_to_mfn(p2m);
}
return idx != 0;
}
/* Try to install p2m mapping; fail if intermediate bits missing */
bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn)
{
unsigned topidx, mididx, idx;
if (unlikely(xen_feature(XENFEAT_auto_translated_physmap))) {
BUG_ON(pfn != mfn && mfn != INVALID_P2M_ENTRY);
return true;
}
if (unlikely(pfn >= MAX_P2M_PFN)) {
BUG_ON(mfn != INVALID_P2M_ENTRY);
return true;
}
topidx = p2m_top_index(pfn);
mididx = p2m_mid_index(pfn);
idx = p2m_index(pfn);
/* For sparse holes were the p2m leaf has real PFN along with
* PCI holes, stick in the PFN as the MFN value.
*/
if (mfn != INVALID_P2M_ENTRY && (mfn & IDENTITY_FRAME_BIT)) {
if (p2m_top[topidx][mididx] == p2m_identity)
return true;
/* Swap over from MISSING to IDENTITY if needed. */
if (p2m_top[topidx][mididx] == p2m_missing) {
WARN_ON(cmpxchg(&p2m_top[topidx][mididx], p2m_missing,
p2m_identity) != p2m_missing);
return true;
}
}
if (p2m_top[topidx][mididx] == p2m_missing)
return mfn == INVALID_P2M_ENTRY;
p2m_top[topidx][mididx][idx] = mfn;
return true;
}
bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn)
{
unsigned topidx, mididx, idx;
if (unlikely(xen_feature(XENFEAT_auto_translated_physmap))) {
BUG_ON(pfn != mfn && mfn != INVALID_P2M_ENTRY);
return true;
}
if (unlikely(pfn >= MAX_P2M_PFN)) {
BUG_ON(mfn != INVALID_P2M_ENTRY);
return true;
}
topidx = p2m_top_index(pfn);
mididx = p2m_mid_index(pfn);
idx = p2m_index(pfn);
if (mfn != INVALID_P2M_ENTRY && (mfn & IDENTITY_FRAME_BIT)) {
if (p2m_top[topidx][mididx] == p2m_identity)
return true;
if (p2m_top[topidx][mididx] == p2m_missing) {
WARN_ON(cmpxchg(&p2m_top[topidx][mididx], p2m_missing,
p2m_identity) != p2m_missing);
return true;
}
}
if (p2m_top[topidx][mididx] == p2m_missing)
return mfn == INVALID_P2M_ENTRY;
p2m_top[topidx][mididx][idx] = mfn;
return true;
}
/*
* Fully allocate the p2m structure for a given pfn. We need to check
* that both the top and mid levels are allocated, and make sure the
* parallel mfn tree is kept in sync. We may race with other cpus, so
* the new pages are installed with cmpxchg; if we lose the race then
* simply free the page we allocated and use the one that's there.
*/
static bool alloc_p2m(unsigned long pfn)
{
unsigned topidx, mididx;
unsigned long ***top_p, **mid;
unsigned long *top_mfn_p, *mid_mfn;
topidx = p2m_top_index(pfn);
mididx = p2m_mid_index(pfn);
top_p = &p2m_top[topidx];
mid = *top_p;
if (mid == p2m_mid_missing) {
/* Mid level is missing, allocate a new one */
mid = alloc_p2m_page();
if (!mid)
return false;
p2m_mid_init(mid);
if (cmpxchg(top_p, p2m_mid_missing, mid) != p2m_mid_missing)
free_p2m_page(mid);
}
top_mfn_p = &p2m_top_mfn[topidx];
mid_mfn = p2m_top_mfn_p[topidx];
BUG_ON(virt_to_mfn(mid_mfn) != *top_mfn_p);
if (mid_mfn == p2m_mid_missing_mfn) {
/* Separately check the mid mfn level */
unsigned long missing_mfn;
unsigned long mid_mfn_mfn;
mid_mfn = alloc_p2m_page();
if (!mid_mfn)
return false;
p2m_mid_mfn_init(mid_mfn);
missing_mfn = virt_to_mfn(p2m_mid_missing_mfn);
mid_mfn_mfn = virt_to_mfn(mid_mfn);
if (cmpxchg(top_mfn_p, missing_mfn, mid_mfn_mfn) != missing_mfn)
free_p2m_page(mid_mfn);
else
p2m_top_mfn_p[topidx] = mid_mfn;
}
if (p2m_top[topidx][mididx] == p2m_identity ||
p2m_top[topidx][mididx] == p2m_missing) {
/* p2m leaf page is missing */
unsigned long *p2m;
unsigned long *p2m_orig = p2m_top[topidx][mididx];
p2m = alloc_p2m_page();
if (!p2m)
return false;
p2m_init(p2m);
