[PATCH v5 0/3] iommu: Clean up cookie and sw_msi in struct iommu_domain

[PATCH v5 0/3] iommu: Clean up cookie and sw_msi in struct iommu_domain

[Nicolin Chen]

A few things in iommu_domain structure (such as iova_cookie, iommufd_hwpt,
fault handler, and etc) are exclusive to certain types of iommu_domains.
So, all of them can be seen as domain cookies in different cookie types.

Furthermore, iova_cookie is shared with the msi_cookie use case. It could
be cleaner by decoupling these too.

Define an enum iommu_domain_cookie_type to fit all those cookies in.

Since there are only two sw_msi implementations, check domain->cookie_type
in iommu_dma_prepare_msi() to call the corresponding sw_msi function.

This is a clean-up series for the previous sw_msi Part-1 core series. It's
on github:
https://github.com/nicolinc/iommufd/commits/iommufd_msi_cleanup-v5

Changelog
v5
 * Add IMPORT line for IOMMUFD_INTERNAL and change IOMMUFD_DRIVER_CORE
   to a "bool" module, fixing build module errors reported by Arnd:
   https://lore.kernel.org/all/20250324210329.2809869-1-arnd@kernel.org/
 * In iommu_dma_prepare_msi(), let all IDENTITY DOMAINs pass through,
   fixing the regression with IDENTITY domains reported by Nathan:
   https://lore.kernel.org/linux-iommu/20250324162558.GA198799@ax162/
v4
 https://lore.kernel.org/all/cover.1741294235.git.nicolinc@nvidia.com/
 * Rebase on top of a bug fix for hwpt_iommufd cookie
   https://lore.kernel.org/all/20250305211800.229465-1-nicolinc@nvidia.com/
 * Add Reviewed-by from Robin and Kevin
 * Add missing "break;" in iommu_domain_free()
 * Drop "linux/msi.h" header from the iommufd/device code
 * Set iommufd_sw_msi_install's SYMBOL to "IOMMUFD_INTERNAL"
 * Update commit messages for typo fixing and size comparison
 * Add a local msi_page_list to cache cookie_msi_pages(domain) return
 * Add an inline iommufd_group_setup_msi() for !CONFIG_IRQ_MSI_IOMMU
v3
 https://lore.kernel.org/all/cover.1741034885.git.nicolinc@nvidia.com/
 * Integrate Robin's patch
   https://lore.kernel.org/linux-iommu/4e68d5820be06adc1b34fc0d1c9399481151daee.1740742271.git.robin.murphy@arm.com/
   replacing private_data_owner with the new cookie_type
 * Move iommu_sw_msi stub from the public header to iommu-priv.h
v2
 https://lore.kernel.org/all/cover.1740705776.git.nicolinc@nvidia.com/
 * Drop sw_msi function pointer
 * Add a new private_data_owner tag in iommu_domain
 * Let iommu core call the two sw_msi implementations directly
v1
 https://lore.kernel.org/all/cover.1740600272.git.nicolinc@nvidia.com/

Thanks
Nicolin

Nicolin Chen (2):
  iommufd: Move iommufd_sw_msi and related functions to driver.c
  iommu: Drop sw_msi from iommu_domain

Robin Murphy (1):
  iommu: Sort out domain user data

 drivers/iommu/iommufd/Kconfig           |   2 +-
 drivers/iommu/dma-iommu.h               |  14 ++
 drivers/iommu/iommu-priv.h              |  13 ++
 drivers/iommu/iommufd/iommufd_private.h |   7 +-
 include/linux/iommu.h                   |  35 ++--
 drivers/iommu/dma-iommu.c               | 208 ++++++++++++------------
 drivers/iommu/iommu-sva.c               |   1 +
 drivers/iommu/iommu.c                   |  36 +++-
 drivers/iommu/iommufd/device.c          | 131 +--------------
 drivers/iommu/iommufd/driver.c          | 126 ++++++++++++++
 drivers/iommu/iommufd/hw_pagetable.c    |   6 +-
 11 files changed, 323 insertions(+), 256 deletions(-)


base-commit: da0c56520e880441d0503d0cf0d6853dcfb5f1a4
-- 
2.43.0

[PATCH v5 1/3] iommu: Sort out domain user data

[Nicolin Chen]

From: Robin Murphy <robin.murphy@arm.com>

When DMA/MSI cookies were made first-class citizens back in commit
46983fcd67ac ("iommu: Pull IOVA cookie management into the core"), there
was no real need to further expose the two different cookie types.
However, now that IOMMUFD wants to add a third type of MSI-mapping
cookie, we do have a nicely compelling reason to properly dismabiguate
things at the domain level beyond just vaguely guessing from the domain
type.

Meanwhile, we also effectively have another "cookie" in the form of the
anonymous union for other user data, which isn't much better in terms of
being vague and unenforced. The fact is that all these cookie types are
mutually exclusive, in the sense that combining them makes zero sense
and/or would be catastrophic (iommu_set_fault_handler() on an SVA
domain, anyone?) - the only combination which *might* be reasonable is
perhaps a fault handler and an MSI cookie, but nobody's doing that at
the moment, so let's rule it out as well for the sake of being clear and
robust. To that end, we pull DMA and MSI cookies apart a little more,
mostly to clear up the ambiguity at domain teardown, then for clarity
(and to save a little space), move them into the union, whose ownership
we can then properly describe and enforce entirely unambiguously.

[nicolinc: rebase on latest tree; use prefix IOMMU_COOKIE_; merge unions
           in iommu_domain; add IOMMU_COOKIE_IOMMUFD for iommufd_hwpt]

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
---
 drivers/iommu/dma-iommu.h            |   5 +
 include/linux/iommu.h                |  20 ++-
 drivers/iommu/dma-iommu.c            | 194 ++++++++++++++-------------
 drivers/iommu/iommu-sva.c            |   1 +
 drivers/iommu/iommu.c                |  18 ++-
 drivers/iommu/iommufd/hw_pagetable.c |   3 +
 6 files changed, 143 insertions(+), 98 deletions(-)

diff --git a/drivers/iommu/dma-iommu.h b/drivers/iommu/dma-iommu.h
index c12d63457c76..9cca11806e5d 100644
--- a/drivers/iommu/dma-iommu.h
+++ b/drivers/iommu/dma-iommu.h
@@ -13,6 +13,7 @@ void iommu_setup_dma_ops(struct device *dev);
 
 int iommu_get_dma_cookie(struct iommu_domain *domain);
 void iommu_put_dma_cookie(struct iommu_domain *domain);
+void iommu_put_msi_cookie(struct iommu_domain *domain);
 
 int iommu_dma_init_fq(struct iommu_domain *domain);
 
@@ -40,6 +41,10 @@ static inline void iommu_put_dma_cookie(struct iommu_domain *domain)
 {
 }
 
+static inline void iommu_put_msi_cookie(struct iommu_domain *domain)
+{
+}
+
 static inline void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list)
 {
 }
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index e93d2e918599..06cc14e9993d 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -41,6 +41,7 @@ struct iommu_dirty_ops;
 struct notifier_block;
 struct iommu_sva;
 struct iommu_dma_cookie;
+struct iommu_dma_msi_cookie;
 struct iommu_fault_param;
 struct iommufd_ctx;
 struct iommufd_viommu;
@@ -165,6 +166,15 @@ struct iommu_domain_geometry {
 	bool force_aperture;       /* DMA only allowed in mappable range? */
 };
 
