Re: [Qemu-devel] [PATCH RFC v3 00/14] VT-d: vfio enablement and misc enhances

[Michael S. Tsirkin]

On Fri, Jan 13, 2017 at 11:06:26AM +0800, Peter Xu wrote:
> v3:
> - fix style error reported by patchew
> - fix comment in domain switch patch: use "IOMMU address space" rather
>   than "IOMMU region" [Kevin]
> - add ack-by for Paolo in patch:
>   "memory: add section range info for IOMMU notifier"
>   (this is seperately collected besides this thread)
> - remove 3 patches which are merged already (from Jason)
> - rebase to master b6c0897

So 1-6 look like nice cleanups to me. Should I merge them now?

> v2:
> - change comment for "end" parameter in vtd_page_walk() [Tianyu]
> - change comment for "a iova" to "an iova" [Yi]
> - fix fault printed val for GPA address in vtd_page_walk_level (debug
>   only)
> - rebased to master (rather than Aviv's v6 series) and merged Aviv's
>   series v6: picked patch 1 (as patch 1 in this series), dropped patch
>   2, re-wrote patch 3 (as patch 17 of this series).
> - picked up two more bugfix patches from Jason's DMAR series
> - picked up the following patch as well:
>   "[PATCH v3] intel_iommu: allow dynamic switch of IOMMU region"
> 
> This RFC series is a re-work for Aviv B.D.'s vfio enablement series
> with vt-d:
> 
>   https://lists.gnu.org/archive/html/qemu-devel/2016-11/msg01452.html
> 
> Aviv has done a great job there, and what we still lack there are
> mostly the following:
> 
> (1) VFIO got duplicated IOTLB notifications due to splitted VT-d IOMMU
>     memory region.
> 
> (2) VT-d still haven't provide a correct replay() mechanism (e.g.,
>     when IOMMU domain switches, things will broke).
> 
> This series should have solved the above two issues.
> 
> Online repo:
> 
>   https://github.com/xzpeter/qemu/tree/vtd-vfio-enablement-v2
> 
> I would be glad to hear about any review comments for above patches.
> 
> =========
> Test Done
> =========
> 
> Build test passed for x86_64/arm/ppc64.
> 
> Simply tested with x86_64, assigning two PCI devices to a single VM,
> boot the VM using:
> 
> bin=x86_64-softmmu/qemu-system-x86_64
> $bin -M q35,accel=kvm,kernel-irqchip=split -m 1G \
>      -device intel-iommu,intremap=on,eim=off,cache-mode=on \
>      -netdev user,id=net0,hostfwd=tcp::5555-:22 \
>      -device virtio-net-pci,netdev=net0 \
>      -device vfio-pci,host=03:00.0 \
>      -device vfio-pci,host=02:00.0 \
>      -trace events=".trace.vfio" \
>      /var/lib/libvirt/images/vm1.qcow2
> 
> pxdev:bin [vtd-vfio-enablement]# cat .trace.vfio
> vtd_page_walk*
> vtd_replay*
> vtd_inv_desc*
> 
> Then, in the guest, run the following tool:
> 
>   
> https://github.com/xzpeter/clibs/blob/master/gpl/userspace/vfio-bind-group/vfio-bind-group.c
> 
> With parameter:
> 
>   ./vfio-bind-group 00:03.0 00:04.0
> 
> Check host side trace log, I can see pages are replayed and mapped in
> 00:04.0 device address space, like:
> 
> ...
> vtd_replay_ce_valid replay valid context device 00:04.00 hi 0x401 lo 
> 0x38fe1001
> vtd_page_walk Page walk for ce (0x401, 0x38fe1001) iova range 0x0 - 
> 0x8000000000
> vtd_page_walk_level Page walk (base=0x38fe1000, level=3) iova range 0x0 - 
> 0x8000000000
> vtd_page_walk_level Page walk (base=0x35d31000, level=2) iova range 0x0 - 
> 0x40000000
> vtd_page_walk_level Page walk (base=0x34979000, level=1) iova range 0x0 - 
> 0x200000
> vtd_page_walk_one Page walk detected map level 0x1 iova 0x0 -> gpa 0x22dc3000 
> mask 0xfff perm 3
> vtd_page_walk_one Page walk detected map level 0x1 iova 0x1000 -> gpa 
> 0x22e25000 mask 0xfff perm 3
> vtd_page_walk_one Page walk detected map level 0x1 iova 0x2000 -> gpa 
> 0x22e12000 mask 0xfff perm 3
> vtd_page_walk_one Page walk detected map level 0x1 iova 0x3000 -> gpa 
> 0x22e2d000 mask 0xfff perm 3
> vtd_page_walk_one Page walk detected map level 0x1 iova 0x4000 -> gpa 
> 0x12a49000 mask 0xfff perm 3
> vtd_page_walk_one Page walk detected map level 0x1 iova 0x5000 -> gpa 
> 0x129bb000 mask 0xfff perm 3
> vtd_page_walk_one Page walk detected map level 0x1 iova 0x6000 -> gpa 
> 0x128db000 mask 0xfff perm 3
> vtd_page_walk_one Page walk detected map level 0x1 iova 0x7000 -> gpa 
> 0x12a80000 mask 0xfff perm 3
> vtd_page_walk_one Page walk detected map level 0x1 iova 0x8000 -> gpa 
> 0x12a7e000 mask 0xfff perm 3
> vtd_page_walk_one Page walk detected map level 0x1 iova 0x9000 -> gpa 
> 0x12b22000 mask 0xfff perm 3
> vtd_page_walk_one Page walk detected map level 0x1 iova 0xa000 -> gpa 
> 0x12b41000 mask 0xfff perm 3
> ...
> 
> =========
> Todo List
> =========
> 
> - error reporting for the assigned devices (as Tianyu has mentioned)
> 
> - per-domain address-space: A better solution in the future may be -
>   we maintain one address space per IOMMU domain in the guest (so
>   multiple devices can share a same address space if they are sharing
>   the same IOMMU domains in the guest), rather than one address space
>   per device (which is current implementation of vt-d). However that's
>   a step further than this series, and let's see whether we can first
>   provide a workable version of device assignment with vt-d
>   protection.
> 
> - more to come...
> 
> Thanks,
> 
> Aviv Ben-David (1):
>   IOMMU: add option to enable VTD_CAP_CM to vIOMMU capility exposoed to
>     guest
> 
> Peter Xu (13):
>   intel_iommu: simplify irq region translation
>   intel_iommu: renaming gpa to iova where proper
>   intel_iommu: fix trace for inv desc handling
>   intel_iommu: fix trace for addr translation
>   intel_iommu: vtd_slpt_level_shift check level
>   memory: add section range info for IOMMU notifier
>   memory: provide iommu_replay_all()
>   memory: introduce memory_region_notify_one()
>   memory: add MemoryRegionIOMMUOps.replay() callback
>   intel_iommu: provide its own replay() callback
>   intel_iommu: do replay when context invalidate
>   intel_iommu: allow dynamic switch of IOMMU region
>   intel_iommu: enable vfio devices
> 
>  hw/i386/intel_iommu.c          | 589 
> +++++++++++++++++++++++++++++++----------
>  hw/i386/intel_iommu_internal.h |   1 +
>  hw/i386/trace-events           |  28 ++
>  hw/vfio/common.c               |   7 +-
>  include/exec/memory.h          |  30 +++
>  include/hw/i386/intel_iommu.h  |  12 +
>  memory.c                       |  42 ++-
>  7 files changed, 557 insertions(+), 152 deletions(-)
> 
> -- 
> 2.7.4