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Commit 83d51ab4 authored by David Vrabel's avatar David Vrabel Committed by Konrad Rzeszutek Wilk
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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: default avatarDavid Vrabel <david.vrabel@citrix.com>
Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
parent 96dc08b3

arch/x86/xen/enlighten.c

+0 −1
Original line number Diff line number Diff line
@@ -1308,7 +1308,6 @@ asmlinkage void __init xen_start_kernel(void) 


	xen_raw_console_write("mapping kernel into physical memory\n");

	pgd = xen_setup_kernel_pagetable(pgd, xen_start_info->nr_pages);

	xen_ident_map_ISA();



	/* Allocate and initialize top and mid mfn levels for p2m structure */

	xen_build_mfn_list_list();

arch/x86/xen/mmu.c

+0 −23
Original line number Diff line number Diff line
@@ -1929,29 +1929,6 @@ static void xen_set_fixmap(unsigned idx, phys_addr_t phys, pgprot_t prot) 
#endif

}



void __init xen_ident_map_ISA(void)

{

	unsigned long pa;



	/*

	 * If we're dom0, then linear map the ISA machine addresses into

	 * the kernel's address space.

	 */

	if (!xen_initial_domain())

		return;



	xen_raw_printk("Xen: setup ISA identity maps\n");



	for (pa = ISA_START_ADDRESS; pa < ISA_END_ADDRESS; pa += PAGE_SIZE) {

		pte_t pte = mfn_pte(PFN_DOWN(pa), PAGE_KERNEL_IO);



		if (HYPERVISOR_update_va_mapping(PAGE_OFFSET + pa, pte, 0))

			BUG();

	}



	xen_flush_tlb();

}



static void __init xen_post_allocator_init(void)

{

	pv_mmu_ops.set_pte = xen_set_pte;

arch/x86/xen/setup.c

+34 −7
Original line number Diff line number Diff line
@@ -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;

		}

	}

arch/x86/xen/xen-ops.h

+0 −1
Original line number Diff line number Diff line
@@ -28,7 +28,6 @@ void xen_setup_shared_info(void); 
void xen_build_mfn_list_list(void);

void xen_setup_machphys_mapping(void);

pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn);

void xen_ident_map_ISA(void);

void xen_reserve_top(void);

extern unsigned long xen_max_p2m_pfn;