[PATCH v4 16/16] vfio: powerpc/spapr: Enable Dynamic DMA windows
Alexey Kardashevskiy
aik at ozlabs.ru
Wed Jul 30 19:36:52 EST 2014
On 07/30/2014 07:31 PM, Alexey Kardashevskiy wrote:
> This defines and implements VFIO IOMMU API required to support
> Dynamic DMA windows defined in the SPAPR specification. The ioctl handlers
> implement host-size part of corresponding RTAS calls:
> - VFIO_IOMMU_SPAPR_TCE_QUERY - ibm,query-pe-dma-window;
> - VFIO_IOMMU_SPAPR_TCE_CREATE - ibm,create-pe-dma-window;
> - VFIO_IOMMU_SPAPR_TCE_REMOVE - ibm,remove-pe-dma-window;
> - VFIO_IOMMU_SPAPR_TCE_RESET - ibm,reset-pe-dma-window.
>
> The VFIO IOMMU driver does basic sanity checks and calls corresponding
> SPAPR TCE functions. At the moment only IODA2 (POWER8 PCI host bridge)
> implements them.
>
> This advertises VFIO_IOMMU_SPAPR_TCE_FLAG_DDW capability via
> VFIO_IOMMU_SPAPR_TCE_GET_INFO.
>
> This calls reset() when IOMMU is being disabled (happens when VFIO stops
> using it).
>
> Signed-off-by: Alexey Kardashevskiy <aik at ozlabs.ru>
> ---
> arch/powerpc/platforms/powernv/pci-ioda.c | 1 +
> drivers/vfio/vfio_iommu_spapr_tce.c | 173 +++++++++++++++++++++++++++++-
> include/uapi/linux/vfio.h | 37 ++++++-
> 3 files changed, 209 insertions(+), 2 deletions(-)
>
> diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
> index 6a847b2..f51afe2 100644
> --- a/arch/powerpc/platforms/powernv/pci-ioda.c
> +++ b/arch/powerpc/platforms/powernv/pci-ioda.c
> @@ -859,6 +859,7 @@ static long pnv_pci_ioda2_ddw_create(struct spapr_tce_iommu_group *data,
>
> /* Copy "invalidate" register address */
> tbl64->it_index = pe->tce32.table.it_index;
> + tbl64->it_group = pe->tce32.table.it_group;
Just noticed. This does not belong here, this must be moved to earlier patch.
> tbl64->it_type = TCE_PCI_SWINV_CREATE | TCE_PCI_SWINV_FREE |
> TCE_PCI_SWINV_PAIR;
> tbl64->it_map = (void *) 0xDEADBEEF; /* poison */
> diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c
> index 48b256c..32e2804 100644
> --- a/drivers/vfio/vfio_iommu_spapr_tce.c
> +++ b/drivers/vfio/vfio_iommu_spapr_tce.c
> @@ -45,6 +45,7 @@ struct tce_container {
> struct mutex lock;
> struct iommu_group *grp;
> bool enabled;
> + unsigned long start64;
> };
>
>
> @@ -123,19 +124,36 @@ static void tce_iommu_disable(struct tce_container *container)
>
> container->enabled = false;
>
> - if (!container->grp || !current->mm)
> + if (!container->grp)
> return;
>
> data = iommu_group_get_iommudata(container->grp);
> if (!data || !data->iommu_owner || !data->ops->get_table)
> return;
>
> + /* Try resetting, there might have been a 64bit window */
> + if (data->ops->reset)
> + data->ops->reset(data);
> +
> + if (!current->mm)
> + return;
> +
> tbl = data->ops->get_table(data, TCE_DEFAULT_WINDOW);
> if (!tbl)
> return;
>
> decrement_locked_vm((tbl->it_size << tbl->it_page_shift) >>
> PAGE_SHIFT);
> +
> + if (!container->start64)
> + return;
> +
> + tbl = data->ops->get_table(data, container->start64);
> + if (!tbl)
