From patchwork Thu Apr 30 10:29:06 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 11519791 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2F5CE14B4 for ; Thu, 30 Apr 2020 10:29:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0B8D92137B for ; Thu, 30 Apr 2020 10:29:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="fm39ePLN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726839AbgD3K3y (ORCPT ); Thu, 30 Apr 2020 06:29:54 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:43361 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726378AbgD3K3x (ORCPT ); Thu, 30 Apr 2020 06:29:53 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1588242591; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=SZ5IMSF8ZkjNCkTQzjTv952CxqGeCi/XaPtFmGo7H8U=; b=fm39ePLNVN1RuPVswXNCmUj7p06bS1/kxRMLGUuq9/cIB6i/h9JjD34LG3b/pJuhEHf5/7 r6redKOruVYad9KUaLG6RdMovt51NVUQlG1s6QUBwsO0Cju6+FTsqa7e3kIySuN458STLv smKwi2Qq0ez3rV9LoJ34ytMxgMEilAw= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-431-WETd19g0OlqD5GCQnge_oQ-1; Thu, 30 Apr 2020 06:29:44 -0400 X-MC-Unique: WETd19g0OlqD5GCQnge_oQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 6843A100CCC1; Thu, 30 Apr 2020 10:29:40 +0000 (UTC) Received: from t480s.redhat.com (ovpn-113-172.ams2.redhat.com [10.36.113.172]) by smtp.corp.redhat.com (Postfix) with ESMTP id 591C45EDEE; Thu, 30 Apr 2020 10:29:32 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, virtio-dev@lists.oasis-open.org, virtualization@lists.linux-foundation.org, linuxppc-dev@lists.ozlabs.org, linux-acpi@vger.kernel.org, linux-nvdimm@lists.01.org, linux-hyperv@vger.kernel.org, linux-s390@vger.kernel.org, xen-devel@lists.xenproject.org, Michal Hocko , Andrew Morton , "Michael S . Tsirkin" , David Hildenbrand , Wei Liu , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , "Rafael J. Wysocki" , Len Brown , Greg Kroah-Hartman , Dan Williams , Vishal Verma , Dave Jiang , "K. Y. Srinivasan" , Haiyang Zhang , Stephen Hemminger , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , Jason Wang , Boris Ostrovsky , Juergen Gross , Stefano Stabellini , Thomas Gleixner , Pingfan Liu , Leonardo Bras , Nathan Lynch , Oscar Salvador , Michal Hocko , Baoquan He , Wei Yang , Pankaj Gupta , Eric Biederman Subject: [PATCH v2 1/3] mm/memory_hotplug: Prepare passing flags to add_memory() and friends Date: Thu, 30 Apr 2020 12:29:06 +0200 Message-Id: <20200430102908.10107-2-david@redhat.com> In-Reply-To: <20200430102908.10107-1-david@redhat.com> References: <20200430102908.10107-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org We soon want to pass flags - prepare for that. This patch is based on a similar patch by Oscar Salvador: https://lkml.kernel.org/r/20190625075227.15193-3-osalvador@suse.de Acked-by: Wei Liu Cc: Michael Ellerman Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: "Rafael J. Wysocki" Cc: Len Brown Cc: Greg Kroah-Hartman Cc: Dan Williams Cc: Vishal Verma Cc: Dave Jiang Cc: "K. Y. Srinivasan" Cc: Haiyang Zhang Cc: Stephen Hemminger Cc: Wei Liu Cc: Heiko Carstens Cc: Vasily Gorbik Cc: Christian Borntraeger Cc: "Michael S. Tsirkin" Cc: Jason Wang Cc: Boris Ostrovsky Cc: Juergen Gross Cc: Stefano Stabellini Cc: Andrew Morton Cc: Thomas Gleixner Cc: Pingfan Liu Cc: Leonardo Bras Cc: Nathan Lynch Cc: Oscar Salvador Cc: Michal Hocko Cc: Baoquan He Cc: Wei Yang Cc: Pankaj Gupta Cc: Eric Biederman Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-kernel@vger.kernel.org Cc: linux-acpi@vger.kernel.org Cc: linux-nvdimm@lists.01.org Cc: linux-hyperv@vger.kernel.org Cc: linux-s390@vger.kernel.org Cc: virtualization@lists.linux-foundation.org Cc: xen-devel@lists.xenproject.org Signed-off-by: David Hildenbrand --- arch/powerpc/platforms/powernv/memtrace.c | 2 +- arch/powerpc/platforms/pseries/hotplug-memory.c | 2 +- drivers/acpi/acpi_memhotplug.c | 2 +- drivers/base/memory.c | 2 +- drivers/dax/kmem.c | 2 +- drivers/hv/hv_balloon.c | 2 +- drivers/s390/char/sclp_cmd.c | 2 +- drivers/xen/balloon.c | 2 +- include/linux/memory_hotplug.h | 7 ++++--- mm/memory_hotplug.c | 11 ++++++----- 10 files changed, 18 insertions(+), 16 deletions(-) diff --git a/arch/powerpc/platforms/powernv/memtrace.c b/arch/powerpc/platforms/powernv/memtrace.c index 13b369d2cc45..a7475d18c671 100644 --- a/arch/powerpc/platforms/powernv/memtrace.c +++ b/arch/powerpc/platforms/powernv/memtrace.c @@ -224,7 +224,7 @@ static int memtrace_online(void) ent->mem = 0; } - if (add_memory(ent->nid, ent->start, ent->size)) { + if (add_memory(ent->nid, ent->start, ent->size, 0)) { pr_err("Failed to add trace memory to node %d\n", ent->nid); ret += 1; diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c index 5ace2f9a277e..ae44eba46ca0 100644 --- a/arch/powerpc/platforms/pseries/hotplug-memory.c +++ b/arch/powerpc/platforms/pseries/hotplug-memory.c @@ -646,7 +646,7 @@ static int dlpar_add_lmb(struct drmem_lmb *lmb) block_sz = memory_block_size_bytes(); /* Add the memory */ - rc = __add_memory(lmb->nid, lmb->base_addr, block_sz); + rc = __add_memory(lmb->nid, lmb->base_addr, block_sz, 0); if (rc) { invalidate_lmb_associativity_index(lmb); return rc; diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c index e294f44a7850..d91b3584d4b2 100644 --- a/drivers/acpi/acpi_memhotplug.c +++ b/drivers/acpi/acpi_memhotplug.c @@ -207,7 +207,7 @@ static int acpi_memory_enable_device(struct acpi_memory_device *mem_device) if (node < 0) node = memory_add_physaddr_to_nid(info->start_addr); - result = __add_memory(node, info->start_addr, info->length); + result = __add_memory(node, info->start_addr, info->length, 0); /* * If the memory block has been used by the kernel, add_memory() diff --git a/drivers/base/memory.c b/drivers/base/memory.c index 2b09b68b9f78..c0ef7d9e310a 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -432,7 +432,7 @@ static ssize_t probe_store(struct device *dev, struct device_attribute *attr, nid = memory_add_physaddr_to_nid(phys_addr); ret = __add_memory(nid, phys_addr, - MIN_MEMORY_BLOCK_SIZE * sections_per_block); + MIN_MEMORY_BLOCK_SIZE * sections_per_block, 0); if (ret) goto out; diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c index 3d0a7e702c94..e159184e0ba0 100644 --- a/drivers/dax/kmem.c +++ b/drivers/dax/kmem.c @@ -65,7 +65,7 @@ int dev_dax_kmem_probe(struct device *dev) new_res->flags = IORESOURCE_SYSTEM_RAM; new_res->name = dev_name(dev); - rc = add_memory(numa_node, new_res->start, resource_size(new_res)); + rc = add_memory(numa_node, new_res->start, resource_size(new_res), 0); if (rc) { release_resource(new_res); kfree(new_res); diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c index 32e3bc0aa665..0194bed1a573 100644 --- a/drivers/hv/hv_balloon.c +++ b/drivers/hv/hv_balloon.c @@ -726,7 +726,7 @@ static void hv_mem_hot_add(unsigned long start, unsigned long size, nid = memory_add_physaddr_to_nid(PFN_PHYS(start_pfn)); ret = add_memory(nid, PFN_PHYS((start_pfn)), - (HA_CHUNK << PAGE_SHIFT)); + (HA_CHUNK << PAGE_SHIFT), 0); if (ret) { pr_err("hot_add memory failed error is %d\n", ret); diff --git a/drivers/s390/char/sclp_cmd.c b/drivers/s390/char/sclp_cmd.c index a864b21af602..a6a908244c74 100644 --- a/drivers/s390/char/sclp_cmd.c +++ b/drivers/s390/char/sclp_cmd.c @@ -406,7 +406,7 @@ static void __init add_memory_merged(u16 rn) if (!size) goto skip_add; for (addr = start; addr < start + size; addr += block_size) - add_memory(0, addr, block_size); + add_memory(0, addr, block_size, 0); skip_add: first_rn = rn; num = 1; diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index 0c142bcab79d..6ec0373fa624 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -347,7 +347,7 @@ static enum bp_state reserve_additional_memory(void) mutex_unlock(&balloon_mutex); /* add_memory_resource() requires the device_hotplug lock */ lock_device_hotplug(); - rc = add_memory_resource(nid, resource); + rc = add_memory_resource(nid, resource, 0); unlock_device_hotplug(); mutex_lock(&balloon_mutex); diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 7dca9cd6076b..0151fb935c09 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -339,9 +339,10 @@ extern void set_zone_contiguous(struct zone *zone); extern void clear_zone_contiguous(struct zone *zone); extern void __ref free_area_init_core_hotplug(int nid); -extern int __add_memory(int nid, u64 start, u64 size); -extern int add_memory(int nid, u64 start, u64 size); -extern int add_memory_resource(int nid, struct resource *resource); +extern int __add_memory(int nid, u64 start, u64 size, unsigned long flags); +extern int add_memory(int nid, u64 start, u64 size, unsigned long flags); +extern int add_memory_resource(int nid, struct resource *resource, + unsigned long flags); extern void move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn, unsigned long nr_pages, struct vmem_altmap *altmap); extern void remove_pfn_range_from_zone(struct zone *zone, diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 555137bd0882..c01be92693e3 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1004,7 +1004,8 @@ static int online_memory_block(struct memory_block *mem, void *arg) * * we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ -int __ref add_memory_resource(int nid, struct resource *res) +int __ref add_memory_resource(int nid, struct resource *res, + unsigned long flags) { struct mhp_params params = { .pgprot = PAGE_KERNEL }; u64 start, size; @@ -1082,7 +1083,7 @@ int __ref add_memory_resource(int nid, struct resource *res) } /* requires device_hotplug_lock, see add_memory_resource() */ -int __ref __add_memory(int nid, u64 start, u64 size) +int __ref __add_memory(int nid, u64 start, u64 size, unsigned long flags) { struct resource *res; int ret; @@ -1091,18 +1092,18 @@ int __ref __add_memory(int nid, u64 start, u64 size) if (IS_ERR(res)) return PTR_ERR(res); - ret = add_memory_resource(nid, res); + ret = add_memory_resource(nid, res, flags); if (ret < 0) release_memory_resource(res); return ret; } -int add_memory(int nid, u64 start, u64 size) +int add_memory(int nid, u64 start, u64 size, unsigned long flags) { int rc; lock_device_hotplug(); - rc = __add_memory(nid, start, size); + rc = __add_memory(nid, start, size, flags); unlock_device_hotplug(); return rc; From patchwork Thu Apr 30 10:29:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 11519799 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id EFE4C14B4 for ; Thu, 30 Apr 2020 10:29:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D87462137B for ; 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Thu, 30 Apr 2020 06:29:51 -0400 X-MC-Unique: ZkDsTUQ-OxW7sjqOoV_anw-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 920BB45F; Thu, 30 Apr 2020 10:29:49 +0000 (UTC) Received: from t480s.redhat.com (ovpn-113-172.ams2.redhat.com [10.36.113.172]) by smtp.corp.redhat.com (Postfix) with ESMTP id B43035EDEB; Thu, 30 Apr 2020 10:29:40 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, virtio-dev@lists.oasis-open.org, virtualization@lists.linux-foundation.org, linuxppc-dev@lists.ozlabs.org, linux-acpi@vger.kernel.org, linux-nvdimm@lists.01.org, linux-hyperv@vger.kernel.org, linux-s390@vger.kernel.org, xen-devel@lists.xenproject.org, Michal Hocko , Andrew Morton , "Michael S . Tsirkin" , David Hildenbrand , Michal Hocko , Pankaj Gupta , Wei Yang , Baoquan He , Eric Biederman Subject: [PATCH v2 2/3] mm/memory_hotplug: Introduce MHP_NO_FIRMWARE_MEMMAP Date: Thu, 30 Apr 2020 12:29:07 +0200 Message-Id: <20200430102908.10107-3-david@redhat.com> In-Reply-To: <20200430102908.10107-1-david@redhat.com> References: <20200430102908.10107-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org Some devices/drivers that add memory via add_memory() and friends (e.g., dax/kmem, but also virtio-mem in the future) don't want to create entries in /sys/firmware/memmap/ - primarily to hinder kexec from adding this memory to the boot memmap of the kexec kernel. In fact, such memory is never exposed via the firmware memmap as System RAM (e.g., e820), so exposing this memory via /sys/firmware/memmap/ is wrong: "kexec needs the raw