Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932623AbbDUPfK (ORCPT ); Tue, 21 Apr 2015 11:35:10 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:57721 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932585AbbDUPfE (ORCPT ); Tue, 21 Apr 2015 11:35:04 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Juergen Gross , David Vrabel , Luis Henriques Subject: [PATCH 3.16.y-ckt 116/144] xen/balloon: before adding hotplugged memory, set frames to invalid Date: Tue, 21 Apr 2015 16:31:41 +0100 Message-Id: <1429630329-21748-117-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1429630329-21748-1-git-send-email-luis.henriques@canonical.com> References: <1429630329-21748-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2340 Lines: 63 3.16.7-ckt10 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Juergen Gross commit 3c56b3a12ce52f361468cbdd2f79b2f3b8da0ea6 upstream. Commit 25b884a83d487fd62c3de7ac1ab5549979188482 ("x86/xen: set regions above the end of RAM as 1:1") introduced a regression. To be able to add memory pages which were added via memory hotplug to a pv domain, the pages must be "invalid" instead of "identity" in the p2m list before they can be added. Suggested-by: David Vrabel Signed-off-by: Juergen Gross Reviewed-by: Daniel Kiper Signed-off-by: David Vrabel Signed-off-by: Luis Henriques --- drivers/xen/balloon.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index 5c660c77f03b..8db7abb6ef5a 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -227,6 +227,29 @@ static enum bp_state reserve_additional_memory(long credit) balloon_hotplug = round_up(balloon_hotplug, PAGES_PER_SECTION); nid = memory_add_physaddr_to_nid(hotplug_start_paddr); +#ifdef CONFIG_XEN_HAVE_PVMMU + /* + * add_memory() will build page tables for the new memory so + * the p2m must contain invalid entries so the correct + * non-present PTEs will be written. + * + * If a failure occurs, the original (identity) p2m entries + * are not restored since this region is now known not to + * conflict with any devices. + */ + if (!xen_feature(XENFEAT_auto_translated_physmap)) { + unsigned long pfn, i; + + pfn = PFN_DOWN(hotplug_start_paddr); + for (i = 0; i < balloon_hotplug; i++) { + if (!set_phys_to_machine(pfn + i, INVALID_P2M_ENTRY)) { + pr_warn("set_phys_to_machine() failed, no memory added\n"); + return BP_ECANCELED; + } + } + } +#endif + rc = add_memory(nid, hotplug_start_paddr, balloon_hotplug << PAGE_SHIFT); if (rc) { -- 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/