> + return;
> +
> + decrement_locked_vm((tbl->it_size << tbl->it_page_shift) >>
> + PAGE_SHIFT);
> }
>
> static void *tce_iommu_open(unsigned long arg)
> @@ -210,6 +228,8 @@ static long tce_iommu_ioctl(void *iommu_data,
> info.dma32_window_start = tbl->it_offset << tbl->it_page_shift;
> info.dma32_window_size = tbl->it_size << tbl->it_page_shift;
> info.flags = 0;
> + if (data->ops->query && data->ops->create && data->ops->remove)
> + info.flags |= VFIO_IOMMU_SPAPR_TCE_FLAG_DDW;
>
> if (copy_to_user((void __user *)arg, &info, minsz))
> return -EFAULT;
> @@ -335,6 +355,157 @@ static long tce_iommu_ioctl(void *iommu_data,
> tce_iommu_disable(container);
> mutex_unlock(&container->lock);
> return 0;
> +
> + case VFIO_IOMMU_SPAPR_TCE_QUERY: {
> + struct vfio_iommu_spapr_tce_query query;
> + struct spapr_tce_iommu_group *data;
> +
> + if (WARN_ON(!container->grp))
> + return -ENXIO;
> +
> + data = iommu_group_get_iommudata(container->grp);
> +
> + minsz = offsetofend(struct vfio_iommu_spapr_tce_query,
> + page_size_mask);
> +
> + if (copy_from_user(&query, (void __user *)arg, minsz))
> + return -EFAULT;
> +
> + if (query.argsz < minsz)
> + return -EINVAL;
> +
> + if (!data->ops->query || !data->iommu_owner)
> + return -ENOSYS;
> +
> + ret = data->ops->query(data,
> + &query.windows_available,
> + &query.page_size_mask);
> +
> + if (ret)
> + return ret;
> +
> + if (copy_to_user((void __user *)arg, &query, minsz))
> + return -EFAULT;
> +
> + return 0;
> + }
> + case VFIO_IOMMU_SPAPR_TCE_CREATE: {
> + struct vfio_iommu_spapr_tce_create create;
> + struct spapr_tce_iommu_group *data;
> + struct iommu_table *tbl;
> +
> + if (WARN_ON(!container->grp))
> + return -ENXIO;
> +
> + data = iommu_group_get_iommudata(container->grp);
> +
> + minsz = offsetofend(struct vfio_iommu_spapr_tce_create,
> + start_addr);
> +
> + if (copy_from_user(&create, (void __user *)arg, minsz))
> + return -EFAULT;
> +
> + if (create.argsz < minsz)
> + return -EINVAL;
> +
> + if (!data->ops->create || !data->iommu_owner)
> + return -ENOSYS;
> +
> + BUG_ON(!data || !data->ops || !data->ops->remove);
> +
> + ret = data->ops->create(data, create.page_shift,
> + create.window_shift, &tbl);
> + if (ret)
> + return ret;
> +
> + ret = try_increment_locked_vm((tbl->it_size <<
> + tbl->it_page_shift) >> PAGE_SHIFT);
> + if (ret) {
> + data->ops->remove(data, tbl);
> + return ret;
> + }
> +
> + create.start_addr = tbl->it_offset << tbl->it_page_shift;
> +
> + if (copy_to_user((void __user *)arg, &create, minsz)) {
> + data->ops->remove(data, tbl);
> + decrement_locked_vm((tbl->it_size <<
> + tbl->it_page_shift) >> PAGE_SHIFT);
> + return -EFAULT;
> + }
> +
> + return ret;
> + }
> + case VFIO_IOMMU_SPAPR_TCE_REMOVE: {
> + struct vfio_iommu_spapr_tce_remove remove;
> + struct spapr_tce_iommu_group *data;
> + struct iommu_table *tbl;
> +
> + if (WARN_ON(!container->grp))
> + return -ENXIO;
> +
> + data = iommu_group_get_iommudata(container->grp);
> +
