Re: [PATCH v6 01/15] vfio/type1: Refactor vfio_iommu_type1_ioctl()

Alex Williamson
2020-07-28T15:54:01Z

On Mon, 27 Jul 2020 23:27:30 -0700
Liu Yi L <yi.l.liu@intel.com> wrote:

> This patch refactors the vfio_iommu_type1_ioctl() to use switch instead of
> if-else, and each command got a helper function.
>
> Cc: Kevin Tian <kevin.tian@intel.com>
> CC: Jacob Pan <jacob.jun.pan@linux.intel.com>
> Cc: Alex Williamson <alex.williamson@redhat.com>
> Cc: Eric Auger <eric.auger@redhat.com>
> Cc: Jean-Philippe Brucker <jean-philippe@linaro.org>
> Cc: Joerg Roedel <joro@8bytes.org>
> Cc: Lu Baolu <baolu.lu@linux.intel.com>
> Reviewed-by: Eric Auger <eric.auger@redhat.com>
> Suggested-by: Christoph Hellwig <hch@infradead.org>
> Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
> ---

FYI, this commit is already in my next branch and linux-next as of
today, you can drop it from future series. Thanks,

Alex

> v4 -> v5:
> *) address comments from Eric Auger, add r-b from Eric.
> ---
> drivers/vfio/vfio_iommu_type1.c | 394 ++++++++++++++++++++++------------------
> 1 file changed, 213 insertions(+), 181 deletions(-)
>
> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
> index 5e556ac..3bd70ff 100644
> --- a/drivers/vfio/vfio_iommu_type1.c
> +++ b/drivers/vfio/vfio_iommu_type1.c
> @@ -2453,6 +2453,23 @@ static int vfio_domains_have_iommu_cache(struct vfio_iommu *iommu)
> return ret;
> }
>
> +static int vfio_iommu_type1_check_extension(struct vfio_iommu *iommu,
> + unsigned long arg)
> +{
> + switch (arg) {
> + case VFIO_TYPE1_IOMMU:
> + case VFIO_TYPE1v2_IOMMU:
> + case VFIO_TYPE1_NESTING_IOMMU:
> + return 1;
> + case VFIO_DMA_CC_IOMMU:
> + if (!iommu)
> + return 0;
> + return vfio_domains_have_iommu_cache(iommu);
> + default:
> + return 0;
> + }
> +}
> +
> static int vfio_iommu_iova_add_cap(struct vfio_info_cap *caps,
> struct vfio_iommu_type1_info_cap_iova_range *cap_iovas,
> size_t size)
> @@ -2529,241 +2546,256 @@ static int vfio_iommu_migration_build_caps(struct vfio_iommu *iommu,
> return vfio_info_add_capability(caps, &cap_mig.header, sizeof(cap_mig));
> }
>
> -static long vfio_iommu_type1_ioctl(void *iommu_data,
> - unsigned int cmd, unsigned long arg)
> +static int vfio_iommu_type1_get_info(struct vfio_iommu *iommu,
> + unsigned long arg)
> {
> - struct vfio_iommu *iommu = iommu_data;
> + struct vfio_iommu_type1_info info;
> unsigned long minsz;
> + struct vfio_info_cap caps = { .buf = NULL, .size = 0 };
> + unsigned long capsz;
> + int ret;
>
> - if (cmd == VFIO_CHECK_EXTENSION) {
> - switch (arg) {
> - case VFIO_TYPE1_IOMMU:
> - case VFIO_TYPE1v2_IOMMU:
> - case VFIO_TYPE1_NESTING_IOMMU:
> - return 1;
> - case VFIO_DMA_CC_IOMMU:
> - if (!iommu)
> - return 0;
> - return vfio_domains_have_iommu_cache(iommu);
> - default:
> - return 0;
> - }
