[Qemu-devel] [PATCH v6 00/26] IOMMU: Enable interrupt remapping for Intel IOMMU

[Peter Xu]

Hi, all,

This is v6 for Intel IOMMU IR support. This series introduced quite
a few new patches based on v5. Sorry for that (Yes, Jan is
contributing to it as well, though most of which are really good
ideas for me :). Hopefully we can get its convergence in this
version.

To make the review easier, I tried to keep all the existing patches
and indexes (also, this is easier for me too to do the
modifications, and logically I feel this make more sense and clean,
please let me know if I am wrong). Patches 1-18 are v5 patches, and
patches 19-26 are newly added patches.

All the new patches may need more review, many of them are outside
Intel IOMMU scope, and touching other part of codes, which I am
still not very sure about.

Testing is only covering basic smoke test for the following matrix:

- IR enabled/disable
- kernel irqchip off/split
- network device: tap with/without vhost, e1000

Here's the change log. Please review. Thanks,

v6 changes:
- patch 10: use write_with_attrs() rather than write(), preparing
  for SID verification [Jan]
- patch 17-18: add r-b line from Radim [Radim]
- new patch 19: put together Jan's EIM patch [Jan]
- new patch 20: add SID validation process
- new patch 21-22: introduce X86IOMMU class, which is the parent of
  IntelIOMMU class. Patch 21 only introduce the class and did
  nothing, patch 22 cleaned up all the vtd_*() hooks into x86
  ones. This is only a start. In the future, we can abstract more
  things into X86IOMMU class, like iotlb, address spaces mgmt,
  etc. [Jan]
- new patch 23-25: this is to do IEC notify to all irqfd consumers
  like vhost/vfio. patch 23 changed interface for
  kvm_irqchip_add_msi_route(), provide vector info rather than a raw
  MSI message. Patch 24 added new hooks to do arch-specific
  notification on addition/deletion of msi routes. Patch 25 is x86
  specific, which added one more IEC notifier for msi routes. [Jan]
- new patch 26: this is to partially solve the issue that Jan has
  encountered (1 sec delay when invalidating IR cache).

v5 changes:
- patch 10: add vector checking for IOAPIC interrupts (this may help
  debug in the future, will only generate warning if specify
  IOMMU_DEBUG)
- patch 13: replace error_report() with a trace. [Jan]
- patch 14: rename parameter "intr" to "intremap", to be aligned
  with kernel parameter [Jan]
- patch 15: fix comments for vtd_iec_notify_fn
- patch 17 & 18 (added): fix issue when IR enabled with devices
  using level-triggered interrupts, like e1000. Adding it to the end
  of series, since this issue never happen without IR.

  Patch 17 adds read-only check for IOAPIC entries.
  Patch 18 clears remote IRR bit when entry configured as
  edge-triggered.

v4 changes (all patch number corresponds to v3):
- add one patch at the start of v3 series: I missed to send the
  first patch in v3. adding it in. [Jan]
- patch 9: add support for compatible mode (no reason not to support
  it, if not, we will get some warnings when using split irqchip)
- patch 11: further simplify ioapic_update_kvm_routes() using the
  helper function.
- patch 12: tweak on kvm_arch_fixup_msi_route() rather than
  ioapic_update_kvm_routes() only. [Radim]
- add patch 15: introduce IEC (Interrupt Entry Cache) invalidation
  notifier list. We can register to this list if we want to be
  notified when we got IR invalidation requests [Radim]
- add patch 16: let IOAPIC the first consumer for the above IEC
  notifier list. [Radim]
- several other trivial fixes (like moving some defines from .c to
  .h, moving several lines of changes from one patch to another to
  make it make more sense, etc.)

v3 changes (all patch numbers corresponds to v2):
- patch 1 (-> v3 patch 13)
  - move to the end of series [Alex]
- patch 10 (dropped)
  - drop this one, since re-worked on IOAPIC support, so we do not
    need this any more.
- patch 12 (-> v3 patch 10)
  - leverage MSI path for IOAPIC IR [Jan]
- patch 13 (v3 -> patch 9)
  - remove vtd_interrupt_remap_msi() declaration by reordering the
    functions [mst]
  - vtd_generate_msi_message(): init msg using {}, remove FIXME
    [mst]
- new patches
  - v3 patch 11: introduce ioapic_entry_parse() helper function
  - v3 patch 12: add support for kernel-irqchip=split. This needs
    more reviews, logically this should enable lots of things:
        splitted irqchip, irqfd, vhost, and irqfd support for
        passthrough devices (not tested). Please refer to the patch for
        more information.

v2 changes:
- patch 1
  - rename "int_remap" to "intr" in several places [Marcel]
  - remove "Intel" specific words in desc or commit message, prepare
    itself with further AMD support [Marcel]
  - avoid using object_property_get_bool() [Marcel]
- patch 5
  - use PCI bus number 0xff rather than 0xf0 for the IOAPIC scope
    definition. (please let me know if anyone knows how I can avoid
        user using PCI bus number 0xff... TIA)
- patch 11
  - fix comments [Marcel]
- all
  - remove intr_supported variable [Marcel]

This patchset provide very basic functionalities for interrupt
remapping (IR) support of the emulated Intel IOMMU device.

