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Commit 3249b7e1 authored by Ian Campbell's avatar Ian Campbell Committed by H. Peter Anvin
Browse files

x86, vmi: Disable highmem PTE allocation even when CONFIG_HIGHPTE=y 



Preventing HIGHPTE allocations under VMI will allow us to remove the
kmap_atomic_pte paravirt op.

Signed-off-by: default avatarIan Campbell <ian.campbell@citrix.com>
LKML-Reference: <1267204562-11844-2-git-send-email-ian.campbell@citrix.com>
Acked-by: default avatarAlok Kataria <akataria@vmware.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
parent 817a824b

arch/x86/kernel/vmi_32.c

+11 −12
Original line number Diff line number Diff line
@@ -33,6 +33,7 @@ 
#include <asm/fixmap.h>

#include <asm/apicdef.h>

#include <asm/apic.h>

#include <asm/pgalloc.h>

#include <asm/processor.h>

#include <asm/timer.h>

#include <asm/vmi_time.h>
@@ -272,19 +273,11 @@ static void *vmi_kmap_atomic_pte(struct page *page, enum km_type type) 
	void *va = kmap_atomic(page, type);



	/*

	 * Internally, the VMI ROM must map virtual addresses to physical

	 * addresses for processing MMU updates.  By the time MMU updates

	 * are issued, this information is typically already lost.

	 * Fortunately, the VMI provides a cache of mapping slots for active

	 * page tables.

	 *

	 * We use slot zero for the linear mapping of physical memory, and

	 * in HIGHPTE kernels, slot 1 and 2 for KM_PTE0 and KM_PTE1.

	 *

	 *  args:                 SLOT                 VA    COUNT PFN

	 * We disable highmem allocations for page tables so we should never

	 * see any calls to kmap_atomic_pte on a highmem page.

	 */

	BUG_ON(type != KM_PTE0 && type != KM_PTE1);

	vmi_ops.set_linear_mapping((type - KM_PTE0)+1, va, 1, page_to_pfn(page));



	BUG_ON(PageHighmem(page));



	return va;

}
@@ -640,6 +633,12 @@ static inline int __init activate_vmi(void) 
	u64 reloc;

	const struct vmi_relocation_info *rel = (struct vmi_relocation_info *)&reloc;



	/*

	 * Prevent page tables from being allocated in highmem, even if

	 * CONFIG_HIGHPTE is enabled.

	 */

	__userpte_alloc_gfp &= ~__GFP_HIGHMEM;



	if (call_vrom_func(vmi_rom, vmi_init) != 0) {

		printk(KERN_ERR "VMI ROM failed to initialize!");

		return 0;