Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932255Ab1DLRlT (ORCPT ); Tue, 12 Apr 2011 13:41:19 -0400 Received: from rcsinet10.oracle.com ([148.87.113.121]:22063 "EHLO rcsinet10.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932093Ab1DLRlR (ORCPT ); Tue, 12 Apr 2011 13:41:17 -0400 Message-ID: <4DA48EA9.70109@kernel.org> Date: Tue, 12 Apr 2011 10:40:57 -0700 From: Yinghai Lu User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.14) Gecko/20110221 SUSE/3.1.8 Thunderbird/3.1.8 MIME-Version: 1.0 To: stefano.stabellini@eu.citrix.com CC: linux-kernel@vger.kernel.org, xen-devel@lists.xensource.com, konrad.wilk@oracle.com, jeremy@goop.org, hpa@linux.intel.com, mingo@elte.hu, "H. Peter Anvin" Subject: Re: [PATCH 2/4] x86,xen: introduce x86_init.mapping.pagetable_reserve References: <1302607192-21355-2-git-send-email-stefano.stabellini@eu.citrix.com> In-Reply-To: <1302607192-21355-2-git-send-email-stefano.stabellini@eu.citrix.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Source-IP: acsmt358.oracle.com [141.146.40.158] X-Auth-Type: Internal IP X-CT-RefId: str=0001.0A090201.4DA48EAF.014F,ss=1,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5229 Lines: 142 On 04/12/2011 04:19 AM, stefano.stabellini@eu.citrix.com wrote: > From: Stefano Stabellini > > Introduce a new x86_init hook called pagetable_reserve that during the > initial memory mapping is used to reserve a range of memory addresses for > kernel pagetable usage. > > On native it just calls memblock_x86_reserve_range while on xen it also > takes care of setting the spare memory previously allocated > for kernel pagetable pages from RO to RW, so that it can be used for > other purposes. > > Signed-off-by: Stefano Stabellini > Cc: Yinghai Lu > Cc: H. Peter Anvin > Cc: Ingo Molnar Acked-by: Yinghai Lu > --- > arch/x86/include/asm/pgtable_types.h | 1 + > arch/x86/include/asm/x86_init.h | 9 +++++++++ > arch/x86/kernel/x86_init.c | 4 ++++ > arch/x86/mm/init.c | 9 +++++++-- > arch/x86/xen/mmu.c | 15 +++++++++++++++ > 5 files changed, 36 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h > index 7db7723..d56187c 100644 > --- a/arch/x86/include/asm/pgtable_types.h > +++ b/arch/x86/include/asm/pgtable_types.h > @@ -299,6 +299,7 @@ int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn, > /* Install a pte for a particular vaddr in kernel space. */ > void set_pte_vaddr(unsigned long vaddr, pte_t pte); > > +extern void native_pagetable_reserve(u64 start, u64 end); > #ifdef CONFIG_X86_32 > extern void native_pagetable_setup_start(pgd_t *base); > extern void native_pagetable_setup_done(pgd_t *base); > diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h > index 643ebf2..d66b3a2 100644 > --- a/arch/x86/include/asm/x86_init.h > +++ b/arch/x86/include/asm/x86_init.h > @@ -68,6 +68,14 @@ struct x86_init_oem { > }; > > /** > + * struct x86_init_mapping - platform specific initial kernel pagetable setup > + * @pagetable_reserve: reserve a range of addresses for kernel pagetable usage > + */ > +struct x86_init_mapping { > + void (*pagetable_reserve)(u64 start, u64 end); > +}; > + > +/** > * struct x86_init_paging - platform specific paging functions > * @pagetable_setup_start: platform specific pre paging_init() call > * @pagetable_setup_done: platform specific post paging_init() call > @@ -123,6 +131,7 @@ struct x86_init_ops { > struct x86_init_mpparse mpparse; > struct x86_init_irqs irqs; > struct x86_init_oem oem; > + struct x86_init_mapping mapping; > struct x86_init_paging paging; > struct x86_init_timers timers; > struct x86_init_iommu iommu; > diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c > index c11514e..75ef4b1 100644 > --- a/arch/x86/kernel/x86_init.c > +++ b/arch/x86/kernel/x86_init.c > @@ -61,6 +61,10 @@ struct x86_init_ops x86_init __initdata = { > .banner = default_banner, > }, > > + .mapping = { > + .pagetable_reserve = native_pagetable_reserve, > + }, > + > .paging = { > .pagetable_setup_start = native_pagetable_setup_start, > .pagetable_setup_done = native_pagetable_setup_done, > diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c > index 286d289..ed0650b 100644 > --- a/arch/x86/mm/init.c > +++ b/arch/x86/mm/init.c > @@ -81,6 +81,11 @@ static void __init find_early_table_space(unsigned long end, int use_pse, > end, pgt_buf_start<< PAGE_SHIFT, pgt_buf_top<< PAGE_SHIFT); > } > > +void native_pagetable_reserve(u64 start, u64 end) > +{ > + memblock_x86_reserve_range(start, end, "PGTABLE"); > +} > + > struct map_range { > unsigned long start; > unsigned long end; > @@ -273,8 +278,8 @@ unsigned long __init_refok init_memory_mapping(unsigned long start, > __flush_tlb_all(); > > if (!after_bootmem&& pgt_buf_end> pgt_buf_start) > - memblock_x86_reserve_range(pgt_buf_start<< PAGE_SHIFT, > - pgt_buf_end<< PAGE_SHIFT, "PGTABLE"); > + x86_init.mapping.pagetable_reserve(PFN_PHYS(pgt_buf_start), > + PFN_PHYS(pgt_buf_end)); > > if (!after_bootmem) > early_memtest(start, end); > diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c > index 6b833db..fec8680 100644 > --- a/arch/x86/xen/mmu.c > +++ b/arch/x86/xen/mmu.c > @@ -1275,6 +1275,20 @@ static __init void xen_pagetable_setup_start(pgd_t *base) > { > } > > +static __init void xen_mapping_pagetable_reserve(u64 start, u64 end) > +{ > + /* reserve the range used */ > + memblock_x86_reserve_range(start, end, "PGTABLE"); > + > + /* set as RW the rest */ > + printk(KERN_DEBUG "xen: setting RW the range %llx - %llx\n", end, > + PFN_PHYS(pgt_buf_top)); > + while (end< PFN_PHYS(pgt_buf_top)) { > + make_lowmem_page_readwrite(__va(end)); > + end += PAGE_SIZE; > + } > +} > + it would be more cleaner to xen code if you make mark start/end to RO, and not make them all before as RO. Thanks Yinghai Lu -- 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/