By default, IR is disabled to be better compatible with current
QEMU. To enable IR, we can using the following command to boot a
IR-supported VM with virtio-net device with vhost (still do not
support kvm-ioapic, so we need to specify kernel-irqchip={split|off}
here):

$ qemu-system-x86_64 -M q35,iommu=on,intr=on,kernel-irqchip=split \
     -enable-kvm -m 1024 \
         -netdev tap,id=net0,vhost=on \
     -device virtio-net-pci,netdev=user.0 \
     -monitor telnet::3333,server,nowait \
         /var/lib/libvirt/images/vm1.qcow2

When guest boots, we can verify whether IR enabled by grepping the
dmesg like:

Feb 19 11:21:23 localhost.localdomain kernel: DMAR-IR: IOAPIC id 0 under DRHD 
base  0xfed90000 IOMMU 0
Feb 19 11:21:23 localhost.localdomain kernel: DMAR-IR: Enabled IRQ remapping in 
x2apic mode

Currently supported:

- Emulated/Splitted irqchip
- Generic PCI Devices
- vhost devices
- pass through device support? Not tested, but suppose it should work.
- IEC (Interrupt Entry Cache) cache invalidation notification
- EIM (from Jan)
- IRTE Source-id validation

TODO List:

- explicit IEC invalidation (currently, we do update without
  checking. Also, we can process QI invalidation in bulk, as Jan
  suggested)
- IR fault reporting
- migration support (for IOMMU as general?)
- more?

Jan Kiszka (1):
  intel_iommu: Add support for Extended Interrupt Mode

Peter Xu (25):
  acpi: enable INTR for DMAR report structure
  intel_iommu: allow queued invalidation for IR
  intel_iommu: set IR bit for ECAP register
  acpi: add DMAR scope definition for root IOAPIC
  intel_iommu: define interrupt remap table addr register
  intel_iommu: handle interrupt remap enable
  intel_iommu: define several structs for IOMMU IR
  intel_iommu: provide helper function vtd_get_iommu
  intel_iommu: add IR translation faults defines
  intel_iommu: Add support for PCI MSI remap
  q35: ioapic: add support for emulated IOAPIC IR
  ioapic: introduce ioapic_entry_parse() helper
  intel_iommu: add support for split irqchip
  q35: add "intremap" parameter to enable IR
  intel_iommu: introduce IEC notifiers
  ioapic: register VT-d IEC invalidate notifier
  ioapic: keep RO bits for IOAPIC entry
  ioapic: clear remote irr bit for edge-triggered interrupts
  intel_iommu: add SID validation for IR
  x86-iommu: introduce parent class
  x86-iommu: replace existing VT-d hooks into X86 ones
  kvm-irqchip: simplify kvm_irqchip_add_msi_route
  kvm-irqchip: i386: add hook for add/remove virq
  kvm-irqchip: x86: add msi route notify fn
  kvm-irqchip: do explicit commit when update irq

 hw/core/machine.c                 |  22 ++
 hw/i386/Makefile.objs             |   2 +-
 hw/i386/acpi-build.c              |  38 ++--
 hw/i386/intel_iommu.c             | 429 +++++++++++++++++++++++++++++++++++++-
 hw/i386/intel_iommu_internal.h    |  49 ++++-
 hw/i386/kvm/pci-assign.c          |  10 +-
 hw/i386/pc.c                      |   3 +
 hw/i386/x86-iommu.c               |  91 ++++++++
 hw/intc/ioapic.c                  | 158 ++++++++++----
 hw/misc/ivshmem.c                 |   4 +-
 hw/pci-host/q35.c                 |  17 +-
 hw/pci/pci.c                      |  15 ++
 hw/vfio/pci.c                     |  12 +-
 hw/virtio/virtio-pci.c            |  10 +-
 include/hw/acpi/acpi-defs.h       |  15 ++
 include/hw/boards.h               |   1 +
 include/hw/i386/apic-msidef.h     |   1 +
 include/hw/i386/intel_iommu.h     | 147 ++++++++++++-
 include/hw/i386/ioapic_internal.h |   6 +
 include/hw/i386/pc.h              |   4 +
 include/hw/i386/x86-iommu.h       | 110 ++++++++++
 include/hw/pci-host/q35.h         |   9 +
 include/hw/pci/pci.h              |   2 +
 include/sysemu/kvm.h              |  21 +-
 kvm-all.c                         |  14 +-
 kvm-stub.c                        |   6 +-
 target-arm/kvm.c                  |  11 +
 target-i386/kvm.c                 |  98 ++++++++-
 target-mips/kvm.c                 |  11 +
 target-ppc/kvm.c                  |  11 +
 target-s390x/kvm.c                |  11 +
 trace-events                      |   6 +
 32 files changed, 1232 insertions(+), 112 deletions(-)
 create mode 100644 hw/i386/x86-iommu.c
 create mode 100644 include/hw/i386/x86-iommu.h

-- 
2.4.11