Commit-ID: 3249b7e1df6380e9d7bb3238f64f445bf614f787
Gitweb: http://git.kernel.org/tip/3249b7e1df6380e9d7bb3238f64f445bf614f787
Author: Ian Campbell <ian.campbell@xxxxxxxxxx>
AuthorDate: Fri, 26 Feb 2010 17:16:01 +0000
Committer: H. Peter Anvin <hpa@xxxxxxxxx>
CommitDate: Sat, 27 Feb 2010 14:41:16 -0800
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: Ian Campbell <ian.campbell@xxxxxxxxxx>
LKML-Reference: <1267204562-11844-2-git-send-email-ian.campbell@xxxxxxxxxx>
Acked-by: Alok Kataria <akataria@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxx>
---
arch/x86/kernel/vmi_32.c | 23 +++++++++++------------
1 files changed, 11 insertions(+), 12 deletions(-)
diff --git a/arch/x86/kernel/vmi_32.c b/arch/x86/kernel/vmi_32.c
index d430e4c..58aca86 100644
--- a/arch/x86/kernel/vmi_32.c
+++ b/arch/x86/kernel/vmi_32.c
@@ -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;
--
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