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[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 Cc: linux-kernel@vger.kernel.org, patches@linaro.org, pbonzini@redhat.com, kim.phillips@freescale.com, b.reynal@virtualopensystems.com, feng.wu@intel.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-Removed-Original-Auth: Dkim didn't pass. X-Original-Sender: eric.auger@linaro.org X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of patch+caf_=patchwork-forward=linaro.org@linaro.org designates 209.85.217.169 as permitted sender) smtp.mail=patch+caf_=patchwork-forward=linaro.org@linaro.org Precedence: list Mailing-list: list patchwork-forward@linaro.org; contact patchwork-forward+owners@linaro.org List-ID: X-Google-Group-Id: 836684582541 List-Post: , List-Help: , List-Archive: List-Unsubscribe: , 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);