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 X-Spam-Level: X-Spam-Status: No, score=-16.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D7B18C433E9 for ; Tue, 2 Feb 2021 17:28:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9D90264ECE for ; Tue, 2 Feb 2021 17:28:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237458AbhBBR2B (ORCPT ); Tue, 2 Feb 2021 12:28:01 -0500 Received: from mail.kernel.org ([198.145.29.99]:45110 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233758AbhBBRZu (ORCPT ); Tue, 2 Feb 2021 12:25:50 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 525F464F86; Tue, 2 Feb 2021 17:25:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1612286710; bh=WQY5AvDumycq/ElML3+ROe/hqNmEzEwK8b3q6Dbry9k=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=fYcazlak18I761FxGJzqUtfmUf+KiFIKU/JkEU+oOKEKxaK8RkKjKLXxb7JwdobpM NEC4q0d69E7ZIG3YIwDon/dNbdbxbcPj8VxjyT6eNi2KQGBfIhBJjyuFIASXX3zjgB v6FuBy5/ogyiuuyKh5Q94LECgwLZL8XeZiOc3xXMPNnN0JyuaGuCBMcUIRcKZZDDTS ai5j50f1vO6pGSB9xsAVxp5ScPGqpH+re2MtDluvKgRzKi+x0SBJh7pVPGANCl6c5s GTl5sGkHKVQss9JDgIjpTFBjblHUX3CUelFdZSqRVX8cKIP5SrqZsI7m75kuCsV13l o+ALF4cGwk+PA== Date: Tue, 2 Feb 2021 11:25:08 -0600 From: Bjorn Helgaas To: Leon Romanovsky Cc: Bjorn Helgaas , Saeed Mahameed , Leon Romanovsky , Jason Gunthorpe , Alexander Duyck , Jakub Kicinski , linux-pci@vger.kernel.org, linux-rdma@vger.kernel.org, netdev@vger.kernel.org, Don Dutile , Alex Williamson , "David S . Miller" Subject: Re: [PATCH mlx5-next v5 3/4] net/mlx5: Dynamically assign MSI-X vectors count Message-ID: <20210202172508.GA113855@bjorn-Precision-5520> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210126085730.1165673-4-leon@kernel.org> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Tue, Jan 26, 2021 at 10:57:29AM +0200, Leon Romanovsky wrote: > From: Leon Romanovsky > > The number of MSI-X vectors is PCI property visible through lspci, that > field is read-only and configured by the device. The static assignment > of an amount of MSI-X vectors doesn't allow utilize the newly created > VF because it is not known to the device the future load and configuration > where that VF will be used. > > To overcome the inefficiency in the spread of such MSI-X vectors, we > allow the kernel to instruct the device with the needed number of such > vectors. > > Such change immediately increases the amount of MSI-X vectors for the > system with @ VFs from 12 vectors per-VF, to be 32 vectors per-VF. Not knowing anything about mlx5, it looks like maybe this gets some parameters from firmware on the device, then changes the way MSI-X vectors are distributed among VFs? I don't understand the implications above about "static assignment" and "inefficiency in the spread." I guess maybe this takes advantage of the fact that you know how many VFs are enabled, so if NumVFs is less that TotalVFs, you can assign more vectors to each VF? If that's the case, spell it out a little bit. The current text makes it sound like you discovered brand new MSI-X vectors somewhere, regardless of how many VFs are enabled, which doesn't sound right. > Before this patch: > [root@server ~]# lspci -vs 0000:08:00.2 > 08:00.2 Ethernet controller: Mellanox Technologies MT27800 Family [ConnectX-5 Virtual Function] > .... > Capabilities: [9c] MSI-X: Enable- Count=12 Masked- > > After