> - } else if (cmd == VFIO_IOMMU_GET_INFO) {
> - struct vfio_iommu_type1_info info;
> - struct vfio_info_cap caps = { .buf = NULL, .size = 0 };
> - unsigned long capsz;
> - int ret;
> -
> - minsz = offsetofend(struct vfio_iommu_type1_info, iova_pgsizes);
> + minsz = offsetofend(struct vfio_iommu_type1_info, iova_pgsizes);
>
> - /* For backward compatibility, cannot require this */
> - capsz = offsetofend(struct vfio_iommu_type1_info, cap_offset);
> + /* For backward compatibility, cannot require this */
> + capsz = offsetofend(struct vfio_iommu_type1_info, cap_offset);
>
> - if (copy_from_user(&info, (void __user *)arg, minsz))
> - return -EFAULT;
> + if (copy_from_user(&info, (void __user *)arg, minsz))
> + return -EFAULT;
>
> - if (info.argsz < minsz)
> - return -EINVAL;
> + if (info.argsz < minsz)
> + return -EINVAL;
>
> - if (info.argsz >= capsz) {
> - minsz = capsz;
> - info.cap_offset = 0; /* output, no-recopy necessary */
> - }
> + if (info.argsz >= capsz) {
> + minsz = capsz;
> + info.cap_offset = 0; /* output, no-recopy necessary */
> + }
>
> - mutex_lock(&iommu->lock);
> - info.flags = VFIO_IOMMU_INFO_PGSIZES;
> + mutex_lock(&iommu->lock);
> + info.flags = VFIO_IOMMU_INFO_PGSIZES;
>
> - info.iova_pgsizes = iommu->pgsize_bitmap;
> + info.iova_pgsizes = iommu->pgsize_bitmap;
>
> - ret = vfio_iommu_migration_build_caps(iommu, &caps);
> + ret = vfio_iommu_migration_build_caps(iommu, &caps);
>
> - if (!ret)
> - ret = vfio_iommu_iova_build_caps(iommu, &caps);
> + if (!ret)
> + ret = vfio_iommu_iova_build_caps(iommu, &caps);
>
> - mutex_unlock(&iommu->lock);
> + mutex_unlock(&iommu->lock);
>
> - if (ret)
> - return ret;
> + if (ret)
> + return ret;
>
> - if (caps.size) {
> - info.flags |= VFIO_IOMMU_INFO_CAPS;
> + if (caps.size) {
> + info.flags |= VFIO_IOMMU_INFO_CAPS;
>
> - if (info.argsz < sizeof(info) + caps.size) {
> - info.argsz = sizeof(info) + caps.size;
> - } else {
> - vfio_info_cap_shift(&caps, sizeof(info));
> - if (copy_to_user((void __user *)arg +
> - sizeof(info), caps.buf,
> - caps.size)) {
> - kfree(caps.buf);
> - return -EFAULT;
> - }
> - info.cap_offset = sizeof(info);
> + if (info.argsz < sizeof(info) + caps.size) {
> + info.argsz = sizeof(info) + caps.size;
> + } else {
> + vfio_info_cap_shift(&caps, sizeof(info));
> + if (copy_to_user((void __user *)arg +
> + sizeof(info), caps.buf,
> + caps.size)) {
> + kfree(caps.buf);
> + return -EFAULT;
> }
> -
> - kfree(caps.buf);
> + info.cap_offset = sizeof(info);
> }
>
> - return copy_to_user((void __user *)arg, &info, minsz) ?
> - -EFAULT : 0;
> + kfree(caps.buf);
> + }
>
> - } else if (cmd == VFIO_IOMMU_MAP_DMA) {
> - struct vfio_iommu_type1_dma_map map;
> - uint32_t mask = VFIO_DMA_MAP_FLAG_READ |
> - VFIO_DMA_MAP_FLAG_WRITE;
> + return copy_to_user((void __user *)arg, &info, minsz) ?
