From patchwork Fri Mar 8 23:05:23 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alex Williamson X-Patchwork-Id: 13587426 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 6D6B93A1C4 for ; Fri, 8 Mar 2024 23:06:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709939174; cv=none; b=hbtOhtxKGKk4cOY5Gg9PaPhDjzLkTV8yNhxuQrXZAwTZn8Kv8SXytg5vg1mNKC+A3hnX/9B8Kc4C7GkkEfRIYOeu8KaajB0NwvLJqt1DPBIhwt794ZkSETYeUi1lDStzRejMkzxwNkRx3dedezN+nRgzPsSwTHvz8r/R5+iQEj4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709939174; c=relaxed/simple; bh=RRNuwGOodP63KJuqXtOzgGIXmJxXs5aKT4xUnjW/L3M=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=LrfPMTXjPT6zcXV4vk314zspgNfOcFDzVtY/P0ej11KNcJO1NqOMYCMXBGk+tCSgUf0EI1wlEwlUMN4NhYZNqepirmiQHrq+pYih7q1gJmsRlOfI3zBZjkDUj6Dt2L5CyDIzK8ndO+a4ObviDdtdt4zKHcAPRFwE2ibQ55yzqXg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=BsH+yC9H; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="BsH+yC9H" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1709939171; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=6LsYRp/Tbqx78yCSxYtu/4eHgx9ZiAm6cb+pYYvgz1s=; b=BsH+yC9H2sWgqu3uuKoeUAPvcjBV858LM8tdxl5uBz4YfQRuBrG2HZU8lqKG+wNka+YJNn hjVwAlkaW/aMZFymFhnwaejaxr/R/3Z8f0nyXHChCLh6OIdRMUzdDbPcVC4caZYYQLFDFj xVvkQZL2KKuJr8M9s/vabFhHxs8vUx4= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-221-aSK38dycPjW6tp_5qnzF2A-1; Fri, 08 Mar 2024 18:06:08 -0500 X-MC-Unique: aSK38dycPjW6tp_5qnzF2A-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 960B2800264; Fri, 8 Mar 2024 23:06:07 +0000 (UTC) Received: from omen.home.shazbot.org (unknown [10.22.8.4]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8D44436FF; Fri, 8 Mar 2024 23:06:06 +0000 (UTC) From: Alex Williamson To: alex.williamson@redhat.com Cc: kvm@vger.kernel.org, eric.auger@redhat.com, clg@redhat.com, reinette.chatre@intel.com, linux-kernel@vger.kernel.org, kevin.tian@intel.com, stable@vger.kernel.org Subject: [PATCH v2 2/7] vfio/pci: Lock external INTx masking ops Date: Fri, 8 Mar 2024 16:05:23 -0700 Message-ID: <20240308230557.805580-3-alex.williamson@redhat.com> In-Reply-To: <20240308230557.805580-1-alex.williamson@redhat.com> References: <20240308230557.805580-1-alex.williamson@redhat.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.1 Mask operations through config space changes to DisINTx may race INTx configuration changes via ioctl. Create wrappers that add locking for paths outside of the core interrupt code. In particular, irq_type is updated holding igate, therefore testing is_intx() requires holding igate. For example clearing DisINTx from config space can otherwise race changes of the interrupt configuration. This aligns interfaces which may trigger the INTx eventfd into two camps, one side serialized by igate and the other only enabled while INTx is configured. A subsequent patch introduces synchronization for the latter flows. Cc: stable@vger.kernel.org Fixes: 89e1f7d4c66d ("vfio: Add PCI device driver") Reported-by: Reinette Chatre Reviewed-by: Kevin Tian Reviewed-by: Reinette Chatre Signed-off-by: Alex Williamson Reviewed-by: Eric Auger --- drivers/vfio/pci/vfio_pci_intrs.c | 34 +++++++++++++++++++++++++------ 1 file changed, 28 insertions(+), 6 deletions(-) diff --git a/drivers/vfio/pci/vfio_pci_intrs.c b/drivers/vfio/pci/vfio_pci_intrs.c index 136101179fcb..75c85eec21b3 100644 --- a/drivers/vfio/pci/vfio_pci_intrs.c +++ b/drivers/vfio/pci/vfio_pci_intrs.c @@ -99,13 +99,15 @@ static void vfio_send_intx_eventfd(void *opaque, void *unused) } /* Returns true if the INTx vfio_pci_irq_ctx.masked value is changed. */ -bool vfio_pci_intx_mask(struct vfio_pci_core_device *vdev) +static bool __vfio_pci_intx_mask(struct vfio_pci_core_device *vdev) { struct pci_dev *pdev = vdev->pdev; struct vfio_pci_irq_ctx *ctx; unsigned long flags; bool masked_changed = false; + lockdep_assert_held(&vdev->igate); + spin_lock_irqsave(&vdev->irqlock, flags); /* @@ -143,6 +145,17 @@ bool vfio_pci_intx_mask(struct vfio_pci_core_device *vdev) return masked_changed; } +bool vfio_pci_intx_mask(struct vfio_pci_core_device *vdev) +{ + bool mask_changed; + + mutex_lock(&vdev->igate); + mask_changed = __vfio_pci_intx_mask(vdev); + mutex_unlock(&vdev->igate); + + return mask_changed; +} + /* * If this is triggered by an eventfd, we can't call eventfd_signal * or else we'll deadlock on the eventfd wait queue. Return >0 when @@ -194,12 +207,21 @@ static int vfio_pci_intx_unmask_handler(void *opaque, void *unused) return ret; } -void vfio_pci_intx_unmask(struct vfio_pci_core_device *vdev) +static void __vfio_pci_intx_unmask(struct vfio_pci_core_device *vdev) { + lockdep_assert_held(&vdev->igate); + if (vfio_pci_intx_unmask_handler(vdev, NULL) > 0) vfio_send_intx_eventfd(vdev, NULL); } +void vfio_pci_intx_unmask(struct vfio_pci_core_device *vdev) +{ + mutex_lock(&vdev->igate); + __vfio_pci_intx_unmask(vdev); + mutex_unlock(&vdev->igate); +} + static irqreturn_t vfio_intx_handler(int irq, void *dev_id) { struct vfio_pci_core_device *vdev = dev_id; @@ -563,11 +585,11 @@ static int vfio_pci_set_intx_unmask(struct vfio_pci_core_device *vdev, return -EINVAL; if (flags & VFIO_IRQ_SET_DATA_NONE) { - vfio_pci_intx_unmask(vdev); + __vfio_pci_intx_unmask(vdev); } else if (flags & VFIO_IRQ_SET_DATA_BOOL) { uint8_t unmask = *(uint8_t *)data; if (unmask) - vfio_pci_intx_unmask(vdev); + __vfio_pci_intx_unmask(vdev); } else if (flags & VFIO_IRQ_SET_DATA_EVENTFD) { struct vfio_pci_irq_ctx *ctx = vfio_irq_ctx_get(vdev, 0); int32_t fd = *(int32_t *)data; @@ -594,11 +616,11 @@ static int vfio_pci_set_intx_mask(struct vfio_pci_core_device *vdev, return -EINVAL; if (flags & VFIO_IRQ_SET_DATA_NONE) { - vfio_pci_intx_mask(vdev); + __vfio_pci_intx_mask(vdev); } else if (flags & VFIO_IRQ_SET_DATA_BOOL) { uint8_t mask = *(uint8_t *)data; if (mask) - vfio_pci_intx_mask(vdev); + __vfio_pci_intx_mask(vdev); } else if (flags & VFIO_IRQ_SET_DATA_EVENTFD) { return -ENOTTY; /* XXX implement me */ }