From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Wang Subject: Re: [PATCH 4/7] vDPA: implement IRQ offloading helpers in vDPA core Date: Mon, 13 Jul 2020 16:27:08 +0800 Message-ID: <6e8b267c-0734-1d9b-d3da-e2e6f44f7847@redhat.com> References: <1594565366-3195-1-git-send-email-lingshan.zhu@intel.com> <1594565366-3195-4-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: <1594565366-3195-4-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, kvm@vger.kernel.org, netdev@vger.kernel.org, dan.daly@intel.com List-Id: virtualization@lists.linuxfoundation.org On 2020/7/12 下午10:49, Zhu Lingshan wrote: > This commit implements IRQ offloading helpers 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 if irq_bypass is enabled. > > vdpa_setup_irq() and vdpa_unsetup_irq(): supportive functions, > will call vhost_vdpa helpers. > > Signed-off-by: Zhu Lingshan This patch should go before patch 3. > --- > drivers/vdpa/vdpa.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++ > drivers/vhost/Kconfig | 1 + > drivers/vhost/vdpa.c | 2 ++ > include/linux/vdpa.h | 11 +++++++++++ > 4 files changed, 60 insertions(+) > > diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c > index ff6562f..d8eba01 100644 > --- a/drivers/vdpa/vdpa.c > +++ b/drivers/vdpa/vdpa.c > @@ -163,6 +163,52 @@ 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); > + > +#ifdef CONFIG_HAVE_KVM_IRQ_BYPASS Let's don't do the check here. It's the responsibility of driver to decide what it should do. > + if (drv->setup_vq_irq) > + drv->setup_vq_irq(vdev, qid, irq); > +#endif > +} > + > +static void vdpa_unsetup_irq(struct vdpa_device *vdev, int qid) > +{ > + struct vdpa_driver *drv = drv_to_vdpa(vdev->dev.driver); > + > +#ifdef CONFIG_HAVE_KVM_IRQ_BYPASS > + if (drv->unsetup_vq_irq) > + drv->unsetup_vq_irq(vdev, qid); > +#endif > +} > + > +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) > +{ > + 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); I'd like to squash the vdpa_setup_irq logic here. > + > + 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/drivers/vhost/Kconfig b/drivers/vhost/Kconfig Let squash the vhost patch into patch 3. > index d3688c6..587fbae 100644 > --- a/drivers/vhost/Kconfig > +++ b/drivers/vhost/Kconfig > @@ -65,6 +65,7 @@ config VHOST_VDPA > tristate "Vhost driver for vDPA-based backend" > depends on EVENTFD > select VHOST > + select IRQ_BYPASS_MANAGER > depends on VDPA > help > This kernel module can be loaded in host kernel to accelerate > diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c > index 92683e4..6e25158 100644 > --- a/drivers/vhost/vdpa.c > +++ b/drivers/vhost/vdpa.c > @@ -1020,6 +1020,8 @@ static void vhost_vdpa_remove(struct vdpa_device *vdpa) > }, > .probe = vhost_vdpa_probe, > .remove = vhost_vdpa_remove, > + .setup_vq_irq = vhost_vdpa_setup_vq_irq, > + .unsetup_vq_irq = vhost_vdpa_unsetup_vq_irq, > }; > > static int __init vhost_vdpa_init(void) > diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h > index 239db79..9f9b245 100644 > --- a/include/linux/vdpa.h > +++ b/include/linux/vdpa.h > @@ -220,17 +220,28 @@ 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); > +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); > +void vdpa_free_vq_irq(struct device *dev, struct vdpa_device *vdev, int irq, > + int qid, void *dev_id); You need to document the devres implications of those two helpers. > + > > /** > * 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 bypass for a vhost_vdpa vq. > + * @unsetup_vq_irq: unsetup irq bypass for a vhost_vdpa vq. Though irq bypass is used by vhost-vdpa, it's not necessarily to be true in the future. So it's better not to mention irqbypass in the doc here. Thanks > */ > 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); > }; > > #define vdpa_register_driver(drv) \