diff mbox

[v9,2/7] vfio/type1: vfio_find_dma accepting a type argument

Message ID 1462362858-2925-3-git-send-email-eric.auger@linaro.org (mailing list archive)
State New, archived
Headers show

Commit Message

Eric Auger May 4, 2016, 11:54 a.m. UTC
In our RB-tree we now have slots of different types (USER and RESERVED).
It becomes useful to be able to search for dma slots of a specific type or
any type. This patch proposes an implementation for that modality and also
changes the existing callers using the USER type.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
---
 drivers/vfio/vfio_iommu_type1.c | 63 ++++++++++++++++++++++++++++++++++-------
 1 file changed, 53 insertions(+), 10 deletions(-)

Comments

Alex Williamson May 9, 2016, 10:49 p.m. UTC | #1
On Wed,  4 May 2016 11:54:13 +0000
Eric Auger <eric.auger@linaro.org> wrote:

> In our RB-tree we now have slots of different types (USER and RESERVED).
> It becomes useful to be able to search for dma slots of a specific type or
> any type. This patch proposes an implementation for that modality and also
> changes the existing callers using the USER type.
> 
> Signed-off-by: Eric Auger <eric.auger@linaro.org>
> ---
>  drivers/vfio/vfio_iommu_type1.c | 63 ++++++++++++++++++++++++++++++++++-------
>  1 file changed, 53 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
> index aaf5a6c..2d769d4 100644
> --- a/drivers/vfio/vfio_iommu_type1.c
> +++ b/drivers/vfio/vfio_iommu_type1.c
> @@ -98,23 +98,64 @@ struct vfio_group {
>   * into DMA'ble space using the IOMMU
>   */
>  
> -static struct vfio_dma *vfio_find_dma(struct vfio_iommu *iommu,
> -				      dma_addr_t start, size_t size)
> +/**
> + * vfio_find_dma_from_node: looks for a dma slot intersecting a window
> + * from a given rb tree node
> + * @top: top rb tree node where the search starts (including this node)
> + * @start: window start
> + * @size: window size
> + * @type: window type
> + */
> +static struct vfio_dma *vfio_find_dma_from_node(struct rb_node *top,
> +						dma_addr_t start, size_t size,
> +						enum vfio_iova_type type)
>  {
> -	struct rb_node *node = iommu->dma_list.rb_node;
> +	struct rb_node *node = top;
> +	struct vfio_dma *dma;
>  
>  	while (node) {
> -		struct vfio_dma *dma = rb_entry(node, struct vfio_dma, node);
> -
> +		dma = rb_entry(node, struct vfio_dma, node);
>  		if (start + size <= dma->iova)
>  			node = node->rb_left;
>  		else if (start >= dma->iova + dma->size)
>  			node = node->rb_right;
>  		else
> +			break;
> +	}
> +	if (!node)
> +		return NULL;
> +
> +	/* a dma slot intersects our window, check the type also matches */
> +	if (type == VFIO_IOVA_ANY || dma->type == type)
> +		return dma;
> +
> +	/* restart 2 searches skipping the current node */
> +	if (start < dma->iova) {
> +		dma = vfio_find_dma_from_node(node->rb_left, start,
> +					      size, type);
> +		if (dma)
>  			return dma;
>  	}
> +	if (start + size > dma->iova + dma->size)
> +		dma = vfio_find_dma_from_node(node->rb_right, start,
> +					      size, type);

It might be nice to split this little bit of trickery out to a separate
patch so that you can better explain what it does.  It's really not
needed until we start creating user-type entries, so it shouldn't hurt
bisection.