+enum iommu_domain_cookie_type {
+	IOMMU_COOKIE_NONE,
+	IOMMU_COOKIE_DMA_IOVA,
+	IOMMU_COOKIE_DMA_MSI,
+	IOMMU_COOKIE_FAULT_HANDLER,
+	IOMMU_COOKIE_SVA,
+	IOMMU_COOKIE_IOMMUFD,
+};
+
 /* Domain feature flags */
 #define __IOMMU_DOMAIN_PAGING	(1U << 0)  /* Support for iommu_map/unmap */
 #define __IOMMU_DOMAIN_DMA_API	(1U << 1)  /* Domain for use in DMA-API
@@ -211,12 +221,12 @@ struct iommu_domain_geometry {
 
 struct iommu_domain {
 	unsigned type;
+	enum iommu_domain_cookie_type cookie_type;
 	const struct iommu_domain_ops *ops;
 	const struct iommu_dirty_ops *dirty_ops;
 	const struct iommu_ops *owner; /* Whose domain_alloc we came from */
 	unsigned long pgsize_bitmap;	/* Bitmap of page sizes in use */
 	struct iommu_domain_geometry geometry;
-	struct iommu_dma_cookie *iova_cookie;
 	int (*iopf_handler)(struct iopf_group *group);
 
 #if IS_ENABLED(CONFIG_IRQ_MSI_IOMMU)
@@ -224,10 +234,10 @@ struct iommu_domain {
 		      phys_addr_t msi_addr);
 #endif
 
-	union { /* Pointer usable by owner of the domain */
-		struct iommufd_hw_pagetable *iommufd_hwpt; /* iommufd */
-	};
-	union { /* Fault handler */
+	union { /* cookie */
+		struct iommu_dma_cookie *iova_cookie;
+		struct iommu_dma_msi_cookie *msi_cookie;
+		struct iommufd_hw_pagetable *iommufd_hwpt;
 		struct {
 			iommu_fault_handler_t handler;
 			void *handler_token;
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 94263ed2c564..31a7b4b81656 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -42,11 +42,6 @@ struct iommu_dma_msi_page {
 	phys_addr_t		phys;
 };
 
-enum iommu_dma_cookie_type {
-	IOMMU_DMA_IOVA_COOKIE,
-	IOMMU_DMA_MSI_COOKIE,
-};
-
 enum iommu_dma_queue_type {
 	IOMMU_DMA_OPTS_PER_CPU_QUEUE,
 	IOMMU_DMA_OPTS_SINGLE_QUEUE,
@@ -59,35 +54,31 @@ struct iommu_dma_options {
 };
 
 struct iommu_dma_cookie {
-	enum iommu_dma_cookie_type	type;
+	struct iova_domain iovad;
+	struct list_head msi_page_list;
+	/* Flush queue */
 	union {
-		/* Full allocator for IOMMU_DMA_IOVA_COOKIE */
-		struct {
-			struct iova_domain	iovad;
-			/* Flush queue */
-			union {
-				struct iova_fq	*single_fq;
-				struct iova_fq	__percpu *percpu_fq;
-			};
-			/* Number of TLB flushes that have been started */
-			atomic64_t		fq_flush_start_cnt;
-			/* Number of TLB flushes that have been finished */
-			atomic64_t		fq_flush_finish_cnt;
-			/* Timer to regularily empty the flush queues */
-			struct timer_list	fq_timer;
-			/* 1 when timer is active, 0 when not */
-			atomic_t		fq_timer_on;
-		};
-		/* Trivial linear page allocator for IOMMU_DMA_MSI_COOKIE */
-		dma_addr_t		msi_iova;
+		struct iova_fq *single_fq;
+		struct iova_fq __percpu *percpu_fq;
 	};
-	struct list_head		msi_page_list;
-
+	/* Number of TLB flushes that have been started */
+	atomic64_t fq_flush_start_cnt;
+	/* Number of TLB flushes that have been finished */
+	atomic64_t fq_flush_finish_cnt;
+	/* Timer to regularily empty the flush queues */
+	struct timer_list fq_timer;
+	/* 1 when timer is active, 0 when not */
+	atomic_t fq_timer_on;
 	/* Domain for flush queue callback; NULL if flush queue not in use */
-	struct iommu_domain		*fq_domain;
+	struct iommu_domain *fq_domain;
 	/* Options for dma-iommu use */
-	struct iommu_dma_options	options;
-	struct mutex			mutex;
+	struct iommu_dma_options options;
+	struct mutex mutex;
+};
+
+struct iommu_dma_msi_cookie {
+	dma_addr_t msi_iova;
+	struct list_head msi_page_list;
 };
 
 static DEFINE_STATIC_KEY_FALSE(iommu_deferred_attach_enabled);
@@ -369,40 +360,26 @@ int iommu_dma_init_fq(struct iommu_domain *domain)
 	return 0;
 }
 
-static inline size_t cookie_msi_granule(struct iommu_dma_cookie *cookie)
-{
-	if (cookie->type == IOMMU_DMA_IOVA_COOKIE)
-		return cookie->iovad.granule;
-	return PAGE_SIZE;
-}
-
-static struct iommu_dma_cookie *cookie_alloc(enum iommu_dma_cookie_type type)
-{
-	struct iommu_dma_cookie *cookie;
-
-	cookie = kzalloc(sizeof(*cookie), GFP_KERNEL);
-	if (cookie) {
-		INIT_LIST_HEAD(&cookie->msi_page_list);
-		cookie->type = type;
-	}
-	return cookie;
-}
-
 /**
  * iommu_get_dma_cookie - Acquire DMA-API resources for a domain
  * @domain: IOMMU domain to prepare for DMA-API usage
  */
 int iommu_get_dma_cookie(struct iommu_domain *domain)
 {
-	if (domain->iova_cookie)
+	struct iommu_dma_cookie *cookie;
+
+	if (domain->cookie_type != IOMMU_COOKIE_NONE)
 		return -EEXIST;
 
-	domain->iova_cookie = cookie_alloc(IOMMU_DMA_IOVA_COOKIE);
-	if (!domain->iova_cookie)
+	cookie = kzalloc(sizeof(*cookie), GFP_KERNEL);
+	if (!cookie)
 		return -ENOMEM;
 
-	mutex_init(&domain->iova_cookie->mutex);
+	mutex_init(&cookie->mutex);
+	INIT_LIST_HEAD(&cookie->msi_page_list);
 	iommu_domain_set_sw_msi(domain, iommu_dma_sw_msi);
+	domain->cookie_type = IOMMU_COOKIE_DMA_IOVA;
+	domain->iova_cookie = cookie;
 	return 0;
 }
 
@@ -420,29 +397,30 @@ int iommu_get_dma_cookie(struct iommu_domain *domain)
  */
 int iommu_get_msi_cookie(struct iommu_domain *domain, dma_addr_t base)
 {
-	struct iommu_dma_cookie *cookie;
+	struct iommu_dma_msi_cookie *cookie;
 
 	if (domain->type != IOMMU_DOMAIN_UNMANAGED)
 		return -EINVAL;
 
-	if (domain->iova_cookie)
+	if (domain->cookie_type != IOMMU_COOKIE_NONE)
 		return -EEXIST;
 
