From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752260AbbBRKcX (ORCPT ); Wed, 18 Feb 2015 05:32:23 -0500 Received: from smtp02.citrix.com ([66.165.176.63]:9967 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751245AbbBRKcW (ORCPT ); Wed, 18 Feb 2015 05:32:22 -0500 X-IronPort-AV: E=Sophos;i="5.09,600,1418083200"; d="scan'208";a="228064441" Message-ID: <54E46A33.9030401@citrix.com> Date: Wed, 18 Feb 2015 10:32:19 +0000 From: David Vrabel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.4.0 MIME-Version: 1.0 To: Juergen Gross , , , , , Subject: Re: [Xen-devel] [PATCH 02/13] xen: anchor linear p2m list in shared info structure References: <1424242326-26611-1-git-send-email-jgross@suse.com> <1424242326-26611-3-git-send-email-jgross@suse.com> In-Reply-To: <1424242326-26611-3-git-send-email-jgross@suse.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 8bit X-DLP: MIA2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 18/02/15 06:51, Juergen Gross wrote: > The linear p2m list should be anchored in the shared info structure I'm not really sure what you mean by "anchored". > read by the Xen tools to be able to support 64 bit pv-domains larger > than 512 MB. Additionally the linear p2m list interface includes a > generation count which is changed prior to and after each mapping > change of the p2m list. Reading the generation count the Xen tools can > detect changes of the mappings and re-read the p2m list eventually. [...] > --- a/arch/x86/xen/p2m.c > +++ b/arch/x86/xen/p2m.c > @@ -256,6 +256,10 @@ void xen_setup_mfn_list_list(void) > HYPERVISOR_shared_info->arch.pfn_to_mfn_frame_list_list = > virt_to_mfn(p2m_top_mfn); > HYPERVISOR_shared_info->arch.max_pfn = xen_max_p2m_pfn; > + HYPERVISOR_shared_info->arch.p2m_generation = 0; > + HYPERVISOR_shared_info->arch.p2m_vaddr = (unsigned long)xen_p2m_addr; > + HYPERVISOR_shared_info->arch.p2m_cr3 = > + xen_pfn_to_cr3(virt_to_mfn(swapper_pg_dir)); > } > > /* Set up p2m_top to point to the domain-builder provided p2m pages */ > @@ -469,8 +473,10 @@ static pte_t *alloc_p2m_pmd(unsigned long addr, pte_t *pte_pg) > > ptechk = lookup_address(vaddr, &level); > if (ptechk == pte_pg) { > + HYPERVISOR_shared_info->arch.p2m_generation++; > set_pmd(pmdp, > __pmd(__pa(pte_newpg[i]) | _KERNPG_TABLE)); > + HYPERVISOR_shared_info->arch.p2m_generation++; Do these increments of p2m_generation need to be atomic? David