Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932594AbbDMMkA (ORCPT ); Mon, 13 Apr 2015 08:40:00 -0400 Received: from mail-wi0-f176.google.com ([209.85.212.176]:35212 "EHLO mail-wi0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932326AbbDMMcu (ORCPT ); Mon, 13 Apr 2015 08:32:50 -0400 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 Cc: linux-kernel@vger.kernel.org, patches@linaro.org, feng.wu@intel.com, b.reynal@virtualopensystems.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> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3301 Lines: 127 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); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/