From fdbe574eb69312a7fbe09674d69c01b80e4ed9dc Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Thu, 19 Jan 2017 20:57:46 +0000 Subject: iommu/dma: Allow MSI-only cookies IOMMU domain users such as VFIO face a similar problem to DMA API ops with regard to mapping MSI messages in systems where the MSI write is subject to IOMMU translation. With the relevant infrastructure now in place for managed DMA domains, it's actually really simple for other users to piggyback off that and reap the benefits without giving up their own IOVA management, and without having to reinvent their own wheel in the MSI layer. Allow such users to opt into automatic MSI remapping by dedicating a region of their IOVA space to a managed cookie, and extend the mapping routine to implement a trivial linear allocator in such cases, to avoid the needless overhead of a full-blown IOVA domain. Signed-off-by: Robin Murphy Reviewed-by: Tomasz Nowicki Reviewed-by: Eric Auger Tested-by: Eric Auger Tested-by: Tomasz Nowicki Tested-by: Bharat Bhushan Signed-off-by: Will Deacon --- include/linux/dma-iommu.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/linux') diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h index 7f7e9a7e3839..28df844a23b6 100644 --- a/include/linux/dma-iommu.h +++ b/include/linux/dma-iommu.h @@ -27,6 +27,7 @@ int iommu_dma_init(void); /* Domain management interface for IOMMU drivers */ int iommu_get_dma_cookie(struct iommu_domain *domain); +int iommu_get_msi_cookie(struct iommu_domain *domain, dma_addr_t base); void iommu_put_dma_cookie(struct iommu_domain *domain); /* Setup call for arch DMA mapping code */ @@ -86,6 +87,11 @@ static inline int iommu_get_dma_cookie(struct iommu_domain *domain) return -ENODEV; } +static inline int iommu_get_msi_cookie(struct iommu_domain *domain, dma_addr_t base) +{ + return -ENODEV; +} + static inline void iommu_put_dma_cookie(struct iommu_domain *domain) { } -- cgit v1.2.3 From e5b5234a36ca283158721d3d2e0cddfa324abdf9 Mon Sep 17 00:00:00 2001 From: Eric Auger Date: Thu, 19 Jan 2017 20:57:47 +0000 Subject: iommu: Rename iommu_dm_regions into iommu_resv_regions We want to extend the callbacks used for dm regions and use them for reserved regions. Reserved regions can be - directly mapped regions - regions that cannot be iommu mapped (PCI host bridge windows, ...) - MSI regions (because they belong to another address space or because they are not translated by the IOMMU and need special handling) So let's rename the struct and also the callbacks. Signed-off-by: Eric Auger Acked-by: Robin Murphy Reviewed-by: Tomasz Nowicki Tested-by: Tomasz Nowicki Tested-by: Bharat Bhushan Signed-off-by: Will Deacon --- include/linux/iommu.h | 29 +++++++++++++++-------------- 1 file changed, 15 insertions(+), 14 deletions(-) (limited to 'include/linux') diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 0ff5111f6959..bfecb8b74078 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -118,13 +118,13 @@ enum iommu_attr { }; /** - * struct iommu_dm_region - descriptor for a direct mapped memory region + * struct iommu_resv_region - descriptor for a reserved memory region * @list: Linked list pointers * @start: System physical start address of the region * @length: Length of the region in bytes * @prot: IOMMU Protection flags (READ/WRITE/...) */ -struct iommu_dm_region { +struct iommu_resv_region { struct list_head list; phys_addr_t start; size_t length; @@ -150,9 +150,9 @@ struct iommu_dm_region { * @device_group: find iommu group for a particular device * @domain_get_attr: Query domain attributes * @domain_set_attr: Change domain attributes - * @get_dm_regions: Request list of direct mapping requirements for a device - * @put_dm_regions: Free list of direct mapping requirements for a device - * @apply_dm_region: Temporary helper call-back for iova reserved ranges + * @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 * @domain_window_enable: Configure and enable a particular window for a domain * @domain_window_disable: Disable a particular window for a domain * @domain_set_windows: Set the number of windows for a domain @@ -184,11 +184,12 @@ struct iommu_ops { int (*domain_set_attr)(struct iommu_domain *domain, enum iommu_attr attr, void *data); - /* Request/Free a list of direct mapping requirements for a device */ - void (*get_dm_regions)(struct device *dev, struct list_head *list); - void (*put_dm_regions)(struct device *dev, struct list_head *list); - void (*apply_dm_region)(struct device *dev, struct iommu_domain *domain, - struct iommu_dm_region *region); + /* Request/Free a list of reserved regions for a device */ + void (*get_resv_regions)(struct device *dev, struct list_head *list); + void (*put_resv_regions)(struct device *dev, struct list_head *list); + void (*apply_resv_region)(struct device *dev, + struct