From patchwork Thu Mar 19 14:55:45 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Auger X-Patchwork-Id: 6050501 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id E1E829F318 for ; Thu, 19 Mar 2015 15:09:20 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 61593202F8 for ; Thu, 19 Mar 2015 15:09:15 +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 D2BFD20519 for ; Thu, 19 Mar 2015 15:09:09 +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 1YYc1A-0002lr-Ed; Thu, 19 Mar 2015 15:05:52 +0000 Received: from mail-wg0-f42.google.com ([74.125.82.42]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1YYbuW-00051g-F9 for linux-arm-kernel@lists.infradead.org; Thu, 19 Mar 2015 14:59:01 +0000 Received: by wgdm6 with SMTP id m6so64800543wgd.2 for ; Thu, 19 Mar 2015 07:58:37 -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=GF//3VoRwtUsJ0Q4B+2+D/KGVoUCF0T/ygXy+Krp1owF16kc7SGeiUFXp4uqyhzSo9 xuxvcDupevFRIWYGlXiHALfbCRQimogjCjISnd1UVFSiELQVakWEsX7XnXEsO00oRmY8 9X8F+Q/aR+nc8f3ep+817bvpkbXwP/lGRQLO9mMNUkOt0l/5CjPI2WYuTmGnEj8NjDW6 6f80DVnYhxtEukqsZPZrsVetxxCp/yR46fojZBY0fIS0oYtxFdiTjds+Kd492qjB4rfA S4ix5h9DedZjVjosvNaJMj0GqlodkPye5NZmyHFZElDnB2DUNWfAmRrRgEsw4hHl0sRh GpOQ== X-Gm-Message-State: ALoCoQlwzpSS2Xcfkml7qL7/BP5Gwd+0UtU6Iv2q0aCBxAcm+3nBxpJbDWq+0mnL0kVLqwZ+8M/+ X-Received: by 10.180.39.33 with SMTP id m1mr17277608wik.26.1426777117484; Thu, 19 Mar 2015 07:58:37 -0700 (PDT) Received: from gnx2579.gnb.st.com (weg38-3-78-232-41-119.fbx.proxad.net. [78.232.41.119]) by mx.google.com with ESMTPSA id a6sm1695350wiy.17.2015.03.19.07.58.35 (version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 19 Mar 2015 07:58:36 -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, kvm@vger.kernel.org, alex.williamson@redhat.com Subject: [RFC v5 07/13] KVM: kvm-vfio: wrappers to VFIO external API device helpers Date: Thu, 19 Mar 2015 15:55:45 +0100 Message-Id: <1426776951-24901-8-git-send-email-eric.auger@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1426776951-24901-1-git-send-email-eric.auger@linaro.org> References: <1426776951-24901-1-git-send-email-eric.auger@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150319_075900_721076_C80DDB7B X-CRM114-Status: GOOD ( 13.84 ) X-Spam-Score: -0.7 (/) Cc: kim.phillips@freescale.com, b.reynal@virtualopensystems.com, patches@linaro.org, linux-kernel@vger.kernel.org, pbonzini@redhat.com, feng.wu@intel.com 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);