From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f54.google.com (mail-wr1-f54.google.com [209.85.221.54]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6DD2B2857EF for ; Wed, 18 Jun 2025 12:06:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.54 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750248400; cv=none; b=e/SNge64AFM7SXCLJ/W48+zl3gpjqPzRW6QwDZqX3r7cv7pa+Wg4TWfcpoMpp3MS7JBwTN22Vfd8mGCAanXYOSgibVHblBGMjw4xuW6edP/O/uXilc2leRXA3y0XPNLmSwp3osMjmcVbiNfQ+NiherRdFvAz/U+9RFP4RFjIwDM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750248400; c=relaxed/simple; bh=uHxdHDEOTugKk9J9OjXhzGtnevhg6NmN+nEaYePZyBs=; h=Message-ID:Date:MIME-Version:Subject:To:References:From: In-Reply-To:Content-Type; b=QZJdUDxj93LamdHZTCCNJnV43rq7WTWST/S1xFZ8gKSH1GFhx5137rk/HHtyKNX2BSqy1W9sShK81/FvfWoaMQxVXYsZL7KWGLztIWqVqgSs0v7OSw/Uh2xu65t8cP7pf/8ixGY4lRIvYdDkRDjP/PhSkaKWFe/nHf71kl1+cA8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=6wind.com; spf=pass smtp.mailfrom=6wind.com; dkim=pass (2048-bit key) header.d=6wind.com header.i=@6wind.com header.b=JJ93Vs09; arc=none smtp.client-ip=209.85.221.54 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=6wind.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=6wind.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=6wind.com header.i=@6wind.com header.b="JJ93Vs09" Received: by mail-wr1-f54.google.com with SMTP id ffacd0b85a97d-3a4e749d7b2so781093f8f.0 for ; Wed, 18 Jun 2025 05:06:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=6wind.com; s=google; t=1750248395; x=1750853195; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:organization:content-language :from:references:to:subject:reply-to:user-agent:mime-version:date :message-id:from:to:cc:subject:date:message-id:reply-to; bh=JtO+1zIjYRJs86fkY6zRnbrPpWElMpbcIKEvz5ZokbE=; b=JJ93Vs09UqhWNKfOla6mVm0IhZe801JCzrtmvhxNqOz/gJZRs4hFVDOHyp9rpQTQ82 3NfJ1NBqW70yLaMGN/jyZvWkT7y9MMa2Wo83I0tsr3ya4KibsolV8zVlX8+LA9+M1QWR rUXoNopGgy/gMgeBiOvCLasWIPYgCrDeOYs67SUJuyAXfDDlv1HaR931T7f8+HHIgvMc qNf1y+MsZMt6LibMCllUm6iwM/CPFUJhSl8SiRPMTFuLR/S6iMDQzQQR6ayU+HxiDZlS oSeQQ8VmCVKopHXul5/3zf2qFxq3tArRJEqb6djQYYmCYxkWaeYyc/zF0z/VTvdv6o4H S2KQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1750248395; x=1750853195; h=content-transfer-encoding:in-reply-to:organization:content-language :from:references:to:subject:reply-to:user-agent:mime-version:date :message-id:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=JtO+1zIjYRJs86fkY6zRnbrPpWElMpbcIKEvz5ZokbE=; b=eZyVhLXn8HXgCutmkDXdReYzg2QDTA9gJTU42tt55mNEMsK/GYRQeCS6Ce5mSfSsHB T+4npCPM8f+5A3h9IZDzy2ENg+dXWMbdzG4uRfG4kS7X60CMAKZ/qDMoS4T7IEh0aL5H 8MpyXYMx2KlOTRSUw/zS901fwT1UuexslG4U8NArbIc2c5AHCHoI0i//uwpOIlOGhB87 0tmCatQOPnJTJSzPiS4CZWU+ASvURRsvj+a7Ak6cRzu+wyTUwZkyMmJ5H4gM73zYls9E XWuMwMO9EZSazvgt0g4P0nA/1SYNjcR2pD+Kq0nCrMaEFYcg8ZrEImDQbEuuT6VXUmXx LK+g== X-Forwarded-Encrypted: i=1; AJvYcCVaICH8JlsdwPyWLZLUCGw0EDmsI/UZ4J14IoJxem2LbsT/fTlONrPbF+Gr0wi7wvoN3RnH/IbCXM+ZOac=@vger.kernel.org X-Gm-Message-State: AOJu0Yym7K2BR3RwydKetgiZiHVk7TdHRBaYxIKqWKcBjJuUFr7UAjMY LjaqEvnHXr39WiUZPq5ag5Meo6sKP13ujqom3hYgyLP9h5/s/RBkGBfvBtBUn9H7NWY= X-Gm-Gg: ASbGnct1UMCmMKRXmau2HS1vTMZx/hKonBrMI/ev1rfecGFyv3ruGNhODvfozhv8/e5 3cT1uv8zgFbeBhKEoljsHJZnDjwxuncc+QmaVGGloZFCYFhN70OHuFL2SWt72WXlmOpA6ncypao sfNywmnVbBHvcqbQJ+2SQ76a16EpvY0XPJ25ZRLZG11ASRrJEQgq736mEhREqV6LhUrrK70cTOV xy4OJtbpgDiTxrOJeO1xo6SNnZQD1qnzgDqi3hxUS3P+n5orrKY8U+bOPyOb95a2uvOaX3hjI4q