From patchwork Mon Nov 27 12:32:27 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michal Privoznik X-Patchwork-Id: 13469488 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 A9AA3C4167B for ; Mon, 27 Nov 2023 12:34:11 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1r7ao1-0002zM-Ku; Mon, 27 Nov 2023 07:33:41 -0500 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 1r7any-0002yh-UM for qemu-devel@nongnu.org; Mon, 27 Nov 2023 07:33:39 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1r7anx-0000Ic-Dz for qemu-devel@nongnu.org; Mon, 27 Nov 2023 07:33:38 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1701088416; 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; bh=SC/qOzYy2aa58HZ8c/Dgyqetb4HOv/g97gogYJmILO0=; b=ItT8CzNG5llnHV8gvRyZA1A8w7OcAq4Xf1bUlbQNGQOqlkcDobAAmdSXSk8bE363CHcPZ2 tTfL/8Cul84BtVHslKXgnXLtIlvJBmPdKeop5Lx//vwYKtTBnYjhO6rLBnkOudcpDsyZig uPT0LG3gvT5gm97skhx3aCSTeBRQFZs= 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-250-Ig1Z86nUNU2Jj2dMe5Lr0Q-1; Mon, 27 Nov 2023 07:32:31 -0500 X-MC-Unique: Ig1Z86nUNU2Jj2dMe5Lr0Q-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (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 8465588D017 for ; Mon, 27 Nov 2023 12:32:31 +0000 (UTC) Received: from maggie.brq.redhat.com (unknown [10.43.3.102]) by smtp.corp.redhat.com (Postfix) with ESMTP id D4A2FC15883; Mon, 27 Nov 2023 12:32:30 +0000 (UTC) From: Michal Privoznik To: qemu-devel@nongnu.org Cc: david@redhat.com, imammedo@redhat.com Subject: [PATCH] hostmem: Round up memory size for qemu_madvise() in host_memory_backend_memory_complete() Date: Mon, 27 Nov 2023 13:32:27 +0100 Message-ID: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.8 Received-SPF: pass client-ip=170.10.133.124; envelope-from=mprivozn@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, 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_H3=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 Simple reproducer: qemu.git $ ./build/qemu-system-x86_64 \ -m size=8389632k,slots=16,maxmem=25600000k \ -object '{"qom-type":"memory-backend-file","id":"ram-node0","mem-path":"/hugepages2M/","prealloc":true,"size":8590983168,"host-nodes":[0],"policy":"bind"}' \ -numa node,nodeid=0,cpus=0,memdev=ram-node0 With current master I get: qemu-system-x86_64: cannot bind memory to host NUMA nodes: Invalid argument The problem is that memory size (8193MiB) is not an integer multiple of underlying pagesize (2MiB) which triggers a check inside of madvise(), since we can't really set a madvise() policy just to a fraction of a page. Signed-off-by: Michal Privoznik --- backends/hostmem.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/backends/hostmem.c b/backends/hostmem.c index 747e7838c0..4e88d048de 100644 --- a/backends/hostmem.c +++ b/backends/hostmem.c @@ -326,9 +326,10 @@ host_memory_backend_memory_complete(UserCreatable *uc, Error **errp) HostMemoryBackendClass *bc = MEMORY_BACKEND_GET_CLASS(uc); Error *local_err = NULL; void *ptr; - uint64_t sz; if (bc->alloc) { + uint64_t sz; + bc->alloc(backend, &local_err); if (local_err) { goto out; @@ -337,6 +338,11 @@ host_memory_backend_memory_complete(UserCreatable *uc, Error **errp) ptr = memory_region_get_ram_ptr(&backend->mr); sz = memory_region_size(&backend->mr); + /* Round up size to be an integer multiple of pagesize, because + * madvise() does not really like setting advices on a fraction of a + * page. */ + sz = ROUND_UP(sz, qemu_ram_pagesize(backend->mr.ram_block)); + if (backend->merge) { qemu_madvise(ptr, sz, QEMU_MADV_MERGEABLE); }