Messages in this thread | | | Subject | Re: [PATCH v4 6/8] vfio/mdev: Add iommu place holders in mdev_device | From | Lu Baolu <> | Date | Fri, 16 Nov 2018 09:20:48 +0800 |
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Hi,
On 11/16/18 5:31 AM, Kirti Wankhede wrote: > > > On 11/7/2018 7:18 AM, Lu Baolu wrote: >> Hi Alex, >> >> On 11/7/18 7:53 AM, Alex Williamson wrote: >>> On Mon, 5 Nov 2018 15:34:06 +0800 >>> Lu Baolu <baolu.lu@linux.intel.com> wrote: >>> >>>> A parent device might create different types of mediated >>>> devices. For example, a mediated device could be created >>>> by the parent device with full isolation and protection >>>> provided by the IOMMU. One usage case could be found on >>>> Intel platforms where a mediated device is an assignable >>>> subset of a PCI, the DMA requests on behalf of it are all >>>> tagged with a PASID. Since IOMMU supports PASID-granular >>>> translations (scalable mode in vt-d 3.0), this mediated >>>> device could be individually protected and isolated by an >>>> IOMMU. >>>> >>>> This patch adds two new members in struct mdev_device: >>>> * iommu_device >>>> - This, if set, indicates that the mediated device could >>>> be fully isolated and protected by IOMMU via attaching >>>> an iommu domain to this device. If empty, it indicates >>>> using vendor defined isolation. >>>> >>>> * iommu_domain >>>> - This is a place holder for an iommu domain. A domain >>>> could be store here for later use once it has been >>>> attached to the iommu_device of this mdev. >>>> >>>> Below helpers are added to set and get above iommu device >>>> and iommu domain pointers. >>>> >>>> * mdev_set/get_iommu_device(dev, iommu_device) >>>> - Set or get the iommu device which represents this mdev >>>> in IOMMU's device scope. Drivers don't need to set the >>>> iommu device if it uses vendor defined isolation. >>>> >>>> * mdev_set/get_iommu_domain(domain) >>>> - A iommu domain which has been attached to the iommu >>>> device in order to protect and isolate the mediated >>>> device will be kept in the mdev data structure and >>>> could be retrieved later. >>>> >>>> Cc: Ashok Raj <ashok.raj@intel.com> >>>> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com> >>>> Cc: Kevin Tian <kevin.tian@intel.com> >>>> Cc: Liu Yi L <yi.l.liu@intel.com> >>>> Suggested-by: Kevin Tian <kevin.tian@intel.com> >>>> Suggested-by: Alex Williamson <alex.williamson@redhat.com> >>>> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> >>>> --- >>>> drivers/vfio/mdev/mdev_core.c | 36 ++++++++++++++++++++++++++++++++ >>>> drivers/vfio/mdev/mdev_private.h | 2 ++ >>>> include/linux/mdev.h | 23 ++++++++++++++++++++ >>>> 3 files changed, 61 insertions(+) >>>> >>>> diff --git a/drivers/vfio/mdev/mdev_core.c >>>> b/drivers/vfio/mdev/mdev_core.c >>>> index 0212f0ee8aea..5119809225c5 100644 >>>> --- a/drivers/vfio/mdev/mdev_core.c >>>> +++ b/drivers/vfio/mdev/mdev_core.c >>>> @@ -390,6 +390,42 @@ int mdev_device_remove(struct device *dev, bool >>>> force_remove) >>>> return 0; >>>> } >>>> +int mdev_set_iommu_device(struct device *dev, struct device >>>> *iommu_device) >>>> +{ >>>> + struct mdev_device *mdev = to_mdev_device(dev); >>>> + >>>> + mdev->iommu_device = iommu_device; >>>> + >>>> + return 0; >>>> +} >>>> +EXPORT_SYMBOL(mdev_set_iommu_device); >>>> + >>>> +struct device *mdev_get_iommu_device(struct device *dev) >>>> +{ >>>> + struct mdev_device *mdev = to_mdev_device(dev); >>>> + >>>> + return mdev->iommu_device; >>>> +} >>>> +EXPORT_SYMBOL(mdev_get_iommu_device); >>>> + >>>> +int mdev_set_iommu_domain(struct device *dev, void *domain) >>>> +{ >>>> + struct mdev_device *mdev = to_mdev_device(dev); >>>> + >>>> + mdev->iommu_domain = domain; >>>> + >>>> + return 0; >>>> +} >>>> +EXPORT_SYMBOL(mdev_set_iommu_domain); >>>> + >>>> +void *mdev_get_iommu_domain(struct