From patchwork Wed Mar 15 20:59:25 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Reinette Chatre X-Patchwork-Id: 13176646 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 35B17C6FD1D for ; Wed, 15 Mar 2023 21:00:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232656AbjCOVAG (ORCPT ); Wed, 15 Mar 2023 17:00:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59190 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232498AbjCOU7o (ORCPT ); Wed, 15 Mar 2023 16:59:44 -0400 Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0E780900B3; Wed, 15 Mar 2023 13:59:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1678913983; x=1710449983; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=j7plS9ITT8roz2joqbCS1lpsy17/bXANdR8t6kDnulg=; b=E3UsmQCiMcWdyW1wAxNvUQFxJ8gvF3cBRFkpFljnC3vbIyWaY9clqiiI /lTbNWGpZQSXopz0Is1lvrQz+Mzt8t1pnAO72R7oVDPKBB2GvlAptb+Sk 4haoMhBdjxDjsllTl/KpvYXgcRCGWs30xEapHgqb7MeykJCssHlBYAwqw TC8OTXbE7AWt7bF4F+tiLbHffOxSeDPIDnuVJtVuL+khjdIPOom8GaJ9u TmDsJGVlQ0iLtZbaps3AmAkTl0F/AKMcR2gdegucLzuqeZ1ynPG8hpbSu H1G00pXlKUicpC65vIDsNXph9Uwl8XIv9rveWG+pFVgI5ROaMiGdGHw8a A==; X-IronPort-AV: E=McAfee;i="6500,9779,10650"; a="326176524" X-IronPort-AV: E=Sophos;i="5.98,262,1673942400"; d="scan'208";a="326176524" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Mar 2023 13:59:39 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10650"; a="853747225" X-IronPort-AV: E=Sophos;i="5.98,262,1673942400"; d="scan'208";a="853747225" Received: from rchatre-ws.ostc.intel.com ([10.54.69.144]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Mar 2023 13:59:39 -0700 From: Reinette Chatre To: jgg@nvidia.com, yishaih@nvidia.com, shameerali.kolothum.thodi@huawei.com, kevin.tian@intel.com, alex.williamson@redhat.com Cc: tglx@linutronix.de, darwi@linutronix.de, kvm@vger.kernel.org, dave.jiang@intel.com, jing2.liu@intel.com, ashok.raj@intel.com, fenghua.yu@intel.com, tom.zanussi@linux.intel.com, reinette.chatre@intel.com, linux-kernel@vger.kernel.org Subject: [RFC PATCH 5/8] vfio/pci: Remove interrupt context counter Date: Wed, 15 Mar 2023 13:59:25 -0700 Message-Id: <3154c63905481b5747a7457b275e2bce403b6f84.1678911529.git.reinette.chatre@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org struct vfio_pci_core_device::num_ctx counts how many interrupt contexts have been allocated. When all interrupt contexts are allocated simultaneously num_ctx provides the upper bound of all vectors that can be used as indices into the interrupt context array. With the upcoming support for dynamic MSI-X the number of interrupt contexts does not necessarily span the range of allocated interrupts. Consequently, num_ctx is no longer a trusted upper bound for valid indices. Stop using num_ctx to determine if a provided vector is valid, use the existence of interrupt context directly. Introduce a helper that ensures a provided interrupt range is allocated before any user requested action is taken. This maintains existing behavior (early exit without modifications) when user space attempts to modify a range of vectors that includes unallocated interrupts. The checks that ensure that user space provides a range of vectors that is valid