From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752884AbbBRGwQ (ORCPT ); Wed, 18 Feb 2015 01:52:16 -0500 Received: from cantor2.suse.de ([195.135.220.15]:37001 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752539AbbBRGwN (ORCPT ); Wed, 18 Feb 2015 01:52:13 -0500 From: Juergen Gross To: linux-kernel@vger.kernel.org, xen-devel@lists.xensource.com, konrad.wilk@oracle.com, david.vrabel@citrix.com, boris.ostrovsky@oracle.com Cc: Juergen Gross Subject: [PATCH 02/13] xen: anchor linear p2m list in shared info structure Date: Wed, 18 Feb 2015 07:51:55 +0100 Message-Id: <1424242326-26611-3-git-send-email-jgross@suse.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1424242326-26611-1-git-send-email-jgross@suse.com> References: <1424242326-26611-1-git-send-email-jgross@suse.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The linear p2m list should be anchored in the shared info structure 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. Signed-off-by: Juergen Gross --- arch/x86/xen/p2m.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c index f18fd1d..df73cc5 100644 --- 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++; pte_newpg[i] = NULL; } @@ -568,8 +574,10 @@ static bool alloc_p2m(unsigned long pfn) spin_lock_irqsave(&p2m_update_lock, flags); if (pte_pfn(*ptep) == p2m_pfn) { + HYPERVISOR_shared_info->arch.p2m_generation++; set_pte(ptep, pfn_pte(PFN_DOWN(__pa(p2m)), PAGE_KERNEL)); + HYPERVISOR_shared_info->arch.p2m_generation++; if (mid_mfn) mid_mfn[mididx] = virt_to_mfn(p2m); p2m = NULL; @@ -621,6 +629,11 @@ bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn) return true; } + /* + * The interface requires atomic updates on p2m elements. + * xen_safe_write_ulong() is using __put_user which does an atomic + * store via asm(). + */ if (likely(!xen_safe_write_ulong(xen_p2m_addr + pfn, mfn))) return true; -- 2.1.4