-	cookie = cookie_alloc(IOMMU_DMA_MSI_COOKIE);
+	cookie = kzalloc(sizeof(*cookie), GFP_KERNEL);
 	if (!cookie)
 		return -ENOMEM;
 
 	cookie->msi_iova = base;
-	domain->iova_cookie = cookie;
+	INIT_LIST_HEAD(&cookie->msi_page_list);
 	iommu_domain_set_sw_msi(domain, iommu_dma_sw_msi);
+	domain->cookie_type = IOMMU_COOKIE_DMA_MSI;
+	domain->msi_cookie = cookie;
 	return 0;
 }
 EXPORT_SYMBOL(iommu_get_msi_cookie);
 
 /**
  * iommu_put_dma_cookie - Release a domain's DMA mapping resources
- * @domain: IOMMU domain previously prepared by iommu_get_dma_cookie() or
- *          iommu_get_msi_cookie()
+ * @domain: IOMMU domain previously prepared by iommu_get_dma_cookie()
  */
 void iommu_put_dma_cookie(struct iommu_domain *domain)
 {
@@ -454,20 +432,27 @@ void iommu_put_dma_cookie(struct iommu_domain *domain)
 		return;
 #endif
 
-	if (!cookie)
-		return;
-
-	if (cookie->type == IOMMU_DMA_IOVA_COOKIE && cookie->iovad.granule) {
+	if (cookie->iovad.granule) {
 		iommu_dma_free_fq(cookie);
 		put_iova_domain(&cookie->iovad);
 	}
+	list_for_each_entry_safe(msi, tmp, &cookie->msi_page_list, list)
+		kfree(msi);
+	kfree(cookie);
+}
 
-	list_for_each_entry_safe(msi, tmp, &cookie->msi_page_list, list) {
-		list_del(&msi->list);
+/**
+ * iommu_put_msi_cookie - Release a domain's MSI mapping resources
+ * @domain: IOMMU domain previously prepared by iommu_get_msi_cookie()
+ */
+void iommu_put_msi_cookie(struct iommu_domain *domain)
+{
+	struct iommu_dma_msi_cookie *cookie = domain->msi_cookie;
+	struct iommu_dma_msi_page *msi, *tmp;
+
+	list_for_each_entry_safe(msi, tmp, &cookie->msi_page_list, list)
 		kfree(msi);
-	}
 	kfree(cookie);
-	domain->iova_cookie = NULL;
 }
 
 /**
@@ -687,7 +672,7 @@ static int iommu_dma_init_domain(struct iommu_domain *domain, struct device *dev
 	struct iova_domain *iovad;
 	int ret;
 
-	if (!cookie || cookie->type != IOMMU_DMA_IOVA_COOKIE)
+	if (!cookie || domain->cookie_type != IOMMU_COOKIE_DMA_IOVA)
 		return -EINVAL;
 
 	iovad = &cookie->iovad;
@@ -777,9 +762,9 @@ static dma_addr_t iommu_dma_alloc_iova(struct iommu_domain *domain,
 	struct iova_domain *iovad = &cookie->iovad;
 	unsigned long shift, iova_len, iova;
 
-	if (cookie->type == IOMMU_DMA_MSI_COOKIE) {
-		cookie->msi_iova += size;
-		return cookie->msi_iova - size;
+	if (domain->cookie_type == IOMMU_COOKIE_DMA_MSI) {
+		domain->msi_cookie->msi_iova += size;
+		return domain->msi_cookie->msi_iova - size;
 	}
 
 	shift = iova_shift(iovad);
@@ -816,16 +801,16 @@ static dma_addr_t iommu_dma_alloc_iova(struct iommu_domain *domain,
 	return (dma_addr_t)iova << shift;
 }
 
-static void iommu_dma_free_iova(struct iommu_dma_cookie *cookie,
-		dma_addr_t iova, size_t size, struct iommu_iotlb_gather *gather)
+static void iommu_dma_free_iova(struct iommu_domain *domain, dma_addr_t iova,
+				size_t size, struct iommu_iotlb_gather *gather)
 {
-	struct iova_domain *iovad = &cookie->iovad;
+	struct iova_domain *iovad = &domain->iova_cookie->iovad;
 
 	/* The MSI case is only ever cleaning up its most recent allocation */
-	if (cookie->type == IOMMU_DMA_MSI_COOKIE)
-		cookie->msi_iova -= size;
+	if (domain->cookie_type == IOMMU_COOKIE_DMA_MSI)
+		domain->msi_cookie->msi_iova -= size;
 	else if (gather && gather->queued)
-		queue_iova(cookie, iova_pfn(iovad, iova),
+		queue_iova(domain->iova_cookie, iova_pfn(iovad, iova),
 				size >> iova_shift(iovad),
 				&gather->freelist);
 	else
@@ -853,7 +838,7 @@ static void __iommu_dma_unmap(struct device *dev, dma_addr_t dma_addr,
 
 	if (!iotlb_gather.queued)
 		iommu_iotlb_sync(domain, &iotlb_gather);
-	iommu_dma_free_iova(cookie, dma_addr, size, &iotlb_gather);
+	iommu_dma_free_iova(domain, dma_addr, size, &iotlb_gather);
 }
 
 static dma_addr_t __iommu_dma_map(struct device *dev, phys_addr_t phys,
@@ -881,7 +866,7 @@ static dma_addr_t __iommu_dma_map(struct device *dev, phys_addr_t phys,
 		return DMA_MAPPING_ERROR;
 
 	if (iommu_map(domain, iova, phys - iova_off, size, prot, GFP_ATOMIC)) {
-		iommu_dma_free_iova(cookie, iova, size, NULL);
+		iommu_dma_free_iova(domain, iova, size, NULL);
 		return DMA_MAPPING_ERROR;
 	}
 	return iova + iova_off;
@@ -1018,7 +1003,7 @@ static struct page **__iommu_dma_alloc_noncontiguous(struct device *dev,
 out_free_sg:
 	sg_free_table(sgt);
 out_free_iova:
-	iommu_dma_free_iova(cookie, iova, size, NULL);
+	iommu_dma_free_iova(domain, iova, size, NULL);
 out_free_pages:
 	__iommu_dma_free_pages(pages, count);
 	return NULL;
@@ -1495,7 +1480,7 @@ int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
 	return __finalise_sg(dev, sg, nents, iova);
 
 out_free_iova:
-	iommu_dma_free_iova(cookie, iova, iova_len, NULL);
+	iommu_dma_free_iova(domain, iova, iova_len, NULL);
 out_restore_sg:
 	__invalidate_sg(sg, nents);
 out:
@@ -1773,17 +1758,47 @@ void iommu_setup_dma_ops(struct device *dev)
 	dev->dma_iommu = false;
 }
 
+static bool has_msi_cookie(const struct iommu_domain *domain)
+{
+	return domain && (domain->cookie_type == IOMMU_COOKIE_DMA_IOVA ||
+			  domain->cookie_type == IOMMU_COOKIE_DMA_MSI);
+}
+
+static size_t cookie_msi_granule(const struct iommu_domain *domain)
+{
+	switch (domain->cookie_type) {
+	case IOMMU_COOKIE_DMA_IOVA:
+		return domain->iova_cookie->iovad.granule;
+	case IOMMU_COOKIE_DMA_MSI:
+		return PAGE_SIZE;
+	default:
+		unreachable();
+	};
+}
+
+static struct list_head *cookie_msi_pages(const struct iommu_domain *domain)
+{
+	switch (domain->cookie_type) {
+	case IOMMU_COOKIE_DMA_IOVA:
+		return &domain->iova_cookie->msi_page_list;
+	case IOMMU_COOKIE_DMA_MSI:
+		return &domain->msi_cookie->msi_page_list;
+	default:
+		unreachable();
+	};
+}
+
 static struct iommu_dma_msi_page *iommu_dma_get_msi_page(struct device *dev,
 		phys_addr_t msi_addr, struct iommu_domain *domain)
 {
-	struct iommu_dma_cookie *cookie = domain->iova_cookie;
+	struct list_head *msi_page_list = cookie_msi_pages(domain);
 	struct iommu_dma_msi_page *msi_page;
 	dma_addr_t iova;
 	int prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO;
-	size_t size = cookie_msi_granule(cookie);
+	size_t size = cookie_msi_granule(domain);
 
 	msi_addr &= ~(phys_addr_t)(size - 1);
-	list_for_each_entry(msi_page, &cookie->msi_page_list, list)
+	list_for_each_entry(msi_page, msi_page_list, list)
 		if (msi_page->phys == msi_addr)
 			return msi_page;
 
