From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from canpmsgout01.his.huawei.com (canpmsgout01.his.huawei.com [113.46.200.216]) (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 A86883A7820 for ; Fri, 27 Mar 2026 10:21:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=113.46.200.216 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774606914; cv=none; b=Cl6rq0HAbAbbsORqXkoKokQ5fkn1OhJOJ211OMjs61E4KsgTiWxmfrx0GyJxCvrBizT8gyQtULXXKC2GPih2sXCXYa3v8DprZbVmt4z9Vrvd06JmPb8Wym+q28yH/P6M4obe8Gs8HOcS0UmAYSH1i1utwd+a4s6MFwBQvzkUcnw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774606914; c=relaxed/simple; bh=/hLTkMOnRZlkVVUaPsFPfKFZCv0rp634k38n/a8O3/g=; h=Message-ID:Date:MIME-Version:From:To:CC:Subject:Content-Type; b=i9lhxZpeJH4lJkyl90dpYAxPeXG88M7T7HTinXFsA0/xy1/ARIvdmJ5kg6PqfsVxeg+wJfMEx1I5hCZaNXv+R+bZ0BunJZhaBEmZDreaJXfREt62nOW5u91I0iJrdq7YYAvV7IjR6wEjaAlmebnK4nkgLeABngr6C5XW8g/de6Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b=Poar77jd; arc=none smtp.client-ip=113.46.200.216 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b="Poar77jd" dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=IZqQrxOJ+/fPREYLH6yjljOestDU/g/f7XNhlIo3KmQ=; b=Poar77jdH47hoD4CDmNRxjbUjWlAIY3TqU7S4Ro2/WicplXw4UtK7cOExbUIVt/2rKvgoZPQb pde0Gt8C5QR4Bbae6P+kHeZ93w+Hgj2byp/UfjQcbyuKpoEWqQA+LmpsPvGs1mvpA0nilJQ53EW AMG0iMg1eBa4qUMXl2uJioc= Received: from mail.maildlp.com (unknown [172.19.162.140]) by canpmsgout01.his.huawei.com (SkyGuard) with ESMTPS id 4fhxPW0Fd7z1T4Kj; Fri, 27 Mar 2026 18:16:15 +0800 (CST) Received: from kwepemj200003.china.huawei.com (unknown [7.202.194.15]) by mail.maildlp.com (Postfix) with ESMTPS id ED2BB2022B; Fri, 27 Mar 2026 18:21:48 +0800 (CST) Received: from [10.67.120.170] (10.67.120.170) by kwepemj200003.china.huawei.com (7.202.194.15) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Fri, 27 Mar 2026 18:21:47 +0800 Message-ID: Date: Fri, 27 Mar 2026 18:21:47 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird From: Qinxin Xia To: CC: , , , , , , , , , , , , , , , , , , , , , , , , Linuxarm Subject: [Question mpam mpam/snapshot+extras/v6.18-rc1] Question with Configuring iommu_group in 'task' Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-ClientProxiedBy: kwepems500001.china.huawei.com (7.221.188.70) To kwepemj200003.china.huawei.com (7.202.194.15) Hello everyone! In earlier versions, mpam supports the configuration of iommu_groups. 823 static ssize_t rdtgroup_tasks_write(struct kernfs_open_file *of, 824 char *buf, size_t nbytes, loff_t off) 825 { 826 struct rdtgroup *rdtgrp; 827 int iommu_group_id; 828 bool is_iommu; 829 char *pid_str; 830 int ret = 0; 831 pid_t pid; 832 833 rdtgrp = rdtgroup_kn_lock_live(of->kn); 834 if (!rdtgrp) { 835 rdtgroup_kn_unlock(of->kn); 836 return -ENOENT; 837 } 838 rdt_last_cmd_clear(); 839 840 if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED || 841 rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { 842 ret = -EINVAL; 843 rdt_last_cmd_puts("Pseudo-locking in progress\n"); 844 goto unlock; 845 } 846 847 while (buf && buf[0] != '\0' && buf[0] != '\n') { 848 pid_str = strim(strsep(&buf, ",")); 849 850 is_iommu = string_is_iommu_group(pid_str, &iommu_group_id); What puzzles me is why we would put it under 'task'—this seems a little strange to users.It seems they are not related.Why don't we add a new interface like 'iommu'? 851 if (is_iommu) 852 ret = rdtgroup_move_iommu(iommu_group_id, rdtgrp, of); 853 else if (kstrtoint(pid_str, 0, &pid)) { 854 rdt_last_cmd_printf("Task list parsing error pid %s\n", pid_str); 855 ret = -EINVAL; 856 break; 857 } 858 859 if (pid < 0) { 860 rdt_last_cmd_printf("Invalid pid %d\n", pid); 861 ret = -EINVAL; 862 break; 863 } 864 In future glue versions, will you re-enable support for iommu_group, and if so, will the configuration scheme be changed? -- Thanks, Qinxin