if (cmpxchg(&mid[mididx], p2m_orig, p2m) != p2m_orig)
free_p2m_page(p2m);
else
mid_mfn[mididx] = virt_to_mfn(p2m);
}
return true;
}
static int p2m_dump_show(struct seq_file *m, void *v)
{
static const char * const level_name[] = { "top", "middle",
"entry", "abnormal", "error"};
#define TYPE_IDENTITY 0
#define TYPE_MISSING 1
#define TYPE_PFN 2
#define TYPE_UNKNOWN 3
static const char * const type_name[] = {
[TYPE_IDENTITY] = "identity",
[TYPE_MISSING] = "missing",
[TYPE_PFN] = "pfn",
[TYPE_UNKNOWN] = "abnormal"};
unsigned long pfn, prev_pfn_type = 0, prev_pfn_level = 0;
unsigned int uninitialized_var(prev_level);
unsigned int uninitialized_var(prev_type);
if (!p2m_top)
return 0;
for (pfn = 0; pfn < MAX_DOMAIN_PAGES; pfn++) {
unsigned topidx = p2m_top_index(pfn);
unsigned mididx = p2m_mid_index(pfn);
unsigned idx = p2m_index(pfn);
unsigned lvl, type;
lvl = 4;
type = TYPE_UNKNOWN;
if (p2m_top[topidx] == p2m_mid_missing) {
lvl = 0; type = TYPE_MISSING;
} else if (p2m_top[topidx] == NULL) {
lvl = 0; type = TYPE_UNKNOWN;
} else if (p2m_top[topidx][mididx] == NULL) {
lvl = 1; type = TYPE_UNKNOWN;
} else if (p2m_top[topidx][mididx] == p2m_identity) {
lvl = 1; type = TYPE_IDENTITY;
} else if (p2m_top[topidx][mididx] == p2m_missing) {
lvl = 1; type = TYPE_MISSING;
} else if (p2m_top[topidx][mididx][idx] == 0) {
lvl = 2; type = TYPE_UNKNOWN;
} else if (p2m_top[topidx][mididx][idx] == IDENTITY_FRAME(pfn)) {
lvl = 2; type = TYPE_IDENTITY;
} else if (p2m_top[topidx][mididx][idx] == INVALID_P2M_ENTRY) {
lvl = 2; type = TYPE_MISSING;
} else if (p2m_top[topidx][mididx][idx] == pfn) {
lvl = 2; type = TYPE_PFN;
} else if (p2m_top[topidx][mididx][idx] != pfn) {
lvl = 2; type = TYPE_PFN;
}
if (pfn == 0) {
prev_level = lvl;
prev_type = type;
}
if (pfn == MAX_DOMAIN_PAGES-1) {
lvl = 3;
type = TYPE_UNKNOWN;
}
if (prev_type != type) {
seq_printf(m, " [0x%lx->0x%lx] %s\n",
prev_pfn_type, pfn, type_name[prev_type]);
prev_pfn_type = pfn;
prev_type = type;
}
if (prev_level != lvl) {
seq_printf(m, " [0x%lx->0x%lx] level %s\n",
prev_pfn_level, pfn, level_name[prev_level]);
prev_pfn_level = pfn;
prev_level = lvl;
}
}
return 0;
#undef TYPE_IDENTITY
#undef TYPE_MISSING
#undef TYPE_PFN
#undef TYPE_UNKNOWN
}
/*
* Fully allocate the p2m structure for a given pfn. We need to check
* that both the top and mid levels are allocated, and make sure the
* parallel mfn tree is kept in sync. We may race with other cpus, so
* the new pages are installed with cmpxchg; if we lose the race then
* simply free the page we allocated and use the one that's there.
*/
static bool alloc_p2m(unsigned long pfn)
{
unsigned topidx;
unsigned long *top_mfn_p, *mid_mfn;
pte_t *ptep, *pte_pg;
unsigned int level;
unsigned long flags;
unsigned long addr = (unsigned long)(xen_p2m_addr + pfn);
unsigned long p2m_pfn;
ptep = lookup_address(addr, &level);
BUG_ON(!ptep || level != PG_LEVEL_4K);
pte_pg = (pte_t *)((unsigned long)ptep & ~(PAGE_SIZE - 1));
if (pte_pg == p2m_missing_pte || pte_pg == p2m_identity_pte) {
/* PMD level is missing, allocate a new one */
ptep = alloc_p2m_pmd(addr, pte_pg);
if (!ptep)
return false;
}
if (p2m_top_mfn && pfn < MAX_P2M_PFN) {
topidx = p2m_top_index(pfn);
top_mfn_p = &p2m_top_mfn[topidx];
mid_mfn = ACCESS_ONCE(p2m_top_mfn_p[topidx]);
BUG_ON(virt_to_mfn(mid_mfn) != *top_mfn_p);
if (mid_mfn == p2m_mid_missing_mfn) {
/* Separately check the mid mfn level */
unsigned long missing_mfn;
unsigned long mid_mfn_mfn;
unsigned long old_mfn;
