From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:51298) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ULUS8-00073c-Ni for qemu-devel@nongnu.org; Fri, 29 Mar 2013 04:14:26 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ULUS4-0006CM-Ti for qemu-devel@nongnu.org; Fri, 29 Mar 2013 04:14:24 -0400 Received: from mail-ea0-x22d.google.com ([2a00:1450:4013:c01::22d]:51336) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ULUS4-0006CE-N5 for qemu-devel@nongnu.org; Fri, 29 Mar 2013 04:14:20 -0400 Received: by mail-ea0-f173.google.com with SMTP id k11so109058eaj.18 for ; Fri, 29 Mar 2013 01:14:19 -0700 (PDT) Sender: Paolo Bonzini Message-ID: <51554D56.5080004@redhat.com> Date: Fri, 29 Mar 2013 09:14:14 +0100 From: Paolo Bonzini MIME-Version: 1.0 References: <8300718.16452772.1364465611936.JavaMail.root@redhat.com> <1364525606.10253.69.camel@haakon2.linux-iscsi.org> In-Reply-To: <1364525606.10253.69.camel@haakon2.linux-iscsi.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH V3 WIP 3/3] disable vhost_verify_ring_mappings check List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Nicholas A. Bellinger" Cc: Kevin O'Connor , kvm@vger.kernel.org, "Michael S. Tsirkin" , Stefan Hajnoczi , seabios-devel , qemu-devel@nongnu.org, virtualization@lists.linux-foundation.org, target-devel@vger.kernel.org, Stefan Hajnoczi , Asias He Il 29/03/2013 03:53, Nicholas A. Bellinger ha scritto: > On Thu, 2013-03-28 at 06:13 -0400, Paolo Bonzini wrote: >>> I think it's the right thing to do, but maybe not the right place >>> to do this, need to reset after all IO is done, before >>> ring memory is write protected. >> >> Our emails are crossing each other unfortunately, but I want to >> reinforce this: ring memory is not write protected. > > Understood. However, AFAICT the act of write protecting these ranges > for ROM generates the offending callbacks to vhost_set_memory(). > > The part that I'm missing is if ring memory is not being write protected > by make_bios_readonly_intel(), why are the vhost_set_memory() calls > being invoked..? Because mappings change for the region that contains the ring. vhost doesn't know yet that the changes do not affect ring memory, vhost_set_memory() is called exactly to ascertain that. Paolo > >> Remember that >> SeaBIOS can even provide virtio-scsi access to DOS, so you must >> not reset the device. It must remain functional all the time, >> and the OS's own driver will reset it when it's started. >> > > Mmmm, so a vp_reset() is out of the question then.. > > --nab > > > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >