[RFC PATCH v2 0/8] ACPI/IORT: Support for IORT RMR node
Auger Eric
eric.auger at redhat.com
Thu Apr 15 10:48:57 BST 2021
Hi Shameer,
+ Jean-Philippe
On 11/19/20 1:11 PM, Shameer Kolothum wrote:
> RFC v1 --> v2:
> - Added a generic interface for IOMMU drivers to retrieve all the
> RMR info associated with a given IOMMU.
> - SMMUv3 driver gets the RMR list during probe() and installs
> bypass STEs for all the SIDs in the RMR list. This is to keep
> the ongoing traffic alive(if any) during SMMUv3 reset. This is
> based on the suggestions received for v1 to take care of the
> EFI framebuffer use case. Only sanity tested for now.
> - During the probe/attach device, SMMUv3 driver reserves any
> RMR region associated with the device such that there is a unity
> mapping for them in SMMU.
> ---
>
> The series adds support to IORT RMR nodes specified in IORT
> Revision E -ARM DEN 0049E[0]. RMR nodes are used to describe memory
> ranges that are used by endpoints and require a unity mapping
> in SMMU.
>
> We have faced issues with 3408iMR RAID controller cards which
> fail to boot when SMMU is enabled. This is because these controllers
> make use of host memory for various caching related purposes and when
> SMMU is enabled the iMR firmware fails to access these memory regions
> as there is no mapping for them. IORT RMR provides a way for UEFI to
> describe and report these memory regions so that the kernel can make
> a unity mapping for these in SMMU.
>
> RFC because, Patch #1 is to update the actbl2.h and should be done
> through acpica update. I have send out a pull request[1] for that.
>
> Tests:
>
> With a UEFI, that reports the RMR for the dev,
> ....
> [16F0h 5872 1] Type : 06
> [16F1h 5873 2] Length : 007C
> [16F3h 5875 1] Revision : 00
> [1038h 0056 2] Reserved : 00000000
> [1038h 0056 2] Identifier : 00000000
> [16F8h 5880 4] Mapping Count : 00000001
> [16FCh 5884 4] Mapping Offset : 00000040
>
> [1700h 5888 4] Number of RMR Descriptors : 00000002
> [1704h 5892 4] RMR Descriptor Offset : 00000018
>
> [1708h 5896 8] Base Address of RMR : 0000E6400000
> [1710h 5904 8] Length of RMR : 000000100000
> [1718h 5912 4] Reserved : 00000000
>
> [171Ch 5916 8] Base Address of RMR : 0000000027B00000
> [1724h 5924 8] Length of RMR : 0000000000C00000
> [172Ch 5932 4] Reserved : 00000000
>
> [1730h 5936 4] Input base : 00000000
> [1734h 5940 4] ID Count : 00000001
> [1738h 5944 4] Output Base : 00000003
> [173Ch 5948 4] Output Reference : 00000064
> [1740h 5952 4] Flags (decoded below) : 00000001
> Single Mapping : 1
Following Jean-Philippe's suggestion I have used your series for nested
stage SMMUv3 integration, ie. to simplify the MSI nested stage mapping.
Host allocates hIOVA -> physical doorbell (pDB) as it normally does for
VFIO device passthrough. IOVA Range is 0x8000000 - 0x8100000.
I expose this MIS IOVA range to the guest as an RMR and as a result
guest has a flat mapping for this range. As the physical device is
programmed with hIOVA we have the following mapping:
IOVA IPA PA
hIOVA -> hIOVA -> pDB
S1 s2
This works.
The only weird thing is that I need to expose 256 RMRs due to the
'Single Mapping' mandatory flag. I need to have 1 RMR per potential SID
on the bus.
I will post a new version of SMMUv3 nested stage soon for people to test
& compare. Obviously this removes a bunch of code on both SMMU/VFIO and
QEMU code so I think this solution looks better overall.
Thanks
Eric
> ...
>
> Without the series the RAID controller initialization fails as
> below,
>
> ...
