On 25/01/2019 08:55, Auger Eric wrote: > Hi Jean-Philippe, > > On 1/25/19 9:39 AM, Auger Eric wrote: >> Hi Jean-Philippe, >> >> On 1/11/19 7:16 PM, Jean-Philippe Brucker wrote: >>> On 08/01/2019 10:26, Eric Auger wrote: >>>> 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/level (ARM/VTD terminology) while to host >>>> owns the stage/level 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 set the pasid table information. >>>> >>>> A generic iommu_pasid_table_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 two specializations of this struct, >>>> for PASID table passing and ARM SMMUv3. >>> >>> Last sentence is a bit confusing. With SMMUv3 it is also used for the >>> PASID table, even when it only has one entry and PASID is disabled. >> OK removed >>> >>>> 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/ >>>> >>>> v2 -> v3: >>>> - replace unbind/bind by set_pasid_table >>>> - move table pointer and pasid bits in the generic part of the struct >>>> >>>> v1 -> v2: >>>> - restore the original pasid table name >>>> - remove the struct device * parameter in the API >>>> - reworked iommu_pasid_smmuv3 >>>> --- >>>> drivers/iommu/iommu.c | 10 ++++++++ >>>> include/linux/iommu.h | 14 +++++++++++ >>>> include/uapi/linux/iommu.h | 50 ++++++++++++++++++++++++++++++++++++++ >>>> 3 files changed, 74 insertions(+) >>>> create mode 100644 include/uapi/linux/iommu.h >>>> >>>> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c >>>> index 3ed4db334341..0f2b7f1fc7c8 100644 >>>> --- a/drivers/iommu/iommu.c >>>> +++ b/drivers/iommu/iommu.c >>>> @@ -1393,6 +1393,16 @@ int iommu_attach_device(struct iommu_domain *domain, struct device *dev) >>>> } >>>> EXPORT_SYMBOL_GPL(iommu_attach_device); >>>> >>>> +int iommu_set_pasid_table(struct iommu_domain *domain, >>>> + struct iommu_pasid_table_config *cfg) >>>> +{ >>>> + if (unlikely(!domain->ops->set_pasid_table)) >>>> + return -ENODEV; >>>> + >>>> + return domain->ops->set_pasid_table(domain, cfg); >>>> +} >>>> +EXPORT_SYMBOL_GPL(iommu_set_pasid_table); >>>> + >>>> 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 e90da6b6f3d1..1da2a2357ea4 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) >>>> @@ -184,6 +185,7 @@ struct iommu_resv_region { >>>> * @domain_window_disable: Disable a particular window for a domain >>>> * @of_xlate: add OF master IDs to iommu grouping >>>> * @pgsize_bitmap: bitmap of all possible supported page sizes >>>> + * @set_pasid_table: set pasid table >>>> */ >>>> struct iommu_ops { >>>> bool (*capable)(enum iommu_cap); >>>> @@ -226,6 +228,9 @@ 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 (*set_pasid_table)(struct iommu_domain *domain, >>>> + struct iommu_pasid_table_config *cfg); >>>> + >>>> unsigned long pgsize_bitmap; >>>> }; >>>> >>>> @@ -287,6 +292,8 @@ 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_set_pasid_table(struct iommu_domain *domain, >>>> + struct iommu_pasid_table_config *cfg); >>>> extern struct iommu_domain *iommu_get_domain_for_dev(struct device *dev); >>>> extern struct iommu_domain *iommu_get_dma_domain(struct device *dev); >>>> extern int iommu_map(struct iommu_domain *domain, unsigned long iova, >>>> @@ -696,6 +703,13 @@ const struct iommu_ops *iommu_ops_from_fwnode(struct fwnode_handle *fwnode) >>>> return NULL; >>>> } >>>> >>>> +static inline >>>> +int iommu_set_pasid_table(struct