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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen-unstable] [IA64] memory exchange: support memory exchange
# HG changeset patch
# User awilliam@xxxxxxxxxxx
# Node ID 39562deee9b8e8aa8c7e9217ef0b389c44e975fb
# Parent 056622b0f8f7ccfe0cbdb86128f6409cb887f465
[IA64] memory exchange: support memory exchange
Signed-off-by: Isaku Yamahata <yamahata@xxxxxxxxxxxxx>
---
xen/arch/ia64/xen/mm.c | 124 +++++++++++++++++++++++++++++++------------------
1 files changed, 80 insertions(+), 44 deletions(-)
diff -r 056622b0f8f7 -r 39562deee9b8 xen/arch/ia64/xen/mm.c
--- a/xen/arch/ia64/xen/mm.c Fri Jun 23 15:13:54 2006 -0600
+++ b/xen/arch/ia64/xen/mm.c Fri Jun 23 15:16:10 2006 -0600
@@ -969,7 +969,8 @@ assign_domain_page_replace(struct domain
if (mfn != old_mfn) {
struct page_info* old_page = mfn_to_page(old_mfn);
- if (page_get_owner(old_page) == d) {
+ if (page_get_owner(old_page) == d ||
+ page_get_owner(old_page) == NULL) {
BUG_ON(get_gpfn_from_mfn(old_mfn) != (mpaddr >> PAGE_SHIFT));
set_gpfn_from_mfn(old_mfn, INVALID_M2P_ENTRY);
}
@@ -1068,7 +1069,10 @@ zap_domain_page_one(struct domain *d, un
pte_t ret_pte;
again:
- BUG_ON(page_get_owner(mfn_to_page(mfn)) != d);
+ // memory_exchange() calls guest_physmap_remove_page() with
+ // a stealed page. i.e. page owner = NULL.
+ BUG_ON(page_get_owner(mfn_to_page(mfn)) != d &&
+ page_get_owner(mfn_to_page(mfn)) != NULL);
old_arflags = pte_val(*pte) & ~_PAGE_PPN_MASK;
old_pte = pfn_pte(mfn, __pgprot(old_arflags));
new_pte = __pte(0);
@@ -1093,14 +1097,22 @@ zap_domain_page_one(struct domain *d, un
page = mfn_to_page(mfn);
BUG_ON((page->count_info & PGC_count_mask) == 0);
- if (page_get_owner(page) == d) {
+ if (page_get_owner(page) == d ||
+ page_get_owner(page) == NULL) {
+ // exchange_memory() calls
+ // steal_page()
+ // page owner is set to NULL
+ // guest_physmap_remove_page()
+ // zap_domain_page_one()
BUG_ON(get_gpfn_from_mfn(mfn) != (mpaddr >> PAGE_SHIFT));
set_gpfn_from_mfn(mfn, INVALID_M2P_ENTRY);
}
domain_page_flush(d, mpaddr, mfn, INVALID_MFN);
- try_to_clear_PGC_allocate(d, page);
+ if (page_get_owner(page) != NULL) {
+ try_to_clear_PGC_allocate(d, page);
+ }
put_page(page);
}
@@ -1250,6 +1262,11 @@ destroy_grant_host_mapping(unsigned long
}
// heavily depends on the struct page layout.
+// gnttab_transfer() calls steal_page() with memflags = 0
+// For grant table transfer, we must fill the page.
+// memory_exchange() calls steal_page() with memflags = MEMF_no_refcount
+// For memory exchange, we don't have to fill the page because
+// memory_exchange() does it.
int
steal_page(struct domain *d, struct page_info *page, unsigned int memflags)
{
@@ -1258,40 +1275,49 @@ steal_page(struct domain *d, struct page
#endif
u32 _d, _nd;
u64 x, nx, y;
- unsigned long gpfn;
- struct page_info *new;
- unsigned long new_mfn;
- int ret;
- new = alloc_domheap_page(d);
- if (new == NULL) {
- DPRINTK("alloc_domheap_page() failed\n");
+
+ if (page_get_owner(page) != d) {
+ DPRINTK("%s d 0x%p owner 0x%p\n", __func__, d, page_get_owner(page));
return -1;
}
- // zero out pages for security reasons
- clear_page(page_to_virt(new));
- // assign_domain_page_cmpxchg_rel() has release semantics
- // so smp_mb() isn't needed.
-
- ret = get_page(new, d);
- BUG_ON(ret == 0);
-
- gpfn = get_gpfn_from_mfn(page_to_mfn(page));
- if (gpfn == INVALID_M2P_ENTRY) {
- free_domheap_page(new);
- return -1;
- }
- new_mfn = page_to_mfn(new);
- set_gpfn_from_mfn(new_mfn, gpfn);
- // smp_mb() isn't needed because assign_domain_pge_cmpxchg_rel()
- // has release semantics.
