Hi Yi Liu, On 08/24/2018 02:53 PM, Liu, Yi L wrote: > Hi Eric, > >> From: iommu-bounces@xxxxxxxxxxxxxxxxxxxxxxxxxx [mailto:iommu- >> bounces@xxxxxxxxxxxxxxxxxxxxxxxxxx] On Behalf Of Eric Auger >> Sent: Thursday, August 23, 2018 8:17 PM >> Subject: [RFC 01/13] iommu: Introduce bind_guest_stage API >> >> From: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx> >> >> In virtualization use case, when a guest is assigned >> a PCI host device, protected by a virtual IOMMU on a guest, >> the physical IOMMU must be programmed to be consistent with >> the guest mappings. If the physical IOMMU supports two >> translation stages it makes sense to program guest mappings >> onto the first stage while to host owns the stage 2. >> >> In that case, it is mandated to trap on guest configuration >> settings and pass those to the physical iommu driver. >> >> This patch adds a new API to the iommu subsystem that allows >> to bind and unbind the guest configuration data to the host. >> >> A generic iommu_guest_stage_config struct is introduced in >> a new iommu.h uapi header. This is going to be used by the VFIO >> user API. We foresee at least 2 specialization of this struct, >> for PASID table passing and ARM SMMUv3. >> >> Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@xxxxxxx> >> Signed-off-by: Liu, Yi L <yi.l.liu@xxxxxxxxxxxxxxx> >> Signed-off-by: Ashok Raj <ashok.raj@xxxxxxxxx> >> Signed-off-by: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx> >> Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx> >> >> --- >> >> This patch generalizes the API introduced by Jacob & co-authors in >> https://lwn.net/Articles/754331/ >> --- >> drivers/iommu/iommu.c | 19 +++++++++++++++ >> include/linux/iommu.h | 23 ++++++++++++++++++ >> include/uapi/linux/iommu.h | 59 >> ++++++++++++++++++++++++++++++++++++++++++++++ >> 3 files changed, 101 insertions(+) >> create mode 100644 include/uapi/linux/iommu.h >> >> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c >> index 63b3756..5156172 100644 >> --- a/drivers/iommu/iommu.c >> +++ b/drivers/iommu/iommu.c >> @@ -1326,6 +1326,25 @@ int iommu_attach_device(struct iommu_domain >> *domain, struct device *dev) >> } >> EXPORT_SYMBOL_GPL(iommu_attach_device); >> >> +int iommu_bind_guest_stage(struct iommu_domain *domain, struct device *dev, >> + struct iommu_guest_stage_config *cfg) >> +{ >> + if (unlikely(!domain->ops->bind_guest_stage)) >> + return -ENODEV; >> + >> + return domain->ops->bind_guest_stage(domain, dev, cfg); >> +} >> +EXPORT_SYMBOL_GPL(iommu_bind_guest_stage); >> + >> +void iommu_unbind_guest_stage(struct iommu_domain *domain, struct device >> *dev) >> +{ >> + if (unlikely(!domain->ops->unbind_guest_stage)) >> + return; >> + >> + domain->ops->unbind_guest_stage(domain, dev); >> +} >> +EXPORT_SYMBOL_GPL(iommu_unbind_guest_stage); >> + >> static void __iommu_detach_device(struct iommu_domain *domain, >> struct device *dev) >> { >> diff --git a/include/linux/iommu.h b/include/linux/iommu.h >> index 19938ee..aec853d 100644 >> --- a/include/linux/iommu.h >> +++ b/include/linux/iommu.h >> @@ -25,6 +25,7 @@ >> #include <linux/errno.h> >> #include <linux/err.h> >> #include <linux/of.h> >> +#include <uapi/linux/iommu.h> >> >> #define IOMMU_READ (1 << 0) >> #define IOMMU_WRITE (1 << 1) >> @@ -187,6 +188,8 @@ struct iommu_resv_region { >> * @domain_get_windows: Return the number of windows for a domain >> * @of_xlate: add OF master IDs to iommu grouping >> * @pgsize_bitmap: bitmap of all possible supported page sizes >> + * @bind_guest_stage: program the guest stage configuration >> + * @unbind_guest_stage: unbind the guest stage and restore defaults >> */ >> struct iommu_ops { >> bool (*capable)(enum iommu_cap); >> @@ -235,6 +238,11 @@ struct iommu_ops { >> int (*of_xlate)(struct device *dev, struct of_phandle_args *args); >> bool (*is_attach_deferred)(struct iommu_domain *domain, struct device >> *dev); >> >> + int (*bind_guest_stage)(struct iommu_domain *domain, struct device *dev, >> + struct iommu_guest_stage_config *cfg); >> + void (*unbind_guest_stage)(struct iommu_domain *domain, >> + struct device *dev); >> + >> unsigned long pgsize_bitmap; >> }; >> >> @@ -296,6 +304,10 @@ extern int iommu_attach_device(struct iommu_domain >> *domain, >> struct device *dev); >> extern void iommu_detach_device(struct iommu_domain *domain, >> struct device *dev); >> +extern int iommu_bind_guest_stage(struct iommu_domain *domain, >> + struct device *dev, struct iommu_guest_stage_config *cfg); >> +extern void iommu_unbind_guest_stage(struct iommu_domain *domain, >> + struct device *dev); >> extern struct iommu_domain *iommu_get_domain_for_dev(struct device *dev); >> extern int iommu_map(struct iommu_domain *domain, unsigned long iova, >> phys_addr_t paddr, size_t size, int prot); >> @@ -696,6 +708,17 @@ const struct iommu_ops *iommu_ops_from_fwnode(struct >> fwnode_handle *fwnode) >> return NULL; >> } >> >> +static inline >> +int iommu_bind_guest_stage(struct iommu_domain *domain, struct device *dev, >> + struct iommu_guest_stage_config *cfg) >> +{ >> + return -ENODEV; >> +} >> +static inline >> +void iommu_unbind_guest_stage(struct iommu_domain *domain, struct device >> *dev) >> +{ >> +} >> + >> #endif /* CONFIG_IOMMU_API */ >> >> #endif /* __LINUX_IOMMU_H */ >> diff --git a/include/uapi/linux/iommu.h b/include/uapi/linux/iommu.h >> new file mode 100644 >> index 0000000..2d1593c >> --- /dev/null >> +++ b/include/uapi/linux/iommu.h >> @@ -0,0 +1,59 @@ >> +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ >> +/* >> + * IOMMU user API definitions >> + * >> + * >> + * This program is free software; you can redistribute it and/or modify >> + * it under the terms of the GNU General Public License version 2 as >> + * published by the Free Software Foundation. >> + */ >> + >> +#ifndef _UAPI_IOMMU_H >> +#define _UAPI_IOMMU_H >> + >> +#include <linux/types.h> >> + >> +/** >> + * PASID table data used to bind guest PASID table to the host IOMMU. This will >> + * enable guest managed first level page tables. >> + * @version: for future extensions and identification of the data format >> + * @bytes: size of this structure >> + * @base_ptr: PASID table pointer >> + * @pasid_bits: number of bits supported in the guest PASID table, must be >> less >> + * or equal than the host supported PASID size. >> + */ >> +struct iommu_pasid_table_config { >> + __u32 version; >> +#define PASID_TABLE_CFG_VERSION_1 1 >> + __u32 bytes; >> + __u64 base_ptr; >> + __u8 pasid_bits; >> +}; >> + >> +/** >> + * Stream Table Entry S1 info >> + * @disabled: the smmu is disabled >> + * @bypassed: stage 1 is bypassed >> + * @aborted: aborted >> + * @cdptr_dma: GPA of the Context Descriptor >> + * @asid: address space identified associated to the CD >> + */ >> +struct iommu_smmu_s1_config { >> + __u8 disabled; >> + __u8 bypassed; >> + __u8 aborted; >> + __u64 cdptr_dma; > > If I'm getting it correctly, so with cdptr_dma configed on > host, hardware can access guest's CD table when nested > stage is setup on host. Is it? If yes, I think it is similar with > the base_ptr field in struct iommu_pasid_table_config. Yes you're right, this is similar to base_ptr. Thanks Eric > >> + __u16 asid; >> +}; >> + >> +struct iommu_guest_stage_config { >> +#define PASID_TABLE (1 << 0) >> +#define SMMUV3_S1_CFG (1 << 1) >> + __u32 flags; >> + union { >> + struct iommu_pasid_table_config pasidt; >> + struct iommu_smmu_s1_config smmu_s1; >> + }; >> +}; >> + >> +#endif /* _UAPI_IOMMU_H */ > > Thanks, > Yi Liu >
