Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752356AbbFHMHK (ORCPT ); Mon, 8 Jun 2015 08:07:10 -0400 Received: from cantor2.suse.de ([195.135.220.15]:43045 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751278AbbFHMHC (ORCPT ); Mon, 8 Jun 2015 08:07:02 -0400 From: Juergen Gross To: xen-devel@lists.xensource.com, konrad.wilk@oracle.com, david.vrabel@citrix.com, boris.ostrovsky@oracle.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: Juergen Gross Subject: [Patch V4 02/16] xen: save linear p2m list address in shared info structure Date: Mon, 8 Jun 2015 14:06:43 +0200 Message-Id: <1433765217-16333-3-git-send-email-jgross@suse.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1433765217-16333-1-git-send-email-jgross@suse.com> References: <1433765217-16333-1-git-send-email-jgross@suse.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2834 Lines: 75 The virtual address of the linear p2m list should be stored in the shared info structure read by the Xen tools to be able to support 64 bit pv-domains larger than 512 GB. 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 Reviewed-by: David Vrabel --- arch/x86/xen/p2m.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c index b47124d..703f803 100644 --- a/arch/x86/xen/p2m.c +++ b/arch/x86/xen/p2m.c @@ -262,6 +262,10 @@ 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 */ @@ -477,8 +481,12 @@ 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++; + wmb(); /* Tools are synchronizing via p2m_generation. */ set_pmd(pmdp, __pmd(__pa(pte_newpg[i]) | _KERNPG_TABLE)); + wmb(); /* Tools are synchronizing via p2m_generation. */ + HYPERVISOR_shared_info->arch.p2m_generation++; pte_newpg[i] = NULL; } @@ -576,8 +584,12 @@ 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++; + wmb(); /* Tools are synchronizing via p2m_generation. */ set_pte(ptep, pfn_pte(PFN_DOWN(__pa(p2m)), PAGE_KERNEL)); + wmb(); /* Tools are synchronizing via p2m_generation. */ + HYPERVISOR_shared_info->arch.p2m_generation++; if (mid_mfn) mid_mfn[mididx] = virt_to_mfn(p2m); p2m = NULL; @@ -629,6 +641,11 @@ 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 -- 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/