Re: [Qemu-devel] [PATCH v8 0/9] VT-d: vfio enablement and misc enhances

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, Apr 06, 2017 at 03:08:35PM +0800, Peter Xu wrote:
> This is v8 of vt-d vfio enablement series.
> 
> v8
> - remove patches 1-9 since merged already
> - add David's r-b for all the patches
> - add Aviv's s-o-b in the last patch
> - rename iommu to iommu_dmar [Jason]
> - rename last patch subject to "remote IOTLB" [Jason]
> - pick up jason's two patches to fix vhost breakage

I only see one (6/9) - is a patch missing or misattributed?

> - let vhost leverage the new IOMMU notifier interface

Which patch does this?

> v7:
> - for the two traces patches: Change subjects. Remove vtd_err() and
>   vtd_err_nonzero_rsvd() tracers, instead using standalone trace for
>   each of the places. Don't remove any DPRINTF() if there is no
>   replacement. [Jason]
> - add r-b and a-b for Alex/David/Jason.
> - in patch "intel_iommu: renaming gpa to iova where proper", convert
>   one more place where I missed [Jason]
> - fix the place where I should use "~0ULL" not "~0" [Jason]
> - squash patch 16 into 18 [Jason]
> 
> v6:
> - do unmap in all cases when replay [Jason]
> - do global replay even if context entry is invalidated [Jason]
> - when iommu reset, send unmap to all registered notifiers [Jason]
> - use rcu read lock to protect the whole vfio_iommu_map_notify()
>   [Alex, Paolo]
> 
> v5:
> - fix patch 4 subject too long, and error spelling [Eric]
> - add ack-by for alex in patch 1 [Alex]
> - squashing patch 19/20 into patch 18 [Jason]
> - fix comments in vtd_page_walk() [Jason]
> - remove all error_report() [Jason]
> - add comment for patch 18, mention about that enabled vhost without
>   ATS as well [Jason]
> - remove skipped debug thing during page walk [Jason]
> - remove duplicated page walk trace [Jason]
> - some tunings in vtd_address_space_unmap(), to provide correct iova
>   and addr_mask. For this, I tuned this patch as well a bit:
>   "memory: add section range info for IOMMU notifier"
>   to loosen the range check
> 
> v4:
> - convert all error_report()s into traces (in the two patches that did
>   that)
> - rebased to Jason's DMAR series (master + one more patch:
>   "[PATCH V4 net-next] vhost_net: device IOTLB support")
> - let vhost use the new api iommu_notifier_init() so it won't break
>   vhost dmar [Jason]
> - touch commit message of the patch:
>   "intel_iommu: provide its own replay() callback"
>   old replay is not a dead loop, but it will just consume lots of time
>   [Jason]
> - add comment for patch:
>   "intel_iommu: do replay when context invalidate"
>   telling why replay won't be a problem even without CM=1 [Jason]
> - remove a useless comment line [Jason]
> - remove dmar_enabled parameter for vtd_switch_address_space() and
>   vtd_switch_address_space_all() [Mst, Jason]
> - merged the vfio patches in, to support unmap of big ranges at the
>   beginning ("[PATCH RFC 0/3] vfio: allow to notify unmap for very big
>   region")
> - using caching_mode instead of cache_mode_enabled, and "caching-mode"
>   instead of "cache-mode" [Kevin]
> - when receive context entry invalidation, we unmap the entire region
>   first, then replay [Alex]
> - fix commit message for patch:
>   "intel_iommu: simplify irq region translation" [Kevin]
> - handle domain/global invalidation, and notify where proper [Jason,
>   Kevin]
> 
> 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
> 
> 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-v8
> 
> 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,caching-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.
> 
> - don't need to notify IOTLB (psi/gsi/global) invalidations to devices
>   that with ATS enabled
> 
> - investigate when guest map page while mask contains existing mapped
>   pages (e.g. map 12k-16k first, then map 0-12k)
> 
> - coalesce unmap during page walk (currently, we send it once per
>   page)
> 
> - when do PSI for unmap, whether we can send one notify directly
>   instead of walking over the page table?
> 
> - more to come...
> 
> Thanks,
> 
> Jason Wang (1):
>   intel_iommu: use the correct memory region for device IOTLB
>     notification
> 
> Peter Xu (8):
>   memory: add section range info for IOMMU notifier
>   memory: provide IOMMU_NOTIFIER_FOREACH macro
>   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: allow dynamic switch of IOMMU region
>   intel_iommu: enable remote IOTLB
> 
>  hw/i386/intel_iommu.c          | 442 +++++++++++++++++++++++++++++++++++++++--
>  hw/i386/intel_iommu_internal.h |   1 +
>  hw/i386/trace-events           |  10 +-
>  hw/vfio/common.c               |  12 +-
>  hw/virtio/vhost.c              |  10 +-
>  include/exec/memory.h          |  49 ++++-
>  include/hw/i386/intel_iommu.h  |  10 +
>  memory.c                       |  52 ++++-
>  8 files changed, 552 insertions(+), 34 deletions(-)
> 
> -- 
> 2.7.4