> [ 12.631117] megaraid_sas 0000:03:00.0: FW supports sync cache : Yes
> [ 12.637360] megaraid_sas 0000:03:00.0: megasas_disable_intr_fusion is called outbound_intr_mask:0x40000009
> [ 18.776377] megaraid_sas 0000:03:00.0: Init cmd return status FAILED for SCSI host 0
> [ 23.019383] megaraid_sas 0000:03:00.0: Waiting for FW to come to ready state
> [ 106.684281] megaraid_sas 0000:03:00.0: FW in FAULT state, Fault code:0x10000 subcode:0x0 func:megasas_transition_to_ready
> [ 106.695186] megaraid_sas 0000:03:00.0: System Register set:
> [ 106.889787] megaraid_sas 0000:03:00.0: Failed to transition controller to ready for scsi0.
> [ 106.910475] megaraid_sas 0000:03:00.0: Failed from megasas_init_fw 6407
> estuary:/$
>
> With the series, now the kernel has direct mapping for the dev as
> below,
>
> estuary:/$ cat /sys/kernel/iommu_groups/0/reserved_regions
> 0x0000000008000000 0x00000000080fffff msi
> 0x0000000027b00000 0x00000000286fffff direct
> 0x00000000e6400000 0x00000000e64fffff direct
> estuary:/$
>
> ....
> [ 12.254318] megaraid_sas 0000:03:00.0: megasas_disable_intr_fusion is called outbound_intr_mask:0x40000009
> [ 12.739089] megaraid_sas 0000:03:00.0: FW provided supportMaxExtLDs: 0 max_lds: 32
> [ 12.746628] megaraid_sas 0000:03:00.0: controller type : iMR(0MB)
> [ 12.752694] megaraid_sas 0000:03:00.0: Online Controller Reset(OCR) : Enabled
> [ 12.759798] megaraid_sas 0000:03:00.0: Secure JBOD support : Yes
> [ 12.765778] megaraid_sas 0000:03:00.0: NVMe passthru support : Yes
> [ 12.771931] megaraid_sas 0000:03:00.0: FW provided TM TaskAbort/Reset timeou: 6 secs/60 secs
> [ 12.780503] megaraid_sas 0000:03:00.0: JBOD sequence map support : Yes
> [ 12.787000] megaraid_sas 0000:03:00.0: PCI Lane Margining support : No
> [ 12.819179] megaraid_sas 0000:03:00.0: NVME page size : (4096)
> [ 12.825672] megaraid_sas 0000:03:00.0: megasas_enable_intr_fusion is called outbound_intr_mask:0x40000000
> [ 12.835199] megaraid_sas 0000:03:00.0: INIT adapter done
> [ 12.873932] megaraid_sas 0000:03:00.0: pci id : (0x1000)/(0x0017)/(0x19e5)/(0xd213)
> [ 12.881644] megaraid_sas 0000:03:00.0: unevenspan support : no
> [ 12.887451] megaraid_sas 0000:03:00.0: firmware crash dump : no
> [ 12.893344] megaraid_sas 0000:03:00.0: JBOD sequence map : enabled
>
> RAID controller init is now success and can detect the drives
> attached as well.
>
> Thanks,
> Shameer
>
> [0]. https://developer.arm.com/documentation/den0049/latest/
> [1]. https://github.com/acpica/acpica/pull/638
>
> Shameer Kolothum (8):
> ACPICA: IORT: Update for revision E
> ACPI/IORT: Add support for RMR node parsing
> iommu/dma: Introduce generic helper to retrieve RMR info
> ACPI/IORT: Add RMR memory regions reservation helper
> iommu/arm-smmu-v3: Introduce strtab init helper
> iommu/arm-smmu-v3: Add bypass flag to arm_smmu_write_strtab_ent()
> iommu/arm-smmu-v3: Get associated RMR info and install bypass STE
> iommu/arm-smmu-v3: Reserve any RMR regions associated with a dev
>
> drivers/acpi/arm64/iort.c | 182 +++++++++++++++++++-
> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 112 ++++++++++--
> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 2 +
> drivers/iommu/dma-iommu.c | 39 +++++
> include/acpi/actbl2.h | 25 ++-
> include/linux/acpi_iort.h | 6 +
> include/linux/dma-iommu.h | 7 +
> include/linux/iommu.h | 16 ++
> 8 files changed, 367 insertions(+), 22 deletions(-)
>
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