Revert "dma-iommu: Implement NESTED_MSI cookie"

virt inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I61SPO
CVE: NA

--------------------------------

This reverts commit 15700dc0.
Signed-off-by: NKunkun Jiang <jiangkunkun@huawei.com>
Reviewed-by: NKeqian Zhu <zhukeqian1@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/iommu/dma-iommu.c

@@ -27,15 +27,12 @@
 struct iommu_dma_msi_page {
 	struct list_head	list;
 	dma_addr_t		iova;
-	dma_addr_t		gpa;
 	phys_addr_t		phys;
-	size_t			s1_granule;
 };
 
 enum iommu_dma_cookie_type {
 	IOMMU_DMA_IOVA_COOKIE,
 	IOMMU_DMA_MSI_COOKIE,
-	IOMMU_DMA_NESTED_MSI_COOKIE,
 };
 
 struct iommu_dma_cookie {
@@ -47,8 +44,6 @@ struct iommu_dma_cookie {
 		dma_addr_t		msi_iova;
 	};
 	struct list_head		msi_page_list;
-	/* used in nested mode only */
-	spinlock_t			msi_lock;
 
 	/* Domain for flush queue callback; NULL if flush queue not in use */
 	struct iommu_domain		*fq_domain;
@@ -67,7 +62,6 @@ static struct iommu_dma_cookie *cookie_alloc(enum iommu_dma_cookie_type type)
 
 	cookie = kzalloc(sizeof(*cookie), GFP_KERNEL);
 	if (cookie) {
-		spin_lock_init(&cookie->msi_lock);
 		INIT_LIST_HEAD(&cookie->msi_page_list);
 		cookie->type = type;
 	}
@@ -101,17 +95,14 @@ EXPORT_SYMBOL(iommu_get_dma_cookie);
  *
  * Users who manage their own IOVA allocation and do not want DMA API support,
  * but would still like to take advantage of automatic MSI remapping, can use
- * this to initialise their own domain appropriately. Users may reserve a
+ * this to initialise their own domain appropriately. Users should reserve a
  * contiguous IOVA region, starting at @base, large enough to accommodate the
  * number of PAGE_SIZE mappings necessary to cover every MSI doorbell address
- * used by the devices attached to @domain. The other way round is to provide
- * usable iova pages through the iommu_dma_bind_guest_msi API (nested stages
- * use case)
+ * used by the devices attached to @domain.
  */
 int iommu_get_msi_cookie(struct iommu_domain *domain, dma_addr_t base)
 {
 	struct iommu_dma_cookie *cookie;
-	int nesting, ret;
 
 	if (domain->type != IOMMU_DOMAIN_UNMANAGED)
 		return -EINVAL;
@@ -119,16 +110,10 @@ int iommu_get_msi_cookie(struct iommu_domain *domain, dma_addr_t base)
 	if (domain->iova_cookie)
 		return -EEXIST;
 
-	ret = iommu_domain_get_attr(domain, DOMAIN_ATTR_NESTING, &nesting);
-	if (!ret && nesting)
-		cookie = cookie_alloc(IOMMU_DMA_NESTED_MSI_COOKIE);
-	else
 	cookie = cookie_alloc(IOMMU_DMA_MSI_COOKIE);
-
 	if (!cookie)
 		return -ENOMEM;
 
-	if (!nesting)
 	cookie->msi_iova = base;
 	domain->iova_cookie = cookie;
 	return 0;
@@ -153,116 +138,15 @@ void iommu_put_dma_cookie(struct iommu_domain *domain)
 	if (cookie->type == IOMMU_DMA_IOVA_COOKIE && cookie->iovad.granule)
 		put_iova_domain(&cookie->iovad);
 
