From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45205) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zly6G-0002fl-7j for qemu-devel@nongnu.org; Tue, 13 Oct 2015 07:50:40 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Zly6B-0005HE-QN for qemu-devel@nongnu.org; Tue, 13 Oct 2015 07:50:36 -0400 Received: from relay.parallels.com ([195.214.232.42]:53479) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zly6B-0005Gu-C9 for qemu-devel@nongnu.org; Tue, 13 Oct 2015 07:50:31 -0400 Message-ID: <561CEFE9.3060708@virtuozzo.com> Date: Tue, 13 Oct 2015 14:50:01 +0300 From: Vladimir Sementsov-Ogievskiy MIME-Version: 1.0 References: <1444535584-18220-1-git-send-email-guangrong.xiao@linux.intel.com> <1444535584-18220-12-git-send-email-guangrong.xiao@linux.intel.com> In-Reply-To: <1444535584-18220-12-git-send-email-guangrong.xiao@linux.intel.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v3 11/32] hostmem-file: use whole file size if possible List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Xiao Guangrong , 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 11.10.2015 06:52, 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 | 47 +++++++++++++++++++++++++++++++++++++++++++---- > 1 file changed, 43 insertions(+), 4 deletions(-) > > diff --git a/backends/hostmem-file.c b/backends/hostmem-file.c > index 9097a57..adf2835 100644 > --- a/backends/hostmem-file.c > +++ b/backends/hostmem-file.c > @@ -9,6 +9,9 @@ > * This work is licensed under the terms of the GNU GPL, version 2 or later. > * See the COPYING file in the top-level directory. > */ > +#include > +#include > + > #include "qemu-common.h" > #include "sysemu/hostmem.h" > #include "sysemu/sysemu.h" > @@ -33,20 +36,56 @@ struct HostMemoryBackendFile { > char *mem_path; > }; > > +static uint64_t get_file_size(const char *file) > +{ > + struct stat stat_buf; > + uint64_t size = 0; > + int fd; > + > + fd = open(file, O_RDONLY); > + if (fd < 0) { > + return 0; > + } > + > + if (stat(file, &stat_buf) < 0) { > + goto exit; > + } > + > + if ((S_ISBLK(stat_buf.st_mode)) && !ioctl(fd, BLKGETSIZE64, &size)) { > + goto exit; > + } > + > + size = lseek(fd, 0, SEEK_END); > + if (size == -1) { > + size = 0; > + } > +exit: > + close(fd); > + return size; > +} > + > static void > 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) { > + /* > + * use the whole file size if @size is not specified. > + */ > + backend->size = get_file_size(fb->mem_path); > + } > + > + if (!backend->size) { > + error_setg(errp, "can't create backend with size 0"); > + return; > + } in case of any error in get_file_size (open, stat, lseek) it will write about "backend with size 0" which may be not appropriate.. > + > backend->force_prealloc = mem_prealloc; > memory_region_init_ram_from_file(&backend->mr, OBJECT(backend), > object_get_canonical_path(OBJECT(backend)), -- Best regards, Vladimir * now, @virtuozzo.com instead of @parallels.com. Sorry for this inconvenience.