| Message ID | 20201117032139.50988-3-farman@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [RFC,1/2] vfio-mdev: Wire in a request handler for mdev parent | expand |
On Tue, 17 Nov 2020 04:21:39 +0100 Eric Farman <farman@linux.ibm.com> wrote: > The device is being unplugged, so pass the request to userspace to > ask for a graceful cleanup. This should free up the thread that > would otherwise loop waiting for the device to be fully released. > > Signed-off-by: Eric Farman <farman@linux.ibm.com> > --- > drivers/s390/cio/vfio_ccw_ops.c | 26 ++++++++++++++++++++++++++ > drivers/s390/cio/vfio_ccw_private.h | 4 ++++ > include/uapi/linux/vfio.h | 1 + > 3 files changed, 31 insertions(+) > (...) > @@ -607,6 +611,27 @@ static ssize_t vfio_ccw_mdev_ioctl(struct mdev_device *mdev, > } > } > > +/* Request removal of the device*/ > +static void vfio_ccw_mdev_request(struct mdev_device *mdev, unsigned int count) > +{ > + struct vfio_ccw_private *private = dev_get_drvdata(mdev_parent_dev(mdev)); > + > + if (!private) > + return; > + > + if (private->req_trigger) { > + if (!(count % 10)) > + dev_notice_ratelimited(mdev_dev(private->mdev), > + "Relaying device request to user (#%u)\n", > + count); > + > + eventfd_signal(private->req_trigger, 1); > + } else if (count == 0) { > + dev_notice(mdev_dev(private->mdev), > + "No device request channel registered, blocked until released by user\n"); > + } > +} This looks like the vfio-pci request handler, so probably good :) Still have to read up on the QEMU side, but a LGTM for now.
On Thu, 19 Nov 2020 12:43:26 +0100 Cornelia Huck <cohuck@redhat.com> wrote: > On Tue, 17 Nov 2020 04:21:39 +0100 > Eric Farman <farman@linux.ibm.com> wrote: > > > The device is being unplugged, so pass the request to userspace to > > ask for a graceful cleanup. This should free up the thread that > > would otherwise loop waiting for the device to be fully released. > > > > Signed-off-by: Eric Farman <farman@linux.ibm.com> > > --- > > drivers/s390/cio/vfio_ccw_ops.c | 26 ++++++++++++++++++++++++++ > > drivers/s390/cio/vfio_ccw_private.h | 4 ++++ > > include/uapi/linux/vfio.h | 1 + > > 3 files changed, 31 insertions(+) > > > > (...) > > > @@ -607,6 +611,27 @@ static ssize_t vfio_ccw_mdev_ioctl(struct mdev_device *mdev, > > } > > } > > > > +/* Request removal of the device*/ > > +static void vfio_ccw_mdev_request(struct mdev_device *mdev, unsigned int count) > > +{ > > + struct vfio_ccw_private *private = dev_get_drvdata(mdev_parent_dev(mdev)); > > + > > + if (!private) > > + return; > > + > > + if (private->req_trigger) { > > + if (!(count % 10)) > > + dev_notice_ratelimited(mdev_dev(private->mdev), > > + "Relaying device request to user (#%u)\n", > > + count); > > + > > + eventfd_signal(private->req_trigger, 1); > > + } else if (count == 0) { > > + dev_notice(mdev_dev(private->mdev), > > + "No device request channel registered, blocked until released by user\n"); > > + } > > +} > > This looks like the vfio-pci request handler, so probably good :) > > Still have to read up on the QEMU side, but a LGTM for now. And now that I've looked at the QEMU code: Reviewed-by: Cornelia Huck <cohuck@redhat.com>
diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c index 8b3ed5b45277..68106be4ba7a 100644 --- a/drivers/s390/cio/vfio_ccw_ops.c +++ b/drivers/s390/cio/vfio_ccw_ops.c @@ -394,6 +394,7 @@ static int vfio_ccw_mdev_get_irq_info(struct vfio_irq_info *info) switch (info->index) { case VFIO_CCW_IO_IRQ_INDEX: case VFIO_CCW_CRW_IRQ_INDEX: + case VFIO_CCW_REQ_IRQ_INDEX: info->count = 1; info->flags = VFIO_IRQ_INFO_EVENTFD; break; @@ -424,6 +425,9 @@ static int vfio_ccw_mdev_set_irqs(struct mdev_device *mdev, case VFIO_CCW_CRW_IRQ_INDEX: ctx = &private->crw_trigger; break; + case VFIO_CCW_REQ_IRQ_INDEX: + ctx = &private->req_trigger; + break; default: return -EINVAL; } @@ -607,6 +611,27 @@ static ssize_t vfio_ccw_mdev_ioctl(struct mdev_device *mdev, } } +/* Request removal of the device*/ +static void vfio_ccw_mdev_request(struct mdev_device *mdev, unsigned int count) +{ + struct vfio_ccw_private *private = dev_get_drvdata(mdev_parent_dev(mdev)); + + if (!private) + return; + + if (private->req_trigger) { + if (!(count % 10)) + dev_notice_ratelimited(mdev_dev(private->mdev), + "Relaying device request to user (#%u)\n", + count); + + eventfd_signal(private->req_trigger, 1); + } else if (count == 0) { + dev_notice(mdev_dev(private->mdev), + "No device request channel registered, blocked until released by user\n"); + } +} + static const struct mdev_parent_ops vfio_ccw_mdev_ops = { .owner = THIS_MODULE, .supported_type_groups = mdev_type_groups, @@ -617,6 +642,7 @@ static const struct mdev_parent_ops vfio_ccw_mdev_ops = { .read = vfio_ccw_mdev_read, .write = vfio_ccw_mdev_write, .ioctl = vfio_ccw_mdev_ioctl, + .request = vfio_ccw_mdev_request, }; int vfio_ccw_mdev_reg(struct subchannel *sch) diff --git a/drivers/s390/cio/vfio_ccw_private.h b/drivers/s390/cio/vfio_ccw_private.h index 8723156b29ea..b2c762eb42b9 100644 --- a/drivers/s390/cio/vfio_ccw_private.h +++ b/drivers/s390/cio/vfio_ccw_private.h @@ -84,7 +84,10 @@ struct vfio_ccw_crw { * @irb: irb info received from interrupt * @scsw: scsw info * @io_trigger: eventfd ctx for signaling userspace I/O results + * @crw_trigger: eventfd ctx for signaling userspace CRW information + * @req_trigger: eventfd ctx for signaling userspace to return device * @io_work: work for deferral process of I/O handling + * @crw_work: work for deferral process of CRW handling */ struct vfio_ccw_private { struct subchannel *sch; @@ -108,6 +111,7 @@ struct vfio_ccw_private { struct eventfd_ctx *io_trigger; struct eventfd_ctx *crw_trigger; + struct eventfd_ctx *req_trigger; struct work_struct io_work; struct work_struct crw_work; } __aligned(8); diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h index 2f313a238a8f..d1812777139f 100644 --- a/include/uapi/linux/vfio.h +++ b/include/uapi/linux/vfio.h @@ -820,6 +820,7 @@ enum { enum { VFIO_CCW_IO_IRQ_INDEX, VFIO_CCW_CRW_IRQ_INDEX, + VFIO_CCW_REQ_IRQ_INDEX, VFIO_CCW_NUM_IRQS };
The device is being unplugged, so pass the request to userspace to ask for a graceful cleanup. This should free up the thread that would otherwise loop waiting for the device to be fully released. Signed-off-by: Eric Farman <farman@linux.ibm.com> --- drivers/s390/cio/vfio_ccw_ops.c | 26 ++++++++++++++++++++++++++ drivers/s390/cio/vfio_ccw_private.h | 4 ++++ include/uapi/linux/vfio.h | 1 + 3 files changed, 31 insertions(+)