-
- ret = assign_domain_page_cmpxchg_rel(d, gpfn << PAGE_SHIFT, page, new,
- ASSIGN_writable);
- if (ret < 0) {
- DPRINTK("assign_domain_page_cmpxchg_rel failed %d\n", ret);
- set_gpfn_from_mfn(new_mfn, INVALID_M2P_ENTRY);
- free_domheap_page(new);
- return -1;
+
+ if (!(memflags & MEMF_no_refcount)) {
+ unsigned long gpfn;
+ struct page_info *new;
+ unsigned long new_mfn;
+ int ret;
+
+ new = alloc_domheap_page(d);
+ if (new == NULL) {
+ DPRINTK("alloc_domheap_page() failed\n");
+ return -1;
+ }
+ // zero out pages for security reasons
+ clear_page(page_to_virt(new));
+ // assign_domain_page_cmpxchg_rel() has release semantics
+ // so smp_mb() isn't needed.
+
+ ret = get_page(new, d);
+ BUG_ON(ret == 0);
+
+ gpfn = get_gpfn_from_mfn(page_to_mfn(page));
+ if (gpfn == INVALID_M2P_ENTRY) {
+ free_domheap_page(new);
+ return -1;
+ }
+ new_mfn = page_to_mfn(new);
+ set_gpfn_from_mfn(new_mfn, gpfn);
+ // smp_mb() isn't needed because assign_domain_pge_cmpxchg_rel()
+ // has release semantics.
+
+ ret = assign_domain_page_cmpxchg_rel(d, gpfn << PAGE_SHIFT, page, new,
+ ASSIGN_writable);
+ if (ret < 0) {
+ DPRINTK("assign_domain_page_cmpxchg_rel failed %d\n", ret);
+ set_gpfn_from_mfn(new_mfn, INVALID_M2P_ENTRY);
+ free_domheap_page(new);
+ return -1;
+ }
}
spin_lock(&d->page_alloc_lock);
@@ -1310,28 +1336,40 @@ steal_page(struct domain *d, struct page
// page->u.inused._domain = 0;
_nd = x >> 32;
- if (unlikely((x & (PGC_count_mask | PGC_allocated)) !=
- (1 | PGC_allocated)) ||
+ if (unlikely(!(memflags & MEMF_no_refcount) &&
+ ((x & (PGC_count_mask | PGC_allocated)) !=
+ (1 | PGC_allocated))) ||
+
+ // when MEMF_no_refcount, page isn't de-assigned from
+ // this domain yet. So count_info = 2
+ unlikely((memflags & MEMF_no_refcount) &&
+ ((x & (PGC_count_mask | PGC_allocated)) !=
+ (2 | PGC_allocated))) ||
+
unlikely(_nd != _d)) {
struct domain* nd = unpickle_domptr(_nd);
if (nd == NULL) {
DPRINTK("gnttab_transfer: Bad page %p: ed=%p(%u) 0x%x, "
"sd=%p 0x%x,"
- " caf=%016lx, taf=%" PRtype_info "\n",
+ " caf=%016lx, taf=%" PRtype_info
+ " memflags 0x%x\n",
(void *) page_to_mfn(page),
d, d->domain_id, _d,
nd, _nd,
x,
- page->u.inuse.type_info);
+ page->u.inuse.type_info,
+ memflags);
} else {
DPRINTK("gnttab_transfer: Bad page %p: ed=%p(%u) 0x%x, "
"sd=%p(%u) 0x%x,"
- " caf=%016lx, taf=%" PRtype_info "\n",
+ " caf=%016lx, taf=%" PRtype_info
+ " memflags 0x%x\n",
(void *) page_to_mfn(page),
d, d->domain_id, _d,
nd, nd->domain_id, _nd,
x,
- page->u.inuse.type_info);
+ page->u.inuse.type_info,
+ memflags);
}
spin_unlock(&d->page_alloc_lock);
return -1;
@@ -1361,8 +1399,6 @@ guest_physmap_add_page(struct domain *d,
BUG_ON(!mfn_valid(mfn));
ret = get_page(mfn_to_page(mfn), d);
BUG_ON(ret == 0);
- BUG_ON(page_get_owner(mfn_to_page(mfn)) == d &&
- get_gpfn_from_mfn(mfn) != INVALID_M2P_ENTRY);
set_gpfn_from_mfn(mfn, gpfn);
smp_mb();
assign_domain_page_replace(d, gpfn << PAGE_SHIFT, mfn, ASSIGN_writable);
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