2023-12-05 07:11:55

by Yi Liu

[permalink] [raw]
Subject: Re: [PATCH v7 09/12] iommu: Make iommu_queue_iopf() more generic

On 2023/11/15 11:02, Lu Baolu wrote:
> Make iommu_queue_iopf() more generic by making the iopf_group a minimal
> set of iopf's that an iopf handler of domain should handle and respond
> to. Add domain parameter to struct iopf_group so that the handler can
> retrieve and use it directly.
>
> Change iommu_queue_iopf() to forward groups of iopf's to the domain's
> iopf handler. This is also a necessary step to decouple the sva iopf
> handling code from this interface.
>
> Signed-off-by: Lu Baolu <[email protected]>
> Reviewed-by: Kevin Tian <[email protected]>
> Tested-by: Yan Zhao <[email protected]>
> ---
> include/linux/iommu.h | 4 +--
> drivers/iommu/iommu-sva.h | 6 ++---
> drivers/iommu/io-pgfault.c | 55 +++++++++++++++++++++++++++++---------
> drivers/iommu/iommu-sva.c | 3 +--
> 4 files changed, 48 insertions(+), 20 deletions(-)
>
> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> index 0d3c5a56b078..96f6f210093e 100644
> --- a/include/linux/iommu.h
> +++ b/include/linux/iommu.h
> @@ -130,6 +130,7 @@ struct iopf_group {
> struct list_head faults;
> struct work_struct work;
> struct device *dev;
> + struct iommu_domain *domain;
> };
>
> /**
> @@ -209,8 +210,7 @@ struct iommu_domain {
> unsigned long pgsize_bitmap; /* Bitmap of page sizes in use */
> struct iommu_domain_geometry geometry;
> struct iommu_dma_cookie *iova_cookie;
> - enum iommu_page_response_code (*iopf_handler)(struct iommu_fault *fault,
> - void *data);
> + int (*iopf_handler)(struct iopf_group *group);
> void *fault_data;
> union {
> struct {
> diff --git a/drivers/iommu/iommu-sva.h b/drivers/iommu/iommu-sva.h
> index de7819c796ce..27c8da115b41 100644
> --- a/drivers/iommu/iommu-sva.h
> +++ b/drivers/iommu/iommu-sva.h
> @@ -22,8 +22,7 @@ int iopf_queue_flush_dev(struct device *dev);
> struct iopf_queue *iopf_queue_alloc(const char *name);
> void iopf_queue_free(struct iopf_queue *queue);
> int iopf_queue_discard_partial(struct iopf_queue *queue);
> -enum iommu_page_response_code
> -iommu_sva_handle_iopf(struct iommu_fault *fault, void *data);
> +int iommu_sva_handle_iopf(struct iopf_group *group);
>
> #else /* CONFIG_IOMMU_SVA */
> static inline int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev)
> @@ -62,8 +61,7 @@ static inline int iopf_queue_discard_partial(struct iopf_queue *queue)
> return -ENODEV;
> }
>
> -static inline enum iommu_page_response_code
> -iommu_sva_handle_iopf(struct iommu_fault *fault, void *data)
> +static inline int iommu_sva_handle_iopf(struct iopf_group *group)
> {
> return IOMMU_PAGE_RESP_INVALID;
> }
> diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c
> index 09e05f483b4f..544653de0d45 100644
> --- a/drivers/iommu/io-pgfault.c
> +++ b/drivers/iommu/io-pgfault.c
> @@ -13,6 +13,9 @@
>
> #include "iommu-sva.h"
>
> +enum iommu_page_response_code
> +iommu_sva_handle_mm(struct iommu_fault *fault, struct mm_struct *mm);
> +
> static void iopf_free_group(struct iopf_group *group)
> {
> struct iopf_fault *iopf, *next;
> @@ -45,23 +48,18 @@ static void iopf_handler(struct work_struct *work)
> {
> struct iopf_fault *iopf;
> struct iopf_group *group;
> - struct iommu_domain *domain;
> enum iommu_page_response_code status = IOMMU_PAGE_RESP_SUCCESS;
>
> group = container_of(work, struct iopf_group, work);
> - domain = iommu_get_domain_for_dev_pasid(group->dev,
> - group->last_fault.fault.prm.pasid, 0);
> - if (!domain || !domain->iopf_handler)
> - status = IOMMU_PAGE_RESP_INVALID;
> -
> list_for_each_entry(iopf, &group->faults, list) {
> /*
> * For the moment, errors are sticky: don't handle subsequent
> * faults in the group if there is an error.
> */
> - if (status == IOMMU_PAGE_RESP_SUCCESS)
> - status = domain->iopf_handler(&iopf->fault,
> - domain->fault_data);
> + if (status != IOMMU_PAGE_RESP_SUCCESS)
> + break;
> +
> + status = iommu_sva_handle_mm(&iopf->fault, group->domain->mm);
> }
>
> iopf_complete_group(group->dev, &group->last_fault, status);
> @@ -113,6 +111,7 @@ int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev)
> int ret;
> struct iopf_group *group;
> struct iopf_fault *iopf, *next;
> + struct iommu_domain *domain = NULL;
> struct iommu_fault_param *iopf_param;
> struct dev_iommu *param = dev->iommu;
>
> @@ -143,6 +142,23 @@ int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev)
> return 0;
> }
>
> + if (fault->prm.flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID) {
> + domain = iommu_get_domain_for_dev_pasid(dev, fault->prm.pasid, 0);
> + if (IS_ERR(domain))
> + domain = NULL;
> + }
> +
> + if (!domain)
> + domain = iommu_get_domain_for_dev(dev);
> +
> + if (!domain || !domain->iopf_handler) {
> + dev_warn_ratelimited(dev,
> + "iopf (pasid %d) without domain attached or handler installed\n",
> + fault->prm.pasid);
> + ret = -ENODEV;
> + goto cleanup_partial;
> + }
> +
> group = kzalloc(sizeof(*group), GFP_KERNEL);
> if (!group) {
> /*
> @@ -157,8 +173,8 @@ int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev)
> group->dev = dev;
> group->last_fault.fault = *fault;
> INIT_LIST_HEAD(&group->faults);
> + group->domain = domain;
> list_add(&group->last_fault.list, &group->faults);
> - INIT_WORK(&group->work, iopf_handler);
>
> /* See if we have partial faults for this group */
> list_for_each_entry_safe(iopf, next, &iopf_param->partial, list) {
> @@ -167,9 +183,13 @@ int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev)
> list_move(&iopf->list, &group->faults);
> }
>
> - queue_work(iopf_param->queue->wq, &group->work);
> - return 0;
> + mutex_unlock(&iopf_param->lock);
> + ret = domain->iopf_handler(group);
> + mutex_lock(&iopf_param->lock);