mteGyxWPqgjulDJ/nNf4J3AnxBJavFh+MpDqNajFSFqPZzs4zDM3XTz30E1SFFJibWmMMbvMXvt GwbKvfw== X-Google-Smtp-Source: AGHT+IHw8NEafcpaIypnwCtdzWnvZDL+f6HF2yLjNIyemROAVUnq+qOCCQ7uNSAQajDmZhfC1cJ+LQ== X-Received: by 2002:a05:6000:4203:b0:3a4:dbdf:7152 with SMTP id ffacd0b85a97d-3a585f7d67fmr2085596f8f.14.1750248391929; Wed, 18 Jun 2025 05:06:31 -0700 (PDT) Received: from [172.31.99.185] ([185.13.181.2]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4532e224956sm207704175e9.4.2025.06.18.05.06.30 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 18 Jun 2025 05:06:30 -0700 (PDT) Message-ID: <6107dcb2-51a3-42f8-b856-f443c0e2a60d@6wind.com> Date: Wed, 18 Jun 2025 14:06:30 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Reply-To: nicolas.dichtel@6wind.com Subject: Re: [PATCH v12 1/1] vhost: Reintroduces support of kthread API and adds mode selection To: Cindy Lu , jasowang@redhat.com, mst@redhat.com, michael.christie@oracle.com, sgarzare@redhat.com, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org References: <20250616062922.682558-1-lulu@redhat.com> <20250616062922.682558-2-lulu@redhat.com> From: Nicolas Dichtel Content-Language: en-US Organization: 6WIND In-Reply-To: <20250616062922.682558-2-lulu@redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Le 16/06/2025 à 08:28, Cindy Lu a écrit : > This patch reintroduces kthread mode for vhost workers and provides > configuration to select between kthread and task worker. > > - Add 'fork_owner' parameter to vhost_dev to let users select kthread > or task mode. Default mode is task mode(VHOST_FORK_OWNER_TASK). > > - Reintroduce kthread mode support: > * Bring back the original vhost_worker() implementation, > and renamed to vhost_run_work_kthread_list(). > * Add cgroup support for the kthread > * Introduce struct vhost_worker_ops: > - Encapsulates create / stop / wake‑up callbacks. > - vhost_worker_create() selects the proper ops according to > inherit_owner. > > - Userspace configuration interface: > * New IOCTLs: > - VHOST_SET_FORK_FROM_OWNER lets userspace select task mode > (VHOST_FORK_OWNER_TASK) or kthread mode (VHOST_FORK_OWNER_KTHREAD) > - VHOST_GET_FORK_FROM_OWNER reads the current worker mode > * Expose module parameter 'fork_from_owner_default' to allow system > administrators to configure the default mode for vhost workers > * Kconfig option CONFIG_VHOST_ENABLE_FORK_OWNER_CONTROL controls whether > these IOCTLs and the parameter are available (for distros that may > want to disable them) > > - The VHOST_NEW_WORKER functionality requires fork_owner to be set > to true, with validation added to ensure proper configuration > > This partially reverts or improves upon: > commit 6e890c5d5021 ("vhost: use vhost_tasks for worker threads") > commit 1cdaafa1b8b4 ("vhost: replace single worker pointer with xarray") > > Signed-off-by: Cindy Lu > --- > drivers/vhost/Kconfig | 17 +++ > drivers/vhost/vhost.c | 244 ++++++++++++++++++++++++++++++++++--- > drivers/vhost/vhost.h | 22 ++++ > include/uapi/linux/vhost.h | 29 +++++ > 4 files changed, 294 insertions(+), 18 deletions(-) > > diff --git a/drivers/vhost/Kconfig b/drivers/vhost/Kconfig > index 020d4fbb947c..1b3602b1f8e2 100644 > --- a/drivers/vhost/Kconfig > +++ b/drivers/vhost/Kconfig > @@ -95,4 +95,21 @@ config VHOST_CROSS_ENDIAN_LEGACY > > If unsure, say "N". > > +config VHOST_ENABLE_FORK_OWNER_CONTROL > + bool "Enable VHOST_ENABLE_FORK_OWNER_CONTROL" > + default n Why disabling this option by default? Regards, Nicolas