From patchwork Mon Jan 18 13:13:02 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anshuman Khandual X-Patchwork-Id: 12027319 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B9016C433DB for ; Mon, 18 Jan 2021 13:13:15 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 6AF6922B4E for ; Mon, 18 Jan 2021 13:13:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6AF6922B4E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 037326B0253; Mon, 18 Jan 2021 08:13:15 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id F29756B0254; Mon, 18 Jan 2021 08:13:14 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E3ED36B026E; Mon, 18 Jan 2021 08:13:14 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0079.hostedemail.com [216.40.44.79]) by kanga.kvack.org (Postfix) with ESMTP id CFED86B0253 for ; Mon, 18 Jan 2021 08:13:14 -0500 (EST) Received: from smtpin30.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 9ABEC181AF5C3 for ; Mon, 18 Jan 2021 13:13:14 +0000 (UTC) X-FDA: 77718936708.30.bean82_381731927549 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin30.hostedemail.com (Postfix) with ESMTP id 72F69180B3C96 for ; Mon, 18 Jan 2021 13:13:14 +0000 (UTC) X-HE-Tag: bean82_381731927549 X-Filterd-Recvd-Size: 7395 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf41.hostedemail.com (Postfix) with ESMTP for ; Mon, 18 Jan 2021 13:13:13 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id D709A106F; Mon, 18 Jan 2021 05:13:12 -0800 (PST) Received: from p8cg001049571a15.arm.com (unknown [10.163.89.163]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id E12693F719; Mon, 18 Jan 2021 05:13:05 -0800 (PST) From: Anshuman Khandual To: linux-mm@kvack.org, akpm@linux-foundation.org, david@redhat.com, hca@linux.ibm.com, catalin.marinas@arm.com Cc: Anshuman Khandual , Oscar Salvador , Vasily Gorbik , Will Deacon , Ard Biesheuvel , Mark Rutland , linux-arm-kernel@lists.infradead.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, "Michael S. Tsirkin" , Jason Wang , Pankaj Gupta , Michal Hocko , Wei Yang , teawater , Pankaj Gupta , Jonathan Cameron Subject: [PATCH RFC] virtio-mem: check against memhp_get_pluggable_range() which memory we can hotplug Date: Mon, 18 Jan 2021 18:43:02 +0530 Message-Id: <1610975582-12646-5-git-send-email-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1610975582-12646-1-git-send-email-anshuman.khandual@arm.com> References: <1610975582-12646-1-git-send-email-anshuman.khandual@arm.com> X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: David Hildenbrand Right now, we only check against MAX_PHYSMEM_BITS - but turns out there are more restrictions of which memory we can actually hotplug, especially om arm64 or s390x once we support them: we might receive something like -E2BIG or -ERANGE from add_memory_driver_managed(), stopping device operation. So, check right when initializing the device which memory we can add, warning the user. Try only adding actually pluggable ranges: in the worst case, no memory provided by our device is pluggable. In the usual case, we expect all device memory to be pluggable, and in corner cases only some memory at the end of the device-managed memory region to not be pluggable. Cc: "Michael S. Tsirkin" Cc: Jason Wang Cc: Pankaj Gupta Cc: Michal Hocko Cc: Oscar Salvador Cc: Wei Yang Cc: Andrew Morton Cc: catalin.marinas@arm.com Cc: teawater Cc: Anshuman Khandual Cc: Pankaj Gupta Cc: Jonathan Cameron Cc: hca@linux.ibm.com Cc: Vasily Gorbik Cc: Will Deacon Cc: Ard Biesheuvel Cc: Mark Rutland Cc: Heiko Carstens Cc: Michal Hocko Signed-off-by: David Hildenbrand Signed-off-by: Anshuman Khandual --- drivers/virtio/virtio_mem.c | 40 +++++++++++++++++++++++++------------ 1 file changed, 27 insertions(+), 13 deletions(-) diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c index 9fc9ec4a25f5..1fe40b2d7b6d 100644 --- a/drivers/virtio/virtio_mem.c +++ b/drivers/virtio/virtio_mem.c @@ -2222,7 +2222,7 @@ static int virtio_mem_unplug_pending_mb(struct virtio_mem *vm) */ static void virtio_mem_refresh_config(struct virtio_mem *vm) { - const uint64_t phys_limit = 1UL << MAX_PHYSMEM_BITS; + const struct range pluggable_range = memhp_get_pluggable_range(true); uint64_t new_plugged_size, usable_region_size, end_addr; /* the plugged_size is just a reflection of what _we_ did previously */ @@ -2234,15 +2234,25 @@ static void virtio_mem_refresh_config(struct virtio_mem *vm) /* calculate the last usable memory block id */ virtio_cread_le(vm->vdev, struct virtio_mem_config, usable_region_size, &usable_region_size); - end_addr = vm->addr + usable_region_size; - end_addr = min(end_addr, phys_limit); + end_addr = min(vm->addr + usable_region_size - 1, + pluggable_range.end); - if (vm->in_sbm) - vm->sbm.last_usable_mb_id = - virtio_mem_phys_to_mb_id(end_addr) - 1; - else - vm->bbm.last_usable_bb_id = - virtio_mem_phys_to_bb_id(vm, end_addr) - 1; + if (vm->in_sbm) { + vm->sbm.last_usable_mb_id = virtio_mem_phys_to_mb_id(end_addr); + if (!IS_ALIGNED(end_addr + 1, memory_block_size_bytes())) + vm->sbm.last_usable_mb_id--; + } else { + vm->bbm.last_usable_bb_id = virtio_mem_phys_to_bb_id(vm, + end_addr); + if (!IS_ALIGNED(end_addr + 1, vm->bbm.bb_size)) + vm->bbm.last_usable_bb_id--; + } + /* + * If we cannot plug any of our device memory (e.g., nothing in the + * usable region is addressable), the last usable memory block id will + * be smaller than the first usable memory block id. We'll stop + * attempting to add memory with -ENOSPC from our main loop. + */ /* see if there is a request to change the size */ virtio_cread_le(vm->vdev, struct virtio_mem_config, requested_size, @@ -2364,6 +2374,7 @@ static int virtio_mem_init_vq(struct virtio_mem *vm) static int virtio_mem_init(struct virtio_mem *vm) { + const struct range pluggable_range = memhp_get_pluggable_range(true); const uint64_t phys_limit = 1UL << MAX_PHYSMEM_BITS; uint64_t sb_size, addr; uint16_t node_id; @@ -2405,9 +2416,10 @@ static int virtio_mem_init(struct virtio_mem *vm) if (!IS_ALIGNED(vm->addr + vm->region_size, memory_block_size_bytes())) dev_warn(&vm->vdev->dev, "The alignment of the physical end address can make some memory unusable.\n"); - if (vm->addr + vm->region_size > phys_limit) + if (vm->addr < pluggable_range.start || + vm->addr + vm->region_size - 1 > pluggable_range.end) dev_warn(&vm->vdev->dev, - "Some memory is not addressable. This can make some memory unusable.\n"); + "Some device memory is not addressable/pluggable. This can make some memory unusable.\n"); /* * We want subblocks to span at least MAX_ORDER_NR_PAGES and @@ -2429,7 +2441,8 @@ static int virtio_mem_init(struct virtio_mem *vm) vm->sbm.sb_size; /* Round up to the next full memory block */ - addr = vm->addr + memory_block_size_bytes() - 1; + addr = max_t(uint64_t, vm->addr, pluggable_range.start) + + memory_block_size_bytes() - 1; vm->sbm.first_mb_id = virtio_mem_phys_to_mb_id(addr); vm->sbm.next_mb_id = vm->sbm.first_mb_id; } else { @@ -2450,7 +2463,8 @@ static int virtio_mem_init(struct virtio_mem *vm) } /* Round up to the next aligned big block */ - addr = vm->addr + vm->bbm.bb_size - 1; + addr = max_t(uint64_t, vm->addr, pluggable_range.start) + + vm->bbm.bb_size - 1; vm->bbm.first_bb_id = virtio_mem_phys_to_bb_id(vm, addr); vm->bbm.next_bb_id = vm->bbm.first_bb_id; }