-	spin_lock(&cookie->msi_lock);
 	list_for_each_entry_safe(msi, tmp, &cookie->msi_page_list, list) {
-		if (cookie->type == IOMMU_DMA_NESTED_MSI_COOKIE && msi->phys) {
-			size_t size = cookie_msi_granule(cookie);
-
-			WARN_ON(iommu_unmap(domain, msi->gpa, size) != size);
-		}
 		list_del(&msi->list);
 		kfree(msi);
 	}
-	spin_unlock(&cookie->msi_lock);
 	kfree(cookie);
 	domain->iova_cookie = NULL;
 }
 EXPORT_SYMBOL(iommu_put_dma_cookie);
 
-/**
- * iommu_dma_bind_guest_msi - Allows to pass the stage 1
- * binding of a virtual MSI doorbell used by @dev.
- *
- * @domain: domain handle
- * @giova: guest iova
- * @gpa: gpa of the virtual doorbell
- * @size: size of the granule used for the stage1 mapping
- *
- * In nested stage use case, the user can provide IOVA/IPA bindings
- * corresponding to a guest MSI stage 1 mapping. When the host needs
- * to map its own MSI doorbells, it can use @gpa as stage 2 input
- * and map it onto the physical MSI doorbell.
- */
-int iommu_dma_bind_guest_msi(struct iommu_domain *domain,
-			     dma_addr_t giova, phys_addr_t gpa, size_t size)
-{
-	struct iommu_dma_cookie *cookie = domain->iova_cookie;
-	struct iommu_dma_msi_page *msi;
-	int ret = 0;
-
-	if (!cookie)
-		return -EINVAL;
-
-	if (cookie->type != IOMMU_DMA_NESTED_MSI_COOKIE)
-		return -EINVAL;
-
-	/*
-	 * we currently do not support S1 granule larger than S2 one
-	 * as this would oblige to have multiple S2 mappings for a
-	 * single S1 one
-	 */
-	if (size > cookie_msi_granule(cookie))
-		return -EINVAL;
-
-	giova = giova & ~(dma_addr_t)(size - 1);
-	gpa = gpa & ~(phys_addr_t)(size - 1);
-
-	spin_lock(&cookie->msi_lock);
-
-	list_for_each_entry(msi, &cookie->msi_page_list, list) {
-		if (msi->iova == giova)
-			goto unlock; /* this page is already registered */
-	}
-
-	msi = kzalloc(sizeof(*msi), GFP_ATOMIC);
-	if (!msi) {
-		ret = -ENOMEM;
-		goto unlock;
-	}
-
-	msi->iova = giova;
-	msi->gpa = gpa;
-	msi->s1_granule = size;
-	list_add(&msi->list, &cookie->msi_page_list);
-unlock:
-	spin_unlock(&cookie->msi_lock);
-	return ret;
-}
-EXPORT_SYMBOL(iommu_dma_bind_guest_msi);
-
-void iommu_dma_unbind_guest_msi(struct iommu_domain *domain, dma_addr_t giova)
-{
-	struct iommu_dma_cookie *cookie = domain->iova_cookie;
-	struct iommu_dma_msi_page *msi;
-
-	if (!cookie)
-		return;
-
-	if (cookie->type != IOMMU_DMA_NESTED_MSI_COOKIE)
-		return;
-
-	spin_lock(&cookie->msi_lock);
-
-	list_for_each_entry(msi, &cookie->msi_page_list, list) {
-		dma_addr_t aligned_giova =
-			giova & ~(dma_addr_t)(msi->s1_granule - 1);
-
-		if (msi->iova == aligned_giova) {
-			if (msi->phys) {
-				/* unmap the stage 2 */
-				size_t size = cookie_msi_granule(cookie);
-
-				WARN_ON(iommu_unmap(domain, msi->gpa, size) != size);
-			}
-			list_del(&msi->list);
-			kfree(msi);
-			break;
-		}
-	}
-	spin_unlock(&cookie->msi_lock);
-}
-EXPORT_SYMBOL(iommu_dma_unbind_guest_msi);
-
 /**
  * iommu_dma_get_resv_regions - Reserved region driver helper
  * @dev: Device from iommu_get_resv_regions()
@@ -1314,58 +1198,6 @@ void iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size)
 		 dev_name(dev));
 }
 
