Received: by 2002:ac0:946b:0:0:0:0:0 with SMTP id j40csp1685629imj; Thu, 14 Feb 2019 10:17:44 -0800 (PST) X-Google-Smtp-Source: AHgI3IbaUzCiS3NCqQCIcU0kxm1FVVhZC3FuitoQH2/tzwuph31DbJn/9AA3nTIGTJnisrEIFSi0 X-Received: by 2002:a63:fb0a:: with SMTP id o10mr1153997pgh.259.1550168264317; Thu, 14 Feb 2019 10:17:44 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1550168264; cv=none; d=google.com; s=arc-20160816; b=xDAF1GW7yDfEvPbX6HdrH9J1l1p3J1verzrNhd9Zk0AcY+uo3vhO9PQHqvbpcL1HtV Czh3drFD/BJxmJp03CkYwY8E3tHPD7ddmTeW5rWutJC8Xzi5dGyWvkFAeBvR01dvQqi4 327rnaUfaf1NHxZrjaE1G8lpQk7mTvXuK250wvOtZbTI8/9kOPjJQRFcUbl1/dn0zeSN HenTxzfKOkgpXoJEo9nLpDYXW/NSf1ZOFprF5NcfwZahZUpXSILxUgW8mGI8Ekt8s5RW 2XuR1VqFCThey1du9osBqCnNg+nH5A0/LnE2NAueezK84BJ/pIY22XRkq9Jv8pvl1WN6 Ejqg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:references:in-reply-to:message-id:date :subject:cc:to:from; bh=LbJTBwht9poXC7QUGnhBvoZkF3UNcARyj+Ip1dZ+wro=; b=QVAXFnGemXUZ6VIINC8Rgg2SitNhvOwifsf+B9G8qKCClujaJzt3NT4AhwqGIl31VA gh30HQJH//BLkJrUMegwb5XyaH8J80HA7iIx9qqKtSi0U0vzj8QisnrFtrLvQQXXOJF+ VUGTCxwetr6S8YqzeUPuOIuYzdTcfRM++UwzakYkoIwsZkfQsLy/ZxlBpn3qaXW3Dmyv VxN3Vkjmb09hU/7nVdvzSmynenFvMOZC/dC+ii+NsKkCOR/Mm9WE3DN2lU0NAJyhX0iD o5CNgCLWNGXVk1Y+18KEUesru5pMvv4uEG/VhrcGOxyuPlBGKDZGNMeKXciB8zNCMrgi PrTg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id d142si3002245pfd.93.2019.02.14.10.17.27; Thu, 14 Feb 2019 10:17:44 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405217AbfBNKmv (ORCPT + 99 others); Thu, 14 Feb 2019 05:42:51 -0500 Received: from mx2.suse.de ([195.135.220.15]:55050 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2438500AbfBNKmq (ORCPT ); Thu, 14 Feb 2019 05:42:46 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 375FDB0BE; Thu, 14 Feb 2019 10:42:44 +0000 (UTC) From: Juergen Gross To: linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org, x86@kernel.org, linux-mm@kvack.org Cc: boris.ostrovsky@oracle.com, sstabellini@kernel.org, hpa@zytor.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, Juergen Gross Subject: [PATCH v3 2/2] x86/xen: dont add memory above max allowed allocation Date: Thu, 14 Feb 2019 11:42:40 +0100 Message-Id: <20190214104240.24428-3-jgross@suse.com> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20190214104240.24428-1-jgross@suse.com> References: <20190214104240.24428-1-jgross@suse.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Don't allow memory to be added above the allowed maximum allocation limit set by Xen. Trying to do so would result in cases like the following: [ 584.559652] ------------[ cut here ]------------ [ 584.564897] WARNING: CPU: 2 PID: 1 at ../arch/x86/xen/multicalls.c:129 xen_alloc_pte+0x1c7/0x390() [ 584.575151] Modules linked in: [ 584.578643] Supported: Yes [ 584.581750] CPU: 2 PID: 1 Comm: swapper/0 Not tainted 4.4.120-92.70-default #1 [ 584.590000] Hardware name: Cisco Systems Inc UCSC-C460-M4/UCSC-C460-M4, BIOS C460M4.4.0.1b.0.0629181419 06/29/2018 [ 584.601862] 0000000000000000 ffffffff813175a0 0000000000000000 ffffffff8184777c [ 584.610200] ffffffff8107f4e1 ffff880487eb7000 ffff8801862b79c0 ffff88048608d290 [ 584.618537] 0000000000487eb7 ffffea0000000201 ffffffff81009de7 ffffffff81068561 [ 584.626876] Call Trace: [ 584.629699] [] dump_trace+0x59/0x340 [ 584.635645] [] show_stack_log_lvl+0xea/0x170 [ 584.642391] [] show_stack+0x21/0x40 [ 584.648238] [] dump_stack+0x5c/0x7c [ 584.654085] [] warn_slowpath_common+0x81/0xb0 [ 584.660932] [] xen_alloc_pte+0x1c7/0x390 [ 584.667289] [] pmd_populate_kernel.constprop.6+0x40/0x80 [ 584.675241] [] phys_pmd_init+0x210/0x255 [ 584.681587] [] phys_pud_init+0x1da/0x247 [ 584.687931] [] kernel_physical_mapping_init+0xf5/0x1d4 [ 584.695682] [] init_memory_mapping+0x18d/0x380 [ 584.702631] [] arch_add_memory+0x59/0xf0 Signed-off-by: Juergen Gross --- arch/x86/xen/setup.c | 13 +++++++++++++ drivers/xen/xen-balloon.c | 11 +++++++++++ include/xen/xen.h | 4 ++++ 3 files changed, 28 insertions(+) diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c index d5f303c0e656..0e770f5e5e8c 100644 --- a/arch/x86/xen/setup.c +++ b/arch/x86/xen/setup.c @@ -12,6 +12,7 @@ #include #include #include +#include #include #include @@ -589,6 +590,14 @@ static void __init xen_align_and_add_e820_region(phys_addr_t start, if (type == E820_TYPE_RAM) { start = PAGE_ALIGN(start); end &= ~((phys_addr_t)PAGE_SIZE - 1); +#ifdef CONFIG_MEMORY_HOTPLUG + /* + * Don't allow adding memory not in E820 map while booting the + * system. Once the balloon driver is up it will remove that + * restriction again. + */ + max_mem_size = end; +#endif } e820__range_add(start, end - start, type); @@ -748,6 +757,10 @@ char * __init xen_memory_setup(void) memmap.nr_entries = ARRAY_SIZE(xen_e820_table.entries); set_xen_guest_handle(memmap.buffer, xen_e820_table.entries); +#ifdef CONFIG_MEMORY_HOTPLUG + xen_saved_max_mem_size = max_mem_size; +#endif + op = xen_initial_domain() ? XENMEM_machine_memory_map : XENMEM_memory_map; diff --git a/drivers/xen/xen-balloon.c b/drivers/xen/xen-balloon.c index 2acbfe104e46..a67236b02452 100644 --- a/drivers/xen/xen-balloon.c +++ b/drivers/xen/xen-balloon.c @@ -37,6 +37,7 @@ #include #include #include +#include #include #include @@ -50,6 +51,10 @@ #define BALLOON_CLASS_NAME "xen_memory" +#ifdef CONFIG_MEMORY_HOTPLUG +u64 xen_saved_max_mem_size = 0; +#endif + static struct device balloon_dev; static int register_balloon(struct device *dev); @@ -63,6 +68,12 @@ static void watch_target(struct xenbus_watch *watch, static bool watch_fired; static long target_diff; +#ifdef CONFIG_MEMORY_HOTPLUG + /* The balloon driver will take care of adding memory now. */ + if (xen_saved_max_mem_size) + max_mem_size = xen_saved_max_mem_size; +#endif + err = xenbus_scanf(XBT_NIL, "memory", "target", "%llu", &new_target); if (err != 1) { /* This is ok (for domain0 at least) - so just return */ diff --git a/include/xen/xen.h b/include/xen/xen.h index 0e2156786ad2..d8f1ab43ab56 100644 --- a/include/xen/xen.h +++ b/include/xen/xen.h @@ -46,4 +46,8 @@ struct bio_vec; bool xen_biovec_phys_mergeable(const struct bio_vec *vec1, const struct bio_vec *vec2); +#ifdef CONFIG_MEMORY_HOTPLUG +extern u64 xen_saved_max_mem_size; +#endif + #endif /* _XEN_XEN_H */ -- 2.16.4