@@ -1801,11 +1816,11 @@ static struct iommu_dma_msi_page *iommu_dma_get_msi_page(struct device *dev,
 	INIT_LIST_HEAD(&msi_page->list);
 	msi_page->phys = msi_addr;
 	msi_page->iova = iova;
-	list_add(&msi_page->list, &cookie->msi_page_list);
+	list_add(&msi_page->list, msi_page_list);
 	return msi_page;
 
 out_free_iova:
-	iommu_dma_free_iova(cookie, iova, size, NULL);
+	iommu_dma_free_iova(domain, iova, size, NULL);
 out_free_page:
 	kfree(msi_page);
 	return NULL;
@@ -1817,7 +1832,7 @@ static int iommu_dma_sw_msi(struct iommu_domain *domain, struct msi_desc *desc,
 	struct device *dev = msi_desc_to_dev(desc);
 	const struct iommu_dma_msi_page *msi_page;
 
-	if (!domain->iova_cookie) {
+	if (!has_msi_cookie(domain)) {
 		msi_desc_set_iommu_msi_iova(desc, 0, 0);
 		return 0;
 	}
@@ -1827,9 +1842,8 @@ static int iommu_dma_sw_msi(struct iommu_domain *domain, struct msi_desc *desc,
 	if (!msi_page)
 		return -ENOMEM;
 
-	msi_desc_set_iommu_msi_iova(
-		desc, msi_page->iova,
-		ilog2(cookie_msi_granule(domain->iova_cookie)));
+	msi_desc_set_iommu_msi_iova(desc, msi_page->iova,
+				    ilog2(cookie_msi_granule(domain)));
 	return 0;
 }
 
diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c
index 503c5d23c1ea..ab18bc494eef 100644
--- a/drivers/iommu/iommu-sva.c
+++ b/drivers/iommu/iommu-sva.c
@@ -310,6 +310,7 @@ static struct iommu_domain *iommu_sva_domain_alloc(struct device *dev,
 	}
 
 	domain->type = IOMMU_DOMAIN_SVA;
+	domain->cookie_type = IOMMU_COOKIE_SVA;
 	mmgrab(mm);
 	domain->mm = mm;
 	domain->owner = ops;
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 0ee17893810f..c92e47f333cb 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1953,8 +1953,10 @@ void iommu_set_fault_handler(struct iommu_domain *domain,
 					iommu_fault_handler_t handler,
 					void *token)
 {
-	BUG_ON(!domain);
+	if (WARN_ON(!domain || domain->cookie_type != IOMMU_COOKIE_NONE))
+		return;
 
+	domain->cookie_type = IOMMU_COOKIE_FAULT_HANDLER;
 	domain->handler = handler;
 	domain->handler_token = token;
 }
@@ -2024,9 +2026,19 @@ EXPORT_SYMBOL_GPL(iommu_paging_domain_alloc_flags);
 
 void iommu_domain_free(struct iommu_domain *domain)
 {
-	if (domain->type == IOMMU_DOMAIN_SVA)
+	switch (domain->cookie_type) {
+	case IOMMU_COOKIE_DMA_IOVA:
+		iommu_put_dma_cookie(domain);
+		break;
+	case IOMMU_COOKIE_DMA_MSI:
+		iommu_put_msi_cookie(domain);
+		break;
+	case IOMMU_COOKIE_SVA:
 		mmdrop(domain->mm);
-	iommu_put_dma_cookie(domain);
+		break;
+	default:
+		break;
+	}
 	if (domain->ops->free)
 		domain->ops->free(domain);
 }
diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c
index 9a89f3a28dc5..fded3f07bfa7 100644
--- a/drivers/iommu/iommufd/hw_pagetable.c
+++ b/drivers/iommu/iommufd/hw_pagetable.c
@@ -160,6 +160,7 @@ iommufd_hwpt_paging_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas,
 		}
 	}
 	hwpt->domain->iommufd_hwpt = hwpt;
+	hwpt->domain->cookie_type = IOMMU_COOKIE_IOMMUFD;
 	iommu_domain_set_sw_msi(hwpt->domain, iommufd_sw_msi);
 
 	/*
@@ -257,6 +258,7 @@ iommufd_hwpt_nested_alloc(struct iommufd_ctx *ictx,
 	}
 	hwpt->domain->owner = ops;
 	hwpt->domain->iommufd_hwpt = hwpt;
+	hwpt->domain->cookie_type = IOMMU_COOKIE_IOMMUFD;
 	iommu_domain_set_sw_msi(hwpt->domain, iommufd_sw_msi);
 
 	if (WARN_ON_ONCE(hwpt->domain->type != IOMMU_DOMAIN_NESTED)) {
@@ -315,6 +317,7 @@ iommufd_viommu_alloc_hwpt_nested(struct iommufd_viommu *viommu, u32 flags,
 	}
 	hwpt->domain->iommufd_hwpt = hwpt;
 	hwpt->domain->owner = viommu->iommu_dev->ops;
+	hwpt->domain->cookie_type = IOMMU_COOKIE_IOMMUFD;
 	iommu_domain_set_sw_msi(hwpt->domain, iommufd_sw_msi);
 
 	if (WARN_ON_ONCE(hwpt->domain->type != IOMMU_DOMAIN_NESTED)) {
-- 
2.43.0

[PATCH v5 2/3] iommufd: Move iommufd_sw_msi and related functions to driver.c

[Nicolin Chen]

To provide the iommufd_sw_msi() to the iommu core that is under a different
Kconfig, move it and its related functions to driver.c. Then, stub it into
the iommu-priv header. The iommufd_sw_msi_install() continues to be used by
iommufd internal, so put it in the private header.

Note that iommufd_sw_msi() will be called in the iommu core, replacing the
sw_msi function pointer. Given that IOMMU_API is "bool" in Kconfig, change
IOMMUFD_DRIVER_CORE to "bool" as well.

