Re: [PATCH 4/7] vDPA: implement IRQ offloading helpers in vDPA core
From: Jason Wang <jasowang@redhat.com>
Date: 2020-07-13 08:27:37
Also in:
kvm, virtualization
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 <redacted>
This patch should go before patch 3.
quoted hunk
--- 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.
quoted hunk
+ + 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.
quoted hunk
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 acceleratediff --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) \