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Diffstat (limited to 'arch/x86/xen/p2m.c')
-rw-r--r--arch/x86/xen/p2m.c119
1 files changed, 96 insertions, 23 deletions
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index 76ba0e97e530..95fb2aa5927e 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -22,7 +22,7 @@
*
* P2M_PER_PAGE depends on the architecture, as a mfn is always
* unsigned long (8 bytes on 64-bit, 4 bytes on 32), leading to
- * 512 and 1024 entries respectively.
+ * 512 and 1024 entries respectively.
*
* In short, these structures contain the Machine Frame Number (MFN) of the PFN.
*
@@ -139,11 +139,11 @@
* / | ~0, ~0, .... |
* | \---------------/
* |
- * p2m_missing p2m_missing
- * /------------------\ /------------\
- * | [p2m_mid_missing]+---->| ~0, ~0, ~0 |
- * | [p2m_mid_missing]+---->| ..., ~0 |
- * \------------------/ \------------/
+ * p2m_mid_missing p2m_missing
+ * /-----------------\ /------------\
+ * | [p2m_missing] +---->| ~0, ~0, ~0 |
+ * | [p2m_missing] +---->| ..., ~0 |
+ * \-----------------/ \------------/
*
* where ~0 is INVALID_P2M_ENTRY. IDENTITY is (PFN | IDENTITY_BIT)
*/
@@ -396,7 +396,85 @@ void __init xen_build_dynamic_phys_to_machine(void)
m2p_override_init();
}
+#ifdef CONFIG_X86_64
+#include <linux/bootmem.h>
+unsigned long __init xen_revector_p2m_tree(void)
+{
+ unsigned long va_start;
+ unsigned long va_end;
+ unsigned long pfn;
+ unsigned long pfn_free = 0;
+ unsigned long *mfn_list = NULL;
+ unsigned long size;
+
+ va_start = xen_start_info->mfn_list;
+ /*We copy in increments of P2M_PER_PAGE * sizeof(unsigned long),
+ * so make sure it is rounded up to that */
+ size = PAGE_ALIGN(xen_start_info->nr_pages * sizeof(unsigned long));
+ va_end = va_start + size;
+
+ /* If we were revectored already, don't do it again. */
+ if (va_start <= __START_KERNEL_map && va_start >= __PAGE_OFFSET)
+ return 0;
+
+ mfn_list = alloc_bootmem_align(size, PAGE_SIZE);
+ if (!mfn_list) {
+ pr_warn("Could not allocate space for a new P2M tree!\n");
+ return xen_start_info->mfn_list;
+ }
+ /* Fill it out with INVALID_P2M_ENTRY value */
+ memset(mfn_list, 0xFF, size);
+
+ for (pfn = 0; pfn < ALIGN(MAX_DOMAIN_PAGES, P2M_PER_PAGE); pfn += P2M_PER_PAGE) {
+ unsigned topidx = p2m_top_index(pfn);
+ unsigned mididx;
+ unsigned long *mid_p;
+
+ if (!p2m_top[topidx])
+ continue;
+ if (p2m_top[topidx] == p2m_mid_missing)
+ continue;
+
+ mididx = p2m_mid_index(pfn);
+ mid_p = p2m_top[topidx][mididx];
+ if (!mid_p)
+ continue;
+ if ((mid_p == p2m_missing) || (mid_p == p2m_identity))
+ continue;
+
+ if ((unsigned long)mid_p == INVALID_P2M_ENTRY)
+ continue;
+
+ /* The old va. Rebase it on mfn_list */
+ if (mid_p >= (unsigned long *)va_start && mid_p <= (unsigned long *)va_end) {
+ unsigned long *new;
+
+ if (pfn_free > (size / sizeof(unsigned long))) {
+ WARN(1, "Only allocated for %ld pages, but we want %ld!\n",
+ size / sizeof(unsigned long), pfn_free);
+ return 0;
+ }
+ new = &mfn_list[pfn_free];
+
+ copy_page(new, mid_p);
+ p2m_top[topidx][mididx] = &mfn_list[pfn_free];
