[PATCH 0/3] Add bypass mode support to assigned device

[Zhenzhong Duan]

Currently virtio-iommu's logic to support bypass mode works only for
emulated device. For assigned device, no GPA -> HPA mapping is setup
in IOMMU page table.

Host report below error:
[3713481.750944] dmar_fault: 191 callbacks suppressed
[3713481.750953] DMAR: DRHD: handling fault status reg 302
[3713481.750962] DMAR: [DMA Read NO_PASID] Request device [2f:00.1] fault addr 
0x7ebb0000 [fault reason 0x06] PTE Read access is not set
[3713481.751003] DMAR: DRHD: handling fault status reg 402
[3713481.751007] DMAR: [DMA Read NO_PASID] Request device [2f:00.1] fault addr 
0x7ebb0000 [fault reason 0x06] PTE Read access is not set
[3713481.751023] DMAR: DRHD: handling fault status reg 502
[3713481.751026] DMAR: [DMA Write NO_PASID] Request device [2f:00.1] fault addr 
0x7ebb0000 [fault reason 0x05] PTE Write access is not set
[3713481.751072] DMAR: DRHD: handling fault status reg 602

Guest kernel report below error:
[    3.461716] i40e: Intel(R) Ethernet Connection XL710 Network Driver
[    3.462605] i40e: Copyright (c) 2013 - 2019 Intel Corporation.
[    3.464630] i40e 0000:00:04.0: Adding to iommu group 5
[    3.482093] i40e 0000:00:04.0: fw 0.0.00000 api 0.0 nvm 0.00 0x176953ce 
28.50.1 [8086:37d3] [8086:35d0]
[    3.484295] i40e 0000:00:04.0: eeprom check failed (-62), Tx/Rx traffic 
disabled
[    3.487268] i40e 0000:00:04.0: configure_lan_hmc failed: -49
[    3.489066] i40e: probe of 0000:00:04.0 failed with error -2

Fix it by adding switch beween bypass and iommu address space just like
the virtual VT-d implementation, so that in bypass mode, vfio mapping
is setup.

Tested with four combination of qemu's virtio-iommu.boot-bypass=true/false
with guest kernel's iommu=pt/nopt on x86_64 platform.

Zhenzhong Duan (3):
  virtio-iommu: Add bypass mode support to assigned device
  virtio-iommu: Use recursive lock to avoid deadlock
  virtio-iommu: Add an assert check in translate routine

 hw/virtio/trace-events           |   1 +
 hw/virtio/virtio-iommu.c         | 135 ++++++++++++++++++++++++++++---
 include/hw/virtio/virtio-iommu.h |   4 +-
 3 files changed, 130 insertions(+), 10 deletions(-)

-- 
2.25.1