Hi Jean, On 1/11/19 12:06 PM, Jean-Philippe Brucker wrote: > On 10/01/2019 18:45, Jacob Pan wrote: >> On Tue, 8 Jan 2019 11:26:26 +0100 >> Eric Auger <eric.auger@xxxxxxxxxx> wrote: >> >>> From: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx> >>> >>> Device faults detected by IOMMU can be reported outside IOMMU >>> subsystem for further processing. This patch intends to provide >>> a generic device fault data such that device drivers can be >>> communicated with IOMMU faults without model specific knowledge. >>> >>> The proposed format is the result of discussion at: >>> https://lkml.org/lkml/2017/11/10/291 >>> Part of the code is based on Jean-Philippe Brucker's patchset >>> (https://patchwork.kernel.org/patch/9989315/). >>> >>> The assumption is that model specific IOMMU driver can filter and >>> handle most of the internal faults if the cause is within IOMMU driver >>> control. Therefore, the fault reasons can be reported are grouped >>> and generalized based common specifications such as PCI ATS. >>> >>> Signed-off-by: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx> >>> 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: Eric Auger <eric.auger@xxxxxxxxxx> >>> [moved part of the iommu_fault_event struct in the uapi, enriched >>> the fault reasons to be able to map unrecoverable SMMUv3 errors] >>> --- >>> include/linux/iommu.h | 55 ++++++++++++++++++++++++- >>> include/uapi/linux/iommu.h | 83 >>> ++++++++++++++++++++++++++++++++++++++ 2 files changed, 136 >>> insertions(+), 2 deletions(-) >>> >>> diff --git a/include/linux/iommu.h b/include/linux/iommu.h >>> index 244c1a3d5989..1dedc2d247c2 100644 >>> --- a/include/linux/iommu.h >>> +++ b/include/linux/iommu.h >>> @@ -49,13 +49,17 @@ struct bus_type; >>> struct device; >>> struct iommu_domain; >>> struct notifier_block; >>> +struct iommu_fault_event; >>> >>> /* iommu fault flags */ >>> -#define IOMMU_FAULT_READ 0x0 >>> -#define IOMMU_FAULT_WRITE 0x1 >>> +#define IOMMU_FAULT_READ (1 << 0) >>> +#define IOMMU_FAULT_WRITE (1 << 1) >>> +#define IOMMU_FAULT_EXEC (1 << 2) >>> +#define IOMMU_FAULT_PRIV (1 << 3) >>> >>> typedef int (*iommu_fault_handler_t)(struct iommu_domain *, >>> struct device *, unsigned long, int, void *); >>> +typedef int (*iommu_dev_fault_handler_t)(struct iommu_fault_event *, >>> void *); >>> struct iommu_domain_geometry { >>> dma_addr_t aperture_start; /* First address that can be >>> mapped */ @@ -255,6 +259,52 @@ struct iommu_device { >>> struct device *dev; >>> }; >>> >>> +/** >>> + * struct iommu_fault_event - Generic per device fault data >>> + * >>> + * - PCI and non-PCI devices >>> + * - Recoverable faults (e.g. page request), information based on >>> PCI ATS >>> + * and PASID spec. >>> + * - Un-recoverable faults of device interest >>> + * - DMA remapping and IRQ remapping faults >>> + * >>> + * @fault: fault descriptor >>> + * @device_private: if present, uniquely identify device-specific >>> + * private data for an individual page request. >>> + * @iommu_private: used by the IOMMU driver for storing >>> fault-specific >>> + * data. Users should not modify this field before >>> + * sending the fault response. >>> + */ >>> +struct iommu_fault_event { >>> + struct iommu_fault fault; >>> + u64 device_private; >> I think we want to move device_private to uapi since it gets injected >> into the guest, then returned by guest in case of page response. For >> VT-d we also need 128 bits of private data. VT-d spec. 7.7.1 > > Ah, I didn't notice the format changed in VT-d rev3. On that topic, how > do we manage future extensions to the iommu_fault struct? Should we add > ~48 bytes of padding after device_private, along with some flags telling > which field is valid, or deal with it using a structure version like we > do for the invalidate and bind structs? In the first case, iommu_fault > wouldn't fit in a 64-byte cacheline anymore, but I'm not sure we care. > >> For exception tracking (e.g. unanswered page request), I can add timer >> and list info later when I include PRQ. sounds ok? >>> + u64 iommu_private; > [...] >>> +/** >>> + * struct iommu_fault - Generic fault data >>> + * >>> + * @type contains fault type >>> + * @reason fault reasons if relevant outside IOMMU driver. >>> + * IOMMU driver internal faults are not reported. >>> + * @addr: tells the offending page address >>> + * @fetch_addr: tells the address that caused an abort, if any >>> + * @pasid: contains process address space ID, used in shared virtual >>> memory >>> + * @page_req_group_id: page request group index >>> + * @last_req: last request in a page request group >>> + * @pasid_valid: indicates if the PRQ has a valid PASID >>> + * @prot: page access protection flag: >>> + * IOMMU_FAULT_READ, IOMMU_FAULT_WRITE >>> + */ >>> + >>> +struct iommu_fault { >>> + __u32 type; /* enum iommu_fault_type */ >>> + __u32 reason; /* enum iommu_fault_reason */ >>> + __u64 addr; >>> + __u64 fetch_addr; >>> + __u32 pasid; >>> + __u32 page_req_group_id; >>> + __u32 last_req; >>> + __u32 pasid_valid; >>> + __u32 prot; >>> + __u32 access; > > What does @access contain? Can it be squashed into @prot? it was related to F_ACCESS event record and was a placeholder for reporting access attributes of the input transaction (Rnw, InD, PnU fields). But I wonder whether this is needed to implement such fine level fault reporting. Do we really care? Thanks Eric > > Thanks, > Jean > >> relocated to uapi, Yi can you confirm? >> __u64 device_private[2]; >> >>> +}; >>> #endif /* _UAPI_IOMMU_H */ >> >> _______________________________________________ >> iommu mailing list >> iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx >> https://lists.linuxfoundation.org/mailman/listinfo/iommu >> >
