From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from ws5-mx01.kavi.com (ws5-mx01.kavi.com [34.193.7.191]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id CBCAEC77B79 for ; Wed, 12 Apr 2023 05:23:45 +0000 (UTC) Received: from lists.oasis-open.org (oasis.ws5.connectedcommunity.org [10.110.1.242]) by ws5-mx01.kavi.com (Postfix) with ESMTP id 0E9E5604C9 for ; Wed, 12 Apr 2023 05:23:45 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id 039A99865ED for ; Wed, 12 Apr 2023 05:23:45 +0000 (UTC) Received: from host09.ws5.connectedcommunity.org (host09.ws5.connectedcommunity.org [10.110.1.97]) by lists.oasis-open.org (Postfix) with QMQP id EA26C986510; Wed, 12 Apr 2023 05:23:44 +0000 (UTC) Mailing-List: contact virtio-dev-help@lists.oasis-open.org; run by ezmlm List-ID: Sender: Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id D773D98650E for ; Wed, 12 Apr 2023 05:23:42 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-MC-Unique: bIwbU2DIP_Gfnne_BVTdUA-1 X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1681277020; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=yr1TWzBPyNrEyAvFAzxTLh0FZ63M+yYKfpMJ43cdj0U=; b=4f6ea2TvOCe9IlCK15Pjun5JzdAoD8ET7yH7j9oMJVgJ11ycjFhBd/d4fY1mtjAjwd XOMRGhH7glDKeixeQCEYeO+422UIzC1BBqDzUHfFwudUBqZb5ACN3J5MeiLhOFlib78c jJmh2H3vYFdKPDvqbnzVy1SEq27jhvX90gah/Ix9DzMfW7znDYSkferPVNTY12tgCFLf Onx8ZpblRkdW7btITanDxBINXpjUU0q5beKEg0bBzRbXTyebd3ErbFVTblwdqrHRwJ5N y/7RKGAPFP6Uk8e494+yXP3eacuRE9S6GcpY4wG95fYYAgShZJMcgjL37a8hv5CIoI3U 7qaA== X-Gm-Message-State: AAQBX9eX6ayuN/th6lAHwZAx2/dmXYYuNSYuFLWI9oFZMpcP5kUWT5gG knEijD/6z4wypDTIowz4+9UuFeZfrUtnodJ9XCDWBxuPmYgF85Ah/GhrlLmgE7rfR9JuZb6VTgd MaxDCRi/pT8sQdaD7bLWP2h9QluPw X-Received: by 2002:adf:f546:0:b0:2f2:9198:f0f with SMTP id j6-20020adff546000000b002f291980f0fmr3756690wrp.10.1681277019842; Tue, 11 Apr 2023 22:23:39 -0700 (PDT) X-Google-Smtp-Source: AKy350YWFjB0z2S/iHgvh69qOuEh7o4o7qo7LeD5Aevgl9Lp4ci6lwvBwk0c2XMfikMWl4erjQsAgg== X-Received: by 2002:adf:f546:0:b0:2f2:9198:f0f with SMTP id j6-20020adff546000000b002f291980f0fmr3756667wrp.10.1681277019430; Tue, 11 Apr 2023 22:23:39 -0700 (PDT) Date: Wed, 12 Apr 2023 01:23:35 -0400 From: "Michael S. Tsirkin" To: Parav Pandit Cc: "virtio-dev@lists.oasis-open.org" , "cohuck@redhat.com" , "virtio-comment@lists.oasis-open.org" , Shahaf Shuler Message-ID: <20230412011741-mutt-send-email-mst@kernel.org> References: <20230330225834.506969-1-parav@nvidia.com> <20230412004331-mutt-send-email-mst@kernel.org> <20230412010437-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Subject: [virtio-dev] Re: [virtio-comment] Re: [PATCH 00/11] Introduce transitional mmr pci device On Wed, Apr 12, 2023 at 05:15:40AM +0000, Parav Pandit wrote: > > > > From: virtio-comment@lists.oasis-open.org > open.org> On Behalf Of Michael S. Tsirkin > > > New issue I found today: > > - if guest disables MSI-X host can not disable MSI-X. > > need some other channel to notify device about this. > > > I will look into it. > > > Old issues we discussed before today: > > - reset needs some special handling because real hardware > > can not guarantee returning 0 on the 1st read > When done through the legacy MMR as we discussed, it will. > > > - if guest writes into mac, reusing host mac (which is RO) > > will not work, need extra registers > No. Again legacy interface section of MMR behaves as legacy. > > > - something about notification makes you want to poke > > at modern notification register? which of course > > is its own can of worms with VIRTIO_F_NOTIFICATION_DATA > > changing the format completely. > There is no NOTIFICATION_DATA with legacy. So it is not applicable. > Format is same with only vq index. You are writing into modern register here. *what* are you writing there? with modern register the format depends on features. here you did not negotiate any features. what if NOTIFICATION_DATA is a required feature? with legacy there's no FEATURES_OK so no way to report failure. driver barrels on, sends wrong data in the kick and hangs. Sure, we can add a section to notification register and come up with some behaviour. Without even trying to guess how messy or clean that will be, far from being a small clean contained thing this feature is sticking its fingers in lots of pies. Look I know proposed this originally. I thought it's a small thing too. It was an idea. I am not sure it pans out though. Not all ideas work. -- MST --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org