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Message-ID: <51AD7AC0.6020303@amd.com> Date: Tue, 4 Jun 2013 00:27:28 -0500 From: Suravee Suthikulpanit <suravee.suthikulpanit@....com> To: <suravee.suthikulpanit@....com> CC: <iommu@...ts.linux-foundation.org>, <joro@...tes.org>, <ddutile@...hat.com>, <alex.williamson@...hat.com>, <linux-kernel@...r.kernel.org> Subject: Re: [PATCH 0/3] iommu/amd: IOMMU Error Reporting/Handling/Filtering Ping On 5/22/2013 2:15 PM, suravee.suthikulpanit@....com wrote: > From: Suravee Suthikulpanit <suravee.suthikulpanit@....com> > > This patch set implements framework for handling errors reported via IOMMU > event log. It also implements mechanism to filter/suppress error messages when > IOMMU hardware generates large amount event logs, which is often caused by > devices performing invalid operations or from misconfiguring IOMMU hardware > (e.g. IO_PAGE_FAULT and INVALID_DEVICE_QEQUEST"). > > DEVICE vs IOMMU ERRORS: > ======================= > Event types in AMD IOMMU event log can be categorized as: > - IOMMU error : An error which is specific to IOMMU hardware > - Device error: An error which is specific to a device > - Non-error : Miscelleneous events which are not classified as errors. > This patch set implements frameworks for handling "IOMMU error" and "device error". > For IOMMU error, the driver will log the event in dmesg and panic since the IOMMU > hardware is no longer functioning. For device error, the driver will decode and > log the error in dmesg based on the error logging level specified at boot time. > > ERROR LOGGING LEVEL: > ==================== > The filtering framework introduce 3 levels of event logging, > "AMD_IOMMU_LOG_[DEFAULT|VERBOSE|DEBUG]". Users can specify the level > via a new boot option "amd_iommu_log=[default|verbose|debug]". > - default: Each error message is truncated. Filtering is enabled. > - verbose: Output detail error message. Filtering is enabled. > - debug : Output detail error message. Filtering is disabled. > > ERROR THRESHOLD LEVEL: > ====================== > Error threshold is used by the log filtering logic to determine when to suppress > the errors from a particular device. The threshold is defined as "the number of errors > (X) over a specified period (Y sec)". When the threshold is reached, IOMMU driver will > suppress subsequent error messages from the device for a predefined period (Z sec). > X, Y, and Z is currently hard-coded to 10 errors, 5 sec, and 30 sec. > > DATA STRUCTURE: > =============== > A new structure "struct dte_err_info" is added. It contains error information > specific to each device table entry (DTE). The structure is allocated dynamically > per DTE when IOMMU driver handle device error for the first time. > > ERROR STATES and LOG FILTERING: > ============================================ > The filtering framework define 3 device error states "NONE", "PROBATION" and "SUPPRESS". > 1. From IOMMU driver intialization, all devices are in DEV_ERR_NONE state. > 2. During interupt handling, IOMMU driver processes each entry in the event log. > 3. If an entry is device error, the driver tags DTE with DEV_ERR_PROBATION and > report error via via dmesg. > 4. For non-debug mode, if the device threshold is reached, the device is moved into > DEV_ERR_SUPPRESS state in which all error messages are suppressed. > 5. After the suppress period has passed, the driver put the device in probation state, > and errors are reported once again. If the device continues to generate errors, > it will be re-suppress once the next threshold is reached. > > EXAMPLE OUTPUT: > =============== > AMD-Vi: Event=IO_PAGE_FAULT dev=3:0.0 dom=0x1b addr=0x97040 flg=N Ex Sup M P W Pm Ill Ta > AMD-Vi: Event=IO_PAGE_FAULT dev=3:0.0 dom=0x1b addr=0x97070 flg=N Ex Sup M P W Pm Ill Ta > AMD-Vi: Event=IO_PAGE_FAULT dev=3:0.0 dom=0x1b addr=0x97060 flg=N Ex Sup M P W Pm Ill Ta > AMD-Vi: Event=IO_PAGE_FAULT dev=3:0.0 dom=0x1b addr=0x4970 flg=N Ex Sup M P W Pm Ill Ta > AMD-Vi: Event=IO_PAGE_FAULT dev=3:0.0 dom=0x1b addr=0x98840 flg=N Ex Sup M P W Pm Ill Ta > AMD-Vi: Event=IO_PAGE_FAULT dev=3:0.0 dom=0x1b addr=0x98870 flg=N Ex Sup M P W Pm Ill Ta > AMD-Vi: Event=IO_PAGE_FAULT dev=3:0.0 dom=0x1b addr=0x98860 flg=N Ex Sup M P W Pm Ill Ta > AMD-Vi: Event=IO_PAGE_FAULT dev=3:0.0 dom=0x1b addr=0x4980 flg=N Ex Sup M P W Pm Ill Ta > AMD-Vi: Event=IO_PAGE_FAULT dev=3:0.0 dom=0x1b addr=0x99040 flg=N Ex Sup M P W Pm Ill Ta > AMD-Vi: Event=IO_PAGE_FAULT dev=3:0.0 dom=0x1b addr=0x99060 flg=N Ex Sup M P W Pm Ill Ta > AMD-Vi: Warning: IOMMU error threshold (10) reached for device=3:0.0. Suppress for 30 secs.!!! > > Suravee Suthikulpanit (3): > iommu/amd: Adding amd_iommu_log cmdline option > iommu/amd: Add error handling/reporting/filtering logic > iommu/amd: Remove old event printing logic > > Documentation/kernel-parameters.txt | 10 + > drivers/iommu/Makefile | 2 +- > drivers/iommu/amd_iommu.c | 85 +------- > drivers/iommu/amd_iommu_fault.c | 368 +++++++++++++++++++++++++++++++++++ > drivers/iommu/amd_iommu_init.c | 19 ++ > drivers/iommu/amd_iommu_proto.h | 6 + > drivers/iommu/amd_iommu_types.h | 16 ++ > 7 files changed, 426 insertions(+), 80 deletions(-) > create mode 100644 drivers/iommu/amd_iommu_fault.c > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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