> + -EFAULT : 0;
> +}
>
> - minsz = offsetofend(struct vfio_iommu_type1_dma_map, size);
> +static int vfio_iommu_type1_map_dma(struct vfio_iommu *iommu,
> + unsigned long arg)
> +{
> + struct vfio_iommu_type1_dma_map map;
> + unsigned long minsz;
> + uint32_t mask = VFIO_DMA_MAP_FLAG_READ | VFIO_DMA_MAP_FLAG_WRITE;
>
> - if (copy_from_user(&map, (void __user *)arg, minsz))
> - return -EFAULT;
> + minsz = offsetofend(struct vfio_iommu_type1_dma_map, size);
>
> - if (map.argsz < minsz || map.flags & ~mask)
> - return -EINVAL;
> + if (copy_from_user(&map, (void __user *)arg, minsz))
> + return -EFAULT;
>
> - return vfio_dma_do_map(iommu, &map);
> + if (map.argsz < minsz || map.flags & ~mask)
> + return -EINVAL;
>
> - } else if (cmd == VFIO_IOMMU_UNMAP_DMA) {
> - struct vfio_iommu_type1_dma_unmap unmap;
> - struct vfio_bitmap bitmap = { 0 };
> - int ret;
> + return vfio_dma_do_map(iommu, &map);
> +}
>
> - minsz = offsetofend(struct vfio_iommu_type1_dma_unmap, size);
> +static int vfio_iommu_type1_unmap_dma(struct vfio_iommu *iommu,
> + unsigned long arg)
> +{
> + struct vfio_iommu_type1_dma_unmap unmap;
> + struct vfio_bitmap bitmap = { 0 };
> + unsigned long minsz;
> + int ret;
>
> - if (copy_from_user(&unmap, (void __user *)arg, minsz))
> - return -EFAULT;
> + minsz = offsetofend(struct vfio_iommu_type1_dma_unmap, size);
>
> - if (unmap.argsz < minsz ||
> - unmap.flags & ~VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP)
> - return -EINVAL;
> + if (copy_from_user(&unmap, (void __user *)arg, minsz))
> + return -EFAULT;
>
> - if (unmap.flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) {
> - unsigned long pgshift;
> + if (unmap.argsz < minsz ||
> + unmap.flags & ~VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP)
> + return -EINVAL;
>
> - if (unmap.argsz < (minsz + sizeof(bitmap)))
> - return -EINVAL;
> + if (unmap.flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) {
> + unsigned long pgshift;
>
> - if (copy_from_user(&bitmap,
> - (void __user *)(arg + minsz),
> - sizeof(bitmap)))
> - return -EFAULT;
> + if (unmap.argsz < (minsz + sizeof(bitmap)))
> + return -EINVAL;
>
> - if (!access_ok((void __user *)bitmap.data, bitmap.size))
> - return -EINVAL;
> + if (copy_from_user(&bitmap,
> + (void __user *)(arg + minsz),
> + sizeof(bitmap)))
> + return -EFAULT;
>
> - pgshift = __ffs(bitmap.pgsize);
> - ret = verify_bitmap_size(unmap.size >> pgshift,
> - bitmap.size);
> - if (ret)
> - return ret;
> - }
> + if (!access_ok((void __user *)bitmap.data, bitmap.size))
> + return -EINVAL;
>
> - ret = vfio_dma_do_unmap(iommu, &unmap, &bitmap);
> + pgshift = __ffs(bitmap.pgsize);
> + ret = verify_bitmap_size(unmap.size >> pgshift,
> + bitmap.size);
> if (ret)
> return ret;
> + }
> +
> + ret = vfio_dma_do_unmap(iommu, &unmap, &bitmap);
> + if (ret)
> + return ret;
>
> - return copy_to_user((void __user *)arg, &unmap, minsz) ?
> + return copy_to_user((void __user *)arg, &unmap, minsz) ?