+ p2m_top_mfn_p[topidx][mididx] = virt_to_mfn(&mfn_list[pfn_free]);
+
+ pfn_free += P2M_PER_PAGE;
+
+ }
+ /* This should be the leafs allocated for identity from _brk. */
+ }
+ return (unsigned long)mfn_list;
+
+}
+#else
+unsigned long __init xen_revector_p2m_tree(void)
+{
+ return 0;
+}
+#endif
unsigned long get_phys_to_machine(unsigned long pfn)
{
unsigned topidx, mididx, idx;
@@ -430,7 +508,7 @@ static void free_p2m_page(void *p)
free_page((unsigned long)p);
}
-/*
+/*
* 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
@@ -828,9 +906,6 @@ int m2p_add_override(unsigned long mfn, struct page *page,
xen_mc_issue(PARAVIRT_LAZY_MMU);
}
- /* let's use dev_bus_addr to record the old mfn instead */
- kmap_op->dev_bus_addr = page->index;
- page->index = (unsigned long) kmap_op;
}
spin_lock_irqsave(&m2p_override_lock, flags);
list_add(&page->lru, &m2p_overrides[mfn_hash(mfn)]);
@@ -857,7 +932,8 @@ int m2p_add_override(unsigned long mfn, struct page *page,
return 0;
}
EXPORT_SYMBOL_GPL(m2p_add_override);
-int m2p_remove_override(struct page *page, bool clear_pte)
+int m2p_remove_override(struct page *page,
+ struct gnttab_map_grant_ref *kmap_op)
{
unsigned long flags;
unsigned long mfn;
@@ -887,10 +963,8 @@ int m2p_remove_override(struct page *page, bool clear_pte)
WARN_ON(!PagePrivate(page));
ClearPagePrivate(page);
- if (clear_pte) {
- struct gnttab_map_grant_ref *map_op =
- (struct gnttab_map_grant_ref *) page->index;
- set_phys_to_machine(pfn, map_op->dev_bus_addr);
+ set_phys_to_machine(pfn, page->index);
+ if (kmap_op != NULL) {
if (!PageHighMem(page)) {
struct multicall_space mcs;
struct gnttab_unmap_grant_ref *unmap_op;
@@ -902,13 +976,13 @@ int m2p_remove_override(struct page *page, bool clear_pte)
* issued. In this case handle is going to -1 because
* it hasn't been modified yet.
*/
- if (map_op->handle == -1)
+ if (kmap_op->handle == -1)
xen_mc_flush();
/*
- * Now if map_op->handle is negative it means that the
+ * Now if kmap_op->handle is negative it means that the
* hypercall actually returned an error.
*/
- if (map_op->handle == GNTST_general_error) {
+ if (kmap_op->handle == GNTST_general_error) {
printk(KERN_WARNING "m2p_remove_override: "
"pfn %lx mfn %lx, failed to modify kernel mappings",
pfn, mfn);
@@ -918,8 +992,8 @@ int m2p_remove_override(struct page *page, bool clear_pte)
mcs = xen_mc_entry(
sizeof(struct gnttab_unmap_grant_ref));
unmap_op = mcs.args;
- unmap_op->host_addr = map_op->host_addr;
- unmap_op->handle = map_op->handle;
+ unmap_op->host_addr = kmap_op->host_addr;
+ unmap_op->handle = kmap_op->handle;
unmap_op->dev_bus_addr = 0;
MULTI_grant_table_op(mcs.mc,
@@ -930,10 +1004,9 @@ int m2p_remove_override(struct page *page, bool clear_pte)
set_pte_at(&init_mm, address, ptep,
pfn_pte(pfn, PAGE_KERNEL));
__flush_tlb_single(address);
- map_op->host_addr = 0;
+ kmap_op->host_addr = 0;
}
- } else
- set_phys_to_machine(pfn, page->index);
+ }
/* p2m(m2p(mfn)) == FOREIGN_FRAME(mfn): the mfn is already present
* somewhere in this domain, even before being added to the
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-25 00:16:14 +0100