> +	return dma;
> +}
> +
> +/**
> + * vfio_find_dma: find a dma slot intersecting a given window
> + * @iommu: vfio iommu handle
> + * @start: window base iova
> + * @size: window size
> + * @type: window type
> + */
> +static struct vfio_dma *vfio_find_dma(struct vfio_iommu *iommu,
> +				      dma_addr_t start, size_t size,
> +				      enum vfio_iova_type type)
> +{
> +	struct rb_node *top_node = iommu->dma_list.rb_node;
>  
> -	return NULL;
> +	return vfio_find_dma_from_node(top_node, start, size, type);
>  }
>  
>  static void vfio_link_dma(struct vfio_iommu *iommu, struct vfio_dma *new)
> @@ -488,19 +529,21 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
>  	 * mappings within the range.
>  	 */
>  	if (iommu->v2) {
> -		dma = vfio_find_dma(iommu, unmap->iova, 0);
> +		dma = vfio_find_dma(iommu, unmap->iova, 0, VFIO_IOVA_USER);
>  		if (dma && dma->iova != unmap->iova) {
>  			ret = -EINVAL;
>  			goto unlock;
>  		}
> -		dma = vfio_find_dma(iommu, unmap->iova + unmap->size - 1, 0);
> +		dma = vfio_find_dma(iommu, unmap->iova + unmap->size - 1, 0,
> +				    VFIO_IOVA_USER);
>  		if (dma && dma->iova + dma->size != unmap->iova + unmap->size) {
>  			ret = -EINVAL;
>  			goto unlock;
>  		}
>  	}
>  
> -	while ((dma = vfio_find_dma(iommu, unmap->iova, unmap->size))) {
> +	while ((dma = vfio_find_dma(iommu, unmap->iova, unmap->size,
> +				    VFIO_IOVA_USER))) {
>  		if (!iommu->v2 && unmap->iova > dma->iova)
>  			break;
>  		unmapped += dma->size;
> @@ -604,7 +647,7 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu,
>  
>  	mutex_lock(&iommu->lock);
>  
> -	if (vfio_find_dma(iommu, iova, size)) {
> +	if (vfio_find_dma(iommu, iova, size, VFIO_IOVA_ANY)) {
>  		mutex_unlock(&iommu->lock);
>  		return -EEXIST;
>  	}
Eric Auger May 10, 2016, 2:54 p.m. UTC | #2
Hi Alex,
On 05/10/2016 12:49 AM, Alex Williamson wrote:
> On Wed,  4 May 2016 11:54:13 +0000
> Eric Auger <eric.auger@linaro.org> wrote:
> 
>> In our RB-tree we now have slots of different types (USER and RESERVED).
>> It becomes useful to be able to search for dma slots of a specific type or
>> any type. This patch proposes an implementation for that modality and also
>> changes the existing callers using the USER type.
>>
>> Signed-off-by: Eric Auger <eric.auger@linaro.org>
>> ---
>>  drivers/vfio/vfio_iommu_type1.c | 63 ++++++++++++++++++++++++++++++++++-------
>>  1 file changed, 53 insertions(+), 10 deletions(-)
>>
>> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
>> index aaf5a6c..2d769d4 100644
>> --- a/drivers/vfio/vfio_iommu_type1.c
>> +++ b/drivers/vfio/vfio_iommu_type1.c
>> @@ -98,23 +98,64 @@ struct vfio_group {
>>   * into DMA'ble space using the IOMMU
>>   */
>>  
>> -static struct vfio_dma *vfio_find_dma(struct vfio_iommu *iommu,
>> -				      dma_addr_t start, size_t size)
>> +/**
>> + * vfio_find_dma_from_node: looks for a dma slot intersecting a window
>> + * from a given rb tree node
>> + * @top: top rb tree node where the search starts (including this node)
>> + * @start: window start
>> + * @size: window size
>> + * @type: window type
>> + */
>> +static struct vfio_dma *vfio_find_dma_from_node(struct rb_node *top,
>> +						dma_addr_t start, size_t size,
>> +						enum vfio_iova_type type)
>>  {
>> -	struct rb_node *node = iommu->dma_list.rb_node;
>> +	struct rb_node *node = top;
>> +	struct vfio_dma *dma;
>>  
>>  	while (node) {
>> -		struct vfio_dma *dma = rb_entry(node, struct vfio_dma, node);
>> -
>> +		dma = rb_entry(node, struct vfio_dma, node);
>>  		if (start + size <= dma->iova)
>>  			node = node->rb_left;
>>  		else if (start >= dma->iova + dma->size)
>>  			node = node->rb_right;
>>  		else
>> +			break;
>> +	}
>> +	if (!node)
>> +		return NULL;
>> +
>> +	/* a dma slot intersects our window, check the type also matches */
>> +	if (type == VFIO_IOVA_ANY || dma->type == type)
>> +		return dma;
>> +
>> +	/* restart 2 searches skipping the current node */
>> +	if (start < dma->iova) {
>> +		dma = vfio_find_dma_from_node(node->rb_left, start,
>> +					      size, type);
>> +		if (dma)
>>  			return dma;
>>  	}
>> +	if (start + size > dma->iova + dma->size)
>> +		dma = vfio_find_dma_from_node(node->rb_right, start,
>> +					      size, type);
> 
> It might be nice to split this little bit of trickery out to a separate
> patch so that you can better explain what it does.  It's really not
> needed until we start creating user-type entries, so it shouldn't hurt
> bisection.
OK I will