device *dev) >>>> +{ >>>> + struct mdev_device *mdev = to_mdev_device(dev); >>>> + >>>> + return mdev->iommu_domain; >>>> +} >>>> +EXPORT_SYMBOL(mdev_get_iommu_domain); >>>> + >>>> static int __init mdev_init(void) >>>> { >>>> return mdev_bus_register(); >>>> diff --git a/drivers/vfio/mdev/mdev_private.h >>>> b/drivers/vfio/mdev/mdev_private.h >>>> index b5819b7d7ef7..c01518068e84 100644 >>>> --- a/drivers/vfio/mdev/mdev_private.h >>>> +++ b/drivers/vfio/mdev/mdev_private.h >>>> @@ -34,6 +34,8 @@ struct mdev_device { >>>> struct list_head next; >>>> struct kobject *type_kobj; >>>> bool active; >>>> + struct device *iommu_device; >>>> + void *iommu_domain; >>>> }; >>>> #define to_mdev_device(dev) container_of(dev, struct >>>> mdev_device, dev) >>>> diff --git a/include/linux/mdev.h b/include/linux/mdev.h >>>> index b6e048e1045f..c46777d3e568 100644 >>>> --- a/include/linux/mdev.h >>>> +++ b/include/linux/mdev.h >>>> @@ -14,6 +14,29 @@ >>>> #define MDEV_H >>>> struct mdev_device; >>>> +struct iommu_domain; >>>> + >>>> +/* >>>> + * Called by the parent device driver to set the PCI device which >>>> represents >>> >>> s/PCI // >>> >>> There is no requirement or expectation that the device is PCI. >>> >> >> Fair enough. >> >>>> + * this mdev in iommu protection scope. By default, the iommu device >>>> is NULL, >>>> + * that indicates using vendor defined isolation. >>>> + * >>>> + * @dev: the mediated device that iommu will isolate. >>>> + * @iommu_device: a pci device which represents the iommu for @dev. >>>> + * >>>> + * Return 0 for success, otherwise negative error value. >>>> + */ >>>> +int mdev_set_iommu_device(struct device *dev, struct device >>>> *iommu_device); >>>> + >>>> +struct device *mdev_get_iommu_device(struct device *dev); >>>> + >>>> +/* >>>> + * Called by vfio iommu modules to save the iommu domain after a >>>> domain being >>>> + * attached to the mediated device. >>>> + */ >>>> +int mdev_set_iommu_domain(struct device *dev, void *domain); >>>> + >>>> +void *mdev_get_iommu_domain(struct device *dev); >>> >>> I can't say I really understand the purpose of this, the cover letter >>> indicates this is a placeholder, should we add it separately when we >>> have a requirement for it? >> >> Oh, I am sorry that I used a wrong word. It's not a placeholder for >> something designed for future, but adding two members that will be used >> in the following patches. Since they will be used in anther modules >> (like vfio_iommu), we need function interfaces to get and set them. >> >> mdev->iommu_device: >> - This, if set, indicates that the mediated device could >> be fully isolated and protected by IOMMU via attaching >> an iommu domain to this device. If empty, it indicates >> using vendor defined isolation. >> >> mdev->iommu_domain: >> - This is used to save the pointer of an iommu domain. Once >> a domain has been attached to the iommu_device, it should >> be stored here. >> > > I don't see mdev->iommu_domain is used anywhere in this series of patch. > If this is not being used, then no need to save it. With that symbols > mdev_set/get_iommu_domain(domain) are not required.
Yes. We won't use mdev->iommu_domain in this patch series. It should be used by mdev parent driver to retrieve the default pasid of the domain. Something like:
domain = mdev_get_iommu_domain(dev) pasid = iommu_domain_get_attr(domain, DOMAIN_ATTR_AUXD_ID); reg_write(pasid_reg, pasid);
I am okay if we remove mdev_set/get_iommu_domain from this patch series and add it later when the parent driver comes.
> > Please keep symbols mdev_set/get_iommu_device(dev, iommu_device) non-GPL > same as other exported symbols from mdev_core module.
Yes. It will be fixed in the next version.
> > Thanks, > Kirti >
Best regards, Lu Baolu
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