Since this affects the module size, here is before-n-after size comparison:
[Before]
   text	   data	    bss	    dec	    hex	filename
  18797	    848	     56	  19701	   4cf5	drivers/iommu/iommufd/device.o
    722	     44	      0	    766	    2fe	drivers/iommu/iommufd/driver.o
[After]
   text	   data	    bss	    dec	    hex	filename
  17735     808      56   18599    48a7 drivers/iommu/iommufd/device.o
   3020     180       0    3200     c80 drivers/iommu/iommufd/driver.o

Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
---
 drivers/iommu/iommufd/Kconfig           |   2 +-
 drivers/iommu/iommu-priv.h              |  13 +++
 drivers/iommu/iommufd/iommufd_private.h |   7 +-
 drivers/iommu/iommufd/device.c          | 131 ++----------------------
 drivers/iommu/iommufd/driver.c          | 126 +++++++++++++++++++++++
 5 files changed, 153 insertions(+), 126 deletions(-)

diff --git a/drivers/iommu/iommufd/Kconfig b/drivers/iommu/iommufd/Kconfig
index 0a07f9449fd9..2beeb4f60ee5 100644
--- a/drivers/iommu/iommufd/Kconfig
+++ b/drivers/iommu/iommufd/Kconfig
@@ -1,6 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0-only
 config IOMMUFD_DRIVER_CORE
-	tristate
+	bool
 	default (IOMMUFD_DRIVER || IOMMUFD) if IOMMUFD!=n
 
 config IOMMUFD
diff --git a/drivers/iommu/iommu-priv.h b/drivers/iommu/iommu-priv.h
index b4508423e13b..c74fff25be78 100644
--- a/drivers/iommu/iommu-priv.h
+++ b/drivers/iommu/iommu-priv.h
@@ -5,6 +5,7 @@
 #define __LINUX_IOMMU_PRIV_H
 
 #include <linux/iommu.h>
+#include <linux/msi.h>
 
 static inline const struct iommu_ops *dev_iommu_ops(struct device *dev)
 {
@@ -43,4 +44,16 @@ void iommu_detach_group_handle(struct iommu_domain *domain,
 int iommu_replace_group_handle(struct iommu_group *group,
 			       struct iommu_domain *new_domain,
 			       struct iommu_attach_handle *handle);
+
+#if IS_ENABLED(CONFIG_IOMMUFD_DRIVER_CORE) && IS_ENABLED(CONFIG_IRQ_MSI_IOMMU)
+int iommufd_sw_msi(struct iommu_domain *domain, struct msi_desc *desc,
+		   phys_addr_t msi_addr);
+#else /* !CONFIG_IOMMUFD_DRIVER_CORE || !CONFIG_IRQ_MSI_IOMMU */
+static inline int iommufd_sw_msi(struct iommu_domain *domain,
+				 struct msi_desc *desc, phys_addr_t msi_addr)
+{
+	return -EOPNOTSUPP;
+}
+#endif /* CONFIG_IOMMUFD_DRIVER_CORE && CONFIG_IRQ_MSI_IOMMU */
+
 #endif /* __LINUX_IOMMU_PRIV_H */
diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h
index 8cda9c4672eb..8c49ca16919a 100644
--- a/drivers/iommu/iommufd/iommufd_private.h
+++ b/drivers/iommu/iommufd/iommufd_private.h
@@ -32,8 +32,11 @@ struct iommufd_sw_msi_maps {
 	DECLARE_BITMAP(bitmap, 64);
 };
 
-int iommufd_sw_msi(struct iommu_domain *domain, struct msi_desc *desc,
-		   phys_addr_t msi_addr);
+#ifdef CONFIG_IRQ_MSI_IOMMU
+int iommufd_sw_msi_install(struct iommufd_ctx *ictx,
+			   struct iommufd_hwpt_paging *hwpt_paging,
+			   struct iommufd_sw_msi_map *msi_map);
+#endif
 
 struct iommufd_ctx {
 	struct file *file;
diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c
index bd50146e2ad0..d18ea9a61522 100644
--- a/drivers/iommu/iommufd/device.c
+++ b/drivers/iommu/iommufd/device.c
@@ -5,7 +5,6 @@
 #include <linux/iommufd.h>
 #include <linux/slab.h>
 #include <uapi/linux/iommufd.h>
-#include <linux/msi.h>
 
 #include "../iommu-priv.h"
 #include "io_pagetable.h"
@@ -294,129 +293,7 @@ u32 iommufd_device_to_id(struct iommufd_device *idev)
 }
 EXPORT_SYMBOL_NS_GPL(iommufd_device_to_id, "IOMMUFD");
 
-/*
- * Get a iommufd_sw_msi_map for the msi physical address requested by the irq
- * layer. The mapping to IOVA is global to the iommufd file descriptor, every
- * domain that is attached to a device using the same MSI parameters will use
- * the same IOVA.
- */
-static __maybe_unused struct iommufd_sw_msi_map *
-iommufd_sw_msi_get_map(struct iommufd_ctx *ictx, phys_addr_t msi_addr,
-		       phys_addr_t sw_msi_start)
-{
-	struct iommufd_sw_msi_map *cur;
-	unsigned int max_pgoff = 0;
-
-	lockdep_assert_held(&ictx->sw_msi_lock);
-
-	list_for_each_entry(cur, &ictx->sw_msi_list, sw_msi_item) {
-		if (cur->sw_msi_start != sw_msi_start)
-			continue;
-		max_pgoff = max(max_pgoff, cur->pgoff + 1);
-		if (cur->msi_addr == msi_addr)
-			return cur;
-	}
-
-	if (ictx->sw_msi_id >=
-	    BITS_PER_BYTE * sizeof_field(struct iommufd_sw_msi_maps, bitmap))
-		return ERR_PTR(-EOVERFLOW);
-
-	cur = kzalloc(sizeof(*cur), GFP_KERNEL);
-	if (!cur)
-		return ERR_PTR(-ENOMEM);
-
-	cur->sw_msi_start = sw_msi_start;
-	cur->msi_addr = msi_addr;
-	cur->pgoff = max_pgoff;
-	cur->id = ictx->sw_msi_id++;
-	list_add_tail(&cur->sw_msi_item, &ictx->sw_msi_list);
-	return cur;
-}
-
-static int iommufd_sw_msi_install(struct iommufd_ctx *ictx,
-				  struct iommufd_hwpt_paging *hwpt_paging,
-				  struct iommufd_sw_msi_map *msi_map)
-{
-	unsigned long iova;
-
-	lockdep_assert_held(&ictx->sw_msi_lock);
-
-	iova = msi_map->sw_msi_start + msi_map->pgoff * PAGE_SIZE;
-	if (!test_bit(msi_map->id, hwpt_paging->present_sw_msi.bitmap)) {
-		int rc;
-
-		rc = iommu_map(hwpt_paging->common.domain, iova,
-			       msi_map->msi_addr, PAGE_SIZE,
-			       IOMMU_WRITE | IOMMU_READ | IOMMU_MMIO,
-			       GFP_KERNEL_ACCOUNT);
-		if (rc)
-			return rc;
-		__set_bit(msi_map->id, hwpt_paging->present_sw_msi.bitmap);
-	}
-	return 0;
-}
-
-/*
- * Called by the irq code if the platform translates the MSI address through the
- * IOMMU. msi_addr is the physical address of the MSI page. iommufd will
- * allocate a fd global iova for the physical page that is the same on all
- * domains and devices.
- */
 #ifdef CONFIG_IRQ_MSI_IOMMU
-int iommufd_sw_msi(struct iommu_domain *domain, struct msi_desc *desc,
-		   phys_addr_t msi_addr)
-{
-	struct device *dev = msi_desc_to_dev(desc);
-	struct iommufd_hwpt_paging *hwpt_paging;
-	struct iommu_attach_handle *raw_handle;
-	struct iommufd_attach_handle *handle;
-	struct iommufd_sw_msi_map *msi_map;
-	struct iommufd_ctx *ictx;
-	unsigned long iova;
-	int rc;
-
-	/*
-	 * It is safe to call iommu_attach_handle_get() here because the iommu
-	 * core code invokes this under the group mutex which also prevents any
-	 * change of the attach handle for the duration of this function.
-	 */
-	iommu_group_mutex_assert(dev);
-
-	raw_handle =
-		iommu_attach_handle_get(dev->iommu_group, IOMMU_NO_PASID, 0);
-	if (IS_ERR(raw_handle))
-		return 0;
-	hwpt_paging = find_hwpt_paging(domain->iommufd_hwpt);
-
-	handle = to_iommufd_handle(raw_handle);
-	/* No IOMMU_RESV_SW_MSI means no change to the msi_msg */
-	if (handle->idev->igroup->sw_msi_start == PHYS_ADDR_MAX)
-		return 0;
-
-	ictx = handle->idev->ictx;
-	guard(mutex)(&ictx->sw_msi_lock);
-	/*
-	 * The input msi_addr is the exact byte offset of the MSI doorbell, we
-	 * assume the caller has checked that it is contained with a MMIO region
-	 * that is secure to map at PAGE_SIZE.
-	 */
-	msi_map = iommufd_sw_msi_get_map(handle->idev->ictx,
-					 msi_addr & PAGE_MASK,
-					 handle->idev->igroup->sw_msi_start);
-	if (IS_ERR(msi_map))
-		return PTR_ERR(msi_map);
-
-	rc = iommufd_sw_msi_install(ictx, hwpt_paging, msi_map);
-	if (rc)
-		return rc;
-	__set_bit(msi_map->id, handle->idev->igroup->required_sw_msi.bitmap);
-
-	iova = msi_map->sw_msi_start + msi_map->pgoff * PAGE_SIZE;
-	msi_desc_set_iommu_msi_iova(desc, iova, PAGE_SHIFT);
-	return 0;
-}
-#endif
-
 static int iommufd_group_setup_msi(struct iommufd_group *igroup,
 				   struct iommufd_hwpt_paging *hwpt_paging)
 {
@@ -443,6 +320,14 @@ static int iommufd_group_setup_msi(struct iommufd_group *igroup,
 	}
 	return 0;
 }
+#else
+static inline int
+iommufd_group_setup_msi(struct iommufd_group *igroup,
+			struct iommufd_hwpt_paging *hwpt_paging)
+{
+	return 0;
+}
+#endif
 