Regards

Eric
> 
>> +	return dma;
>> +}
>> +
>> +/**
>> + * vfio_find_dma: find a dma slot intersecting a given window
>> + * @iommu: vfio iommu handle
>> + * @start: window base iova
>> + * @size: window size
>> + * @type: window type
>> + */
>> +static struct vfio_dma *vfio_find_dma(struct vfio_iommu *iommu,
>> +				      dma_addr_t start, size_t size,
>> +				      enum vfio_iova_type type)
>> +{
>> +	struct rb_node *top_node = iommu->dma_list.rb_node;
>>  
>> -	return NULL;
>> +	return vfio_find_dma_from_node(top_node, start, size, type);
>>  }
>>  
>>  static void vfio_link_dma(struct vfio_iommu *iommu, struct vfio_dma *new)
>> @@ -488,19 +529,21 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
>>  	 * mappings within the range.
>>  	 */
>>  	if (iommu->v2) {
>> -		dma = vfio_find_dma(iommu, unmap->iova, 0);
>> +		dma = vfio_find_dma(iommu, unmap->iova, 0, VFIO_IOVA_USER);
>>  		if (dma && dma->iova != unmap->iova) {
>>  			ret = -EINVAL;
>>  			goto unlock;
>>  		}
>> -		dma = vfio_find_dma(iommu, unmap->iova + unmap->size - 1, 0);
>> +		dma = vfio_find_dma(iommu, unmap->iova + unmap->size - 1, 0,
>> +				    VFIO_IOVA_USER);
>>  		if (dma && dma->iova + dma->size != unmap->iova + unmap->size) {
>>  			ret = -EINVAL;
>>  			goto unlock;
>>  		}
>>  	}
>>  
>> -	while ((dma = vfio_find_dma(iommu, unmap->iova, unmap->size))) {
>> +	while ((dma = vfio_find_dma(iommu, unmap->iova, unmap->size,
>> +				    VFIO_IOVA_USER))) {
>>  		if (!iommu->v2 && unmap->iova > dma->iova)
>>  			break;
>>  		unmapped += dma->size;
>> @@ -604,7 +647,7 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu,
>>  
>>  	mutex_lock(&iommu->lock);
>>  
>> -	if (vfio_find_dma(iommu, iova, size)) {
>> +	if (vfio_find_dma(iommu, iova, size, VFIO_IOVA_ANY)) {
>>  		mutex_unlock(&iommu->lock);
>>  		return -EEXIST;
>>  	}
>
diff mbox

Patch

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index aaf5a6c..2d769d4 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -98,23 +98,64 @@  struct vfio_group {
  * into DMA'ble space using the IOMMU
  */
 
