Re: [Qemu-devel] [PATCH 00/13] IOMMU: Enable interrupt remapping for Intel IOMMU

[Jan Kiszka <jan.kiszka@web.de>]

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Hi Peter,

On 2016-02-19 04:30, Peter Xu wrote:
> This patchset provide very basic functionalities for interrupt
> remapping (IR) support of the emulated Intel IOMMU device.

Interesting. Some questions:

- Were you aware of
http://git.kiszka.org/?p=qemu.git;a=shortlog;h=refs/heads/queues/vtd-intremap,
and can you comment on how this relates to your approach? Mine included
HPET support, e.g.

- Rita Sinha is currently working on integrating my old patches with the
split-irqchip to get KVM working (as an Outreachy project). It's
probably a bit unfortunate to consider a different horse that late in to
project. What do you think, how could we benefit from each other?

- Radim was telling me to look on this as well. How do your efforts
correlate?

> 
> 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 basic network (still do not support kvm-ioapic,
> so we need to specify kernel_irqchip=off here):
> 
> $ qemu-system-x86_64 -M q35,iommu=on,int_remap=on,kernel_irqchip=off \
>      -enable-kvm -m 1024 -s \
>      -monitor telnet::3333,server,nowait \
>      -netdev user,id=user.0,hostfwd=tcp::5555-:22 \
>      -device virtio-net-pci,netdev=user.0 \
> 	 /var/lib/libvirt/images/vm1.qcow2
> 
> When guest boots, we can verify whether IR enabled by grepping the
> dmesg like:
> 
> [root@localhost ~]# journalctl -k | grep "DMAR-IR"
> 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 xapic mode
> 
> Currently only two devices are supported:
> 
> - Emulated IOAPIC device
> - PCI Devices
> 
> TODO List:
> 
> - kvm-ioapic support
> - vhost support
> - pass through device support
> - EIM support
> - IR fault reporting
> - source-id validation for IRTE
> - IRTE cache and better queued invalidation
> - migration support (for IOMMU as general?)
> - more?
> 
> Peter Xu (13):
>   q35: add "int-remap" flag to enable intr
>   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
>   ioapic-common: add iommu for IOAPICCommonState
>   intel_iommu: add IR translation faults defines
>   intel_iommu: ioapic: IR support for emulated IOAPIC
>   intel_iommu: Add support for PCI MSI remap
> 
>  hw/core/machine.c                 |  20 ++
>  hw/i386/acpi-build.c              |  41 +++-
>  hw/i386/intel_iommu.c             | 397 +++++++++++++++++++++++++++++++++++++-
>  hw/i386/intel_iommu_internal.h    |  25 +++
>  hw/intc/ioapic.c                  |  36 +++-
>  hw/intc/ioapic_common.c           |   2 +
>  hw/pci-host/q35.c                 |   6 +-
>  include/hw/acpi/acpi-defs.h       |  15 ++
>  include/hw/boards.h               |   1 +
>  include/hw/i386/intel_iommu.h     | 121 ++++++++++++
>  include/hw/i386/ioapic_internal.h |   3 +
>  include/hw/pci/msi.h              |   4 +
>  12 files changed, 651 insertions(+), 20 deletions(-)
> 

Is there a git tree with your patches somewhere?

Thanks,
Jan


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