From patchwork Fri May 31 15:10:47 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Michal Privoznik X-Patchwork-Id: 13681822 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 09B17C27C4F for ; Fri, 31 May 2024 15:12:11 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sD3uS-00008T-0H; Fri, 31 May 2024 11:11:12 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sD3uJ-00005U-7S for qemu-devel@nongnu.org; Fri, 31 May 2024 11:11:04 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sD3uD-0005Wo-Us for qemu-devel@nongnu.org; Fri, 31 May 2024 11:10:59 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1717168253; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=dBn9cyCHNceTfICbu/pOQoQHiwbNTyjHN5kM/7fkG8E=; b=GfUu5AG72Kc3/fa7clMPsXKCJMeMkr4wQSjf68wXSdZSKRMfB1FCfVpdtL9fLctfoS5XHb h+D4NGbhnCRXDoLP1FoapXXtIkr18yj5zPAzQAPoSqBbmC4w+z76bMN83BHbBsEz7UYms3 MOtiUISpjiQODEMiRSh+ekQlZ8pwIKU= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-475-3LWsEf6SMm6tOrFcIhR-Vw-1; Fri, 31 May 2024 11:10:52 -0400 X-MC-Unique: 3LWsEf6SMm6tOrFcIhR-Vw-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id BDE128008A4 for ; Fri, 31 May 2024 15:10:51 +0000 (UTC) Received: from maggie.brq.redhat.com (unknown [10.43.3.102]) by smtp.corp.redhat.com (Postfix) with ESMTP id 69B5A3C27 for ; Fri, 31 May 2024 15:10:51 +0000 (UTC) From: Michal Privoznik To: qemu-devel@nongnu.org Subject: [PATCH v3 4/4] backends/hostmem: Report error when memory size is unaligned Date: Fri, 31 May 2024 17:10:47 +0200 Message-ID: <025d0bdd5e76b334754c09c445fe621090121da5.1717168113.git.mprivozn@redhat.com> In-Reply-To: References: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.1 Received-SPF: pass client-ip=170.10.129.124; envelope-from=mprivozn@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.085, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org If memory-backend-{file,ram} has a size that's not aligned to underlying page size it is not only wasteful, but also may lead to hard to debug behaviour. For instance, in case memory-backend-file and hugepages, madvise() and mbind() fail. Rightfully so, page is the smallest unit they can work with. And even though an error is reported, the root cause it not very clear: qemu-system-x86_64: Couldn't set property 'dump' on 'memory-backend-file': Invalid argument After this commit: qemu-system-x86_64: backend 'memory-backend-file' memory size must be multiple of 2 MiB Signed-off-by: Michal Privoznik Reviewed-by: Philippe Mathieu-Daudé --- backends/hostmem.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/backends/hostmem.c b/backends/hostmem.c index 012a8c190f..4d6c69fe4d 100644 --- a/backends/hostmem.c +++ b/backends/hostmem.c @@ -20,6 +20,7 @@ #include "qom/object_interfaces.h" #include "qemu/mmap-alloc.h" #include "qemu/madvise.h" +#include "qemu/cutils.h" #include "hw/qdev-core.h" #ifdef CONFIG_NUMA @@ -337,6 +338,7 @@ host_memory_backend_memory_complete(UserCreatable *uc, Error **errp) HostMemoryBackendClass *bc = MEMORY_BACKEND_GET_CLASS(uc); void *ptr; uint64_t sz; + size_t pagesize; bool async = !phase_check(PHASE_LATE_BACKENDS_CREATED); if (!bc->alloc) { @@ -348,6 +350,14 @@ host_memory_backend_memory_complete(UserCreatable *uc, Error **errp) ptr = memory_region_get_ram_ptr(&backend->mr); sz = memory_region_size(&backend->mr); + pagesize = qemu_ram_pagesize(backend->mr.ram_block); + + if (!QEMU_IS_ALIGNED(sz, pagesize)) { + g_autofree char *pagesize_str = size_to_str(pagesize); + error_setg(errp, "backend '%s' memory size must be multiple of %s", + object_get_typename(OBJECT(uc)), pagesize_str); + return; + } if (backend->merge && qemu_madvise(ptr, sz, QEMU_MADV_MERGEABLE)) {