From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=42583 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1P9HJ2-0001zV-4a for qemu-devel@nongnu.org; Fri, 22 Oct 2010 09:05:17 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1P9H95-00075O-1h for qemu-devel@nongnu.org; Fri, 22 Oct 2010 08:54:56 -0400 Received: from mail-iw0-f173.google.com ([209.85.214.173]:61546) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1P9H94-00075H-Rz for qemu-devel@nongnu.org; Fri, 22 Oct 2010 08:54:54 -0400 Received: by iwn36 with SMTP id 36so1009429iwn.4 for ; Fri, 22 Oct 2010 05:54:53 -0700 (PDT) Message-ID: <4CC189A6.30807@codemonkey.ws> Date: Fri, 22 Oct 2010 07:55:02 -0500 From: Anthony Liguori MIME-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH 0/3] add usb_detach and usb_attach (v3) References: <1287642991-21114-1-git-send-email-alevy@redhat.com> <4CC03A2D.9030105@redhat.com> <4CC03C6F.4020304@codemonkey.ws> <20101021132723.GE22958@playa.tlv.redhat.com> <20101022104822.5f608f13@doriath> In-Reply-To: <20101022104822.5f608f13@doriath> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Luiz Capitulino Cc: Alon Levy , Gerd Hoffmann , qemu-devel@nongnu.org On 10/22/2010 07:48 AM, Luiz Capitulino wrote: > On Thu, 21 Oct 2010 15:27:23 +0200 > Alon Levy wrote: > > >> On Thu, Oct 21, 2010 at 08:13:19AM -0500, Anthony Liguori wrote: >> >>> On 10/21/2010 08:03 AM, Gerd Hoffmann wrote: >>> >>>> On 10/21/10 08:36, Alon Levy wrote: >>>> >>>>> v2->v3 changes: >>>>> * add configure parameter >>>>> * fix docs >>>>> >>>>> v2 message: >>>>> This patchset uses id like device_del for attaching/detaching usb >>>>> devices. The first two patches ready the way: >>>>> 1. makes qdev_find_recursive non static and in qdev.h >>>>> 2. adds a usb_device_by_id which goes over the usb buses calling >>>>> qdev_find_recursive >>>>> 3. adds the commands that use usb_device_by_id >>>>> >>>>> Alon Levy (3): >>>>> qdev: make qdev_find_recursive public >>>>> usb: add public usb_device_by_id >>>>> monitor: add usb_attach and usb_detach (v2) >>>>> >>>>> >>>> Acked-by: Gerd Hoffmann >>>> >>> Okay, I am still confused about the use-case for this and I don't >>> see any further explanation in the commit messages. I've seen >>> "debugging" but can you be a bit more specific about which cases >>> it's needed for? >>> >> To elaborate a little more, when using a certificates based card >> there is no hardware event (i.e. removing/inserting the physical card) >> that causes a usb_detach/attach to the card (both in passthru and >> emulated), but otoh certificates is good for testing since it decouples >> it from NSS/tcp. So I needed some way to emulate an insert/remove, and >> I saw usb_del, which was pretty close, and voila. This is not the same >> as card remove/reinsert, but it is exactly what will happen to the >> guest when spicec connects/disconnects, since I detach devices on >> disconnect and attach on connect. >> > Looks reasonable to me, specially because this will be protected by > #ifdef DEBUG. I don't see a big deal in merging this. > I'd just like to see better documentation. A command isn't useful for debugging if noone knows how to use it. Guarding with an #ifdef isn't necessary. It should be unconditionally enabled otherwise it will bit rot. > Objections, Anthony? > Not with better docs. Regards, Anthony Liguori >>> This is just adding a HMP command. Is that the right approach or >>> was that an unintentional consequence of rebasing post-HMP/QMP >>> split? >>> > I don't think this should be available under QMP, it's more a debugging > command for USB developers. > > >>> Regards, >>> >>> Anthony Liguori >>> >>> >>>> cheers, >>>> Gerd >>>> >>>> >>>> >>> >>> >> >