2021-01-26 22:37:49

by Shenming Lu

Subject: [RFC PATCH v1 1/4] vfio/type1: Add a bitmap to track IOPF mapped pages

When IOPF enabled, the pages are pinned and mapped on demand, we add
a bitmap to track them.

Signed-off-by: Shenming Lu <[email protected]>
---
drivers/vfio/vfio_iommu_type1.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 0b4dedaa9128..f1d4de5ab094 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -95,6 +95,7 @@ struct vfio_dma {
struct task_struct *task;
struct rb_root pfn_list; /* Ex-user pinned pfn list */
unsigned long *bitmap;
+ unsigned long *iommu_mapped_bitmap; /* IOPF mapped bitmap */
};

struct vfio_group {
@@ -143,6 +144,8 @@ struct vfio_regions {
#define DIRTY_BITMAP_PAGES_MAX ((u64)INT_MAX)
#define DIRTY_BITMAP_SIZE_MAX DIRTY_BITMAP_BYTES(DIRTY_BITMAP_PAGES_MAX)

+#define IOMMU_MAPPED_BITMAP_BYTES(n) DIRTY_BITMAP_BYTES(n)
+
static int put_pfn(unsigned long pfn, int prot);

static struct vfio_group *vfio_iommu_find_iommu_group(struct vfio_iommu *iommu,
@@ -949,6 +952,7 @@ static void vfio_remove_dma(struct vfio_iommu *iommu, struct vfio_dma *dma)
vfio_unlink_dma(iommu, dma);
put_task_struct(dma->task);
vfio_dma_bitmap_free(dma);
+ kfree(dma->iommu_mapped_bitmap);
kfree(dma);
iommu->dma_avail++;
}
@@ -1354,6 +1358,14 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu,
goto out_unlock;
}

+ dma->iommu_mapped_bitmap = kvzalloc(IOMMU_MAPPED_BITMAP_BYTES(size / PAGE_SIZE),
+ GFP_KERNEL);
+ if (!dma->iommu_mapped_bitmap) {
+ ret = -ENOMEM;
+ kfree(dma);
+ goto out_unlock;
+ }
+
iommu->dma_avail--;
dma->iova = iova;
dma->vaddr = vaddr;
--
2.19.1

2021-01-29 23:02:57

by Alex Williamson

Subject: Re: [RFC PATCH v1 1/4] vfio/type1: Add a bitmap to track IOPF mapped pages

On Mon, 25 Jan 2021 17:03:59 +0800
Shenming Lu <[email protected]> wrote:

> When IOPF enabled, the pages are pinned and mapped on demand, we add
> a bitmap to track them.
>
> Signed-off-by: Shenming Lu <[email protected]>
> ---
> drivers/vfio/vfio_iommu_type1.c | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
> index 0b4dedaa9128..f1d4de5ab094 100644
> --- a/drivers/vfio/vfio_iommu_type1.c
> +++ b/drivers/vfio/vfio_iommu_type1.c
> @@ -95,6 +95,7 @@ struct vfio_dma {
> struct task_struct *task;
> struct rb_root pfn_list; /* Ex-user pinned pfn list */
> unsigned long *bitmap;
> + unsigned long *iommu_mapped_bitmap; /* IOPF mapped bitmap */
> };
>
> struct vfio_group {
> @@ -143,6 +144,8 @@ struct vfio_regions {
> #define DIRTY_BITMAP_PAGES_MAX ((u64)INT_MAX)
> #define DIRTY_BITMAP_SIZE_MAX DIRTY_BITMAP_BYTES(DIRTY_BITMAP_PAGES_MAX)
>
> +#define IOMMU_MAPPED_BITMAP_BYTES(n) DIRTY_BITMAP_BYTES(n)
> +
> static int put_pfn(unsigned long pfn, int prot);
>
> static struct vfio_group *vfio_iommu_find_iommu_group(struct vfio_iommu *iommu,
> @@ -949,6 +952,7 @@ static void vfio_remove_dma(struct vfio_iommu *iommu, struct vfio_dma *dma)
> vfio_unlink_dma(iommu, dma);
> put_task_struct(dma->task);
> vfio_dma_bitmap_free(dma);
> + kfree(dma->iommu_mapped_bitmap);
> kfree(dma);
> iommu->dma_avail++;
> }
> @@ -1354,6 +1358,14 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu,
> goto out_unlock;
> }
>
> + dma->iommu_mapped_bitmap = kvzalloc(IOMMU_MAPPED_BITMAP_BYTES(size / PAGE_SIZE),
> + GFP_KERNEL);