> -EFAULT : 0;
> - } else if (cmd == VFIO_IOMMU_DIRTY_PAGES) {
> - struct vfio_iommu_type1_dirty_bitmap dirty;
> - uint32_t mask = VFIO_IOMMU_DIRTY_PAGES_FLAG_START |
> - VFIO_IOMMU_DIRTY_PAGES_FLAG_STOP |
> - VFIO_IOMMU_DIRTY_PAGES_FLAG_GET_BITMAP;
> - int ret = 0;
> +}
>
> - if (!iommu->v2)
> - return -EACCES;
> +static int vfio_iommu_type1_dirty_pages(struct vfio_iommu *iommu,
> + unsigned long arg)
> +{
> + struct vfio_iommu_type1_dirty_bitmap dirty;
> + uint32_t mask = VFIO_IOMMU_DIRTY_PAGES_FLAG_START |
> + VFIO_IOMMU_DIRTY_PAGES_FLAG_STOP |
> + VFIO_IOMMU_DIRTY_PAGES_FLAG_GET_BITMAP;
> + unsigned long minsz;
> + int ret = 0;
>
> - minsz = offsetofend(struct vfio_iommu_type1_dirty_bitmap,
> - flags);
> + if (!iommu->v2)
> + return -EACCES;
>
> - if (copy_from_user(&dirty, (void __user *)arg, minsz))
> - return -EFAULT;
> + minsz = offsetofend(struct vfio_iommu_type1_dirty_bitmap, flags);
>
> - if (dirty.argsz < minsz || dirty.flags & ~mask)
> - return -EINVAL;
> + if (copy_from_user(&dirty, (void __user *)arg, minsz))
> + return -EFAULT;
>
> - /* only one flag should be set at a time */
> - if (__ffs(dirty.flags) != __fls(dirty.flags))
> - return -EINVAL;
> + if (dirty.argsz < minsz || dirty.flags & ~mask)
> + return -EINVAL;
>
> - if (dirty.flags & VFIO_IOMMU_DIRTY_PAGES_FLAG_START) {
> - size_t pgsize;
> + /* only one flag should be set at a time */
> + if (__ffs(dirty.flags) != __fls(dirty.flags))
> + return -EINVAL;
>
> - mutex_lock(&iommu->lock);
> - pgsize = 1 << __ffs(iommu->pgsize_bitmap);
> - if (!iommu->dirty_page_tracking) {
> - ret = vfio_dma_bitmap_alloc_all(iommu, pgsize);
> - if (!ret)
> - iommu->dirty_page_tracking = true;
> - }
> - mutex_unlock(&iommu->lock);
> - return ret;
> - } else if (dirty.flags & VFIO_IOMMU_DIRTY_PAGES_FLAG_STOP) {
> - mutex_lock(&iommu->lock);
> - if (iommu->dirty_page_tracking) {
> - iommu->dirty_page_tracking = false;
> - vfio_dma_bitmap_free_all(iommu);
> - }
> - mutex_unlock(&iommu->lock);
> - return 0;
> - } else if (dirty.flags &
> - VFIO_IOMMU_DIRTY_PAGES_FLAG_GET_BITMAP) {
> - struct vfio_iommu_type1_dirty_bitmap_get range;
> - unsigned long pgshift;
> - size_t data_size = dirty.argsz - minsz;
> - size_t iommu_pgsize;
> -
> - if (!data_size || data_size < sizeof(range))
> - return -EINVAL;
> -
> - if (copy_from_user(&range, (void __user *)(arg + minsz),
> - sizeof(range)))
> - return -EFAULT;
> + if (dirty.flags & VFIO_IOMMU_DIRTY_PAGES_FLAG_START) {
> + size_t pgsize;
>
> - if (range.iova + range.size < range.iova)
> - return -EINVAL;
> - if (!access_ok((void __user *)range.bitmap.data,
> - range.bitmap.size))
> - return -EINVAL;
> + mutex_lock(&iommu->lock);
> + pgsize = 1 << __ffs(iommu->pgsize_bitmap);
> + if (!iommu->dirty_page_tracking) {
> + ret = vfio_dma_bitmap_alloc_all(iommu, pgsize);
> + if (!ret)
> + iommu->dirty_page_tracking = true;
> + }
> + mutex_unlock(&iommu->lock);
> + return ret;
> + } else if (dirty.flags & VFIO_IOMMU_DIRTY_PAGES_FLAG_STOP) {
> + mutex_lock(&iommu->lock);
> + if (iommu->dirty_page_tracking) {
