From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47667) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Ztd2k-0000Ju-B6 for qemu-devel@nongnu.org; Tue, 03 Nov 2015 09:58:39 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Ztd2h-0005sH-3s for qemu-devel@nongnu.org; Tue, 03 Nov 2015 09:58:38 -0500 Received: from mga03.intel.com ([134.134.136.65]:58525) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Ztd2g-0005rG-Uw for qemu-devel@nongnu.org; Tue, 03 Nov 2015 09:58:35 -0500 References: <1446455617-129562-1-git-send-email-guangrong.xiao@linux.intel.com> <1446455617-129562-14-git-send-email-guangrong.xiao@linux.intel.com> <563798B3.4080204@virtuozzo.com> From: Xiao Guangrong Message-ID: <5638CA03.9030607@linux.intel.com> Date: Tue, 3 Nov 2015 22:51:47 +0800 MIME-Version: 1.0 In-Reply-To: <563798B3.4080204@virtuozzo.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v7 13/35] hostmem-file: use whole file size if possible List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Vladimir Sementsov-Ogievskiy , pbonzini@redhat.com, imammedo@redhat.com Cc: ehabkost@redhat.com, kvm@vger.kernel.org, mst@redhat.com, gleb@kernel.org, mtosatti@redhat.com, qemu-devel@nongnu.org, stefanha@redhat.com, dan.j.williams@intel.com, rth@twiddle.net On 11/03/2015 01:09 AM, Vladimir Sementsov-Ogievskiy wrote: > On 02.11.2015 12:13, Xiao Guangrong wrote: >> Use the whole file size if @size is not specified which is useful >> if we want to directly pass a file to guest >> >> Signed-off-by: Xiao Guangrong >> --- >> backends/hostmem-file.c | 22 ++++++++++++++++++---- >> 1 file changed, 18 insertions(+), 4 deletions(-) >> >> diff --git a/backends/hostmem-file.c b/backends/hostmem-file.c >> index 9097a57..ea355c1 100644 >> --- a/backends/hostmem-file.c >> +++ b/backends/hostmem-file.c >> @@ -38,15 +38,29 @@ file_backend_memory_alloc(HostMemoryBackend *backend, Error **errp) >> { >> HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(backend); >> - if (!backend->size) { >> - error_setg(errp, "can't create backend with size 0"); >> - return; >> - } >> if (!fb->mem_path) { >> error_setg(errp, "mem-path property not set"); >> return; >> } >> + if (!backend->size) { >> + Error *local_err = NULL; >> + >> + /* >> + * use the whole file size if @size is not specified. >> + */ >> + backend->size = qemu_file_getlength(fb->mem_path, &local_err); >> + if (local_err) { >> + error_propagate(errp, local_err); >> + return; >> + } >> + } >> + >> + if (!backend->size) { >> + error_setg(errp, "can't create backend on the file whose size is 0"); >> + return; >> + } >> + >> backend->force_prealloc = mem_prealloc; >> memory_region_init_ram_from_file(&backend->mr, OBJECT(backend), >> object_get_canonical_path(OBJECT(backend)), > > why not just It look like it is a common style used in whole QEMU code. > > + if (!backend->size) { > + /* > + * use the whole file size if @size is not specified. > + */ > + backend->size = qemu_file_getlength(fb->mem_path, errp); > + if (*errp) { > + return; > + } > + } > > But i think your way is better. :) > what the purpose of propagating? >