iommu_domain *domain, + struct iommu_resv_region *region); /* Window handling functions */ int (*domain_window_enable)(struct iommu_domain *domain, u32 wnd_nr, @@ -233,8 +234,8 @@ extern phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain, dma_addr_t io extern void iommu_set_fault_handler(struct iommu_domain *domain, iommu_fault_handler_t handler, void *token); -extern void iommu_get_dm_regions(struct device *dev, struct list_head *list); -extern void iommu_put_dm_regions(struct device *dev, struct list_head *list); +extern void iommu_get_resv_regions(struct device *dev, struct list_head *list); +extern void iommu_put_resv_regions(struct device *dev, struct list_head *list); extern int iommu_request_dm_for_dev(struct device *dev); extern int iommu_attach_group(struct iommu_domain *domain, @@ -443,12 +444,12 @@ static inline void iommu_set_fault_handler(struct iommu_domain *domain, { } -static inline void iommu_get_dm_regions(struct device *dev, +static inline void iommu_get_resv_regions(struct device *dev, struct list_head *list) { } -static inline void iommu_put_dm_regions(struct device *dev, +static inline void iommu_put_resv_regions(struct device *dev, struct list_head *list) { } -- cgit v1.2.3 From d30ddcaa7b028049cdfee3a40248002d07b2bbf3 Mon Sep 17 00:00:00 2001 From: Eric Auger Date: Thu, 19 Jan 2017 20:57:48 +0000 Subject: iommu: Add a new type field in iommu_resv_region We introduce a new field to differentiate the reserved region types and specialize the apply_resv_region implementation. Legacy direct mapped regions have IOMMU_RESV_DIRECT type. We introduce 2 new reserved memory types: - IOMMU_RESV_MSI will characterize MSI regions that are mapped - IOMMU_RESV_RESERVED characterize regions that cannot by mapped. Signed-off-by: Eric Auger Tested-by: Tomasz Nowicki Tested-by: Bharat Bhushan Signed-off-by: Will Deacon --- include/linux/iommu.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include/linux') diff --git a/include/linux/iommu.h b/include/linux/iommu.h index bfecb8b74078..233a6bf093bf 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -117,18 +117,25 @@ enum iommu_attr { DOMAIN_ATTR_MAX, }; +/* These are the possible reserved region types */ +#define IOMMU_RESV_DIRECT (1 << 0) +#define IOMMU_RESV_RESERVED (1 << 1) +#define IOMMU_RESV_MSI (1 << 2) + /** * struct iommu_resv_region - descriptor for a reserved memory region * @list: Linked list pointers * @start: System physical start address of the region * @length: Length of the region in bytes * @prot: IOMMU Protection flags (READ/WRITE/...) + * @type: Type of the reserved region */ struct iommu_resv_region { struct list_head list; phys_addr_t start; size_t length; int prot; + int type; }; #ifdef CONFIG_IOMMU_API -- cgit v1.2.3 From 2b20cbba3390a55c511acba2f0f517dd27a528b2 Mon Sep 17 00:00:00 2001 From: Eric Auger Date: Thu, 19 Jan 2017 20:57:49 +0000 Subject: iommu: iommu_alloc_resv_region Introduce a new helper serving the purpose to allocate a reserved region. This will be used in iommu driver implementing reserved region callbacks. Signed-off-by: Eric Auger Reviewed-by: Tomasz Nowicki Tested-by: Tomasz Nowicki Tested-by: Bharat Bhushan Signed-off-by: Will Deacon --- include/linux/iommu.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux') diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 233a6bf093bf..f6bb55d3e606 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -244,6 +244,8 @@ extern void iommu_set_fault_handler(struct iommu_domain *domain, extern void iommu_get_resv_regions(struct device *dev, struct list_head *list); extern void iommu_put_resv_regions(struct device *dev, struct list_head *list); extern int iommu_request_dm_for_dev(struct device *dev); +extern struct iommu_resv_region * +iommu_alloc_resv_region(phys_addr_t start, size_t length, int prot, int type); extern int iommu_attach_group(struct iommu_domain *domain, struct iommu_group *group); -- cgit v1.2.3 From 6c65fb318e8bbf21e939e651028b955324f1d873 Mon Sep 17 00:00:00 2001 From: Eric Auger Date: Thu, 19 Jan 2017 20:57:51 +0000 Subject: iommu: iommu_get_group_resv_regions Introduce iommu_get_group_resv_regions whose role consists in enumerating all devices from the group and collecting their reserved regions. The list is sorted and overlaps between regions of the same type are handled by merging the regions. Signed-off-by: Eric Auger Reviewed-by: Tomasz Nowicki Tested-by: Tomasz Nowicki Tested-by: Bharat Bhushan Signed-off-by: Will Deacon --- include/linux/iommu.