> + iommu->dirty_page_tracking = false;
> + vfio_dma_bitmap_free_all(iommu);
> + }
> + mutex_unlock(&iommu->lock);
> + return 0;
> + } else if (dirty.flags & VFIO_IOMMU_DIRTY_PAGES_FLAG_GET_BITMAP) {
> + struct vfio_iommu_type1_dirty_bitmap_get range;
> + unsigned long pgshift;
> + size_t data_size = dirty.argsz - minsz;
> + size_t iommu_pgsize;
>
> - pgshift = __ffs(range.bitmap.pgsize);
> - ret = verify_bitmap_size(range.size >> pgshift,
> - range.bitmap.size);
> - if (ret)
> - return ret;
> + if (!data_size || data_size < sizeof(range))
> + return -EINVAL;
>
> - mutex_lock(&iommu->lock);
> + if (copy_from_user(&range, (void __user *)(arg + minsz),
> + sizeof(range)))
> + return -EFAULT;
>
> - iommu_pgsize = (size_t)1 << __ffs(iommu->pgsize_bitmap);
> + if (range.iova + range.size < range.iova)
> + return -EINVAL;
> + if (!access_ok((void __user *)range.bitmap.data,
> + range.bitmap.size))
> + return -EINVAL;
>
> - /* allow only smallest supported pgsize */
> - if (range.bitmap.pgsize != iommu_pgsize) {
> - ret = -EINVAL;
> - goto out_unlock;
> - }
> - if (range.iova & (iommu_pgsize - 1)) {
> - ret = -EINVAL;
> - goto out_unlock;
> - }
> - if (!range.size || range.size & (iommu_pgsize - 1)) {
> - ret = -EINVAL;
> - goto out_unlock;
> - }
> + pgshift = __ffs(range.bitmap.pgsize);
> + ret = verify_bitmap_size(range.size >> pgshift,
> + range.bitmap.size);
> + if (ret)
> + return ret;
>
> - if (iommu->dirty_page_tracking)
> - ret = vfio_iova_dirty_bitmap(range.bitmap.data,
> - iommu, range.iova, range.size,
> - range.bitmap.pgsize);
> - else
> - ret = -EINVAL;
> -out_unlock:
> - mutex_unlock(&iommu->lock);
> + mutex_lock(&iommu->lock);
>
> - return ret;
> + iommu_pgsize = (size_t)1 << __ffs(iommu->pgsize_bitmap);
> +
> + /* allow only smallest supported pgsize */
> + if (range.bitmap.pgsize != iommu_pgsize) {
> + ret = -EINVAL;
> + goto out_unlock;
> + }
> + if (range.iova & (iommu_pgsize - 1)) {
> + ret = -EINVAL;
> + goto out_unlock;
> + }
> + if (!range.size || range.size & (iommu_pgsize - 1)) {
> + ret = -EINVAL;
> + goto out_unlock;
> }
> +
> + if (iommu->dirty_page_tracking)
> + ret = vfio_iova_dirty_bitmap(range.bitmap.data,
> + iommu, range.iova,
> + range.size,
> + range.bitmap.pgsize);
> + else
> + ret = -EINVAL;
> +out_unlock:
> + mutex_unlock(&iommu->lock);
> +
> + return ret;
> }
>
> - return -ENOTTY;
> + return -EINVAL;
> +}
> +
> +static long vfio_iommu_type1_ioctl(void *iommu_data,
> + unsigned int cmd, unsigned long arg)
> +{
> + struct vfio_iommu *iommu = iommu_data;
> +
> + switch (cmd) {
> + case VFIO_CHECK_EXTENSION:
> + return vfio_iommu_type1_check_extension(iommu, arg);
> + case VFIO_IOMMU_GET_INFO:
> + return vfio_iommu_type1_get_info(iommu, arg);
> + case VFIO_IOMMU_MAP_DMA:
> + return vfio_iommu_type1_map_dma(iommu, arg);
> + case VFIO_IOMMU_UNMAP_DMA:
> + return vfio_iommu_type1_unmap_dma(iommu, arg);
> + case VFIO_IOMMU_DIRTY_PAGES:
> + return vfio_iommu_type1_dirty_pages(iommu, arg);
> + default:
> + return -ENOTTY;
> + }
> }
>
> static int vfio_iommu_type1_register_notifier(void *iommu_data,