This is a lot of bloat for all the platforms that don't support this
feature. Thanks,

Alex

> + if (!dma->iommu_mapped_bitmap) {
> + ret = -ENOMEM;
> + kfree(dma);
> + goto out_unlock;
> + }
> +
> iommu->dma_avail--;
> dma->iova = iova;
> dma->vaddr = vaddr;

2021-01-30 09:36:33

by Shenming Lu

Subject: Re: [RFC PATCH v1 1/4] vfio/type1: Add a bitmap to track IOPF mapped pages

On 2021/1/30 6:58, Alex Williamson wrote:
> On Mon, 25 Jan 2021 17:03:59 +0800
> Shenming Lu <[email protected]> wrote:
>
>> When IOPF enabled, the pages are pinned and mapped on demand, we add
>> a bitmap to track them.
>>
>> Signed-off-by: Shenming Lu <[email protected]>
>> ---
>> drivers/vfio/vfio_iommu_type1.c | 12 ++++++++++++
>> 1 file changed, 12 insertions(+)
>>
>> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
>> index 0b4dedaa9128..f1d4de5ab094 100644
>> --- a/drivers/vfio/vfio_iommu_type1.c
>> +++ b/drivers/vfio/vfio_iommu_type1.c
>> @@ -95,6 +95,7 @@ struct vfio_dma {
>> struct task_struct *task;
>> struct rb_root pfn_list; /* Ex-user pinned pfn list */
>> unsigned long *bitmap;
>> + unsigned long *iommu_mapped_bitmap; /* IOPF mapped bitmap */
>> };
>>
>> struct vfio_group {
>> @@ -143,6 +144,8 @@ struct vfio_regions {
>> #define DIRTY_BITMAP_PAGES_MAX ((u64)INT_MAX)
>> #define DIRTY_BITMAP_SIZE_MAX DIRTY_BITMAP_BYTES(DIRTY_BITMAP_PAGES_MAX)
>>
>> +#define IOMMU_MAPPED_BITMAP_BYTES(n) DIRTY_BITMAP_BYTES(n)
>> +
>> static int put_pfn(unsigned long pfn, int prot);
>>
>> static struct vfio_group *vfio_iommu_find_iommu_group(struct vfio_iommu *iommu,
>> @@ -949,6 +952,7 @@ static void vfio_remove_dma(struct vfio_iommu *iommu, struct vfio_dma *dma)
>> vfio_unlink_dma(iommu, dma);
>> put_task_struct(dma->task);
>> vfio_dma_bitmap_free(dma);
>> + kfree(dma->iommu_mapped_bitmap);
>> kfree(dma);
>> iommu->dma_avail++;
>> }
>> @@ -1354,6 +1358,14 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu,
>> goto out_unlock;
>> }
>>
>> + dma->iommu_mapped_bitmap = kvzalloc(IOMMU_MAPPED_BITMAP_BYTES(size / PAGE_SIZE),
>> + GFP_KERNEL);
>
> This is a lot of bloat for all the platforms that don't support this
> feature. Thanks,

Yes, I will make this dedicated to IOPF.

Thanks,
Shenming

>
> Alex
>
>> + if (!dma->iommu_mapped_bitmap) {
>> + ret = -ENOMEM;
>> + kfree(dma);
>> + goto out_unlock;
>> + }
>> +
>> iommu->dma_avail--;
>> dma->iova = iova;
>> dma->vaddr = vaddr;
>
> .
>