Hi Christoph, On 3/1/21 9:42 AM, Christoph Hellwig wrote: > Signed-off-by: Christoph Hellwig <hch@xxxxxx> > --- > 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); >