From 21f402093c5ee7363f5ba56916cd5c651b424fef Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 15 Jun 2018 14:57:15 +0100 Subject: [PATCH] iommu: Add IOMMU index concept to IOMMU API MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit If an IOMMU supports mappings that care about the memory transaction attributes, then it no longer has a unique address -> output mapping, but more than one. We can represent these using an IOMMU index, analogous to TCG's mmu indexes. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Reviewed-by: Alex Bennée Message-id: 20180604152941.20374-2-peter.maydell@linaro.org --- include/exec/memory.h | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++ memory.c | 23 +++++++++++++++++++++ 2 files changed, 78 insertions(+) diff --git a/include/exec/memory.h b/include/exec/memory.h index eb2ba06519..fa6e98ee7b 100644 --- a/include/exec/memory.h +++ b/include/exec/memory.h @@ -206,6 +206,20 @@ enum IOMMUMemoryRegionAttr { * to report whenever mappings are changed, by calling * memory_region_notify_iommu() (or, if necessary, by calling * memory_region_notify_one() for each registered notifier). + * + * Conceptually an IOMMU provides a mapping from input address + * to an output TLB entry. If the IOMMU is aware of memory transaction + * attributes and the output TLB entry depends on the transaction + * attributes, we represent this using IOMMU indexes. Each index + * selects a particular translation table that the IOMMU has: + * @attrs_to_index returns the IOMMU index for a set of transaction attributes + * @translate takes an input address and an IOMMU index + * and the mapping returned can only depend on the input address and the + * IOMMU index. + * + * Most IOMMUs don't care about the transaction attributes and support + * only a single IOMMU index. A more complex IOMMU might have one index + * for secure transactions and one for non-secure transactions. */ typedef struct IOMMUMemoryRegionClass { /* private */ @@ -290,6 +304,29 @@ typedef struct IOMMUMemoryRegionClass { */ int (*get_attr)(IOMMUMemoryRegion *iommu, enum IOMMUMemoryRegionAttr attr, void *data); + + /* Return the IOMMU index to use for a given set of transaction attributes. + * + * Optional method: if an IOMMU only supports a single IOMMU index then + * the default implementation of memory_region_iommu_attrs_to_index() + * will return 0. + * + * The indexes supported by an IOMMU must be contiguous, starting at 0. + * + * @iommu: the IOMMUMemoryRegion + * @attrs: memory transaction attributes + */ + int (*attrs_to_index)(IOMMUMemoryRegion *iommu, MemTxAttrs attrs); + + /* Return the number of IOMMU indexes this IOMMU supports. + * + * Optional method: if this method is not provided, then + * memory_region_iommu_num_indexes() will return 1, indicating that + * only a single IOMMU index is supported. + * + * @iommu: the IOMMUMemoryRegion + */ + int (*num_indexes)(IOMMUMemoryRegion *iommu); } IOMMUMemoryRegionClass; typedef struct CoalescedMemoryRange CoalescedMemoryRange; @@ -1055,6 +1092,24 @@ int memory_region_iommu_get_attr(IOMMUMemoryRegion *iommu_mr, void *data); /** + * memory_region_iommu_attrs_to_index: return the IOMMU index to + * use for translations with the given memory transaction attributes. + * + * @iommu_mr: the memory region + * @attrs: the memory transaction attributes + */ +int memory_region_iommu_attrs_to_index(IOMMUMemoryRegion *iommu_mr, + MemTxAttrs attrs); + +/** + * memory_region_iommu_num_indexes: return the total number of IOMMU + * indexes that this IOMMU supports. + * + * @iommu_mr: the memory region + */ +int memory_region_iommu_num_indexes(IOMMUMemoryRegion *iommu_mr); + +/** * memory_region_name: get a memory region's name * * Returns the string that was used to initialize the memory region. diff --git a/memory.c b/memory.c index 3212acc7f4..64f4a55d54 100644 --- a/memory.c +++ b/memory.c @@ -1915,6 +1915,29 @@ int memory_region_iommu_get_attr(IOMMUMemoryRegion *iommu_mr, return imrc->get_attr(iommu_mr, attr, data); } +int memory_region_iommu_attrs_to_index(IOMMUMemoryRegion *iommu_mr, + MemTxAttrs attrs) +{ + IOMMUMemoryRegionClass *imrc = IOMMU_MEMORY_REGION_GET_CLASS(iommu_mr); + + if (!imrc->attrs_to_index) { + return 0; + } + + return imrc->attrs_to_index(iommu_mr, attrs); +} + +int memory_region_iommu_num_indexes(IOMMUMemoryRegion *iommu_mr) +{ + IOMMUMemoryRegionClass *imrc = IOMMU_MEMORY_REGION_GET_CLASS(iommu_mr); + + if (!imrc->num_indexes) { + return 1; + } + + return imrc->num_indexes(iommu_mr); +} + void memory_region_set_log(MemoryRegion *mr, bool log, unsigned client) { uint8_t mask = 1 << client; -- 2.11.4.GIT