Re: [PATCH 15/17] iommu: remove DOMAIN_ATTR_NESTING

Hi Christoph,

On 3/1/21 9:42 AM, Christoph Hellwig wrote:

Signed-off-by: Christoph Hellwig hch@lst.de

drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 40 ++++++--------------- drivers/iommu/arm/arm-smmu/arm-smmu.c | 30 ++++++++++------ drivers/iommu/intel/iommu.c | 28 +++++---------- drivers/iommu/iommu.c | 8 +++++ drivers/vfio/vfio_iommu_type1.c | 5 +-- include/linux/iommu.h | 4 ++- 6 files changed, 50 insertions(+), 65 deletions(-)

As mentionned by Robin, there are series planning to use DOMAIN_ATTR_NESTING to get info about the nested caps of the iommu (ARM and Intel):

[Patch v8 00/10] vfio: expose virtual Shared Virtual Addressing to VMs patches 1, 2, 3

Is the plan to introduce a new domain_get_nesting_info ops then?

Thanks

Eric

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c index bf96172e8c1f71..8e6fee3ea454d3 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -2466,41 +2466,21 @@ static void arm_smmu_dma_enable_flush_queue(struct iommu_domain *domain) to_smmu_domain(domain)->non_strict = true; }

-static int arm_smmu_domain_set_attr(struct iommu_domain *domain,

• 		    enum iommu_attr attr, void *data)
  

+static int arm_smmu_domain_enable_nesting(struct iommu_domain *domain) {

• int ret = 0; struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);

• int ret = -EPERM;

• mutex_lock(&smmu_domain->init_mutex);

• if (domain->type != IOMMU_DOMAIN_UNMANAGED)

• return -EINVAL;
  
  

• switch (domain->type) {
• case IOMMU_DOMAIN_UNMANAGED:

• switch (attr) {
  

• case DOMAIN_ATTR_NESTING:
  

• 	if (smmu_domain->smmu) {
  

• 		ret = -EPERM;
  

• 		goto out_unlock;
  

• 	}
  

• 	if (*(int *)data)
  

• 		smmu_domain->stage = ARM_SMMU_DOMAIN_NESTED;
  

• 	else
  

• 		smmu_domain->stage = ARM_SMMU_DOMAIN_S1;
  

• 	break;
  

• default:
  

• 	ret = -ENODEV;
  

• }
  

• break;
  

• case IOMMU_DOMAIN_DMA:

• ret = -ENODEV;
  

• break;
  

• default:

• ret = -EINVAL;
  

• mutex_lock(&smmu_domain->init_mutex);
• if (!smmu_domain->smmu) {

• smmu_domain->stage = ARM_SMMU_DOMAIN_NESTED;
  

• ret = 0;
  

  }

-out_unlock: mutex_unlock(&smmu_domain->init_mutex);

• return ret;

}

@@ -2603,7 +2583,7 @@ static struct iommu_ops arm_smmu_ops = { .device_group = arm_smmu_device_group, .dma_use_flush_queue = arm_smmu_dma_use_flush_queue, .dma_enable_flush_queue = arm_smmu_dma_enable_flush_queue,

• .domain_set_attr = arm_smmu_domain_set_attr,

• .domain_enable_nesting = arm_smmu_domain_enable_nesting, .of_xlate = arm_smmu_of_xlate, .get_resv_regions = arm_smmu_get_resv_regions, .put_resv_regions = generic_iommu_put_resv_regions,

diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c index e7893e96f5177a..2e17d990d04481 100644 --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c @@ -1497,6 +1497,24 @@ static void arm_smmu_dma_enable_flush_queue(struct iommu_domain *domain) to_smmu_domain(domain)->pgtbl_cfg.quirks |= IO_PGTABLE_QUIRK_NON_STRICT; }

+static int arm_smmu_domain_enable_nesting(struct iommu_domain *domain) +{

• struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
• int ret = -EPERM;
• if (domain->type != IOMMU_DOMAIN_UNMANAGED)

• return -EINVAL;
  

• mutex_lock(&smmu_domain->init_mutex);
• if (!smmu_domain->smmu) {

• smmu_domain->stage = ARM_SMMU_DOMAIN_NESTED;
  

• ret = 0;
  

• }
• mutex_unlock(&smmu_domain->init_mutex);
• return ret;

+}

static int arm_smmu_domain_set_attr(struct iommu_domain *domain, enum iommu_attr attr, void *data) { @@ -1508,17 +1526,6 @@ static int arm_smmu_domain_set_attr(struct iommu_domain *domain, switch(domain->type) { case IOMMU_DOMAIN_UNMANAGED: switch (attr) {

• case DOMAIN_ATTR_NESTING:
  

• 	if (smmu_domain->smmu) {
  

• 		ret = -EPERM;
  

• 		goto out_unlock;
  

• 	}
  

• 	if (*(int *)data)
  

• 		smmu_domain->stage = ARM_SMMU_DOMAIN_NESTED;
  

• 	else
  

• 		smmu_domain->stage = ARM_SMMU_DOMAIN_S1;
  

• 	break;
  

  case DOMAIN_ATTR_IO_PGTABLE_CFG: { struct io_pgtable_domain_attr *pgtbl_cfg = data;

@@ -1603,6 +1610,7 @@ static struct iommu_ops arm_smmu_ops = { .dma_use_flush_queue = arm_smmu_dma_use_flush_queue, .dma_enable_flush_queue = arm_smmu_dma_enable_flush_queue, .domain_set_attr = arm_smmu_domain_set_attr,

