From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 00C7A323D; Tue, 22 Jul 2025 01:18:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753147089; cv=none; b=XiaMb7QzbKSsbINlAfOXgfWNxbvB0aLXOw8RsOA8jhsSczRUUnqmWL0C/XubpFNNbdHeywuxY8evuemKjju1xm6sNpM2aiW5JsB6PegXjR0IsC/b73ynyIngC1JytPrW2biA1Rauf8QCjX7K3WGYUccnnBj1EoofCJydMGuCnN4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753147089; c=relaxed/simple; bh=58G4hQ5/WYB9qMDV9HoXS6b9QDxGVyYptlpx2v3QD/Q=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=p3h/EVFynzDz1ZySlwQuz4u6K+FBkG6qHq8C2EMlpXq097/gn+5wqIjfj/HIg4EYtqosIZYyGcn+VXjoodFbAC64J+lbOMiU/g6By4tlYB+SozWZQonsuEnqey6uRL28qwNNnZqOIblgcHYIAMyG7UYTrhz/ArDGHJqJViT9/1s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=SkvE889j; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="SkvE889j" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B8779C4CEED; Tue, 22 Jul 2025 01:18:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1753147088; bh=58G4hQ5/WYB9qMDV9HoXS6b9QDxGVyYptlpx2v3QD/Q=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=SkvE889jbt5tv9l+yFT7rv5B6aYpVQUYphLe3loTTj5Osrqt+yE7GmeObt1mh/NPo HnoUSXMZiacKTQlKXFI5emlCOhuTWYN5t9/5rsXf7v0uXzquyb1yRBlcpme3PTmNjU QLool18G89qHgen63lJWGy8G2a9E3veXOQrKr36cQe6tvB7GDCHeHP4qHzgOeN+jfE a/CY8n8m2thbYipGA1H+B3SEUMBwkNYA6Vhmvsa2lDMKLjWvAVerqJ4MXTIH7dZqv3 di4zdID86qSBaDL+EVYGGB5uhd8MlXJg/KK2CeNa5au2VC4iJTJynX49EeovcUBwue Q7qW4kf3QIbwQ== Date: Mon, 21 Jul 2025 18:18:07 -0700 From: Jakub Kicinski To: Jason Wang Cc: Cindy Lu , "K. Y. Srinivasan" , Haiyang Zhang , Wei Liu , Dexuan Cui , Andrew Lunn , "David S. Miller" , Eric Dumazet , Paolo Abeni , Simon Horman , Michael Kelley , Shradha Gupta , Kees Cook , Stanislav Fomichev , Kuniyuki Iwashima , Alexander Lobakin , Guillaume Nault , Joe Damato , Ahmed Zaki , "open list:Hyper-V/Azure CORE AND DRIVERS" , "open list:NETWORKING DRIVERS" , open list Subject: Re: [PATCH RESEND] netvsc: transfer lower device max tso size Message-ID: <20250721181807.752af6a4@kernel.org> In-Reply-To: References: <20250718061812.238412-1-lulu@redhat.com> <20250721162834.484d352a@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Tue, 22 Jul 2025 09:04:20 +0800 Jason Wang wrote: > On Tue, Jul 22, 2025 at 7:28=E2=80=AFAM Jakub Kicinski = wrote: > > On Fri, 18 Jul 2025 14:17:55 +0800 Cindy Lu wrote: =20 > > > Subject: [PATCH RESEND] netvsc: transfer lower device max tso size =20 > > > > You say RESEND but I don't see a link to previous posting anywhere. Someone should respond to this part, please. > > I'd rather we didn't extend the magic behavior of hyperv/netvsc any > > further. =20 >=20 > Are you referring to the netdev coupling model of the VF acceleration? Yes, it tries to apply whole bunch of policy automatically in=20 the kernel. > > We have enough problems with it. >=20 > But this fixes a real problem, otherwise nested VM performance will be > broken due to the GSO software segmentation. Perhaps, possibly, a migration plan can be devised, away from the netvsc model, so we don't have to deal with nuggets of joy like: https://lore.kernel.org/all/1752870014-28909-1-git-send-email-haiyangz@linu= x.microsoft.com/