 static int
 iommufd_device_attach_reserved_iova(struct iommufd_device *idev,
diff --git a/drivers/iommu/iommufd/driver.c b/drivers/iommu/iommufd/driver.c
index 75b365561c16..a08ff0f37fc6 100644
--- a/drivers/iommu/iommufd/driver.c
+++ b/drivers/iommu/iommufd/driver.c
@@ -121,5 +121,131 @@ int iommufd_viommu_report_event(struct iommufd_viommu *viommu,
 }
 EXPORT_SYMBOL_NS_GPL(iommufd_viommu_report_event, "IOMMUFD");
 
+#ifdef CONFIG_IRQ_MSI_IOMMU
+/*
+ * Get a iommufd_sw_msi_map for the msi physical address requested by the irq
+ * layer. The mapping to IOVA is global to the iommufd file descriptor, every
+ * domain that is attached to a device using the same MSI parameters will use
+ * the same IOVA.
+ */
+static struct iommufd_sw_msi_map *
+iommufd_sw_msi_get_map(struct iommufd_ctx *ictx, phys_addr_t msi_addr,
+		       phys_addr_t sw_msi_start)
+{
+	struct iommufd_sw_msi_map *cur;
+	unsigned int max_pgoff = 0;
+
+	lockdep_assert_held(&ictx->sw_msi_lock);
+
+	list_for_each_entry(cur, &ictx->sw_msi_list, sw_msi_item) {
+		if (cur->sw_msi_start != sw_msi_start)
+			continue;
+		max_pgoff = max(max_pgoff, cur->pgoff + 1);
+		if (cur->msi_addr == msi_addr)
+			return cur;
+	}
+
+	if (ictx->sw_msi_id >=
+	    BITS_PER_BYTE * sizeof_field(struct iommufd_sw_msi_maps, bitmap))
+		return ERR_PTR(-EOVERFLOW);
+
+	cur = kzalloc(sizeof(*cur), GFP_KERNEL);
+	if (!cur)
+		return ERR_PTR(-ENOMEM);
+
+	cur->sw_msi_start = sw_msi_start;
+	cur->msi_addr = msi_addr;
+	cur->pgoff = max_pgoff;
+	cur->id = ictx->sw_msi_id++;
+	list_add_tail(&cur->sw_msi_item, &ictx->sw_msi_list);
+	return cur;
+}
+
+int iommufd_sw_msi_install(struct iommufd_ctx *ictx,
+			   struct iommufd_hwpt_paging *hwpt_paging,
+			   struct iommufd_sw_msi_map *msi_map)
+{
+	unsigned long iova;
+
+	lockdep_assert_held(&ictx->sw_msi_lock);
+
+	iova = msi_map->sw_msi_start + msi_map->pgoff * PAGE_SIZE;
+	if (!test_bit(msi_map->id, hwpt_paging->present_sw_msi.bitmap)) {
+		int rc;
+
+		rc = iommu_map(hwpt_paging->common.domain, iova,
+			       msi_map->msi_addr, PAGE_SIZE,
+			       IOMMU_WRITE | IOMMU_READ | IOMMU_MMIO,
+			       GFP_KERNEL_ACCOUNT);
+		if (rc)
+			return rc;
+		__set_bit(msi_map->id, hwpt_paging->present_sw_msi.bitmap);
+	}
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(iommufd_sw_msi_install, "IOMMUFD_INTERNAL");
+
+/*
+ * Called by the irq code if the platform translates the MSI address through the
+ * IOMMU. msi_addr is the physical address of the MSI page. iommufd will
+ * allocate a fd global iova for the physical page that is the same on all
+ * domains and devices.
+ */
+int iommufd_sw_msi(struct iommu_domain *domain, struct msi_desc *desc,
+		   phys_addr_t msi_addr)
+{
+	struct device *dev = msi_desc_to_dev(desc);
+	struct iommufd_hwpt_paging *hwpt_paging;
+	struct iommu_attach_handle *raw_handle;
+	struct iommufd_attach_handle *handle;
+	struct iommufd_sw_msi_map *msi_map;
+	struct iommufd_ctx *ictx;
+	unsigned long iova;
+	int rc;
+
+	/*
+	 * It is safe to call iommu_attach_handle_get() here because the iommu
+	 * core code invokes this under the group mutex which also prevents any
+	 * change of the attach handle for the duration of this function.
+	 */
+	iommu_group_mutex_assert(dev);
+
+	raw_handle =
+		iommu_attach_handle_get(dev->iommu_group, IOMMU_NO_PASID, 0);
+	if (IS_ERR(raw_handle))
+		return 0;
+	hwpt_paging = find_hwpt_paging(domain->iommufd_hwpt);
+
+	handle = to_iommufd_handle(raw_handle);
+	/* No IOMMU_RESV_SW_MSI means no change to the msi_msg */
+	if (handle->idev->igroup->sw_msi_start == PHYS_ADDR_MAX)
+		return 0;
+
+	ictx = handle->idev->ictx;
+	guard(mutex)(&ictx->sw_msi_lock);
+	/*
+	 * The input msi_addr is the exact byte offset of the MSI doorbell, we
+	 * assume the caller has checked that it is contained with a MMIO region
+	 * that is secure to map at PAGE_SIZE.
+	 */
+	msi_map = iommufd_sw_msi_get_map(handle->idev->ictx,
+					 msi_addr & PAGE_MASK,
+					 handle->idev->igroup->sw_msi_start);
+	if (IS_ERR(msi_map))
+		return PTR_ERR(msi_map);
+
+	rc = iommufd_sw_msi_install(ictx, hwpt_paging, msi_map);
+	if (rc)
+		return rc;
+	__set_bit(msi_map->id, handle->idev->igroup->required_sw_msi.bitmap);
+
+	iova = msi_map->sw_msi_start + msi_map->pgoff * PAGE_SIZE;
+	msi_desc_set_iommu_msi_iova(desc, iova, PAGE_SHIFT);
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(iommufd_sw_msi, "IOMMUFD");
+#endif
+
 MODULE_DESCRIPTION("iommufd code shared with builtin modules");
+MODULE_IMPORT_NS("IOMMUFD_INTERNAL");
 MODULE_LICENSE("GPL");
-- 
2.43.0

