From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dong Jia Subject: Re: [RFC PATCH v4 1/3] Mediated device Core driver Date: Mon, 6 Jun 2016 14:01:48 +0800 Message-ID: <20160606140148.31ec05f9@oc7835276234> References: <1464119897-10844-1-git-send-email-kwankhede@nvidia.com> <1464119897-10844-2-git-send-email-kwankhede@nvidia.com> <20160603165746.3df39542@oc7835276234> <799479b0-44d5-061f-185a-43df0dba2fb3@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: , , , , , , , , , To: Kirti Wankhede Return-path: Received: from e32.co.us.ibm.com ([32.97.110.150]:47990 "EHLO e32.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750743AbcFFGCD (ORCPT ); Mon, 6 Jun 2016 02:02:03 -0400 Received: from localhost by e32.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 6 Jun 2016 00:02:01 -0600 In-Reply-To: <799479b0-44d5-061f-185a-43df0dba2fb3@nvidia.com> Sender: kvm-owner@vger.kernel.org List-ID: On Mon, 6 Jun 2016 10:57:49 +0530 Kirti Wankhede wrote: > > > On 6/3/2016 2:27 PM, Dong Jia wrote: > > On Wed, 25 May 2016 01:28:15 +0530 > > Kirti Wankhede wrote: > > > > > > ...snip... > > > >> +struct phy_device_ops { > >> + struct module *owner; > >> + const struct attribute_group **dev_attr_groups; > >> + const struct attribute_group **mdev_attr_groups; > >> + > >> + int (*supported_config)(struct device *dev, char *config); > >> + int (*create)(struct device *dev, uuid_le uuid, > >> + uint32_t instance, char *mdev_params); > >> + int (*destroy)(struct device *dev, uuid_le uuid, > >> + uint32_t instance); > >> + int (*start)(uuid_le uuid); > >> + int (*shutdown)(uuid_le uuid); > >> + ssize_t (*read)(struct mdev_device *vdev, char *buf, size_t count, > >> + enum mdev_emul_space address_space, loff_t pos); > >> + ssize_t (*write)(struct mdev_device *vdev, char *buf, size_t count, > >> + enum mdev_emul_space address_space, loff_t pos); > >> + int (*set_irqs)(struct mdev_device *vdev, uint32_t flags, > >> + unsigned int index, unsigned int start, > >> + unsigned int count, void *data); > >> + int (*get_region_info)(struct mdev_device *vdev, int region_index, > >> + struct pci_region_info *region_info); > >> + int (*validate_map_request)(struct mdev_device *vdev, > >> + unsigned long virtaddr, > >> + unsigned long *pfn, unsigned long *size, > >> + pgprot_t *prot); > >> +}; > > > > Dear Kirti: > > > > When I rebased my vfio-ccw patches on this series, I found I need an > > extra 'ioctl' callback in phy_device_ops. > > > > Thanks for taking closer look. As per my knowledge ccw is not PCI > device, right? Correct me if I'm wrong. Dear Kirti: You are right. CCW is different to PCI. The official term is 'Channel I/O device'. They use 'Channels' (co-processors) and CCWs (channel command words) to handle I/O operations. > I'm curious to know. Are you planning to write a driver (vfio-mccw) for > mediated ccw device? I wrote two drivers: 1. A vfio-pccw driver for the physical ccw device, which will reigister the device and callbacks to mdev framework. With this, I could create a mediated ccw device for the physical one then. 2. A vfio-mccw driver for the mediated ccw device, which will add itself to a vfio_group, mimiced what vfio-mpci did. The problem is, vfio-mccw need to implement new ioctls besides the existing ones (VFIO_DEVICE_GET_INFO, etc). And these ioctls really need the physical device help to handle. > > Thanks, > Kirti > > > The ccw physical device only supports one ccw mediated device. And I > > have two new ioctl commands for the ccw mediated device. One is > > to hot-reset the resource in the physical device that allocated for > > the mediated device, the other is to do an I/O instruction translation > > and perform an I/O operation on the physical device. I found the > > existing callbacks could not meet my requirements. > > > > Something like the following would be fine for my case: > > int (*ioctl)(struct mdev_device *vdev, > > unsigned int cmd, > > unsigned long arg); > > > > What do you think about this? > > > > -------- > > Dong Jia > > > -------- Dong Jia