After this change, this function (iommu_queue_iopf) does not queue
anything. Should this function be renamed? Except this, I didn't see
other problem.

Reviewed-by:Yi Liu <[email protected]>

> + if (ret)
> + iopf_free_group(group);
>
> + return ret;
> cleanup_partial:
> list_for_each_entry_safe(iopf, next, &iopf_param->partial, list) {
> if (iopf->fault.prm.grpid == fault->prm.grpid) {
> @@ -181,6 +201,17 @@ int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev)
> }
> EXPORT_SYMBOL_GPL(iommu_queue_iopf);
>
> +int iommu_sva_handle_iopf(struct iopf_group *group)
> +{
> + struct iommu_fault_param *fault_param = group->dev->iommu->fault_param;
> +
> + INIT_WORK(&group->work, iopf_handler);
> + if (!queue_work(fault_param->queue->wq, &group->work))
> + return -EBUSY;
> +
> + return 0;
> +}
> +
> /**
> * iopf_queue_flush_dev - Ensure that all queued faults have been processed
> * @dev: the endpoint whose faults need to be flushed.
> diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c
> index b78671a8a914..ba0d5b7e106a 100644
> --- a/drivers/iommu/iommu-sva.c
> +++ b/drivers/iommu/iommu-sva.c
> @@ -149,11 +149,10 @@ EXPORT_SYMBOL_GPL(iommu_sva_get_pasid);
> * I/O page fault handler for SVA
> */
> enum iommu_page_response_code
> -iommu_sva_handle_iopf(struct iommu_fault *fault, void *data)
> +iommu_sva_handle_mm(struct iommu_fault *fault, struct mm_struct *mm)
> {
> vm_fault_t ret;
> struct vm_area_struct *vma;
> - struct mm_struct *mm = data;
> unsigned int access_flags = 0;
> unsigned int fault_flags = FAULT_FLAG_REMOTE;
> struct iommu_fault_page_request *prm = &fault->prm;

--
Regards,
Yi Liu


2023-12-05 12:13:53

by Baolu Lu

[permalink] [raw]
Subject: Re: [PATCH v7 09/12] iommu: Make iommu_queue_iopf() more generic

On 2023/12/5 15:13, Yi Liu wrote:
>> @@ -157,8 +173,8 @@ int iommu_queue_iopf(struct iommu_fault *fault,
>> struct device *dev)
>>       group->dev = dev;
>>       group->last_fault.fault = *fault;
>>       INIT_LIST_HEAD(&group->faults);
>> +    group->domain = domain;
>>       list_add(&group->last_fault.list, &group->faults);
>> -    INIT_WORK(&group->work, iopf_handler);
>>       /* See if we have partial faults for this group */
>>       list_for_each_entry_safe(iopf, next, &iopf_param->partial, list) {
>> @@ -167,9 +183,13 @@ int iommu_queue_iopf(struct iommu_fault *fault,
>> struct device *dev)
>>               list_move(&iopf->list, &group->faults);
>>       }
>> -    queue_work(iopf_param->queue->wq, &group->work);
>> -    return 0;
>> +    mutex_unlock(&iopf_param->lock);
>> +    ret = domain->iopf_handler(group);
>> +    mutex_lock(&iopf_param->lock);
>
> After this change, this function (iommu_queue_iopf) does not queue
> anything. Should this function be renamed? Except this, I didn't see
> other problem.

It's renamed in the next patch.

>
> Reviewed-by:Yi Liu <[email protected]>

Thank you!

Best regards,
baolu