this patch: > [root@server ~]# lspci -vs 0000:08:00.2 > 08:00.2 Ethernet controller: Mellanox Technologies MT27800 Family [ConnectX-5 Virtual Function] > .... > Capabilities: [9c] MSI-X: Enable- Count=32 Masked- > > Signed-off-by: Leon Romanovsky > --- > .../net/ethernet/mellanox/mlx5/core/main.c | 4 ++ > .../ethernet/mellanox/mlx5/core/mlx5_core.h | 5 ++ > .../net/ethernet/mellanox/mlx5/core/pci_irq.c | 72 +++++++++++++++++++ > .../net/ethernet/mellanox/mlx5/core/sriov.c | 13 +++- > 4 files changed, 92 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/ethernet/mellanox/mlx5/core/main.c b/drivers/net/ethernet/mellanox/mlx5/core/main.c > index ca6f2fc39ea0..79cfcc844156 100644 > --- a/drivers/net/ethernet/mellanox/mlx5/core/main.c > +++ b/drivers/net/ethernet/mellanox/mlx5/core/main.c > @@ -567,6 +567,10 @@ static int handle_hca_cap(struct mlx5_core_dev *dev, void *set_ctx) > if (MLX5_CAP_GEN_MAX(dev, mkey_by_name)) > MLX5_SET(cmd_hca_cap, set_hca_cap, mkey_by_name, 1); > > + if (MLX5_CAP_GEN_MAX(dev, num_total_dynamic_vf_msix)) > + MLX5_SET(cmd_hca_cap, set_hca_cap, num_total_dynamic_vf_msix, > + MLX5_CAP_GEN_MAX(dev, num_total_dynamic_vf_msix)); > + > return set_caps(dev, set_ctx, MLX5_SET_HCA_CAP_OP_MOD_GENERAL_DEVICE); > } > > diff --git a/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h b/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h > index 0a0302ce7144..5babb4434a87 100644 > --- a/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h > +++ b/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h > @@ -172,6 +172,11 @@ int mlx5_irq_attach_nb(struct mlx5_irq_table *irq_table, int vecidx, > struct notifier_block *nb); > int mlx5_irq_detach_nb(struct mlx5_irq_table *irq_table, int vecidx, > struct notifier_block *nb); > + > +int mlx5_set_msix_vec_count(struct mlx5_core_dev *dev, int devfn, > + int msix_vec_count); > +int mlx5_get_default_msix_vec_count(struct mlx5_core_dev *dev, int num_vfs); > + > struct cpumask * > mlx5_irq_get_affinity_mask(struct mlx5_irq_table *irq_table, int vecidx); > struct cpu_rmap *mlx5_irq_get_rmap(struct mlx5_irq_table *table); > diff --git a/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c b/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c > index 6fd974920394..2a35888fcff0 100644 > --- a/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c > +++ b/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c > @@ -55,6 +55,78 @@ static struct mlx5_irq *mlx5_irq_get(struct mlx5_core_dev *dev, int vecidx) > return &irq_table->irq[vecidx]; > } > > +/** > + * mlx5_get_default_msix_vec_count() - Get defaults of number of MSI-X vectors > + * to be set s/defaults of number of/default number of/ s/to be set/to be assigned to each VF/ ? > + * @dev: PF to work on > + * @num_vfs: Number of VFs was asked when SR-IOV was enabled s/Number of VFs was asked when SR-IOV was enabled/Number of enabled VFs/ ? > + **/ Documentation/doc-guide/kernel-doc.rst says kernel-doc comments end with just "*/" (not "**/"). > +int mlx5_get_default_msix_vec_count(struct mlx5_core_dev *dev, int num_vfs) > +{ > + int num_vf_msix, min_msix, max_msix; > + > + num_vf_msix = MLX5_CAP_GEN_MAX(dev, num_total_dynamic_vf_msix); > + if (!num_vf_msix) > + return 0; > + > + min_msix = MLX5_CAP_GEN(dev, min_dynamic_vf_msix_table_size); > + max_msix = MLX5_CAP_GEN(dev, max_dynamic_vf_msix_table_size); > + > + /* Limit maximum number of MSI-X to leave some of them free in the > + * pool and ready to be assigned by the users without need to resize > + * other Vfs. s/number of MSI-X/number of MSI-X vectors/ s/Vfs/VFs/ > + */ > + return max(min(num_vf_msix / num_vfs, max_msix / 2), min_msix); > +} > + > +/** > + * mlx5_set_msix_vec_count() - Set dynamically allocated MSI-X to the VF > + * @dev: PF to work on > + * @function_id: Internal PCI VF function id > + * @msix_vec_count: Number of MSI-X to set s/id/ID/ s/Number of MSI-X/Number of MSI-X vectors/ > + **/ > +int mlx5_set_msix_vec_count(struct mlx5_core_dev *dev, int function_id, > + int msix_vec_count) > +{ > + int sz = MLX5_ST_SZ_BYTES(set_hca_cap_in); > + int num_vf_msix, min_msix, max_msix; > + void *hca_cap, *cap; > + int ret; > + > + num_vf_msix = MLX5_CAP_GEN_MAX(dev, num_total_dynamic_vf_msix); > + if (!num_vf_msix) > + return 0; > + > + if (!MLX5_CAP_GEN(dev, vport_group_manager) || !mlx5_core_is_pf(dev)) > + return -EOPNOTSUPP; > + > + min_msix = MLX5_CAP_GEN(dev, min_dynamic_vf_msix_table_size); > + max_msix = MLX5_CAP_GEN(dev, max_dynamic_vf_msix_table_size); > + > + if (msix_vec_count < min_msix) > + return -EINVAL; > + > + if (msix_vec_count > max_msix) > + return -EOVERFLOW; > + > + hca_cap = kzalloc(sz, GFP_KERNEL); > + if (!hca_cap) > + return -ENOMEM; > + > + cap = MLX5_ADDR_OF(set_hca_cap_in, hca_cap, capability); > + MLX5_SET(cmd_hca_cap, cap, dynamic_msix_table_size, msix_vec_count); > + > + MLX5_SET(set_hca_cap_in, hca_cap, opcode, MLX5_CMD_OP_SET_HCA_CAP); > + MLX5_SET(set_hca_cap_in, hca_cap, other_function, 1); > + MLX5_SET(set_hca_cap_in, hca_cap, function_id, function_id); > + > + MLX5_SET(set_hca_cap_in, hca_cap, op_mod, > + MLX5_SET_HCA_CAP_OP_MOD_GENERAL_DEVICE << 1); > + ret = mlx5_cmd_exec_in(dev, set_hca_cap, hca_cap); > + kfree(hca_cap); > + return ret; > +} > + > int mlx5_irq_attach_nb(struct mlx5_irq_table *irq_table, int vecidx, > struct notifier_block *nb) > { > diff --git a/drivers/net/ethernet/mellanox/mlx5/core/sriov.c b/drivers/net/ethernet/mellanox/mlx5/core/sriov.c > index 3094d20297a9..f0ec86a1c8a6 100644 > --- a/drivers/net/ethernet/mellanox/mlx5/core/sriov.c > +++ b/drivers/net/ethernet/mellanox/mlx5/core/sriov.c > @@ -71,8 +71,7 @@ static int sriov_restore_guids(struct mlx5_core_dev *dev, int vf) > static int mlx5_device_enable_sriov(struct mlx5_core_dev *dev, int num_vfs) > { > struct mlx5_core_sriov *sriov = &dev->priv.sriov; > - int err; > - int vf; > + int err, vf, num_msix_count; > > if (!MLX5_ESWITCH_MANAGER(dev)) > goto enable_vfs_hca; > @@ -85,12 +84,22 @@ static int mlx5_device_enable_sriov(struct mlx5_core_dev *dev, int num_vfs) > } > > enable_vfs_hca: > + num_msix_count = mlx5_get_default_msix_vec_count(dev, num_vfs); > for (vf = 0; vf < num_vfs; vf++) { > err = mlx5_core_enable_hca(dev, vf + 1); > if (err) { > mlx5_core_warn(dev, "failed to enable VF %d (%d)\n", vf, err); > continue; > } > + > + err = mlx5_set_msix_vec_count(dev, vf + 1, num_msix_count); > + if (err) { > + mlx5_core_warn(dev, > + "failed to set MSI-X vector counts VF %d, err %d\n", > + vf, err); > + continue; > + } > + > sriov->vfs_ctx[vf].enabled = 1; > if (MLX5_CAP_GEN(dev, port_type) == MLX5_CAP_PORT_TYPE_IB) { > err = sriov_restore_guids(dev, vf); > -- > 2.29.2 >