From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52035) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1c3ejf-0001eE-0G for qemu-devel@nongnu.org; Mon, 07 Nov 2016 02:52:56 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1c3eja-0000PR-IQ for qemu-devel@nongnu.org; Mon, 07 Nov 2016 02:52:55 -0500 Received: from mx1.redhat.com ([209.132.183.28]:38190) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1c3eja-0000Ov-DE for qemu-devel@nongnu.org; Mon, 07 Nov 2016 02:52:50 -0500 From: Markus Armbruster References: <20161107050859.31058-1-haozhong.zhang@intel.com> Date: Mon, 07 Nov 2016 08:52:47 +0100 In-Reply-To: <20161107050859.31058-1-haozhong.zhang@intel.com> (Haozhong Zhang's message of "Mon, 7 Nov 2016 13:08:56 +0800") Message-ID: <87a8db20c0.fsf@dusky.pond.sub.org> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [Qemu-devel] [PATCH 0/3] hostmem-file: make option 'size' optional List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Haozhong Zhang Cc: qemu-devel@nongnu.org, Eduardo Habkost , Peter Crosthwaite , Paolo Bonzini , Igor Mammedov , Richard Henderson Haozhong Zhang writes: > This patch series is mostly the followup of patch 3 in > "[PATCH v2 0/3] Improve truncation behavior of memory-backend-file" [1][2]. > > For certain usages of memory-backend-file, users simply want to use > the entire backend file (specified by the "mem-path" option). Therefore, > it's not necessary in such cases to specify the file size via the > "size" option. This patch series makes the "size" option of > memory-backend-file optional. In detail, > > 1. if the size of the backend file is not zero and the "size" option > is not present, QEMU will use the file size as the "size" option; > > 2. if the backend file is a non-existing file, an empty file, or a > directory, the "size" option is still needed; > > 3. the "size" option is also needed in cases that QEMU fails to the > backend file size. "fails to the backend file size": are you missing a verb? > Patch 1 is not quite relevant. It adds missing comments on errors > of get_file_size() per Eduardo's suggestion. > > Patch 2 moves the file operations from file_ram_alloc() to > qemu_ram_alloc_from_file(), so that all checks on the file size and > the "size" option, and the related operations on ram block length can > be put in qemu_ram_alloc_from_file() and no duplication is needed. > > Patch 3 actually implements the logic to make the option "size" optional. > > [1] https://lists.nongnu.org/archive/html/qemu-devel/2016-10/msg06823.html > [2] https://lists.nongnu.org/archive/html/qemu-devel/2016-11/msg00251.html > > Haozhong Zhang (3): > exec.c: add comment for errors of get_file_size() > exec.c: move file operations to qemu_ram_alloc_from_file() > hostmem-file: make option 'size' optional > > backends/hostmem-file.c | 28 ++++-- > exec.c | 242 ++++++++++++++++++++++++++++++------------------ > 2 files changed, 170 insertions(+), 100 deletions(-)