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

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

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
LKML-Reference: <1267204562-11844-2-git-send-email-ian.campbell@citrix.com>
Acked-by: Alok Kataria <akataria@vmware.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
This commit is contained in:
Ian Campbell 2010-02-26 17:16:01 +00:00 committed by H. Peter Anvin
parent 817a824b75
commit 3249b7e1df
1 changed files with 11 additions and 12 deletions
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23
arch/x86/kernel/vmi_32.c
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@ -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;