On Fri, May 12, 2017 at 03:58:51PM -0600, Alex Williamson wrote: > On Wed, 26 Apr 2017 18:12:02 +0800 > "Liu, Yi L" <yi.l....@intel.com> wrote: > > > From: "Liu, Yi L" <yi.l....@linux.intel.com> > > > > This patch adds VFIO_IOMMU_SVM_BIND_TASK for potential PASID table > > binding requests. > > > > On VT-d, this IOCTL cmd would be used to link the guest PASID page table > > to host. While for other vendors, it may also be used to support other > > kind of SVM bind request. Previously, there is a discussion on it with > > ARM engineer. It can be found by the link below. This IOCTL cmd may > > support SVM PASID bind request from userspace driver, or page table(cr3) > > bind request from guest. These SVM bind requests would be supported by > > adding different flags. e.g. VFIO_SVM_BIND_PASID is added to support > > PASID bind from userspace driver, VFIO_SVM_BIND_PGTABLE is added to > > support page table bind from guest. > > > > https://patchwork.kernel.org/patch/9594231/ > > > > Signed-off-by: Liu, Yi L <yi.l....@linux.intel.com> > > --- > > include/uapi/linux/vfio.h | 17 +++++++++++++++++ > > 1 file changed, 17 insertions(+) > > > > diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h > > index 519eff3..6b97987 100644 > > --- a/include/uapi/linux/vfio.h > > +++ b/include/uapi/linux/vfio.h > > @@ -547,6 +547,23 @@ struct vfio_iommu_type1_dma_unmap { > > #define VFIO_IOMMU_ENABLE _IO(VFIO_TYPE, VFIO_BASE + 15) > > #define VFIO_IOMMU_DISABLE _IO(VFIO_TYPE, VFIO_BASE + 16) > > > > +/* IOCTL for Shared Virtual Memory Bind */ > > +struct vfio_device_svm { > > + __u32 argsz; > > +#define VFIO_SVM_BIND_PASIDTBL (1 << 0) /* Bind PASID Table */ > > +#define VFIO_SVM_BIND_PASID (1 << 1) /* Bind PASID from userspace > > driver */ > > +#define VFIO_SVM_BIND_PGTABLE (1 << 2) /* Bind guest mmu page table */ > > + __u32 flags; > > + __u32 length; > > + __u8 data[]; > > In the case of VFIO_SVM_BIND_PASIDTBL this is clearly struct > pasid_table_info? So at a minimum this is a union including struct > pasid_table_info. Furthermore how does a user learn what the opaque > data in struct pasid_table_info is without looking at the code? A user > API needs to be clear and documented, not opaque and variable. We > should also have references to the hardware spec for an Intel or ARM > PASID table in uapi. flags should be defined as they're used, let's > not reserve them with the expectation of future use. >
Agree. would add description accordingly. For the flags, I would remove the last two as I wouldn't use. I think Jean would add them in his/her patchset. Anyhow, one of us need to do merge on the flags. Thanks, Yi L > > +}; > > + > > +#define VFIO_SVM_TYPE_MASK (VFIO_SVM_BIND_PASIDTBL | \ > > + VFIO_SVM_BIND_PASID | \ > > + VFIO_SVM_BIND_PGTABLE) > > + > > +#define VFIO_IOMMU_SVM_BIND_TASK _IO(VFIO_TYPE, VFIO_BASE + 22) > > + > > /* -------- Additional API for SPAPR TCE (Server POWERPC) IOMMU -------- */ > > > > /* > >
