Messages in this thread | | | Subject | Re: [PATCH 2/3] vmi: disable highmem PTE allocation even when CONFIG_HIGHPTE=y | From | Alok Kataria <> | Date | Fri, 26 Feb 2010 17:43:41 -0800 |
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On Fri, 2010-02-26 at 09:16 -0800, Ian Campbell wrote: > Preventing HIGHPTE allocations under VMI will allow us to remove the > kmap_atomic_pte paravirt op.
Acked-by: Alok N Kataria <akataria@vmware.com>
Thanks, Alok > > Signed-off-by: Ian Campbell <ian.campbell@citrix.com> > Cc: Alok Kataria <akataria@vmware.com> > Cc: H. Peter Anvin <hpa@zytor.com> > Cc: Ingo Molnar <mingo@elte.hu> > Cc: Jeremy Fitzhardinge <jeremy@goop.org> > --- > 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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