[PATCH v5 3/3] iommu: Drop sw_msi from iommu_domain

[Nicolin Chen]

There are only two sw_msi implementations in the entire system, thus it's
not very necessary to have an sw_msi pointer.

Instead, check domain->cookie_type to call the two sw_msi implementations
directly from the core code.

Suggested-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
---
 drivers/iommu/dma-iommu.h            |  9 +++++++++
 include/linux/iommu.h                | 15 ---------------
 drivers/iommu/dma-iommu.c            | 14 ++------------
 drivers/iommu/iommu.c                | 18 ++++++++++++++++--
 drivers/iommu/iommufd/hw_pagetable.c |  3 ---
 5 files changed, 27 insertions(+), 32 deletions(-)

diff --git a/drivers/iommu/dma-iommu.h b/drivers/iommu/dma-iommu.h
index 9cca11806e5d..eca201c1f963 100644
--- a/drivers/iommu/dma-iommu.h
+++ b/drivers/iommu/dma-iommu.h
@@ -19,6 +19,9 @@ int iommu_dma_init_fq(struct iommu_domain *domain);
 
 void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list);
 
+int iommu_dma_sw_msi(struct iommu_domain *domain, struct msi_desc *desc,
+		     phys_addr_t msi_addr);
+
 extern bool iommu_dma_forcedac;
 
 #else /* CONFIG_IOMMU_DMA */
@@ -49,5 +52,11 @@ static inline void iommu_dma_get_resv_regions(struct device *dev, struct list_he
 {
 }
 
+static inline int iommu_dma_sw_msi(struct iommu_domain *domain,
+				   struct msi_desc *desc, phys_addr_t msi_addr)
+{
+	return -ENODEV;
+}
+
 #endif	/* CONFIG_IOMMU_DMA */
 #endif	/* __DMA_IOMMU_H */
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 06cc14e9993d..e01c855ae8a7 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -229,11 +229,6 @@ struct iommu_domain {
 	struct iommu_domain_geometry geometry;
 	int (*iopf_handler)(struct iopf_group *group);
 
-#if IS_ENABLED(CONFIG_IRQ_MSI_IOMMU)
-	int (*sw_msi)(struct iommu_domain *domain, struct msi_desc *desc,
-		      phys_addr_t msi_addr);
-#endif
-
 	union { /* cookie */
 		struct iommu_dma_cookie *iova_cookie;
 		struct iommu_dma_msi_cookie *msi_cookie;
@@ -254,16 +249,6 @@ struct iommu_domain {
 	};
 };
 
-static inline void iommu_domain_set_sw_msi(
-	struct iommu_domain *domain,
-	int (*sw_msi)(struct iommu_domain *domain, struct msi_desc *desc,
-		      phys_addr_t msi_addr))
-{
-#if IS_ENABLED(CONFIG_IRQ_MSI_IOMMU)
-	domain->sw_msi = sw_msi;
-#endif
-}
-
 static inline bool iommu_is_dma_domain(struct iommu_domain *domain)
 {
 	return domain->type & __IOMMU_DOMAIN_DMA_API;
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 31a7b4b81656..2bd9f80a83fe 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -94,9 +94,6 @@ static int __init iommu_dma_forcedac_setup(char *str)
 }
 early_param("iommu.forcedac", iommu_dma_forcedac_setup);
 
-static int iommu_dma_sw_msi(struct iommu_domain *domain, struct msi_desc *desc,
-			    phys_addr_t msi_addr);
-
 /* Number of entries per flush queue */
 #define IOVA_DEFAULT_FQ_SIZE	256
 #define IOVA_SINGLE_FQ_SIZE	32768
@@ -377,7 +374,6 @@ int iommu_get_dma_cookie(struct iommu_domain *domain)
 
 	mutex_init(&cookie->mutex);
 	INIT_LIST_HEAD(&cookie->msi_page_list);
-	iommu_domain_set_sw_msi(domain, iommu_dma_sw_msi);
 	domain->cookie_type = IOMMU_COOKIE_DMA_IOVA;
 	domain->iova_cookie = cookie;
 	return 0;
@@ -411,7 +407,6 @@ int iommu_get_msi_cookie(struct iommu_domain *domain, dma_addr_t base)
 
 	cookie->msi_iova = base;
 	INIT_LIST_HEAD(&cookie->msi_page_list);
-	iommu_domain_set_sw_msi(domain, iommu_dma_sw_msi);
 	domain->cookie_type = IOMMU_COOKIE_DMA_MSI;
 	domain->msi_cookie = cookie;
 	return 0;
@@ -427,11 +422,6 @@ void iommu_put_dma_cookie(struct iommu_domain *domain)
 	struct iommu_dma_cookie *cookie = domain->iova_cookie;
 	struct iommu_dma_msi_page *msi, *tmp;
 
-#if IS_ENABLED(CONFIG_IRQ_MSI_IOMMU)
-	if (domain->sw_msi != iommu_dma_sw_msi)
-		return;
-#endif
-
 	if (cookie->iovad.granule) {
 		iommu_dma_free_fq(cookie);
 		put_iova_domain(&cookie->iovad);
@@ -1826,8 +1816,8 @@ static struct iommu_dma_msi_page *iommu_dma_get_msi_page(struct device *dev,
 	return NULL;
 }
 
-static int iommu_dma_sw_msi(struct iommu_domain *domain, struct msi_desc *desc,
-			    phys_addr_t msi_addr)
+int iommu_dma_sw_msi(struct iommu_domain *domain, struct msi_desc *desc,
+		     phys_addr_t msi_addr)
 {
 	struct device *dev = msi_desc_to_dev(desc);
 	const struct iommu_dma_msi_page *msi_page;
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index c92e47f333cb..d96e6fabb4da 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -18,6 +18,7 @@
 #include <linux/errno.h>
 #include <linux/host1x_context_bus.h>
 #include <linux/iommu.h>
+#include <linux/iommufd.h>
 #include <linux/idr.h>
 #include <linux/err.h>
 #include <linux/pci.h>
@@ -3650,8 +3651,21 @@ int iommu_dma_prepare_msi(struct msi_desc *desc, phys_addr_t msi_addr)
 		return 0;
 
 	mutex_lock(&group->mutex);
-	if (group->domain && group->domain->sw_msi)
-		ret = group->domain->sw_msi(group->domain, desc, msi_addr);
+	/* An IDENTITY domain must pass through */
+	if (group->domain && group->domain->type != IOMMU_DOMAIN_IDENTITY) {
+		switch (group->domain->cookie_type) {
+		case IOMMU_COOKIE_DMA_MSI:
+		case IOMMU_COOKIE_DMA_IOVA:
+			ret = iommu_dma_sw_msi(group->domain, desc, msi_addr);
+			break;
+		case IOMMU_COOKIE_IOMMUFD:
+			ret = iommufd_sw_msi(group->domain, desc, msi_addr);
+			break;
+		default:
+			ret = -EOPNOTSUPP;
+			break;
+		}
+	}
 	mutex_unlock(&group->mutex);
 	return ret;
 }
diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c
index fded3f07bfa7..8e87ae71e128 100644
--- a/drivers/iommu/iommufd/hw_pagetable.c
+++ b/drivers/iommu/iommufd/hw_pagetable.c
@@ -161,7 +161,6 @@ iommufd_hwpt_paging_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas,
 	}
 	hwpt->domain->iommufd_hwpt = hwpt;
 	hwpt->domain->cookie_type = IOMMU_COOKIE_IOMMUFD;
-	iommu_domain_set_sw_msi(hwpt->domain, iommufd_sw_msi);
 
