From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:49508) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SzpKL-0005AZ-S6 for qemu-devel@nongnu.org; Fri, 10 Aug 2012 09:32:35 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SzpKF-0000xP-Fb for qemu-devel@nongnu.org; Fri, 10 Aug 2012 09:32:33 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51610) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SzpKF-0000x3-7t for qemu-devel@nongnu.org; Fri, 10 Aug 2012 09:32:27 -0400 Date: Fri, 10 Aug 2012 10:33:00 -0300 From: Luiz Capitulino Message-ID: <20120810103300.68fe975b@doriath.home> In-Reply-To: <87pq6zch9g.fsf@blackfin.pond.sub.org> References: <1343869374-23417-1-git-send-email-lcapitulino@redhat.com> <1343869374-23417-12-git-send-email-lcapitulino@redhat.com> <87r4rpr0f9.fsf@blackfin.pond.sub.org> <20120802105403.608761ea@doriath.home> <87pq6zch9g.fsf@blackfin.pond.sub.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 11/34] qmp: query-block: add 'valid_encryption_key' field List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Markus Armbruster Cc: kwolf@redhat.com, aliguori@us.ibm.com, qemu-devel@nongnu.org, mdroth@linux.vnet.ibm.com, pbonzini@redhat.com, eblake@redhat.com On Fri, 10 Aug 2012 09:56:11 +0200 Markus Armbruster wrote: > Revisited this one on review of v2, replying here for context. > > Luiz Capitulino writes: > > > On Thu, 02 Aug 2012 13:35:54 +0200 > > Markus Armbruster wrote: > > > >> Luiz Capitulino writes: > >> > >> > Signed-off-by: Luiz Capitulino > >> > --- > >> > block.c | 1 + > >> > qapi-schema.json | 7 +++++-- > >> > 2 files changed, 6 insertions(+), 2 deletions(-) > >> > > >> > diff --git a/block.c b/block.c > >> > index b38940b..9c113b8 100644 > >> > --- a/block.c > >> > +++ b/block.c > >> > @@ -2445,6 +2445,7 @@ BlockInfoList *qmp_query_block(Error **errp) > >> > info->value->inserted->ro = bs->read_only; > >> > info->value->inserted->drv = g_strdup(bs->drv->format_name); > >> > info->value->inserted->encrypted = bs->encrypted; > >> > + info->value->inserted->valid_encryption_key = bs->valid_key; > >> > if (bs->backing_file[0]) { > >> > info->value->inserted->has_backing_file = true; > >> > info->value->inserted->backing_file = g_strdup(bs->backing_file); > >> > diff --git a/qapi-schema.json b/qapi-schema.json > >> > index bc55ed2..1b2d7f5 100644 > >> > --- a/qapi-schema.json > >> > +++ b/qapi-schema.json > >> > @@ -400,6 +400,8 @@ > >> > # > >> > # @encrypted: true if the backing device is encrypted > >> > # > >> > +# @valid_encryption_key: true if a valid encryption key has been set > >> > +# > >> > # @bps: total throughput limit in bytes per second is specified > >> > # > >> > # @bps_rd: read throughput limit in bytes per second is specified > >> > @@ -419,8 +421,9 @@ > >> > { 'type': 'BlockDeviceInfo', > >> > 'data': { 'file': 'str', 'ro': 'bool', 'drv': 'str', > >> > '*backing_file': 'str', 'encrypted': 'bool', > >> > - 'bps': 'int', 'bps_rd': 'int', 'bps_wr': 'int', > >> > - 'iops': 'int', 'iops_rd': 'int', 'iops_wr': 'int'} } > >> > + 'valid_encryption_key': 'bool', 'bps': 'int', > >> > + 'bps_rd': 'int', 'bps_wr': 'int', 'iops': 'int', > >> > + 'iops_rd': 'int', 'iops_wr': 'int'} } > >> > > >> > ## > >> > # @BlockDeviceIoStatus: > >> > >> BlockDeviceInfo is API, isn't it? > > > > Yes. > > > >> Note that bs->valid_key currently implies bs->encrypted. bs->valid_key > >> && !bs->encrypted is impossible. Should we make valid_encryption_key > >> only available when encrypted? > > > > I don't think so. It's a bool, so it's ok for it to be false when > > encrypted is false. > > What bothers me is encrypted=false, valid_encryption_key=true. Disappearing keys is worse, IMHO (assuming that that situation is impossible in practice, of course). > >> valid_encryption_key is a bit long for my taste. Yours may be > >> different. > > > > We should choose more descriptive and self-documenting names for the > > protocol. Besides, I can't think of anything shorter that won't get > > cryptic. > > > > Suggestions are always welcome though :) > > valid_encryption_key sounds like the value is the valid key. That's exactly what it is. > got_crypt_key? Also avoids "valid". Good, because current encrypted > formats don't actually validate the key; they happily accept any key. That's a block layer bug, not QMP's. QMP clients are going to be misguided by valid_encryption_key the same way they are with the block_passwd command or how we suffer from it internally when calling bdrv_set_key() (which also manifests itself in HMP). Fixing the bug where it is will automatically fix all its instances. > GIGO. In theory, you can trash a disk that way. In practice, we can > hope the guest will refuse to touch the disk, because it can't recognize > partition table / filesystems.