From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758716Ab2HQR4C (ORCPT ); Fri, 17 Aug 2012 13:56:02 -0400 Received: from rcsinet15.oracle.com ([148.87.113.117]:39232 "EHLO rcsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758673Ab2HQRzq (ORCPT ); Fri, 17 Aug 2012 13:55:46 -0400 Date: Fri, 17 Aug 2012 13:45:49 -0400 From: Konrad Rzeszutek Wilk To: Stefano Stabellini Cc: "linux-kernel@vger.kernel.org" , "xen-devel@lists.xensource.com" Subject: Re: [Xen-devel] [PATCH 06/11] xen/mmu: For 64-bit do not call xen_map_identity_early Message-ID: <20120817174549.GA14257@phenom.dumpdata.com> References: <1345133009-21941-1-git-send-email-konrad.wilk@oracle.com> <1345133009-21941-7-git-send-email-konrad.wilk@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: acsinet21.oracle.com [141.146.126.237] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Aug 17, 2012 at 06:41:23PM +0100, Stefano Stabellini wrote: > On Thu, 16 Aug 2012, Konrad Rzeszutek Wilk wrote: > > B/c we do not need it. During the startup the Xen provides > > us with all the memory mapped that we need to function. > > Shouldn't we check to make sure that is actually true (I am thinking at > nr_pt_frames)? I was looking at the source code (hypervisor) to figure it out and that is certainly true. > Or is it actually stated somewhere in the Xen headers? Couldn't find it, but after looking so long at the source code I didn't even bother looking for it. Thought to be honest - I only looked at how the 64-bit pagetables were set up, so I didn't dare to touch the 32-bit. Hence the #ifdef > > > > > Signed-off-by: Konrad Rzeszutek Wilk > > --- > > arch/x86/xen/mmu.c | 11 +++++------ > > 1 files changed, 5 insertions(+), 6 deletions(-) > > > > diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c > > index 7247e5a..a59070b 100644 > > --- a/arch/x86/xen/mmu.c > > +++ b/arch/x86/xen/mmu.c > > @@ -84,6 +84,7 @@ > > */ > > DEFINE_SPINLOCK(xen_reservation_lock); > > > > +#ifdef CONFIG_X86_32 > > /* > > * Identity map, in addition to plain kernel map. This needs to be > > * large enough to allocate page table pages to allocate the rest. > > @@ -91,7 +92,7 @@ DEFINE_SPINLOCK(xen_reservation_lock); > > */ > > #define LEVEL1_IDENT_ENTRIES (PTRS_PER_PTE * 4) > > static RESERVE_BRK_ARRAY(pte_t, level1_ident_pgt, LEVEL1_IDENT_ENTRIES); > > - > > +#endif > > #ifdef CONFIG_X86_64 > > /* l3 pud for userspace vsyscall mapping */ > > static pud_t level3_user_vsyscall[PTRS_PER_PUD] __page_aligned_bss; > > @@ -1628,7 +1629,7 @@ static void set_page_prot(void *addr, pgprot_t prot) > > if (HYPERVISOR_update_va_mapping((unsigned long)addr, pte, 0)) > > BUG(); > > } > > - > > +#ifdef CONFIG_X86_32 > > static void __init xen_map_identity_early(pmd_t *pmd, unsigned long max_pfn) > > { > > unsigned pmdidx, pteidx; > > @@ -1679,7 +1680,7 @@ static void __init xen_map_identity_early(pmd_t *pmd, unsigned long max_pfn) > > > > set_page_prot(pmd, PAGE_KERNEL_RO); > > } > > - > > +#endif > > void __init xen_setup_machphys_mapping(void) > > { > > struct xen_machphys_mapping mapping; > > @@ -1765,14 +1766,12 @@ void __init xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn) > > /* Note that we don't do anything with level1_fixmap_pgt which > > * we don't need. */ > > > > - /* Set up identity map */ > > - xen_map_identity_early(level2_ident_pgt, max_pfn); > > - > > /* Make pagetable pieces RO */ > > set_page_prot(init_level4_pgt, PAGE_KERNEL_RO); > > set_page_prot(level3_ident_pgt, PAGE_KERNEL_RO); > > set_page_prot(level3_kernel_pgt, PAGE_KERNEL_RO); > > set_page_prot(level3_user_vsyscall, PAGE_KERNEL_RO); > > + set_page_prot(level2_ident_pgt, PAGE_KERNEL_RO); > > set_page_prot(level2_kernel_pgt, PAGE_KERNEL_RO); > > set_page_prot(level2_fixmap_pgt, PAGE_KERNEL_RO); > > > > -- > > 1.7.7.6 > > > > > > _______________________________________________ > > Xen-devel mailing list > > Xen-devel@lists.xen.org > > http://lists.xen.org/xen-devel > > > -- > 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/