On 8/20/21 9:24 AM, Alex Williamson wrote:
> 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;
> }
>
Even better. Should I send a new patch?
Thanks,
Anthony
