xen/setup: update VA mapping when releasing memory during setup

In xen_memory_setup(), if a page that is being released has a VA
mapping this must also be updated.  Otherwise, the page will be not
released completely -- it will still be referenced in Xen and won't be
freed util the mapping is removed and this prevents it from being
reallocated at a different PFN.

This was already being done for the ISA memory region in
xen_ident_map_ISA() but on many systems this was omitting a few pages
as many systems marked a few pages below the ISA memory region as
reserved in the e820 map.

This fixes errors such as:

(XEN) page_alloc.c:1148:d0 Over-allocation for domain 0: 2097153 > 2097152
(XEN) memory.c:133:d0 Could not allocate order=0 extent: id=0 memflags=0 (0 of 17)

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This commit is contained in:
David Vrabel
2012-05-03 16:15:42 +01:00
committed by Konrad Rzeszutek Wilk
parent 96dc08b35c
commit 83d51ab473
4 changed files with 34 additions and 32 deletions

View File

@@ -139,6 +139,13 @@ static unsigned long __init xen_do_chunk(unsigned long start,
return len;
}
static unsigned long __init xen_release_chunk(unsigned long start,
unsigned long end)
{
return xen_do_chunk(start, end, true);
}
static unsigned long __init xen_populate_chunk(
const struct e820entry *list, size_t map_size,
unsigned long max_pfn, unsigned long *last_pfn,
@@ -197,6 +204,29 @@ static unsigned long __init xen_populate_chunk(
}
return done;
}
static void __init xen_set_identity_and_release_chunk(
unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages,
unsigned long *released, unsigned long *identity)
{
unsigned long pfn;
/*
* If the PFNs are currently mapped, the VA mapping also needs
* to be updated to be 1:1.
*/
for (pfn = start_pfn; pfn <= max_pfn_mapped && pfn < end_pfn; pfn++)
(void)HYPERVISOR_update_va_mapping(
(unsigned long)__va(pfn << PAGE_SHIFT),
mfn_pte(pfn, PAGE_KERNEL_IO), 0);
if (start_pfn < nr_pages)
*released += xen_release_chunk(
start_pfn, min(end_pfn, nr_pages));
*identity += set_phys_range_identity(start_pfn, end_pfn);
}
static unsigned long __init xen_set_identity_and_release(
const struct e820entry *list, size_t map_size, unsigned long nr_pages)
{
@@ -226,14 +256,11 @@ static unsigned long __init xen_set_identity_and_release(
if (entry->type == E820_RAM)
end_pfn = PFN_UP(entry->addr);
if (start_pfn < end_pfn) {
if (start_pfn < nr_pages)
released += xen_do_chunk(
start_pfn, min(end_pfn, nr_pages), true);
if (start_pfn < end_pfn)
xen_set_identity_and_release_chunk(
start_pfn, end_pfn, nr_pages,
&released, &identity);
identity += set_phys_range_identity(
start_pfn, end_pfn);
}
start = end;
}
}