-/*
- * iommu_dma_get_nested_msi_page - Returns a nested stage MSI page
- * mapping translating into the physical doorbell address @msi_addr
- *
- * In nested mode, the userspace provides the guest
- * gIOVA - gDB stage 1 mappings. When we need to build a stage 2
- * mapping for a physical doorbell (@msi_addr), we look up
- * for an unused S1 mapping and map the gDB onto @msi_addr
- */
-static struct iommu_dma_msi_page *
-iommu_dma_get_nested_msi_page(struct iommu_domain *domain,
-			      phys_addr_t msi_addr)
-{
-	struct iommu_dma_cookie *cookie = domain->iova_cookie;
-	struct iommu_dma_msi_page *iter, *msi_page = NULL;
-	size_t size = cookie_msi_granule(cookie);
-	int prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO;
-
-	spin_lock(&cookie->msi_lock);
-	list_for_each_entry(iter, &cookie->msi_page_list, list)
-		if (iter->phys == msi_addr) {
-			msi_page = iter;
-			goto unlock;
-		}
-
-	/*
-	 * No nested mapping exists for the physical doorbell,
-	 * look for an unused S1 mapping
-	 */
-	list_for_each_entry(iter, &cookie->msi_page_list, list) {
-		int ret;
-
-		if (iter->phys)
-			continue;
-
-		/* do the stage 2 mapping */
-		ret = iommu_map_atomic(domain, iter->gpa, msi_addr, size, prot);
-		if (ret) {
-			pr_warn_once("MSI S2 mapping 0x%llx -> 0x%llx failed (%d)\n",
-				     iter->gpa, msi_addr, ret);
-			goto unlock;
-		}
-		iter->phys = msi_addr;
-		msi_page = iter;
-		goto unlock;
-	}
-	pr_warn_once("No usable S1 MSI mapping found\n");
-unlock:
-	spin_unlock(&cookie->msi_lock);
-	return msi_page;
-}
-
 static struct iommu_dma_msi_page *iommu_dma_get_msi_page(struct device *dev,
 		phys_addr_t msi_addr, struct iommu_domain *domain)
 {
@@ -1376,10 +1208,6 @@ static struct iommu_dma_msi_page *iommu_dma_get_msi_page(struct device *dev,
 	size_t size = cookie_msi_granule(cookie);
 
 	msi_addr &= ~(phys_addr_t)(size - 1);
-
-	if (cookie->type == IOMMU_DMA_NESTED_MSI_COOKIE)
-		return iommu_dma_get_nested_msi_page(domain, msi_addr);
-
 	list_for_each_entry(msi_page, &cookie->msi_page_list, list)
 		if (msi_page->phys == msi_addr)
 			return msi_page;

include/linux/dma-iommu.h

@@ -12,7 +12,6 @@
 #include <linux/dma-mapping.h>
 #include <linux/iommu.h>
 #include <linux/msi.h>
-#include <uapi/linux/iommu.h>
 
 /* Domain management interface for IOMMU drivers */
 int iommu_get_dma_cookie(struct iommu_domain *domain);
@@ -37,9 +36,6 @@ void iommu_dma_compose_msi_msg(struct msi_desc *desc,
 			       struct msi_msg *msg);
 
 void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list);
-int iommu_dma_bind_guest_msi(struct iommu_domain *domain,
-			     dma_addr_t iova, phys_addr_t gpa, size_t size);
-void iommu_dma_unbind_guest_msi(struct iommu_domain *domain, dma_addr_t giova);
 
 #else /* CONFIG_IOMMU_DMA */
 
@@ -78,18 +74,6 @@ static inline void iommu_dma_compose_msi_msg(struct msi_desc *desc,
 {
 }
 
-static inline int
-iommu_dma_bind_guest_msi(struct iommu_domain *domain,
-			 dma_addr_t iova, phys_addr_t gpa, size_t size)
-{
-	return -ENODEV;
-}
-
-static inline void
-iommu_dma_unbind_guest_msi(struct iommu_domain *domain, dma_addr_t giova)
-{
-}
-
 static inline void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list)
 {
 }