-static struct vfio_dma *vfio_find_dma(struct vfio_iommu *iommu,
-				      dma_addr_t start, size_t size)
+/**
+ * vfio_find_dma_from_node: looks for a dma slot intersecting a window
+ * from a given rb tree node
+ * @top: top rb tree node where the search starts (including this node)
+ * @start: window start
+ * @size: window size
+ * @type: window type
+ */
+static struct vfio_dma *vfio_find_dma_from_node(struct rb_node *top,
+						dma_addr_t start, size_t size,
+						enum vfio_iova_type type)
 {
-	struct rb_node *node = iommu->dma_list.rb_node;
+	struct rb_node *node = top;
+	struct vfio_dma *dma;
 
 	while (node) {
-		struct vfio_dma *dma = rb_entry(node, struct vfio_dma, node);
-
+		dma = rb_entry(node, struct vfio_dma, node);
 		if (start + size <= dma->iova)
 			node = node->rb_left;
 		else if (start >= dma->iova + dma->size)
 			node = node->rb_right;
 		else
+			break;
+	}
+	if (!node)
+		return NULL;
+
+	/* a dma slot intersects our window, check the type also matches */
+	if (type == VFIO_IOVA_ANY || dma->type == type)
+		return dma;
+
+	/* restart 2 searches skipping the current node */
+	if (start < dma->iova) {
+		dma = vfio_find_dma_from_node(node->rb_left, start,
+					      size, type);
+		if (dma)
 			return dma;
 	}
+	if (start + size > dma->iova + dma->size)
+		dma = vfio_find_dma_from_node(node->rb_right, start,
+					      size, type);
+	return dma;
+}
+
+/**
+ * vfio_find_dma: find a dma slot intersecting a given window
+ * @iommu: vfio iommu handle
+ * @start: window base iova
+ * @size: window size
+ * @type: window type
+ */
+static struct vfio_dma *vfio_find_dma(struct vfio_iommu *iommu,
+				      dma_addr_t start, size_t size,
+				      enum vfio_iova_type type)
+{
+	struct rb_node *top_node = iommu->dma_list.rb_node;
 
-	return NULL;
+	return vfio_find_dma_from_node(top_node, start, size, type);
 }
 
 static void vfio_link_dma(struct vfio_iommu *iommu, struct vfio_dma *new)
@@ -488,19 +529,21 @@  static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
 	 * mappings within the range.
 	 */
 	if (iommu->v2) {
-		dma = vfio_find_dma(iommu, unmap->iova, 0);
+		dma = vfio_find_dma(iommu, unmap->iova, 0, VFIO_IOVA_USER);
 		if (dma && dma->iova != unmap->iova) {
 			ret = -EINVAL;
 			goto unlock;
 		}
-		dma = vfio_find_dma(iommu, unmap->iova + unmap->size - 1, 0);
+		dma = vfio_find_dma(iommu, unmap->iova + unmap->size - 1, 0,
+				    VFIO_IOVA_USER);
 		if (dma && dma->iova + dma->size != unmap->iova + unmap->size) {
 			ret = -EINVAL;
 			goto unlock;
 		}
 	}
 
-	while ((dma = vfio_find_dma(iommu, unmap->iova, unmap->size))) {
+	while ((dma = vfio_find_dma(iommu, unmap->iova, unmap->size,
+				    VFIO_IOVA_USER))) {
 		if (!iommu->v2 && unmap->iova > dma->iova)
 			break;
 		unmapped += dma->size;
@@ -604,7 +647,7 @@  static int vfio_dma_do_map(struct vfio_iommu *iommu,
 
 	mutex_lock(&iommu->lock);
 
-	if (vfio_find_dma(iommu, iova, size)) {
+	if (vfio_find_dma(iommu, iova, size, VFIO_IOVA_ANY)) {
 		mutex_unlock(&iommu->lock);
 		return -EEXIST;
 	}