> + minsz = offsetofend(struct vfio_iommu_spapr_tce_remove,
> + start_addr);
> +
> + if (copy_from_user(&remove, (void __user *)arg, minsz))
> + return -EFAULT;
> +
> + if (remove.argsz < minsz)
> + return -EINVAL;
> +
> + if (!data->ops->remove || !data->iommu_owner)
> + return -ENOSYS;
> +
> + tbl = data->ops->get_table(data, remove.start_addr);
> + if (!tbl)
> + return -EINVAL;
> +
> + ret = data->ops->remove(data, tbl);
> + if (ret)
> + return ret;
> +
> + decrement_locked_vm((tbl->it_size << tbl->it_page_shift)
> + >> PAGE_SHIFT);
> + return 0;
> + }
> + case VFIO_IOMMU_SPAPR_TCE_RESET: {
> + struct vfio_iommu_spapr_tce_reset reset;
> + struct spapr_tce_iommu_group *data;
> +
> + if (WARN_ON(!container->grp))
> + return -ENXIO;
> +
> + data = iommu_group_get_iommudata(container->grp);
> +
> + minsz = offsetofend(struct vfio_iommu_spapr_tce_reset, argsz);
> +
> + if (copy_from_user(&reset, (void __user *)arg, minsz))
> + return -EFAULT;
> +
> + if (reset.argsz < minsz)
> + return -EINVAL;
> +
> + if (!data->ops->reset || !data->iommu_owner)
> + return -ENOSYS;
> +
> + ret = data->ops->reset(data);
> + if (ret)
> + return ret;
> +
> + if (container->start64) {
> + struct iommu_table *tbl;
> +
> + tbl = data->ops->get_table(data, container->start64);
> + BUG_ON(!tbl);
> +
> + decrement_locked_vm((tbl->it_size << tbl->it_page_shift)
> + >> PAGE_SHIFT);
> + }
> +
> + return 0;
> + }
> }
>
> return -ENOTTY;
> diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
> index cb9023d..8b03381 100644
> --- a/include/uapi/linux/vfio.h
> +++ b/include/uapi/linux/vfio.h
> @@ -448,13 +448,48 @@ struct vfio_iommu_type1_dma_unmap {
> */
> struct vfio_iommu_spapr_tce_info {
> __u32 argsz;
> - __u32 flags; /* reserved for future use */
> + __u32 flags;
> +#define VFIO_IOMMU_SPAPR_TCE_FLAG_DDW 1 /* Support dynamic windows */
> __u32 dma32_window_start; /* 32 bit window start (bytes) */
> __u32 dma32_window_size; /* 32 bit window size (bytes) */
> };
>
> #define VFIO_IOMMU_SPAPR_TCE_GET_INFO _IO(VFIO_TYPE, VFIO_BASE + 12)
>
> +/*
> + * Dynamic DMA windows
> + */
> +struct vfio_iommu_spapr_tce_query {
> + __u32 argsz;
> + /* out */
> + __u32 windows_available;
> + __u32 page_size_mask;
> +};
> +#define VFIO_IOMMU_SPAPR_TCE_QUERY _IO(VFIO_TYPE, VFIO_BASE + 17)
> +
> +struct vfio_iommu_spapr_tce_create {
> + __u32 argsz;
> + /* in */
> + __u32 page_shift;
> + __u32 window_shift;
> + /* out */
> + __u64 start_addr;
> +
> +};
> +#define VFIO_IOMMU_SPAPR_TCE_CREATE _IO(VFIO_TYPE, VFIO_BASE + 18)
> +
> +struct vfio_iommu_spapr_tce_remove {
> + __u32 argsz;
> + /* in */
> + __u64 start_addr;
> +};
> +#define VFIO_IOMMU_SPAPR_TCE_REMOVE _IO(VFIO_TYPE, VFIO_BASE + 19)
> +
> +struct vfio_iommu_spapr_tce_reset {
> + __u32 argsz;
> +};
> +#define VFIO_IOMMU_SPAPR_TCE_RESET _IO(VFIO_TYPE, VFIO_BASE + 20)
> +
> /* ***************************************************************** */
>
> #endif /* _UAPIVFIO_H */
>
--
Alexey
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