firmware-provided memory map to setup the parameter segment of the kernel that should be booted with kexec. Also, the raw memory map is useful for debugging. For that reason, /sys/firmware/memmap is an interface that provides the raw memory map to userspace." [1] We don't have to worry about firmware_map_remove() on the removal path. If there is no entry, it will simply return with -EINVAL. [1] https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-firmware-memmap Cc: Andrew Morton Cc: Michal Hocko Cc: Pankaj Gupta Cc: Wei Yang Cc: Baoquan He Cc: Eric Biederman Signed-off-by: David Hildenbrand Nacked-by: "Eric W. Biederman" --- include/linux/memory_hotplug.h | 8 ++++++++ mm/memory_hotplug.c | 3 ++- 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 0151fb935c09..4ca418a731eb 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -68,6 +68,14 @@ struct mhp_params { pgprot_t pgprot; }; +/* Flags used for add_memory() and friends. */ + +/* + * Don't create entries in /sys/firmware/memmap/. The memory is detected and + * added via a device driver, not via the initial (firmware) memmap. + */ +#define MHP_NO_FIRMWARE_MEMMAP 1 + /* * Zone resizing functions * diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index c01be92693e3..e94ede9cad00 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1062,7 +1062,8 @@ int __ref add_memory_resource(int nid, struct resource *res, BUG_ON(ret); /* create new memmap entry */ - firmware_map_add_hotplug(start, start + size, "System RAM"); + if (!(flags & MHP_NO_FIRMWARE_MEMMAP)) + firmware_map_add_hotplug(start, start + size, "System RAM"); /* device_online() will take the lock when calling online_pages() */ mem_hotplug_done(); From patchwork Thu Apr 30 10:29:08 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 11519805 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1B5A714B4 for ; Thu, 30 Apr 2020 10:30:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F20EF2192A for ; Thu, 30 Apr 2020 10:30:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="eJdl+5kS" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726893AbgD3KaD (ORCPT ); Thu, 30 Apr 2020 06:30:03 -0400 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:39287 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726853AbgD3KaC (ORCPT ); Thu, 30 Apr 2020 06:30:02 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1588242600; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=+3PNEjodfSmVCKHuEI1uD9BcIkwvNKm68jAUXOCtpHs=; b=eJdl+5kSxklF6hY4hhpJgJ5wBqUY+iieKDyUMx+o0m74fIv7Qe4OBqEa/qyIw2TcTwQgmO pdUfpm+ipjSWIQCN+pXan0W3gohsbMPr0+bP6wu02FhT7uqqqVp3SMFAFy3EC4L2JxZjog 0ydh85w5oPR2slQ2l8kE5GcHIMP9PqE= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-276-WVVkTXmBNpi7HsRCgZds0w-1; Thu, 30 Apr 2020 06:29:56 -0400 X-MC-Unique: WVVkTXmBNpi7HsRCgZds0w-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id E3AB28015D1; Thu, 30 Apr 2020 10:29:53 +0000 (UTC) Received: from t480s.redhat.com (ovpn-113-172.ams2.redhat.com [10.36.113.172]) by smtp.corp.redhat.com (Postfix) with ESMTP id E14155EDEE; Thu, 30 Apr 2020 10:29:49 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, virtio-dev@lists.oasis-open.org, virtualization@lists.linux-foundation.org, linuxppc-dev@lists.ozlabs.org, linux-acpi@vger.kernel.org, linux-nvdimm@lists.01.org, linux-hyperv@vger.kernel.org, linux-s390@vger.kernel.org, xen-devel@lists.xenproject.org, Michal Hocko , Andrew Morton , "Michael S . Tsirkin" , David Hildenbrand , Michal Hocko , Pankaj Gupta , Wei Yang , Baoquan He , Dave Hansen , Eric Biederman , Pavel Tatashin , Dan Williams Subject: [PATCH v2 3/3] device-dax: Add system ram (add_memory()) with MHP_NO_FIRMWARE_MEMMAP Date: Thu, 30 Apr 2020 12:29:08 +0200 Message-Id: <20200430102908.10107-4-david@redhat.com> In-Reply-To: <20200430102908.10107-1-david@redhat.com> References: <20200430102908.10107-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org Currently, when adding memory, we create entries in /sys/firmware/memmap/ as "System RAM". This does not reflect the reality and will lead to kexec-tools to add that memory to the fixed-up initial memmap for a kexec kernel (loaded via kexec_load()). The memory will be considered initial System RAM by the kexec kernel. We should let the kexec kernel decide how to use that memory - just as we do during an ordinary reboot. Before configuring the namespace: [root@localhost ~]# cat /proc/iomem ... 