From patchwork Mon Apr 13 12:29:25 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Auger X-Patchwork-Id: 6208751 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id E98DCBF4A6 for ; Mon, 13 Apr 2015 12:42:24 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 0D79D202D1 for ; Mon, 13 Apr 2015 12:42:24 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 28DA020340 for ; Mon, 13 Apr 2015 12:42:23 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1Yhddj-0004Oq-G5; Mon, 13 Apr 2015 12:38:59 +0000 Received: from mail-wi0-f172.google.com ([209.85.212.172]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1YhdY7-0007Di-9c for linux-arm-kernel@lists.infradead.org; Mon, 13 Apr 2015 12:33:12 +0000 Received: by widdi4 with SMTP id di4so49677879wid.0 for ; Mon, 13 Apr 2015 05:32:49 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=d/8jJNZWLBQ3oETU2AwUMA0oxGEsIorL5zSB+t1Tb3A=; b=TW0K//a70kU8bJGw4HigRJUN+PDcgOcD4bvunlOISzOJbb5IpjfZiP4sSk3lOEkRwG xSf7eRAjzx1YEk93Zs22eI00BRdmN7cS8syJMbNF6uUeucvsQIcG/gChAEds6t2+CW/V xTsBsNTifVXNJ87KdJnohdyPjsIpnPNiztIgZCg04AL+z3RqB8taWSmLoRveO+zWwiXI Lf0rPRPoQ3OQUwPHIxR+p+4lcWvNqQOw3JWI8WVx3dPPRVNi9eceQkaLJVfOt0vcJSkn tEmEmZFvWJIZo7NymqLpKz4SUnYuyo1NHEd2IW/sMGlfxi55L0MdlFVesBGR6ueCDQG+ dUCQ== X-Gm-Message-State: ALoCoQmp4+mC8QhCcuWbBiErX7Evryh49d+42M+PTeqGEJHOXw8apGpDUXsKf+C7saGwnfsYkAE/ X-Received: by 10.194.23.39 with SMTP id j7mr28143322wjf.9.1428928369413; Mon, 13 Apr 2015 05:32:49 -0700 (PDT) Received: from gnx2579.gnb.st.com (LCaen-156-56-7-90.w80-11.abo.wanadoo.fr. [80.11.198.90]) by mx.google.com with ESMTPSA id fl14sm2879910wjc.11.2015.04.13.05.32.47 (version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 13 Apr 2015 05:32:48 -0700 (PDT) From: Eric Auger To: eric.auger@st.com, eric.auger@linaro.org, christoffer.dall@linaro.org, marc.zyngier@arm.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, alex.williamson@redhat.com, pbonzini@redhat.com Subject: [RFC v6 10/16] KVM: kvm-vfio: wrappers to VFIO external API device helpers Date: Mon, 13 Apr 2015 14:29:25 +0200 Message-Id: <1428928171-18884-11-git-send-email-eric.auger@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1428928171-18884-1-git-send-email-eric.auger@linaro.org> References: <1428928171-18884-1-git-send-email-eric.auger@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150413_053311_525620_63A94D03 X-CRM114-Status: GOOD ( 13.52 ) X-Spam-Score: -0.7 (/) Cc: b.reynal@virtualopensystems.com, feng.wu@intel.com, linux-kernel@vger.kernel.org, patches@linaro.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Provide wrapper functions that allow KVM-VFIO device code to interact with a vfio device: - kvm_vfio_device_get_external_user gets a handle to a struct vfio_device from the vfio device file descriptor and increments its reference counter, - kvm_vfio_device_put_external_user decrements the reference counter to a vfio device, - kvm_vfio_external_base_device returns a handle to the struct device of the vfio device. Also kvm_vfio_get_vfio_device and kvm_vfio_put_vfio_device helpers are introduced. Signed-off-by: Eric Auger --- v3 -> v4: - wrappers are no more exposed in kvm_host and become kvm/vfio.c static functions - added kvm_vfio_get_vfio_device/kvm_vfio_put_vfio_device in that patch file v2 -> v3: - reword the commit message and title v1 -> v2: - kvm_vfio_external_get_base_device renamed into kvm_vfio_external_base_device - kvm_vfio_external_get_type removed --- virt/kvm/vfio.c | 74 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 74 insertions(+) diff --git a/virt/kvm/vfio.c b/virt/kvm/vfio.c index 620e37f..80a45e4 100644 --- a/virt/kvm/vfio.c +++ b/virt/kvm/vfio.c @@ -60,6 +60,80 @@ static void kvm_vfio_group_put_external_user(struct vfio_group *vfio_group) symbol_put(vfio_group_put_external_user); } +static struct vfio_device *kvm_vfio_device_get_external_user(struct file *filep) +{ + struct vfio_device *vdev; + struct vfio_device *(*fn)(struct file *); + + fn = symbol_get(vfio_device_get_external_user); + if (!fn) + return ERR_PTR(-EINVAL); + + vdev = fn(filep); + + symbol_put(vfio_device_get_external_user); + + return vdev; +} + +static void kvm_vfio_device_put_external_user(struct vfio_device *vdev) +{ + void (*fn)(struct vfio_device *); + + fn = symbol_get(vfio_device_put_external_user); + if (!fn) + return; + + fn(vdev); + + symbol_put(vfio_device_put_external_user); +} + +static struct device *kvm_vfio_external_base_device(struct vfio_device *vdev) +{ + struct device *(*fn)(struct vfio_device *); + struct device *dev; + + fn = symbol_get(vfio_external_base_device); + if (!fn) + return NULL; + + dev = fn(vdev); + + symbol_put(vfio_external_base_device); + + return dev; +} + +/** + * kvm_vfio_get_vfio_device - Returns a handle to a vfio-device + * + * Checks it is a valid vfio device and increments its reference counter + * @fd: file descriptor of the vfio platform device + */ +static struct vfio_device *kvm_vfio_get_vfio_device(int fd) +{ + struct fd f = fdget(fd); + struct vfio_device *vdev; + + if (!f.file) + return ERR_PTR(-EINVAL); + vdev = kvm_vfio_device_get_external_user(f.file); + fdput(f); + return vdev; +} + +/** + * kvm_vfio_put_vfio_device: decrements the reference counter of the + * vfio platform * device + * + * @vdev: vfio_device handle to release + */ +static void kvm_vfio_put_vfio_device(struct vfio_device *vdev) +{ + kvm_vfio_device_put_external_user(vdev); +} + static bool kvm_vfio_group_is_coherent(struct vfio_group *vfio_group) { long (*fn)(struct vfio_group *, unsigned long);