On Thu, 19 Aug 2021 16:53:57 -0700
Anthony Yznaga <anthony.yznaga@xxxxxxxxxx> wrote:
> Fix vfio_find_dma_valid to return WAITED on success if it was necessary
> to wait which mean iommu lock was dropped and reacquired. This allows
> vfio_iommu_type1_pin_pages to recheck vaddr_invalid_count and possibly
> avoid the checking the validity of every vaddr in its list.
>
> Signed-off-by: Anthony Yznaga <anthony.yznaga@xxxxxxxxxx>
> ---
> drivers/vfio/vfio_iommu_type1.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
> index a3e925a41b0d..7ca8c4e95da4 100644
> --- a/drivers/vfio/vfio_iommu_type1.c
> +++ b/drivers/vfio/vfio_iommu_type1.c
> @@ -612,6 +612,7 @@ static int vfio_find_dma_valid(struct vfio_iommu *iommu, dma_addr_t start,
> size_t size, struct vfio_dma **dma_p)
> {
> int ret;
> + int waited = 0;
>
> do {
> *dma_p = vfio_find_dma(iommu, start, size);
> @@ -620,10 +621,10 @@ static int vfio_find_dma_valid(struct vfio_iommu *iommu, dma_addr_t start,
> else if (!(*dma_p)->vaddr_invalid)
> ret = 0;
> else
> - ret = vfio_wait(iommu);
> + ret = waited = vfio_wait(iommu);
> } while (ret > 0);
>
> - return ret;
> + return ret ? ret : waited;
> }
>
> /*
How about...
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 0b4f7c174c7a..0e9217687f5c 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -612,17 +612,17 @@ static int vfio_wait(struct vfio_iommu *iommu)
static int vfio_find_dma_valid(struct vfio_iommu *iommu, dma_addr_t start,
size_t size, struct vfio_dma **dma_p)
{
- int ret;
+ int ret = 0;
do {
*dma_p = vfio_find_dma(iommu, start, size);
if (!*dma_p)
- ret = -EINVAL;
+ return -EINVAL;
else if (!(*dma_p)->vaddr_invalid)
- ret = 0;
+ return ret;
else
ret = vfio_wait(iommu);
- } while (ret > 0);
+ } while (ret == WAITED);
return ret;
}
