Re: [Qemu-devel] [PATCH v10 07/19] vfio iommu type1: Update argument of vaddr_get_pfn()

[Jike Song]

On 10/27/2016 05:29 AM, Kirti Wankhede wrote:
> Update arguments of vaddr_get_pfn() to take struct mm_struct *mm as input
> argument.
> 
> Signed-off-by: Kirti Wankhede <address@hidden>
> Signed-off-by: Neo Jia <address@hidden>
> Change-Id: I885fd4cd4a9f66f4ee2c1caf58267464ec239f52
> ---
>  drivers/vfio/vfio_iommu_type1.c | 25 ++++++++++++++++++-------
>  1 file changed, 18 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
> index 72fee415044a..3d916b965492 100644
> --- a/drivers/vfio/vfio_iommu_type1.c
> +++ b/drivers/vfio/vfio_iommu_type1.c
> @@ -228,20 +228,31 @@ static int put_pfn(unsigned long pfn, int prot)
>       return 0;
>  }
>  
> -static int vaddr_get_pfn(unsigned long vaddr, int prot, unsigned long *pfn)
> +static int vaddr_get_pfn(struct mm_struct *remote_mm, unsigned long vaddr,
> +                      int prot, unsigned long *pfn)
>  {
>       struct page *page[1];
>       struct vm_area_struct *vma;
> +     struct mm_struct *mm = (remote_mm ? remote_mm : current->mm);
>       int ret = -EFAULT;
>  
> -     if (get_user_pages_fast(vaddr, 1, !!(prot & IOMMU_WRITE), page) == 1) {
> +     if (remote_mm) {
> +             down_read(&mm->mmap_sem);
> +             ret = get_user_pages_remote(NULL, mm, vaddr, 1,
> +                                     !!(prot & IOMMU_WRITE), 0, page, NULL);

Hi Kirti,

It seems that get_user_pages_remote has only 7 args but you somehow gives 8
here?

--
Thanks,
Jike

> +             up_read(&mm->mmap_sem);
> +     } else
> +             ret = get_user_pages_fast(vaddr, 1,
> +                                       !!(prot & IOMMU_WRITE), page);
> +
> +     if (ret == 1) {
>               *pfn = page_to_pfn(page[0]);
>               return 0;
>       }
>  
> -     down_read(&current->mm->mmap_sem);
> +     down_read(&mm->mmap_sem);
>  
> -     vma = find_vma_intersection(current->mm, vaddr, vaddr + 1);
> +     vma = find_vma_intersection(mm, vaddr, vaddr + 1);
>  
>       if (vma && vma->vm_flags & VM_PFNMAP) {
>               *pfn = ((vaddr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
> @@ -249,7 +260,7 @@ static int vaddr_get_pfn(unsigned long vaddr, int prot, 
> unsigned long *pfn)
>                       ret = 0;
>       }
>  
> -     up_read(&current->mm->mmap_sem);
> +     up_read(&mm->mmap_sem);
>  
>       return ret;
>  }
> @@ -270,7 +281,7 @@ static long vfio_pin_pages(unsigned long vaddr, long 
> npage,
>       if (!current->mm)
>               return -ENODEV;
>  
> -     ret = vaddr_get_pfn(vaddr, prot, pfn_base);
> +     ret = vaddr_get_pfn(NULL, vaddr, prot, pfn_base);
>       if (ret)
>               return ret;
>  
> @@ -293,7 +304,7 @@ static long vfio_pin_pages(unsigned long vaddr, long 
> npage,
>       for (i = 1, vaddr += PAGE_SIZE; i < npage; i++, vaddr += PAGE_SIZE) {
>               unsigned long pfn = 0;
>  
> -             ret = vaddr_get_pfn(vaddr, prot, &pfn);
> +             ret = vaddr_get_pfn(NULL, vaddr, prot, &pfn);
>               if (ret)
>                       break;
>  
>