Commit a97dae1a authored by David Vrabel's avatar David Vrabel
Browse files

x86/xen: add extra memory for remapped frames during setup 



If the non-RAM regions in the e820 memory map are larger than the size
of the initial balloon, a BUG was triggered as the frames are remaped
beyond the limit of the linear p2m.  The frames are remapped into the
initial balloon area (xen_extra_mem) but not enough of this is
available.

Ensure enough extra memory regions are added for these remapped
frames.

Signed-off-by: default avatarDavid Vrabel <david.vrabel@citrix.com>
Reviewed-by: default avatarJuergen Gross <jgross@suse.com>
parent bc7142cf

arch/x86/xen/setup.c

+9 −4
Original line number Diff line number Diff line
@@ -366,7 +366,7 @@ static void __init xen_do_set_identity_and_remap_chunk( 
static unsigned long __init xen_set_identity_and_remap_chunk(

        const struct e820entry *list, size_t map_size, unsigned long start_pfn,

	unsigned long end_pfn, unsigned long nr_pages, unsigned long remap_pfn,

	unsigned long *released)

	unsigned long *released, unsigned long *remapped)

{

	unsigned long pfn;

	unsigned long i = 0;
@@ -404,6 +404,7 @@ static unsigned long __init xen_set_identity_and_remap_chunk( 
		/* Update variables to reflect new mappings. */

		i += size;

		remap_pfn += size;

		*remapped += size;

	}



	/*
@@ -420,12 +421,13 @@ static unsigned long __init xen_set_identity_and_remap_chunk( 


static void __init xen_set_identity_and_remap(

	const struct e820entry *list, size_t map_size, unsigned long nr_pages,

	unsigned long *released)

	unsigned long *released, unsigned long *remapped)

{

	phys_addr_t start = 0;

	unsigned long last_pfn = nr_pages;

	const struct e820entry *entry;

	unsigned long num_released = 0;

	unsigned long num_remapped = 0;

	int i;



	/*
@@ -452,12 +454,13 @@ static void __init xen_set_identity_and_remap( 
				last_pfn = xen_set_identity_and_remap_chunk(

						list, map_size, start_pfn,

						end_pfn, nr_pages, last_pfn,

						&num_released);

						&num_released, &num_remapped);

			start = end;

		}

	}



	*released = num_released;

	*remapped = num_remapped;



	pr_info("Released %ld page(s)\n", num_released);

}
@@ -577,6 +580,7 @@ char * __init xen_memory_setup(void) 
	struct xen_memory_map memmap;

	unsigned long max_pages;

	unsigned long extra_pages = 0;

	unsigned long remapped_pages;

	int i;

	int op;
@@ -626,9 +630,10 @@ char * __init xen_memory_setup(void) 
	 * underlying RAM.

	 */

	xen_set_identity_and_remap(map, memmap.nr_entries, max_pfn,

				   &xen_released_pages);

				   &xen_released_pages, &remapped_pages);



	extra_pages += xen_released_pages;

	extra_pages += remapped_pages;



	/*

	 * Clamp the amount of extra memory to a EXTRA_MEM_RATIO

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