From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Wang Subject: Re: [PATCH V2 3/6] vDPA: implement IRQ offloading helpers in vDPA core Date: Fri, 17 Jul 2020 12:19:30 +0800 Message-ID: References: <1594898629-18790-1-git-send-email-lingshan.zhu@intel.com> <1594898629-18790-4-git-send-email-lingshan.zhu@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <1594898629-18790-4-git-send-email-lingshan.zhu@intel.com> Content-Language: en-US Sender: kvm-owner@vger.kernel.org To: Zhu Lingshan , mst@redhat.com, alex.williamson@redhat.com, pbonzini@redhat.com, sean.j.christopherson@intel.com, wanpengli@tencent.com Cc: virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, kvm@vger.kernel.org List-Id: virtualization@lists.linuxfoundation.org On 2020/7/16 下午7:23, Zhu Lingshan wrote: > This commit implements IRQ offloading helpers Let's say "vq irq allocate/free helpers" here. > in vDPA core by > introducing two couple of functions: > > vdpa_alloc_vq_irq() and vdpa_free_vq_irq(): request irq and free > irq, will setup irq offloading. > > vdpa_setup_irq() and vdpa_unsetup_irq(): supportive functions, > will call vhost_vdpa helpers. > > Signed-off-by: Zhu Lingshan > Suggested-by: Jason Wang > --- > drivers/vdpa/vdpa.c | 42 ++++++++++++++++++++++++++++++++++++++++++ > include/linux/vdpa.h | 13 +++++++++++++ > 2 files changed, 55 insertions(+) > > diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c > index ff6562f..cce4d91 100644 > --- a/drivers/vdpa/vdpa.c > +++ b/drivers/vdpa/vdpa.c > @@ -163,6 +163,48 @@ void vdpa_unregister_driver(struct vdpa_driver *drv) > } > EXPORT_SYMBOL_GPL(vdpa_unregister_driver); > > +static void vdpa_setup_irq(struct vdpa_device *vdev, int qid, int irq) > +{ > + struct vdpa_driver *drv = drv_to_vdpa(vdev->dev.driver); > + > + if (drv->setup_vq_irq) > + drv->setup_vq_irq(vdev, qid, irq); > +} > + > +static void vdpa_unsetup_irq(struct vdpa_device *vdev, int qid) > +{ > + struct vdpa_driver *drv = drv_to_vdpa(vdev->dev.driver); > + > + if (drv->unsetup_vq_irq) > + drv->unsetup_vq_irq(vdev, qid); Do you need to check the existence of drv before calling unset_vq_irq()? And how can this synchronize with driver releasing and binding? > +} > + > +int vdpa_alloc_vq_irq(struct device *dev, struct vdpa_device *vdev, > + unsigned int irq, irq_handler_t handler, > + unsigned long irqflags, const char *devname, void *dev_id, > + int qid) Let's add comment as what has been done by other exported helpers. > +{ > + int ret; > + > + ret = devm_request_irq(dev, irq, handler, irqflags, devname, dev_id); > + if (ret) > + dev_err(dev, "Failed to request irq for vq %d\n", qid); > + else > + vdpa_setup_irq(vdev, qid, irq); > + > + return ret; > + > +} > +EXPORT_SYMBOL_GPL(vdpa_alloc_vq_irq); > + > +void vdpa_free_vq_irq(struct device *dev, struct vdpa_device *vdev, int irq, > + int qid, void *dev_id) > +{ > + devm_free_irq(dev, irq, dev_id); > + vdpa_unsetup_irq(vdev, qid); > +} > +EXPORT_SYMBOL_GPL(vdpa_free_vq_irq); > + > static int vdpa_init(void) > { > return bus_register(&vdpa_bus); > diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h > index 239db79..7d64d83 100644 > --- a/include/linux/vdpa.h > +++ b/include/linux/vdpa.h > @@ -220,17 +220,30 @@ struct vdpa_device *__vdpa_alloc_device(struct device *parent, > > int vdpa_register_device(struct vdpa_device *vdev); > void vdpa_unregister_device(struct vdpa_device *vdev); > +/* request irq for a vq, setup irq offloading if its a vhost_vdpa vq */ Let's do the documentation in vdpa.c, and again, document the devres implications or j_xxxust name it as vdpa_devm_xxx. > +int vdpa_alloc_vq_irq(struct device *dev, struct vdpa_device *vdev, > + unsigned int irq, irq_handler_t handler, > + unsigned long irqflags, const char *devname, void *dev_id, > + int qid); > +/* free irq for a vq, unsetup irq offloading if its a vhost_vdpa vq */ > +void vdpa_free_vq_irq(struct device *dev, struct vdpa_device *vdev, int irq, > + int qid, void *dev_id); > + > > /** > * vdpa_driver - operations for a vDPA driver > * @driver: underlying device driver > * @probe: the function to call when a device is found. Returns 0 or -errno. > * @remove: the function to call when a device is removed. > + * @setup_vq_irq: setup irq offloading for a vhost_vdpa vq. > + * @unsetup_vq_irq: unsetup offloading for a vhost_vdpa vq. Let's not limit the methods for a specific use case like irq offloading here. > */ > struct vdpa_driver { > struct device_driver driver; > int (*probe)(struct vdpa_device *vdev); > void (*remove)(struct vdpa_device *vdev); > + void (*setup_vq_irq)(struct vdpa_device *vdev, int qid, int irq); > + void (*unsetup_vq_irq)(struct vdpa_device *vdev, int qid); To be consistent with the exported helper, let's use alloc_vq_irq/free_vq_irq Thanks > }; > > #define vdpa_register_driver(drv) \