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include/linux') diff --git a/include/linux/iommu.h b/include/linux/iommu.h index f6bb55d3e606..bec3730dc009 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -246,6 +246,8 @@ extern void iommu_put_resv_regions(struct device *dev, struct list_head *list); extern int iommu_request_dm_for_dev(struct device *dev); extern struct iommu_resv_region * iommu_alloc_resv_region(phys_addr_t start, size_t length, int prot, int type); +extern int iommu_get_group_resv_regions(struct iommu_group *group, + struct list_head *head); extern int iommu_attach_group(struct iommu_domain *domain, struct iommu_group *group); @@ -463,6 +465,12 @@ static inline void iommu_put_resv_regions(struct device *dev, { } +static inline int iommu_get_group_resv_regions(struct iommu_group *group, + struct list_head *head) +{ + return -ENODEV; +} + static inline int iommu_request_dm_for_dev(struct device *dev) { return -ENODEV; -- cgit v1.2.3 From 631a9639ac413da6242cb15558ebd661cf633622 Mon Sep 17 00:00:00 2001 From: Eric Auger Date: Thu, 19 Jan 2017 20:57:57 +0000 Subject: irqdomain: Add irq domain MSI and MSI_REMAP flags We introduce two new enum values for the irq domain flag: - IRQ_DOMAIN_FLAG_MSI indicates the irq domain corresponds to an MSI domain - IRQ_DOMAIN_FLAG_MSI_REMAP indicates the irq domain has MSI remapping capabilities. Those values will be useful to check all MSI irq domains have MSI remapping support when assessing the safety of IRQ assignment to a guest. irq_domain_hierarchical_is_msi_remap() allows to check if an irq domain or any parent implements MSI remapping. Signed-off-by: Eric Auger Reviewed-by: Marc Zyngier Reviewed-by: Tomasz Nowicki Tested-by: Tomasz Nowicki Tested-by: Bharat Bhushan Signed-off-by: Will Deacon --- include/linux/irqdomain.h | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) (limited to 'include/linux') diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h index ffb84604c1de..bc2f5719dace 100644 --- a/include/linux/irqdomain.h +++ b/include/linux/irqdomain.h @@ -183,6 +183,12 @@ enum { /* Irq domain is an IPI domain with single virq */ IRQ_DOMAIN_FLAG_IPI_SINGLE = (1 << 3), + /* Irq domain implements MSIs */ + IRQ_DOMAIN_FLAG_MSI = (1 << 4), + + /* Irq domain implements MSI remapping */ + IRQ_DOMAIN_FLAG_MSI_REMAP = (1 << 5), + /* * Flags starting from IRQ_DOMAIN_FLAG_NONCORE are reserved * for implementation specific purposes and ignored by the @@ -446,6 +452,19 @@ static inline bool irq_domain_is_ipi_single(struct irq_domain *domain) { return domain->flags & IRQ_DOMAIN_FLAG_IPI_SINGLE; } + +static inline bool irq_domain_is_msi(struct irq_domain *domain) +{ + return domain->flags & IRQ_DOMAIN_FLAG_MSI; +} + +static inline bool irq_domain_is_msi_remap(struct irq_domain *domain) +{ + return domain->flags & IRQ_DOMAIN_FLAG_MSI_REMAP; +} + +extern bool irq_domain_hierarchical_is_msi_remap(struct irq_domain *domain); + #else /* CONFIG_IRQ_DOMAIN_HIERARCHY */ static inline void irq_domain_activate_irq(struct irq_data *data) { } static inline void irq_domain_deactivate_irq(struct irq_data *data) { } @@ -477,6 +496,22 @@ static inline bool irq_domain_is_ipi_single(struct irq_domain *domain) { return false; } + +static inline bool irq_domain_is_msi(struct irq_domain *domain) +{ + return false; +} + +static inline bool irq_domain_is_msi_remap(struct irq_domain *domain) +{ + return false; +} + +static inline bool +irq_domain_hierarchical_is_msi_remap(struct irq_domain *domain) +{ + return false; +} #endif /* CONFIG_IRQ_DOMAIN_HIERARCHY */ #else /* CONFIG_IRQ_DOMAIN */ -- cgit v1.2.3 From c7b41f0af38f53e46050b56a5b0e96710097b83c Mon Sep 17 00:00:00 2001 From: Eric Auger Date: Thu, 19 Jan 2017 20:57:59 +0000 Subject: irqdomain: irq_domain_check_msi_remap This new function checks whether all MSI irq domains implement IRQ remapping. This is useful to understand whether VFIO passthrough is safe with respect to interrupts. On ARM typically an MSI controller can sit downstream to the IOMMU without preventing VFIO passthrough. As such any assigned device can write into the MSI doorbell. In case the MSI controller implements IRQ remapping, assigned devices will not be able to trigger interrupts towards the host. On the contrary, the assignment must be emphasized as unsafe with respect to interrupts. Signed-off-by: Eric Auger Reviewed-by: Marc Zyngier Reviewed-by: Tomasz Nowicki Tested-by: Tomasz Nowicki Tested-by: Bharat Bhushan Signed-off-by: Will Deacon --- include/linux/irqdomain.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h index bc2f5719dace..188eced6813e 100644 --- a/include/linux/irqdomain.h +++ b/include/linux/irqdomain.h @@ -222,6 +222,7 @@ struct irq_domain *irq_domain_add_legacy(struct device_node *of_node, void *host_data); extern struct irq_domain *irq_find_matching_fwspec(struct irq_fwspec *fwspec, enum irq_domain_bus_token bus_token); +extern bool irq_domain_check_msi_remap(void); extern void irq_set_default_host(struct irq_domain *host); extern int irq_domain_alloc_descs(int virq, unsigned int nr_irqs, irq_hw_number_t hwirq, int node, -- cgit v1.2.3