From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AA055488DAF for ; Fri, 11 Sep 2026 16:26:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789143962; cv=none; b=ERvG57RjC4VetO2G1q7iQf7GxlTLFi5hw+W+V5wAqlXk0Ve7eibr5Ez767rMpj2fH2IGauH/4ug2dm/EbaL0cHEXAqhnlP2A0j/64YSPoYfZeXQZY6eDvqPUPSP1xml6W2gZFHtN0PHkzUZCqqg0EC8ZrJk9iILuPjm2Ys64nOc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789143962; c=relaxed/simple; bh=bquhT/ngeU3LRCEI/rNOxqGD6easUmuD5vQSEkaa5Kc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=kxIwf9lUYH3Wy8q6A3ylbkrYRbxwfia4ZC1EpeJqSxKL/LV42fdJ3h+oMKwfG2QIJVJ1sxTVKlg8cyCOXEuCFFeBykY3y0qm77p2VdnB1MYmYzH//IhOiy23x1tkA4OL8S/H4yzDzsfEQ3iP36m3gmfOuvsM5fFMZG9SMGOlY38= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=YZFA78TW; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="YZFA78TW" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1789143959; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=4q4XIxW/vwNesCg/a34TUO9RXpsXNeKwK6PzYAFAAaI=; b=YZFA78TWlwmtvD/dvEJp5/lxmzXjHl83Dkb8IjRIFSYIuOwgpn0v/M5tdOS7huqY3yYnka aYTlwO9E3F7sjykOCA1SjA8N70eAuU0eaV7ksfHvxNHHZJou72/WplFdtSeRpX5aywC/Fk HsMYLi/muQaSQ47/5Ujq3Az8nBt/8Rc= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-570-BbleVnsAMvOQUHwFoS9lPQ-1; Fri, 11 Sep 2026 12:25:55 -0400 X-MC-Unique: BbleVnsAMvOQUHwFoS9lPQ-1 X-Mimecast-MFC-AGG-ID: BbleVnsAMvOQUHwFoS9lPQ_1789143952 Received: from mx-prod-int-10.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-10.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.95]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 551D81954B0A; Fri, 11 Sep 2026 16:25:51 +0000 (UTC) Received: from localhost (headnet04.pony-001.prod.iad2.dc.redhat.com [10.2.32.116]) by mx-prod-int-10.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 3E455433; Fri, 11 Sep 2026 16:25:48 +0000 (UTC) Date: Fri, 11 Sep 2026 12:25:47 -0400 From: Stefan Hajnoczi To: Markus Armbruster Cc: Connor Kite , qemu-devel@nongnu.org, "Michael S. Tsirkin" , Stefano Garzarella , Alex =?iso-8859-1?Q?Benn=E9e?= , Viresh Kumar , Gerd Hoffmann , Mathieu Poirier , Manos Pitsidianakis , Raphael Norwitz , Kevin Wolf , Hanna Reitz , =?iso-8859-1?Q?Marc-Andr=E9?= Lureau , Paolo Bonzini , Fam Zheng , Milan Zamazal , Akihiko Odaki , Dmitry Osipenko , qemu-block@nongnu.org, virtio-fs@lists.linux.dev, "Gonglei (Arei)" , zhenwei pi , Daniel =?iso-8859-1?Q?P=2E_Berrang=E9?= , Eric Blake , Jason Wang , Peter Xu , Eugenio =?iso-8859-1?Q?P=E9rez?= , Alyssa Ross , Demi Marie Obenour Subject: Re: [PATCH RFC v2 13/13] net/vhost-user: add memory isolation Message-ID: <20260911162547.GA157639@fedora> References: <20260817-vhost-user-isolated-memory-v2-0-948aae960abb@gmail.com> <20260817-vhost-user-isolated-memory-v2-13-948aae960abb@gmail.com> <87lda12mhy.fsf@pond.sub.org> <87lda010j1.fsf@pond.sub.org> Precedence: bulk X-Mailing-List: virtio-fs@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="KnjVaE+vH1BLpuM3" Content-Disposition: inline In-Reply-To: <87lda010j1.fsf@pond.sub.org> X-Scanned-By: MIMEDefang 3.6 on 10.30.177.95 --KnjVaE+vH1BLpuM3 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Aug 21, 2026 at 07:54:26AM +0200, Markus Armbruster wrote: > Connor Kite writes: >=20 > > On Thu, Aug 20, 2026 at 2:02=E2=80=AFAM Markus Armbruster wrote: > >> > >> > >> Any guidance on when to enable it? > >> > > ... > > > >> Likewise. > >> > > > > In both cases, you would enable this for added security. There's > > obviously a performance hit, but it prevents a potentially misbehaving > > vhost-user backend from reading or modifying undesired portions of > > guest memory, since data transfer occurs wholly via bounce buffers. > > This may be more useful in the generic netdev vhost user case than it > > is with the passt version, but the goal is for the mode to be > > accessible for any vhost-user device. >=20 > Work this into the commit message, please. >=20 > > Do you think guidance is needed here in net.json? I was thinking > > that, if isolation-mode gets to a point of being merged, then > > information like this would make sense somewhere in the online > > documentation, but I'm happy to add something here as well. I was > > just trying to be similarly short and to-the-point as the other option > > descriptions for these structs. >=20 > I think it needs to be somewhere in the user documentation. We have so > many configuration options, and so little guidance on what to do with > them. >=20 > The doc comments in the QAPI schema are reference documentation (they go > into the "QEMU QMP Reference Manual"). Reference documentation should > be concise and to the point. When you have more useful things to say > than fit there, you need to find nother place, and maybe link to it from > the reference docs. >=20 > I suggest to try adding brief guidance to the doc comment, and then we > see how we feel about it. >=20 Here is the vhost-user documentation: docs/system/devices/virtio/vhost-user.rst You could add a section to this document explaining the memory isolation feature. 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