 	/*
 	 * Set the coherency mode before we do iopt_table_add_domain() as some
@@ -259,7 +258,6 @@ iommufd_hwpt_nested_alloc(struct iommufd_ctx *ictx,
 	hwpt->domain->owner = ops;
 	hwpt->domain->iommufd_hwpt = hwpt;
 	hwpt->domain->cookie_type = IOMMU_COOKIE_IOMMUFD;
-	iommu_domain_set_sw_msi(hwpt->domain, iommufd_sw_msi);
 
 	if (WARN_ON_ONCE(hwpt->domain->type != IOMMU_DOMAIN_NESTED)) {
 		rc = -EINVAL;
@@ -318,7 +316,6 @@ iommufd_viommu_alloc_hwpt_nested(struct iommufd_viommu *viommu, u32 flags,
 	hwpt->domain->iommufd_hwpt = hwpt;
 	hwpt->domain->owner = viommu->iommu_dev->ops;
 	hwpt->domain->cookie_type = IOMMU_COOKIE_IOMMUFD;
-	iommu_domain_set_sw_msi(hwpt->domain, iommufd_sw_msi);
 
 	if (WARN_ON_ONCE(hwpt->domain->type != IOMMU_DOMAIN_NESTED)) {
 		rc = -EINVAL;
-- 
2.43.0

Re: [PATCH v5 0/3] iommu: Clean up cookie and sw_msi in struct iommu_domain

[Nicolin Chen]

On Mon, Mar 24, 2025 at 09:05:14PM -0700, Nicolin Chen wrote:
> This is a clean-up series for the previous sw_msi Part-1 core series. It's
> on github:
> https://github.com/nicolinc/iommufd/commits/iommufd_msi_cleanup-v5
> 
> Changelog
> v5
>  * Add IMPORT line for IOMMUFD_INTERNAL and change IOMMUFD_DRIVER_CORE
>    to a "bool" module, fixing build module errors reported by Arnd:
>    https://lore.kernel.org/all/20250324210329.2809869-1-arnd@kernel.org/
>  * In iommu_dma_prepare_msi(), let all IDENTITY DOMAINs pass through,
>    fixing the regression with IDENTITY domains reported by Nathan:
>    https://lore.kernel.org/linux-iommu/20250324162558.GA198799@ax162/

> base-commit: da0c56520e880441d0503d0cf0d6853dcfb5f1a4

Hi Jason,

Assuming that you want to replace the commits in your for-next
tree with these patches, I rebased them on this commit:
da0c56520e88 iommu/arm-smmu-v3: Set MEV bit in nested STE for DoS mitigations

Again, sorry for the trouble.

Nicolin

P.S. Attaching git-diff against the current commit in your tree
"git diff -U1 e009e088d88e8..nicolinc/iommufd_msi_cleanup-v5":

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 0f4cc15ded1c..d96e6fabb4da 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -3653,3 +3653,4 @@ int iommu_dma_prepare_msi(struct msi_desc *desc, phys_addr_t msi_addr)
 	mutex_lock(&group->mutex);
-	if (group->domain) {
+	/* An IDENTITY domain must pass through */
+	if (group->domain && group->domain->type != IOMMU_DOMAIN_IDENTITY) {
 		switch (group->domain->cookie_type) {
diff --git a/drivers/iommu/iommufd/Kconfig b/drivers/iommu/iommufd/Kconfig
index 0a07f9449fd9..2beeb4f60ee5 100644
--- a/drivers/iommu/iommufd/Kconfig
+++ b/drivers/iommu/iommufd/Kconfig
@@ -2,3 +2,3 @@
 config IOMMUFD_DRIVER_CORE
-	tristate
+	bool
 	default (IOMMUFD_DRIVER || IOMMUFD) if IOMMUFD!=n
diff --git a/drivers/iommu/iommufd/driver.c b/drivers/iommu/iommufd/driver.c
index 352513974154..a08ff0f37fc6 100644
--- a/drivers/iommu/iommufd/driver.c
+++ b/drivers/iommu/iommufd/driver.c
@@ -249,2 +249,3 @@ EXPORT_SYMBOL_NS_GPL(iommufd_sw_msi, "IOMMUFD");
 MODULE_DESCRIPTION("iommufd code shared with builtin modules");
+MODULE_IMPORT_NS("IOMMUFD_INTERNAL");
 MODULE_LICENSE("GPL");

Re: [PATCH v5 0/3] iommu: Clean up cookie and sw_msi in struct iommu_domain

[Jason Gunthorpe]

On Mon, Mar 24, 2025 at 09:14:23PM -0700, Nicolin Chen wrote:
> On Mon, Mar 24, 2025 at 09:05:14PM -0700, Nicolin Chen wrote:
> > This is a clean-up series for the previous sw_msi Part-1 core series. It's
> > on github:
> > https://github.com/nicolinc/iommufd/commits/iommufd_msi_cleanup-v5
> > 
> > Changelog
> > v5
> >  * Add IMPORT line for IOMMUFD_INTERNAL and change IOMMUFD_DRIVER_CORE
> >    to a "bool" module, fixing build module errors reported by Arnd:
> >    https://lore.kernel.org/all/20250324210329.2809869-1-arnd@kernel.org/
> >  * In iommu_dma_prepare_msi(), let all IDENTITY DOMAINs pass through,
> >    fixing the regression with IDENTITY domains reported by Nathan:
> >    https://lore.kernel.org/linux-iommu/20250324162558.GA198799@ax162/
> 
> > base-commit: da0c56520e880441d0503d0cf0d6853dcfb5f1a4
> 
> Hi Jason,
> 
> Assuming that you want to replace the commits in your for-next
> tree with these patches, I rebased them on this commit:
> da0c56520e88 iommu/arm-smmu-v3: Set MEV bit in nested STE for DoS mitigations
> 
> Again, sorry for the trouble.

Can you post a v6 please? That is a bit easier

Thanks,
Jason

Re: [PATCH v5 0/3] iommu: Clean up cookie and sw_msi in struct iommu_domain

[Jason Gunthorpe]

On Mon, Mar 24, 2025 at 09:05:14PM -0700, Nicolin Chen wrote:

> Nicolin Chen (2):
>   iommufd: Move iommufd_sw_msi and related functions to driver.c
>   iommu: Drop sw_msi from iommu_domain
> 
> Robin Murphy (1):
>   iommu: Sort out domain user data

Refreshed, thanks

Jason