• .domain_enable_nesting = arm_smmu_domain_enable_nesting, .of_xlate = arm_smmu_of_xlate, .get_resv_regions = arm_smmu_get_resv_regions, .put_resv_regions = generic_iommu_put_resv_regions,

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index eaa80c33f4bc91..0f1374d6612a60 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -5423,32 +5423,22 @@ static bool intel_iommu_is_attach_deferred(struct iommu_domain *domain, }

static int -intel_iommu_domain_set_attr(struct iommu_domain *domain,

• 	    enum iommu_attr attr, void *data)
  

+intel_iommu_domain_enable_nesting(struct iommu_domain *domain) { struct dmar_domain *dmar_domain = to_dmar_domain(domain); unsigned long flags;

• int ret = 0;

• int ret = -ENODEV;

  if (domain->type != IOMMU_DOMAIN_UNMANAGED) return -EINVAL;

• switch (attr) {
• case DOMAIN_ATTR_NESTING:

• spin_lock_irqsave(&device_domain_lock, flags);
  

• if (nested_mode_support() &&
  

•     list_empty(&dmar_domain->devices)) {
  

• 	dmar_domain->flags |= DOMAIN_FLAG_NESTING_MODE;
  

• 	dmar_domain->flags &= ~DOMAIN_FLAG_USE_FIRST_LEVEL;
  

• } else {
  

• 	ret = -ENODEV;
  

• }
  

• spin_unlock_irqrestore(&device_domain_lock, flags);
  

• break;
  

• default:

• ret = -EINVAL;
  

• break;
  

• spin_lock_irqsave(&device_domain_lock, flags);

• if (nested_mode_support() && list_empty(&dmar_domain->devices)) {

• dmar_domain->flags |= DOMAIN_FLAG_NESTING_MODE;
  

• dmar_domain->flags &= ~DOMAIN_FLAG_USE_FIRST_LEVEL;
  

• ret = 0;
  

  }

• spin_unlock_irqrestore(&device_domain_lock, flags);

  return ret;

} @@ -5556,7 +5546,7 @@ const struct iommu_ops intel_iommu_ops = { .domain_alloc = intel_iommu_domain_alloc, .domain_free = intel_iommu_domain_free, .dma_use_flush_queue = intel_iommu_dma_use_flush_queue,

• .domain_set_attr = intel_iommu_domain_set_attr,

• .domain_enable_nesting = intel_iommu_domain_enable_nesting, .attach_dev = intel_iommu_attach_device, .detach_dev = intel_iommu_detach_device, .aux_attach_dev = intel_iommu_aux_attach_device,

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 0f12c4d58cdc42..2e9e058501a953 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -2685,6 +2685,14 @@ int iommu_domain_set_attr(struct iommu_domain *domain, } EXPORT_SYMBOL_GPL(iommu_domain_set_attr);

+int iommu_domain_enable_nesting(struct iommu_domain *domain) +{

• if (!domain->ops->domain_enable_nesting)

• return -EINVAL;
  

• return domain->ops->domain_enable_nesting(domain);

+} +EXPORT_SYMBOL_GPL(iommu_domain_enable_nesting);

void iommu_get_resv_regions(struct device *dev, struct list_head *list) { const struct iommu_ops *ops = dev->bus->iommu_ops; diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index c8e57f22f421c5..9cea4d80dd66ed 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -2320,10 +2320,7 @@ static int vfio_iommu_type1_attach_group(void *iommu_data, }

if (iommu->nesting) {

• int attr = 1;
  

• ret = iommu_domain_set_attr(domain->domain, DOMAIN_ATTR_NESTING,
  

• 			    &attr);
  

• ret = iommu_domain_enable_nesting(domain->domain);
  

  if (ret) goto out_domain; }

diff --git a/include/linux/iommu.h b/include/linux/iommu.h index f30de33c6ff56e..aed88aa3bd3edf 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -107,7 +107,6 @@ enum iommu_cap { */

enum iommu_attr {

• DOMAIN_ATTR_NESTING, /* two stages of translation */ DOMAIN_ATTR_IO_PGTABLE_CFG, DOMAIN_ATTR_MAX,

}; @@ -196,6 +195,7 @@ struct iommu_iotlb_gather {

• @dma_use_flush_queue: Returns %true if a DMA flush queue is used
• @dma_enable_flush_queue: Try to enable the DMA flush queue
• @domain_set_attr: Change domain attributes

• • @domain_enable_nesting: Enable nesting
  • @get_resv_regions: Request list of reserved regions for a device
  • @put_resv_regions: Free list of reserved regions for a device
  • @apply_resv_region: Temporary helper call-back for iova reserved ranges

@@ -248,6 +248,7 @@ struct iommu_ops { void (*dma_enable_flush_queue)(struct iommu_domain *domain); int (*domain_set_attr)(struct iommu_domain *domain, enum iommu_attr attr, void *data);

• int (*domain_enable_nesting)(struct iommu_domain *domain);

  /* Request/Free a list of reserved regions for a device */ void (*get_resv_regions)(struct device *dev, struct list_head *list);

@@ -494,6 +495,7 @@ extern struct iommu_domain *iommu_group_default_domain(struct iommu_group *); bool iommu_dma_use_flush_queue(struct iommu_domain *domain); extern int iommu_domain_set_attr(struct iommu_domain *domain, enum iommu_attr, void *data); +int iommu_domain_enable_nesting(struct iommu_domain *domain);

extern int report_iommu_fault(struct iommu_domain *domain, struct device *dev, unsigned long iova, int flags);