140000000-33fffffff : Persistent Memory 140000000-33fffffff : namespace0.0 3280000000-32ffffffff : PCI Bus 0000:00 After configuring the namespace: [root@localhost ~]# cat /proc/iomem ... 140000000-33fffffff : Persistent Memory 140000000-1481fffff : namespace0.0 148200000-33fffffff : dax0.0 3280000000-32ffffffff : PCI Bus 0000:00 After loading kmem: [root@localhost ~]# cat /proc/iomem ... 140000000-33fffffff : Persistent Memory 140000000-1481fffff : namespace0.0 150000000-33fffffff : dax0.0 150000000-33fffffff : System RAM 3280000000-32ffffffff : PCI Bus 0000:00 After a proper reboot: [root@localhost ~]# cat /proc/iomem ... 140000000-33fffffff : Persistent Memory 140000000-1481fffff : namespace0.0 148200000-33fffffff : dax0.0 3280000000-32ffffffff : PCI Bus 0000:00 Within the kexec kernel before this change: [root@localhost ~]# cat /proc/iomem ... 140000000-33fffffff : Persistent Memory 140000000-1481fffff : namespace0.0 150000000-33fffffff : System RAM 3280000000-32ffffffff : PCI Bus 0000:00 Within the kexec kernel after this change: [root@localhost ~]# cat /proc/iomem ... 140000000-33fffffff : Persistent Memory 140000000-1481fffff : namespace0.0 148200000-33fffffff : dax0.0 3280000000-32ffffffff : PCI Bus 0000:00 /sys/firmware/memmap/ before this change: 0000000000000000-000000000009fc00 (System RAM) 000000000009fc00-00000000000a0000 (Reserved) 00000000000f0000-0000000000100000 (Reserved) 0000000000100000-00000000bffdf000 (System RAM) 00000000bffdf000-00000000c0000000 (Reserved) 00000000feffc000-00000000ff000000 (Reserved) 00000000fffc0000-0000000100000000 (Reserved) 0000000100000000-0000000140000000 (System RAM) 0000000150000000-0000000340000000 (System RAM) /sys/firmware/memmap/ after a proper reboot: 0000000000000000-000000000009fc00 (System RAM) 000000000009fc00-00000000000a0000 (Reserved) 00000000000f0000-0000000000100000 (Reserved) 0000000000100000-00000000bffdf000 (System RAM) 00000000bffdf000-00000000c0000000 (Reserved) 00000000feffc000-00000000ff000000 (Reserved) 00000000fffc0000-0000000100000000 (Reserved) 0000000100000000-0000000140000000 (System RAM) /sys/firmware/memmap/ after this change: 0000000000000000-000000000009fc00 (System RAM) 000000000009fc00-00000000000a0000 (Reserved) 00000000000f0000-0000000000100000 (Reserved) 0000000000100000-00000000bffdf000 (System RAM) 00000000bffdf000-00000000c0000000 (Reserved) 00000000feffc000-00000000ff000000 (Reserved) 00000000fffc0000-0000000100000000 (Reserved) 0000000100000000-0000000140000000 (System RAM) kexec-tools already seem to basically ignore any System RAM that's not on top level when searching for areas to place kexec images - but also for determining crash areas to dump via kdump. This behavior is not changed by this patch. kexec-tools probably has to be fixed to also include this memory in system dumps. Note: kexec_file_load() does the right thing already within the kernel. Cc: Andrew Morton Cc: Michal Hocko Cc: Pankaj Gupta Cc: Wei Yang Cc: Baoquan He Cc: Dave Hansen Cc: Eric Biederman Cc: Pavel Tatashin Cc: Dan Williams Signed-off-by: David Hildenbrand Acked-by: Dave Hansen --- drivers/dax/kmem.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c index e159184e0ba0..929823a79816 100644 --- a/drivers/dax/kmem.c +++ b/drivers/dax/kmem.c @@ -65,7 +65,8 @@ int dev_dax_kmem_probe(struct device *dev) new_res->flags = IORESOURCE_SYSTEM_RAM; new_res->name = dev_name(dev); - rc = add_memory(numa_node, new_res->start, resource_size(new_res), 0); + rc = add_memory(numa_node, new_res->start, resource_size(new_res), + MHP_NO_FIRMWARE_MEMMAP); if (rc) { release_resource(new_res); kfree(new_res);