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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham 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 6D504C43215 for ; Mon, 25 Nov 2019 10:32:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 50D4320835 for ; Mon, 25 Nov 2019 10:32:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727549AbfKYKcf (ORCPT ); Mon, 25 Nov 2019 05:32:35 -0500 Received: from foss.arm.com ([217.140.110.172]:47708 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727543AbfKYKcf (ORCPT ); Mon, 25 Nov 2019 05:32:35 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A15D1328; Mon, 25 Nov 2019 02:32:34 -0800 (PST) Received: from e123195-lin.cambridge.arm.com (e123195-lin.cambridge.arm.com [10.1.196.63]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id B9BF53F52E; Mon, 25 Nov 2019 02:32:33 -0800 (PST) From: Alexandru Elisei To: kvm@vger.kernel.org Cc: will@kernel.org, julien.thierry.kdev@gmail.com, andre.przywara@arm.com, sami.mujawar@arm.com, lorenzo.pieralisi@arm.com Subject: [PATCH kvmtool 04/16] Check that a PCI device's memory size is power of two Date: Mon, 25 Nov 2019 10:30:21 +0000 Message-Id: <20191125103033.22694-5-alexandru.elisei@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191125103033.22694-1-alexandru.elisei@arm.com> References: <20191125103033.22694-1-alexandru.elisei@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org According to the PCI local bus specification [1], a device's memory size must be a power of two. This is also implicit in the mechanism that a CPU uses to get the memory size requirement for a PCI device. The vesa device requests a memory size that isn't a power of two. According to the same spec [1], a device is allowed to consume more memory than it actually requires. As a result, the amount of memory that the vesa device now reserves has been increased. To prevent slip-ups in the future, a few BUILD_BUG_ON statements were added in places where the memory size is known at compile time. [1] PCI Local Bus Specification Revision 3.0, section 6.2.5.1 Signed-off-by: Alexandru Elisei --- hw/vesa.c | 2 ++ include/kvm/util.h | 2 ++ include/kvm/vesa.h | 6 +++++- vfio/pci.c | 5 +++++ virtio/pci.c | 3 +++ 5 files changed, 17 insertions(+), 1 deletion(-) diff --git a/hw/vesa.c b/hw/vesa.c index f3c5114cf4fe..75670a51be5f 100644 --- a/hw/vesa.c +++ b/hw/vesa.c @@ -58,6 +58,8 @@ struct framebuffer *vesa__init(struct kvm *kvm) char *mem; int r; + BUILD_BUG_ON(!is_power_of_two(VESA_MEM_SIZE)); + if (!kvm->cfg.vnc && !kvm->cfg.sdl && !kvm->cfg.gtk) return NULL; diff --git a/include/kvm/util.h b/include/kvm/util.h index 4ca7aa9392b6..e90f1c2db39f 100644 --- a/include/kvm/util.h +++ b/include/kvm/util.h @@ -104,6 +104,8 @@ static inline unsigned long roundup_pow_of_two(unsigned long x) return x ? 1UL << fls_long(x - 1) : 0; } +#define is_power_of_two(x) ((x) ? ((x) & ((x) - 1)) == 0 : 0) + struct kvm; void *mmap_hugetlbfs(struct kvm *kvm, const char *htlbfs_path, u64 size); void *mmap_anon_or_hugetlbfs(struct kvm *kvm, const char *hugetlbfs_path, u64 size); diff --git a/include/kvm/vesa.h b/include/kvm/vesa.h index 0fac11ab5a9f..e7d971343642 100644 --- a/include/kvm/vesa.h +++ b/include/kvm/vesa.h @@ -5,8 +5,12 @@ #define VESA_HEIGHT 480 #define VESA_MEM_ADDR 0xd0000000 -#define VESA_MEM_SIZE (4*VESA_WIDTH*VESA_HEIGHT) #define VESA_BPP 32 +/* + * We actually only need VESA_BPP/8*VESA_WIDTH*VESA_HEIGHT bytes. But the memory + * size must be a power of 2, so we round up. + */ +#define VESA_MEM_SIZE (1 << 21) struct kvm; struct biosregs; diff --git a/vfio/pci.c b/vfio/pci.c index 76e24c156906..914732cc6897 100644 --- a/vfio/pci.c +++ b/vfio/pci.c @@ -831,6 +831,11 @@ static int vfio_pci_configure_bar(struct kvm *kvm, struct vfio_device *vdev, /* Ignore invalid or unimplemented regions */ if (!region->info.size) return 0; + if (!is_power_of_two(region->info.size)) { + vfio_dev_err(vdev, "region is not power of two: 0x%llx", + region->info.size); + return -EINVAL; + } if (pdev->irq_modes & VFIO_PCI_IRQ_MODE_MSIX) { /* Trap and emulate MSI-X table */ diff --git a/virtio/pci.c b/virtio/pci.c index 99653cad2c0f..04e801827df9 100644 --- a/virtio/pci.c +++ b/virtio/pci.c @@ -435,6 +435,9 @@ int virtio_pci__init(struct kvm *kvm, void *dev, struct virtio_device *vdev, vpci->kvm = kvm; vpci->dev = dev; + BUILD_BUG_ON(!is_power_of_two(IOPORT_SIZE)); + BUILD_BUG_ON(!is_power_of_two(PCI_IO_SIZE)); + r = ioport__register(kvm, IOPORT_EMPTY, &virtio_pci__io_ops, IOPORT_SIZE, vdev); if (r < 0) return r; -- 2.20.1