From mboxrd@z Thu Jan 1 00:00:00 1970 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 920D9C77B73 for ; Wed, 19 Apr 2023 07:02:29 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pp1p1-0000Xm-KB; Wed, 19 Apr 2023 03:01:43 -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 1pp1p0-0000XC-8j for qemu-devel@nongnu.org; Wed, 19 Apr 2023 03:01:42 -0400 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 1pp1oy-000162-0I for qemu-devel@nongnu.org; Wed, 19 Apr 2023 03:01:42 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1681887698; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:in-reply-to:in-reply-to: references:references; bh=qA8Zf98TBjT9Zm/oZt+WvS6o2/uR22/cd/q0m9ouWEU=; b=LsfJWxRASXxGigr4wKQ7XvzFgkob7L8Sf6Gfk9nxDqLFhDRA1wvSB+Tl9qQ+ksockke+Fp igVg1mXcw7WosVdFbNZRVutXEJbVh0uQ7HGDARbMN9ptRZnsJ+hWLAvfcpyXv6hJYTX+ab kuFStr3wArmX0bLPUL+Ifk7fH1t3HCA= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-660-qpzW-jeoM_uopy_O94r35w-1; Wed, 19 Apr 2023 03:01:37 -0400 X-MC-Unique: qpzW-jeoM_uopy_O94r35w-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id ED424811E7C for ; Wed, 19 Apr 2023 07:01:36 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.43]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 194EBC16024; Wed, 19 Apr 2023 07:01:35 +0000 (UTC) Date: Wed, 19 Apr 2023 08:01:34 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Peter Xu Cc: qemu-devel@nongnu.org, David Hildenbrand , Paolo Bonzini , Juan Quintela , Leonardo Bras Soares Passos Subject: Re: [PATCH 1/3] hostmem: Detect and cache fs type for file hostmem Message-ID: References: <20230418225749.1049185-1-peterx@redhat.com> <20230418225749.1049185-2-peterx@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20230418225749.1049185-2-peterx@redhat.com> User-Agent: Mutt/2.2.9 (2022-11-12) X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 Received-SPF: pass client-ip=170.10.133.124; envelope-from=berrange@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_H2=-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: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Tue, Apr 18, 2023 at 06:57:47PM -0400, Peter Xu wrote: > Detect the file system for a memory-backend-file object and cache it within > the object if possible when CONFIG_LINUX (using statfs). > > Only support the two important types of memory (tmpfs, hugetlbfs) and keep > the rest as "unknown" for now. > > Signed-off-by: Peter Xu > --- > backends/hostmem-file.c | 37 ++++++++++++++++++++++++++++++++++++- > include/sysemu/hostmem.h | 1 + > 2 files changed, 37 insertions(+), 1 deletion(-) > > diff --git a/backends/hostmem-file.c b/backends/hostmem-file.c > index 25141283c4..2484e45a11 100644 > --- a/backends/hostmem-file.c > +++ b/backends/hostmem-file.c > @@ -18,13 +18,17 @@ > #include "sysemu/hostmem.h" > #include "qom/object_interfaces.h" > #include "qom/object.h" > +#ifdef CONFIG_LINUX > +#include > +#include > +#endif > > OBJECT_DECLARE_SIMPLE_TYPE(HostMemoryBackendFile, MEMORY_BACKEND_FILE) > > > struct HostMemoryBackendFile { > HostMemoryBackend parent_obj; > - > + __fsword_t fs_type; > char *mem_path; > uint64_t align; > bool discard_data; > @@ -52,6 +56,15 @@ file_backend_memory_alloc(HostMemoryBackend *backend, Error **errp) > return; > } > > +#ifdef CONFIG_LINUX > + struct statfs fs; > + if (!statfs(fb->mem_path, &fs)) { > + fb->fs_type = fs.f_type; > + } else { > + fb->fs_type = 0; > + } > +#endif > + > name = host_memory_backend_get_name(backend); > ram_flags = backend->share ? RAM_SHARED : 0; > ram_flags |= backend->reserve ? 0 : RAM_NORESERVE; > @@ -181,6 +194,28 @@ static void file_backend_unparent(Object *obj) > } > } > > +const char *file_memory_backend_get_fs_type(Object *obj) > +{ > +#ifdef CONFIG_LINUX > + HostMemoryBackendFile *fb = (HostMemoryBackendFile *) > + object_dynamic_cast(obj, TYPE_MEMORY_BACKEND_FILE); > + > + if (!fb) { > + goto out; > + } > + > + switch (fb->fs_type) { > + case TMPFS_MAGIC: > + return "tmpfs"; > + case HUGETLBFS_MAGIC: > + return "hugetlbfs"; > + } > + > +out: > +#endif > + return "unknown"; > +} I rather feel this should be returning an enm, not strings, so the caller just does a plain equality test rather than string comparisons With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|