mid_mfn = alloc_p2m_page();
if (!mid_mfn)
return false;
p2m_mid_mfn_init(mid_mfn, p2m_missing);
missing_mfn = virt_to_mfn(p2m_mid_missing_mfn);
mid_mfn_mfn = virt_to_mfn(mid_mfn);
old_mfn = cmpxchg(top_mfn_p, missing_mfn, mid_mfn_mfn);
if (old_mfn != missing_mfn) {
free_p2m_page(mid_mfn);
mid_mfn = mfn_to_virt(old_mfn);
} else {
p2m_top_mfn_p[topidx] = mid_mfn;
}
}
} else {
mid_mfn = NULL;
}
p2m_pfn = pte_pfn(READ_ONCE(*ptep));
if (p2m_pfn == PFN_DOWN(__pa(p2m_identity)) ||
p2m_pfn == PFN_DOWN(__pa(p2m_missing))) {
/* p2m leaf page is missing */
unsigned long *p2m;
p2m = alloc_p2m_page();
if (!p2m)
return false;
if (p2m_pfn == PFN_DOWN(__pa(p2m_missing)))
p2m_init(p2m);
else
p2m_init_identity(p2m, pfn & ~(P2M_PER_PAGE - 1));
spin_lock_irqsave(&p2m_update_lock, flags);
if (pte_pfn(*ptep) == p2m_pfn) {
HYPERVISOR_shared_info->arch.p2m_generation++;
wmb(); /* Tools are synchronizing via p2m_generation. */
set_pte(ptep,
pfn_pte(PFN_DOWN(__pa(p2m)), PAGE_KERNEL));
wmb(); /* Tools are synchronizing via p2m_generation. */
HYPERVISOR_shared_info->arch.p2m_generation++;
if (mid_mfn)
mid_mfn[p2m_mid_index(pfn)] = virt_to_mfn(p2m);
p2m = NULL;
}
spin_unlock_irqrestore(&p2m_update_lock, flags);
if (p2m)
free_p2m_page(p2m);
}
/* Expanded the p2m? */
if (pfn > xen_p2m_last_pfn) {
xen_p2m_last_pfn = pfn;
HYPERVISOR_shared_info->arch.max_pfn = xen_p2m_last_pfn;
}
return true;
}
/*
* Skim over the P2M tree looking at pages that are either filled with
* INVALID_P2M_ENTRY or with 1:1 PFNs. If found, re-use that page and
* replace the P2M leaf with a p2m_missing or p2m_identity.
* Stick the old page in the new P2M tree location.
*/
bool __init early_can_reuse_p2m_middle(unsigned long set_pfn, unsigned long set_mfn)
{
unsigned topidx;
unsigned mididx;
unsigned ident_pfns;
unsigned inv_pfns;
unsigned long *p2m;
unsigned long *mid_mfn_p;
unsigned idx;
unsigned long pfn;
/* We only look when this entails a P2M middle layer */
if (p2m_index(set_pfn))
return false;
for (pfn = 0; pfn <= MAX_DOMAIN_PAGES; pfn += P2M_PER_PAGE) {
topidx = p2m_top_index(pfn);
if (!p2m_top[topidx])
continue;
if (p2m_top[topidx] == p2m_mid_missing)
continue;
mididx = p2m_mid_index(pfn);
p2m = p2m_top[topidx][mididx];
if (!p2m)
continue;
if ((p2m == p2m_missing) || (p2m == p2m_identity))
continue;
if ((unsigned long)p2m == INVALID_P2M_ENTRY)
continue;
ident_pfns = 0;
inv_pfns = 0;
for (idx = 0; idx < P2M_PER_PAGE; idx++) {
/* IDENTITY_PFNs are 1:1 */
if (p2m[idx] == IDENTITY_FRAME(pfn + idx))
ident_pfns++;
else if (p2m[idx] == INVALID_P2M_ENTRY)
inv_pfns++;
else
break;
}
if ((ident_pfns == P2M_PER_PAGE) || (inv_pfns == P2M_PER_PAGE))
goto found;
}
return false;
found:
/* Found one, replace old with p2m_identity or p2m_missing */
p2m_top[topidx][mididx] = (ident_pfns ? p2m_identity : p2m_missing);
/* And the other for save/restore.. */
mid_mfn_p = p2m_top_mfn_p[topidx];
/* NOTE: Even if it is a p2m_identity it should still be point to
* a page filled with INVALID_P2M_ENTRY entries. */
mid_mfn_p[mididx] = virt_to_mfn(p2m_missing);
/* Reset where we want to stick the old page in. */
topidx = p2m_top_index(set_pfn);
mididx = p2m_mid_index(set_pfn);
/* This shouldn't happen */
if (WARN_ON(p2m_top[topidx] == p2m_mid_missing))
early_alloc_p2m(set_pfn);
if (WARN_ON(p2m_top[topidx][mididx] != p2m_missing))
return false;
p2m_init(p2m);
p2m_top[topidx][mididx] = p2m;
mid_mfn_p = p2m_top_mfn_p[topidx];
mid_mfn_p[mididx] = virt_to_mfn(p2m);
return true;
}
