Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966869Ab0B0Bnn (ORCPT ); Fri, 26 Feb 2010 20:43:43 -0500 Received: from smtp-outbound-2.vmware.com ([65.115.85.73]:41287 "EHLO smtp-outbound-2.vmware.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966773Ab0B0Bnl (ORCPT ); Fri, 26 Feb 2010 20:43:41 -0500 Subject: Re: [PATCH 2/3] vmi: disable highmem PTE allocation even when CONFIG_HIGHPTE=y From: Alok Kataria Reply-To: akataria@vmware.com To: Ian Campbell Cc: "linux-kernel@vger.kernel.org" , "H. Peter Anvin" , Ingo Molnar , Jeremy Fitzhardinge In-Reply-To: <1267204562-11844-2-git-send-email-ian.campbell@citrix.com> References: <1267204547.11737.12659.camel@zakaz.uk.xensource.com> <1267204562-11844-2-git-send-email-ian.campbell@citrix.com> Content-Type: text/plain Organization: VMware INC. Date: Fri, 26 Feb 2010 17:43:41 -0800 Message-Id: <1267235021.24798.36.camel@ank32> Mime-Version: 1.0 X-Mailer: Evolution 2.12.3 (2.12.3-8.el5_2.3) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2617 Lines: 74 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 Thanks, Alok > > Signed-off-by: Ian Campbell > Cc: Alok Kataria > Cc: H. Peter Anvin > Cc: Ingo Molnar > Cc: Jeremy Fitzhardinge > --- > 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 > #include > #include > +#include > #include > #include > #include > @@ -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; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/