iommu_domain *domain, >>>> + struct iommu_pasid_table_config *cfg) >>>> +{ >>>> + return -ENODEV; >>>> +} >>>> + >>>> #endif /* CONFIG_IOMMU_API */ >>>> >>>> #ifdef CONFIG_IOMMU_DEBUGFS >>>> diff --git a/include/uapi/linux/iommu.h b/include/uapi/linux/iommu.h >>>> new file mode 100644 >>>> index 000000000000..7a7cf7a3de7c >>>> --- /dev/null >>>> +++ b/include/uapi/linux/iommu.h >>>> @@ -0,0 +1,50 @@ >>>> +/* 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. >>> >>> I don't think we need both the boilerplate and the SPDX header >> OK I only kept the SPDX header. >>> >>>> + */ >>>> + >>>> +#ifndef _UAPI_IOMMU_H >>>> +#define _UAPI_IOMMU_H >>>> + >>>> +#include <linux/types.h> >>>> + >>>> +/** >>>> + * SMMUv3 Stream Table Entry stage 1 related information >>>> + * @abort: shall the STE lead to abort >>>> + * @s1fmt: STE s1fmt field as set by the guest >>>> + * @s1dss: STE s1dss as set by the guest >>>> + * All field names match the smmu 3.0/3.1 spec (ARM IHI 0070A) >>> >>> Not really the case for @abort. Could you clarify whether @abort is >>> valid in combination with @bypass? >>> abort corresponds to !Config[2]. In that case the spec says "report >> abort to device, no event recorded". S1 bypass corresponds to >> Config=0b1x0. What about removing abort in the SMMUv3 specific part and >> encode the stage state in the generic part. See below proposal ... >>>> + */ >>>> +struct iommu_pasid_smmuv3 { >>>> + __u8 abort; >>>> + __u8 s1fmt; >>>> + __u8 s1dss; >>>> +}; >>>> + >>>> +/** >>>> + * PASID table data used to bind guest PASID table to the host IOMMU >>>> + * Note PASID table corresponds to the Context Table on ARM SMMUv3. >>>> + * >>>> + * @version: API version to prepare for future extensions >>>> + * @format: format of the PASID table >>>> + * >>>> + */ >>>> +struct iommu_pasid_table_config { >>>> +#define PASID_TABLE_CFG_VERSION_1 1 >>>> + __u32 version; >>>> +#define IOMMU_PASID_FORMAT_SMMUV3 (1 << 0) >>>> + __u32 format; >>>> + __u64 base_ptr; >>>> + __u8 pasid_bits; >>>> + __u8 bypass >> #define IOMMU_PASID_STREAM_ABORT (1 << 0) >> #define IOMMU_PASID_STREAM_BYPASS (1 << 1) >> #define IOMMU_PASID_STREAM_TRANSLATE (1 << 2) >> __u8 config; > Sorry for the confusion, we don't want a bitfield here as those values > are exclusive. > > What about: > struct iommu_pasid_table_config { > #define PASID_TABLE_CFG_VERSION_1 1 > __u32 version; > #define IOMMU_PASID_FORMAT_SMMUV3 (1 << 0) > __u32 format; > __u64 base_ptr; > __u8 pasid_bits; > #define IOMMU_PASID_CONFIG_BYPASS 1 > #define IOMMU_PASID_CONFIG_ABORT 2 > #define IOMMU_PASID_CONFIG_TRANSLATE 3 Yes, this makes more sense :) > __u8 config; > __u8 padding[6]; > union { > struct iommu_pasid_smmuv3 smmuv3; > }; > }; Thanks, Jean > > Thanks > > Eric >>> >>> We need some padding, in case someone adds a new struct to the union >>> that requires 64-byte alignment >> OK >>> >>> And 'bypass' might not be the right name if we're making it common, >>> maybe 'reset' would be clearer? Or we just need to explain that bypass >>> is the initial state of a nesting domain >> I will add such comment. To me the "bypass" terminology sounds clearer >> than "reset" >>> >>> Thanks, >>> Jean >>> >>>> + union { >>>> + struct iommu_pasid_smmuv3 smmuv3; >>>> + }; >>>> +}; >>>> + >>>> +#endif /* _UAPI_IOMMU_H */ >>>> >>> _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