for the device are untouched. Signed-off-by: Reinette Chatre --- Existing behavior on error paths is not maintained for MSI-X when adding support for dynamic MSI-X. Please see maintainer comments associated with "vfio/pci: Support dynamic MSI-x". drivers/vfio/pci/vfio_pci_intrs.c | 30 ++++++++++++++++++++---------- include/linux/vfio_pci_core.h | 1 - 2 files changed, 20 insertions(+), 11 deletions(-) diff --git a/drivers/vfio/pci/vfio_pci_intrs.c b/drivers/vfio/pci/vfio_pci_intrs.c index bfcf5cb6b435..187a1ba34a16 100644 --- a/drivers/vfio/pci/vfio_pci_intrs.c +++ b/drivers/vfio/pci/vfio_pci_intrs.c @@ -107,6 +107,21 @@ static int vfio_irq_ctx_alloc_num(struct vfio_pci_core_device *vdev, return ret; } +static bool vfio_irq_ctx_range_allocated(struct vfio_pci_core_device *vdev, + unsigned int start, unsigned int count) +{ + struct vfio_pci_irq_ctx *ctx; + unsigned int i; + + for (i = start; i < start + count; i++) { + ctx = xa_load(&vdev->ctx, i); + if (!ctx) + return false; + } + + return true; +} + /* * INTx */ @@ -270,8 +285,6 @@ static int vfio_intx_enable(struct vfio_pci_core_device *vdev) return -EINVAL; } - vdev->num_ctx = 1; - /* * If the virtual interrupt is masked, restore it. Devices * supporting DisINTx can be masked at the hardware level @@ -358,7 +371,6 @@ static void vfio_intx_disable(struct vfio_pci_core_device *vdev) } vfio_intx_set_signal(vdev, -1); vdev->irq_type = VFIO_PCI_NUM_IRQS; - vdev->num_ctx = 0; vfio_irq_ctx_free_all(vdev); } @@ -399,7 +411,6 @@ static int vfio_msi_enable(struct vfio_pci_core_device *vdev, int nvec, bool msi } vfio_pci_memory_unlock_and_restore(vdev, cmd); - vdev->num_ctx = nvec; vdev->irq_type = msix ? VFIO_PCI_MSIX_IRQ_INDEX : VFIO_PCI_MSI_IRQ_INDEX; @@ -423,9 +434,6 @@ static int vfio_msi_set_vector_signal(struct vfio_pci_core_device *vdev, int irq, ret; u16 cmd; - if (vector >= vdev->num_ctx) - return -EINVAL; - ctx = vfio_irq_ctx_get(vdev, vector); if (!ctx) return -EINVAL; @@ -500,7 +508,7 @@ static int vfio_msi_set_block(struct vfio_pci_core_device *vdev, unsigned start, int i, ret = 0; unsigned int j; - if (start >= vdev->num_ctx || start + count > vdev->num_ctx) + if (!vfio_irq_ctx_range_allocated(vdev, start, count)) return -EINVAL; for (i = 0, j = start; i < count && !ret; i++, j++) { @@ -541,7 +549,6 @@ static void vfio_msi_disable(struct vfio_pci_core_device *vdev, bool msix) pci_intx(pdev, 0); vdev->irq_type = VFIO_PCI_NUM_IRQS; - vdev->num_ctx = 0; vfio_irq_ctx_free_all(vdev); } @@ -677,7 +684,10 @@ static int vfio_pci_set_msi_trigger(struct vfio_pci_core_device *vdev, return ret; } - if (!irq_is(vdev, index) || start + count > vdev->num_ctx) + if (!irq_is(vdev, index)) + return -EINVAL; + + if (!vfio_irq_ctx_range_allocated(vdev, start, count)) return -EINVAL; for (i = start; i < start + count; i++) { diff --git a/include/linux/vfio_pci_core.h b/include/linux/vfio_pci_core.h index 61d7873a3973..148fd1ae6c1c 100644 --- a/include/linux/vfio_pci_core.h +++ b/include/linux/vfio_pci_core.h @@ -60,7 +60,6 @@ struct vfio_pci_core_device { spinlock_t irqlock; struct mutex igate; struct xarray ctx; - int num_ctx; int irq_type; int num_regions; struct vfio_pci_region *region;